Strut bearing device, strut type suspension for vehicle, method for manufacturing lower case and seal of strut bearing device, and method for manufacturing upper case and seal of strut bearing device

Abstract

To increase bonding force of a seal of a strut bearing device and also to lower a risk of breakage of a metal mold for molding the seal.SOLUTION: Annular bonding faces D, E of a lower case 3 of a strut bearing device have axially projecting case-side projection parts F, G. The case-side projection parts F, G are in a shape A which is continuous in a circumferential direction and shifts in a radial position along the circumferential direction when viewed from an axial direction. An inner diameter-side seal 8 has a seal-side recessed part H shaped to be fitted to the case-side projection part F. An outer diameter-side seal 9 has a seal-side recessed part I shaped to be fit to the case-side projection part G.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a strut bearing device for use in a strut-type suspension of a vehicle. [Background technology]

[0002] One type of suspension that supports the wheels on the vehicle body with coil springs and has shock absorbers to absorb vertical vibrations is the strut suspension, which has an expandable pillar (strut) with a built-in shock absorber attached to the axle. Strut suspensions are widely used mainly for the front wheels of passenger cars.

[0003] A strut bearing device used on the upper part of a strut suspension has an upper case made of synthetic resin that holds an upper raceway, a lower case made of synthetic resin that holds a lower raceway, and inner and outer seals made of elastomer attached to the lower case (see, for example, Patent Document 1).

[0004] In the strut bearing device of Patent Document 1, the seal lip 62 of the internal seal 60, which is the inner diameter side seal, provided on the inner diameter side of the lower cup 30, which is the lower case, and the seal lips 52, 53 of the external seal 50, which is the outer diameter side seal, provided on the outer diameter side of the lower cup 30, are in sliding contact with the upper cup 40, which is the upper case.

[0005] The lower cup 30 in the strut bearing assembly of Patent Document 1 has a plurality of protruding ribs 36C that protrude into the annular base 61 of the inner seal 60, and also has a plurality of protruding ribs 35C that protrude into the annular base 51 of the outer seal 50. The protruding ribs 35C, 36C are triangular in shape and are spaced apart in the circumferential direction (Figures 2 and 3 of Patent Document 1, claim 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2019 / 0184781 Summary of the Invention [Problem to be solved by the invention]

[0007] In the invention of Patent Document 1, the multiple protruding ribs 36C increase the area of ​​the bonding interface between the inner seal 60 and the lower cup 30, and the multiple protruding ribs 35C increase the area of ​​the bonding interface between the outer seal 50 and the lower cup 30. This increases the bonding strength formed by the chemical bonds at the bonding interface.

[0008] In the invention of Patent Document 1, if the circumferential spacing of the multiple protruding ribs 35C and the circumferential spacing of the multiple protruding ribs 36C are widened, it becomes difficult to increase the bonding strength resulting from the chemical bonds at the bonding interface. On the other hand, if the circumferential spacing of the multiple protruding ribs 35C and the circumferential spacing of the multiple protruding ribs 36C are narrowed in order to increase the bonding strength resulting from the chemical bonds at the bonding interface by increasing the number of the multiple protruding ribs 35C and the number of the multiple protruding ribs 36C, a thin-walled portion is generated in the mold for molding the lower cup 30, increasing the risk of mold damage.

[0009] The present invention aims to increase the bonding strength of a seal in a strut bearing assembly while reducing the risk of damage to the mold used to form the seal. [Means for solving the problem]

[0010] The gist of the present invention is as follows.

[0011] [1] An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A strut bearing device comprising: The upper case and the lower case are made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the upper case or the lower case, The annular joint surface has a case-side convex portion extending in the axial direction or a case-side concave portion receding in the axial direction, a shape of the case side convex portion and the case side concave portion as viewed from the axial direction is continuous in a circumferential direction, and a radial position of the case side convex portion and the case side concave portion varies as the case side convex portion and the case side concave portion extend in the circumferential direction; The seal has a seal-side recess shaped to fit into the case-side protrusion, or a seal-side protrusion shaped to fit into the case-side recess. Strut bearing assembly.

[0012] [2] A strut suspension for a vehicle equipped with the strut bearing device described in [1].

[0013] [3] An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A method for manufacturing the lower case and the seal in a strut bearing device comprising: The lower case is made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the lower case, The annular joint surface of the lower case has a case-side convex portion that advances in the axial direction or a case-side concave portion that retreats in the axial direction, a shape of the case side convex portion and the case side concave portion of the lower case as viewed from the axial direction is continuous in a circumferential direction and a radial position of the case side convex portion and the case side concave portion of the lower case varies as the case side convex portion and the case side concave portion extend in the circumferential direction; an injection molding process of injecting the molten synthetic resin from a gate of a first mold for molding the lower case having the shape; an insert injection molding process in which the lower case removed from the first mold is set as an insert work in a second mold that molds the seal having the shape, and the molten elastomer is injected from a gate of the second mold; Including, A method for manufacturing a lower case and seal of a strut bearing assembly.

[0014] [4] An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A method for manufacturing the upper case and the seal in a strut bearing device comprising: The upper case is made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the upper case, The annular joint surface of the upper case has a case-side convex portion that advances in the axial direction or a case-side concave portion that retreats in the axial direction, a shape of the case side convex portion and the case side concave portion of the upper case as viewed from an axial direction is continuous in a circumferential direction and has a radial position that varies as it goes in the circumferential direction, an injection molding process of injecting the molten synthetic resin from a gate of a first mold for molding the upper case having the shape; an insert injection molding process in which the upper case removed from the first mold is set as an insert work in a second mold that molds the seal having the shape, and the molten elastomer is injected from a gate of the second mold; Including, A method for manufacturing an upper case and seal of a strut bearing assembly. Effect of the Invention

[0015] The strut bearing device according to the present invention as described above, a strut bearing device using a lower case manufactured by the method for manufacturing a lower case of a strut bearing device according to the present invention, and a strut bearing device using an upper case manufactured by the method for manufacturing an upper case of a strut bearing device according to the present invention, provide the following advantageous effects.

[0016] The axial end face, from which the seal lip of the annular base of the seal located radially inward and / or radially outward of the rolling elements of the strut bearing device does not protrude, is in close contact with the annular mating surface of the upper case or the lower case. The annular mating surface has a case-side convex portion that advances in the axial direction or a case-side concave portion that retreats in the axial direction, and the shapes of the case-side convex portion and the case-side concave portion as viewed from the axial direction are continuous in the circumferential direction and have a shape in which the radial position varies as it progresses in the circumferential direction. The seal has a seal-side concave portion shaped to fit into the case-side convex portion, or a seal-side convex portion shaped to fit into the case-side concave portion.

[0017] Therefore, the shape of the joining interface between the seal side recess or protrusion and the case side protrusion or recess as viewed from the axial direction is a wavy shape that continues in the circumferential direction, so the area of ​​the joining interface between the seal and the upper case or lower case to which the seal is joined is increased, and the joining strength due to the chemical bond at the joining interface can be increased. Also, the shape of the joining interface between the seal side recess or protrusion and the case side protrusion or recess as viewed from the axial direction is a wavy shape that continues in the circumferential direction, so the seal and the upper case or lower case to which the seal is joined are engaged in the circumferential direction and the radial direction. Therefore, the seal and the upper case or lower case to which the seal is joined are connected by both chemical bonds and mechanical bonds, increasing the joining reliability. In addition, no thin-walled portion is generated in the mold for molding the upper case or lower case having the case side protrusion or case side recess, so the risk of mold damage can be reduced. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic partial cross-sectional view of a strut-type suspension for a vehicle equipped with a strut bearing device according to an embodiment of the present invention; [Diagram 2] 2 is an enlarged longitudinal sectional view showing a main portion of the strut bearing device, a spring support component, and a coil spring. FIG. [Diagram 3] FIG. 2 is an enlarged longitudinal sectional view of a main portion of the strut bearing device. [Figure 4A] FIG. 2 is a partial vertical cross-sectional perspective view of the upper case as viewed from above. [Figure 4B] FIG. 2 is a perspective view of the upper case as viewed from below. [Diagram 5] FIG. 1 is a partial vertical cross-sectional perspective view seen from above, showing a lower case, an inner diameter side seal, and an outer diameter side seal separated from each other; [Figure 6] 1 is a perspective view of a lower case seen from above, showing the lower case, the inner diameter side seal, and the outer diameter side seal separated from each other; FIG. 2 is a perspective view of the lower case seen from above, showing the inner diameter side seal and the outer diameter side seal separated from each other; [Figure 7] FIG. 2 is an enlarged partial vertical cross-sectional perspective view of a main portion of a lower case as viewed from above. [Figure 8] FIG. [Figure 9A] 5A to 5C are schematic plan views showing examples of the shape of a case side convex portion. [Figure 9B] 9B is a cross-sectional view taken along the line XX in FIG. 9A. [Figure 10A] 13 is a schematic plan view showing a modified example of the shape of the case side protrusion, in which the thickness of the case side protrusion is eliminated for simplification. FIG. [Figure 10B] FIG. 13 is a schematic plan view showing another modified example of the shape of the case side protrusion, which is simplified by eliminating the thickness of the case side protrusion. [Figure 10C] FIG. 13 is a schematic plan view showing yet another modified example of the shape of the case side protrusion, which is simplified by eliminating the thickness of the case side protrusion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] In this specification, the direction parallel to the rotation axis O (see FIG. 1) of the strut bearing device 1 is called the "axial direction" (see, for example, arrow J in FIG. 1), the direction perpendicular to the rotation axis O is called the "radial direction" (see, for example, arrow R in FIG. 1), the radial direction approaching the rotation axis O is called the "radial inward direction" (see, for example, arrow RI in FIG. 1), and the radial direction moving away from the rotation axis O is called the "radial outward direction" (see, for example, arrow RO in FIG. 1). In addition, when the rotation axis O is defined as the vertical direction, the horizontal direction perpendicular to the radial direction centered on the rotation axis O is called the "circumferential direction" (see, for example, arrow C in FIG. 8).

[0021] <Strut suspension> A strut suspension S for a vehicle shown in the partial cross-sectional schematic diagram of Figure 1 is used with an expandable strut 10 incorporating a shock absorber fixed to an axle (not shown) and an upper mount 16 fixed to the vehicle body.

[0022] A strut bearing device 1 is provided on the upper part of the strut suspension S. The strut bearing device 1 supports the vehicle body and oscillates and rotates as the direction of the steered wheels changes due to steering operation. The oscillating angle of the strut bearing device 1 is determined according to the allowable steering angle of the wheels, and is set, for example, in the range of 40° to 50°.

[0023] A coil spring 11, which is a suspension spring, and a dust boot 12 for protecting the oil seal of the shock absorber from foreign matter such as sand are provided on the outer diameter side RO of the strut 10. The strut suspension S is equipped with a spring support part 13 that supports the upper end of the coil spring 11. As shown in the vertical cross section of Figure 2, the spring support part 13 consists of an upper spring seat 14 and an upper insulator 15.

[0024] <Strut bearing device> As shown in the schematic diagram of Figure 1, the vertical cross-sectional views of Figures 2 and 3, the partial vertical cross-sectional oblique view of Figure 4A and the oblique view of Figure 4B, and the partial vertical cross-sectional oblique view of Figure 5, the strut bearing device 1 comprises an upper case 2 and a lower case 3, an upper raceway 4 and a lower raceway 5, rolling elements 6, a retainer 7, an inner diameter side seal 8 and an outer diameter side seal 9, etc.

[0025] The upper case 2 is fixed to the upper end of the strut 10, and the lower case 3 receives an upper spring seat 14 from above. The upper raceway 4 is held in the upper case 2, and the lower raceway 5 is held in the lower case 3. The rolling elements 6 roll between the upper raceway 4 and the lower raceway 5, and the cage 7 holds the rolling elements 6 so that adjacent rolling elements 6 do not come into contact with each other.

[0026] The inner diameter side seal 8 is located on the radial inside RI of the rolling elements 6, and the outer diameter side seal 9 is located on the radial outside RO of the rolling elements 6. In this embodiment, the inner diameter side seal 8 and the outer diameter side seal 9 are joined to the lower case 3.

[0027] The upper race 4 and the lower race 5 are made of steel, and are formed by pressing a steel plate and then quench-hardened after processing. The upper case 2 and the lower case 3 are made of synthetic resin, and the inner diameter side seal 8 and the outer diameter side seal 9 are made of elastomer.

[0028] The synthetic resin used for the upper case 2 and the lower case 3 is, for example, a polyamide resin (PA66, PA46, PA612, PA6, PA9T, PA10T, etc.) and contains, for example, 20 to 60% by weight of glass fiber (GF) as a reinforcing fiber.

[0029] The elastomer used for the inner diameter side seal 8 and the outer diameter side seal 9 is a thermoplastic elastomer (TPE) such as TPS (styrene type), TPO (olefin type), TPU (urethane type), TPA (amide type), or TPEE (ester type).

[0030] <Inner diameter side seal, outer diameter side seal, and annular joint surface> 3, the inner seal 8 has an annular base 8A and a seal lip 8B protruding from the annular base 8A, and the outer seal 9 has an annular base 9A and a seal lip 9B protruding from the annular base 9A. The seal lips 8B, 9B are in sliding contact with the upper case 2.

[0031] As shown in the vertical cross-sectional view of Fig. 3, the partial vertical cross-sectional perspective view of Fig. 5, the perspective view of Fig. 6, and the partial vertical cross-sectional perspective view of Fig. 7, an axial end face 8C from which the seal lip 8B of the annular base 8A of the inner diameter side seal 8 does not protrude is in close contact with an annular joint surface D located on the radially inner side RI of the lower case 3. An axial end face 9C from which the seal lip 9B of the annular base 9A of the outer diameter side seal 9 does not protrude is in close contact with an annular joint surface E located on the radially outer side RO of the lower case 3.

[0032] The annular joint surface D has an upwardly extending case side convex portion F, and the annular joint surface E has an upwardly extending case side convex portion G. The inner diameter side seal 8 has an upwardly extending seal side concave portion H that is shaped to fit into the case side convex portion F, and the outer diameter side seal 9 has an upwardly extending seal side concave portion I that is shaped to fit into the case side convex portion G.

[0033] <Shape of the case-side convex portion and the seal-side concave portion, size of the case-side convex portion and the seal-side concave portion> As shown in the plan view of Fig. 8, the shapes of the case-side convex portions F and G of the lower case 3 as viewed from the axial direction J (Fig. 1) are triangular-wave shapes continuous in the circumferential direction C, that is, a shape A that is continuous in the circumferential direction C and whose position in the radial direction R varies as going in the circumferential direction C. Since the case-side convex portions F and G of the lower case 3 are continuous in the circumferential direction C, the circumferential rigidity of the case-side convex portions F and G increases.

[0034] As shown in the longitudinal sectional view of Fig. 3 and the perspective view of Fig. 6, the seal-side concave portion H of the inner-diameter-side seal 8 is shaped to fit into the case-side convex portion F of the lower case 3, and the seal-side concave portion I of the outer-diameter-side seal 9 is shaped to fit into the case-side convex portion G of the lower case 3. Therefore, the shapes of the seal-side concave portions H and I as viewed from the axial direction J are also triangular-wave shapes continuous in the circumferential direction C, that is, a shape A that is continuous in the circumferential direction C and whose position in the radial direction R varies as going in the circumferential direction C.

[0035] As shown in the schematic plan view of Fig. 9A and Fig. 9B which is the cross-sectional view taken along the arrow X-X of Fig. 9A, the range B in the radial direction R of the case-side convex portion F, that is, the range from the minimum diameter M to the maximum diameter N of the case-side convex portion F, is larger than the minimum diameter K (inner diameter of the annular joint surface D) of the annular base 8A of the inner-diameter-side seal 8 and smaller than the maximum diameter L (outer diameter of the annular joint surface D) of the annular base 8A (M > K, N < L). The same applies to the range in the radial direction R of the case-side convex portion G. Also, as shown in Fig. 9B and the longitudinal sectional view of Fig. 3, the height P of the case-side convex portion F is equal to or less than the height Q of the annular base 8A (P ≤ Q). Similarly, the height of the case-side convex portion G is equal to or less than the height of the annular base 9A.

[0036] The shape A, which is continuous in the circumferential direction C and whose radial R position varies as it goes toward the circumferential direction C when the case side convex parts F, G and the seal side concave parts H, I are viewed from the axial direction J, is not limited to a triangular wave shape continuous in the circumferential direction C as shown in the plan view of FIG. 8 and the schematic plan view of FIG. 9A. For example, it may be a shape in which diamonds are continuously arranged in the circumferential direction C as shown in the schematic plan view of FIG. 10A, a sinusoidal waveform continuous in the circumferential direction C as shown in the schematic plan view of FIG. 10B, or a waveform in which two sinusoidal waves are continuously arranged in the circumferential direction C so that one crest and the other trough are aligned as shown in the schematic plan view of FIG. 10C. In addition, the shape A is not limited to a shape that is periodically repeated in the circumferential direction C, and may not be a shape that is periodically repeated in the circumferential direction C.

[0037] <Manufacturing Method of Lower Case and Seal> Next, an example of a manufacturing method for the lower case 3, the inner diameter side seal 8, and the outer diameter side seal 9 in the strut bearing device 1 will be described.

[0038] (Molding of the lower case, which is the primary molded product) An injection molding process is performed in which molten synthetic resin is injected from a gate of a first mold (not shown) into a cavity of the first mold to mold the lower case 3 having the shape shown in the partial vertical cross-sectional oblique view of FIG. 5 and the oblique view of FIG. 6, thereby molding the lower case 3 having the shape shown above.

[0039] (Secondary molding of seals) The lower case 3 removed from the first mold is set as an insert work in a second mold (not shown) for molding an inner diameter side seal 8 and an outer diameter side seal 9 having shapes shown in the partial vertical cross-sectional perspective view of Fig. 5 and the perspective view of Fig. 6, and the second mold is closed. With the temperature of the second mold adjusted to a predetermined temperature, an insert injection molding process is performed in which molten elastomer is injected into a cavity of the second mold from, for example, three gates of the second mold located at gate position T (see also Fig. 8) that is located below and connected to through hole 19 of the lower case 3.

[0040] As shown in the partial vertical cross-sectional perspective view of Fig. 5 and the perspective view of Fig. 6, a groove 17 connected to a through hole 19 extends radially in the lower case 3, and the inner diameter side and the outer diameter side are connected by the groove 17. Therefore, molten elastomer is filled into the second mold for molding the inner diameter side seal 8 and the outer diameter side seal 9 from the through hole 19 of the lower case 3 through the groove 17, and the inner diameter side seal 8 and the outer diameter side seal 9 having the above shapes are molded.

[0041] As shown in the partial vertical cross-sectional oblique view of Figure 5 and the oblique view of Figure 6, between the inner diameter side seal 8 and the outer diameter side seal 9, a connecting portion 18 is molded in a shape that fits into a groove 17 of the lower case 3, and a cylindrical body 20 connected to the connecting portion 18 is molded in a shape that fits into a through hole 19 of the lower case 3.

[0042] As described above, by simply injecting molten elastomer from, for example, three gates of the second mold, it is possible to mold both the inner diameter side seal 8 and the outer diameter side seal 9. Since the number of gates can be reduced, the mold structure can be simplified, and the mold cost can be reduced.

[0043] By the manufacturing method of the lower case 3 and the inner diameter side seal 8 and the outer diameter side seal 9 as described above, the inner diameter side seal 8 is joined to the annular joint surface D of the lower case 3 by chemical bonds at the joint interface, and the outer diameter side seal 9 is joined to the annular joint surface E of the lower case 3 by chemical bonds at the joint interface. Here, the chemical bonds are chemical bonds formed by polar factors.

[0044] The seal side recess H of the inner diameter side seal 8 fits into the case side convex portion F of the annular joint surface D, and the shape of the case side convex portion F and the seal side recess H viewed from the axial direction J is shape A, which is continuous in the circumferential direction C and the position in the radial direction R varies as it approaches the circumferential direction C. Also, the seal side recess I of the outer diameter side seal 9 fits into the case side convex portion G of the annular joint surface E, and the shape of the case side convex portion G and the seal side recess I viewed from the axial direction J is shape A, which is continuous in the circumferential direction C and the position in the radial direction R varies as it approaches the circumferential direction C.

[0045] As a result, the shape of the joint interface between the seal side recesses H, I and the case side protrusions F, G as viewed from the axial direction J is a continuous wavy shape in the circumferential direction C, so that the area of ​​the joint interface between the inner diameter side seal 8 and the lower case 3 is increased, and the area of ​​the joint interface between the outer diameter side seal 9 and the lower case 3 is increased, and the joint strength due to the chemical bond at the joint interface can be increased. In addition, the shape of the joint interface between the seal side recesses H, I and the case side protrusions F, G as viewed from the axial direction J is a continuous wavy shape in the circumferential direction C, so that the inner diameter side seal 8 and the outer diameter side seal 9 and the lower case 3 are engaged in the circumferential direction C and the radial direction R. Therefore, the inner diameter side seal 8 and the outer diameter side seal 9 and the lower case 3 are connected by both chemical bonding and mechanical bonding, and the joint reliability is improved. In addition, since no thin-walled portion is formed in the first mold for molding the lower case 3 having the case side protrusions F, G, the risk of mold damage can be reduced.

[0046] Furthermore, since the case side protrusions F, G have high circumferential rigidity as described above, circumferential deformation of the annular bases 8A, 9A of the seals 8, 9 is suppressed when the seal lips 8B, 9B of the seals 8, 9 slide against the upper case 2 and sliding torque is generated. Therefore, it is possible to reduce stress generated at the bonding interface between the case side protrusions F, G and the seal side recesses H, I, and high reliability can be maintained for a long period of time.

[0047] In the above explanation, an example has been shown in which the annular joint surfaces D, E of the lower case 3 have case side convex portions F, G, the inner diameter side seal 8 has a seal side concave portion H, and the outer diameter side seal 9 has a seal side concave portion I. The present invention is not limited to such a configuration, and the annular joint surfaces D, E of the lower case 3 may have a "case side concave portion" that recedes downward, and the seals 8, 9 may have a "seal side convex portion" that advances downward. Even in this case, the shape of the "case side concave portion" as viewed from the axial direction J and the shape of the "seal side convex portion" as viewed from the axial direction J are shape A that is continuous in the circumferential direction C and whose position in the radial direction R changes as it approaches the circumferential direction C.

[0048] In the above description, an example has been shown in which the seals 8, 9 are joined to the lower case 3, and the seal lips 8B, 9B slide against the upper case 2. The present invention is not limited to such a configuration, and a configuration in which a seal is joined to the upper case 2, and the seal lip slides against the lower case 3 may be used. In that case, an annular joint surface is provided on the upper case 2, and a "case-side convex portion" that advances downward or a "case-side concave portion" that retreats upward is provided on the annular joint surface, and a "seal-side concave portion" that retreats downward or a "seal-side convex portion" that advances upward is provided on the end face of the annular base of the seal. Even in that case, the shape of the "case-side convex portion" or "case-side concave portion" seen from the axial direction J, and the shape of the "seal-side concave portion" or "seal-side convex portion" seen from the axial direction J are shape A that is continuous in the circumferential direction C and whose position in the radial direction R changes as it approaches the circumferential direction C.

[0049] In the above explanation, an example in which both the inner diameter side seal 8 and the outer diameter side seal 9 are joined to the lower case 3, and an example in which both the inner diameter side seal 8 and the outer diameter side seal 9 are joined to the upper case 2 have been shown, but the inner diameter side seal 8 and the outer diameter side seal 9 may be joined separately to the upper case 2 and the lower case 3. That is, the inner diameter side seal 8 may be joined to the lower case 3 and the outer diameter side seal 9 may be joined to the upper case 2, or the inner diameter side seal 8 may be joined to the upper case 2 and the outer diameter side seal 9 may be joined to the lower case 3.

[0050] <Manufacturing method of upper case and seal> Next, in an example where a seal is joined to the upper case 2, an example of a method for manufacturing the upper case 2 and the seal will be described.

[0051] (Molding of the upper case, which is the primary molded product) An injection molding step is performed in which molten synthetic resin is injected from a gate of a first mold for molding upper case 2 of a required shape into a cavity of said first mold, thereby molding upper case 2 of said shape.

[0052] (Secondary molding of seals) The upper case 2 removed from the first mold is set as an insert work in a second mold for molding a seal of a required shape, and the second mold is closed. With the temperature of the second mold adjusted to a predetermined temperature, an insert injection molding process is performed in which molten elastomer is injected from the gate of the second mold into the cavity of the second mold, and a seal of the required shape is molded. As a result, the bonding interface between the upper case 2 and the seal is bonded by chemical bonding.

[0053] In a preferred embodiment, when the lower case 3 or the upper case 2, which is the primary molded product, is injection molded in the first mold, all or part of the portions of the first mold where the bottom and side surfaces of the annular base of the seal in the lower case 3 or the upper case 2 are joined are roughened by shot blasting or the like. This makes it possible to more firmly join the lower case 3 or the upper case 2 to the base end of the seal, and therefore further increases the joining strength between the lower case 3 or the upper case 2 and the seal.

[0054] The above description of the embodiments is given by way of example only and is not intended to be limiting, and various improvements and modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0055] 1 Strut bearing device 2 Upper case 3 Lower case 4 Upper raceway 5 Lower raceway 6 Rolling elements 7 Cage 8 Inner diameter seal 8A Circular base 8B Seal lip 8C Axial end face where the seal lip does not protrude 9 Outer diameter seal 9A Circular base 9B Seal lip 9C Axial end face where the seal lip does not protrude 10 Strut 11 Coil spring 12 Dust Boots 13 Spring support parts 14 Upper spring seat 15 Upper insulator 16 Upper mount 17 Groove 18 Connecting part 19 Through hole 20 Cylinder A: A shape that is continuous in the circumferential direction and the radial position changes as it moves in the circumferential direction. B Radial range of the case side protrusion C circumferential direction D, E Annular joint surface F, G Case side protrusion H, I Seal side recess J-axis direction K Minimum diameter of the annular base L Maximum diameter of the annular base M Minimum diameter of case side protrusion N Maximum diameter of case side protrusion O Rotation axis P Height of the protrusion on the case side Q Height of the annular base R Radial direction RI radially inward RO radially outward S Strut suspension T-gate position

Claims

1. An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A strut bearing device comprising: The upper case and the lower case are made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the upper case or the lower case, The annular joint surface has a case-side convex portion extending in the axial direction or a case-side concave portion receding in the axial direction, a shape of the case side convex portion and the case side concave portion as viewed from the axial direction is continuous in a circumferential direction, and a radial position of the case side convex portion and the case side concave portion varies as the case side convex portion and the case side concave portion extend in the circumferential direction; The seal has a seal-side recess shaped to fit into the case-side protrusion, or a seal-side protrusion shaped to fit into the case-side recess. Strut bearing assembly.

2. A strut-type suspension for a vehicle comprising the strut bearing device according to claim 1.

3. An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A method for manufacturing the lower case and the seal in a strut bearing device comprising: The lower case is made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the lower case, The annular joint surface of the lower case has a case-side convex portion that advances in the axial direction or a case-side concave portion that retreats in the axial direction, a shape of the case side convex portion and the case side concave portion of the lower case as viewed from the axial direction is continuous in a circumferential direction and a radial position of the case side convex portion and the case side concave portion of the lower case varies as the case side convex portion and the case side concave portion extend in the circumferential direction; an injection molding step of injecting the molten synthetic resin from a gate of a first mold for molding the lower case having the shape; an insert injection molding process in which the lower case removed from the first mold is set as an insert work in a second mold for molding the seal having the shape, and the molten elastomer is injected from a gate of the second mold; Including, A method for manufacturing a lower case and seal of a strut bearing assembly.

4. An upper case and a lower case; an upper raceway held by the upper case; a lower raceway held by the lower case; a rolling element that rolls between the upper raceway and the lower raceway; A seal located radially inward and / or radially outward of the rolling element; A method for manufacturing the upper case and the seal in a strut bearing device comprising: The upper case is made of synthetic resin, The seal is made of an elastomer; The seal has an annular base and a seal lip protruding from the annular base, an axial end surface of the annular base portion from which the seal lip does not protrude is in close contact with an annular joint surface of the upper case, The annular joint surface of the upper case has a case-side convex portion that advances in the axial direction or a case-side concave portion that retreats in the axial direction, a shape of the case side convex portion and the case side concave portion of the upper case as viewed from an axial direction is continuous in a circumferential direction and has a radial position that varies as it goes in the circumferential direction, an injection molding step of injecting the molten synthetic resin from a gate of a first mold for molding the upper case having the shape; an insert injection molding process in which the upper case removed from the first mold is set as an insert work in a second mold for molding the seal having the shape, and the molten elastomer is injected from a gate of the second mold; Including, A method for manufacturing an upper case and seal of a strut bearing assembly.

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