JP2009262732A - Steering wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering wheel capable of forming a weight storage chamber while keeping the joining accuracy in a relatively easy manner, and enhancing the insertion property of a weight and an elastic member in the core of a rim part. <P>SOLUTION: The core of the rim part of the steering wheel is formed of a pipe member in an annular shape, and a weight storage chamber is constituted of a part thereof. An arcuate weight 32 has a columnar attachment part 33 at an intermediate part 32M in the circumferential direction, and is movably arranged in the weight storage chamber when it is inserted in the pipe member from one opening end of the pipe member. A first elastic member 35 comprises a cylindrical attaching part 36 to be attached to the attachment part 33, and a tapered elastic part 37 which is connected to an end 36F on the front side in the inserting direction of the weight 32 with respect to the core of the rim part out of both ends in the circumferential direction of the attaching part 36, and expanded backward in the insertion direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steering wheel used for a steering device such as a vehicle, and more particularly to a steering wheel having a vibration damping function.

Various techniques for suppressing vibration of an annular rim portion have been conventionally developed and proposed for vehicle steering wheels. For example, Patent Document 1 describes a steering wheel in which a weight and an elastic member are arranged inside a rim portion. In this steering wheel, an annular weight is movably disposed inside an annular rim cored bar that forms the skeleton of the rim. Furthermore, elastic members are mounted at a plurality of locations in the circumferential direction of the weight, and the weight is elastically supported by the inner peripheral wall portion of the rim cored bar by these elastic members. As the elastic member, a member whose cross-sectional shape is an annular shape, a member having a cylindrical shape, a member having a cylindrical shape, and a plurality of protrusions around the periphery are disclosed. According to this technique, the vibration can be suppressed by moving the weight while elastically deforming the elastic member in accordance with the vibration of the rim portion (rim portion core metal).
JP 2002-154439 A

  In the steering wheel described in Patent Document 1, an annular ring is used as the weight. For this reason, in order to incorporate the weight into the rim cored bar, it is necessary to use the rim cored bar having a structure divided into a pair of halves having a semicircular cross section. In this configuration, after the weight on which the elastic member is mounted is arranged in one half body, the other half body is joined to the half body. However, in this method, regardless of whether the joining method is welding or adhesion, there are many joining allowances for joining (the area for joining is large), so that there is no problem in sliding and elastic deformation of the elastic member. It is difficult to join both halves precisely and accurately.

  For this, while using an arc-shaped weight as the weight, and using an annular ring made of pipe material as the rim core, the elastic member is mounted from one open end of the pipe material. It is conceivable to insert a measured weight. According to this steering wheel, the joining margin in the rim cored bar is small, and the joining accuracy can be maintained relatively easily. However, if the elastic member described in Patent Document 1 is used for this steering wheel as it is, when the weight and the elastic member are inserted into the rim core metal, the elastic member and the inner peripheral wall portion of the rim core metal are interposed. Large friction is generated. For this reason, the elastic member must be inserted into the rim core with a large force to overcome the friction, which makes the insertion operation difficult.

  The present invention has been made in view of such circumstances, and its object is to relatively easily form a weight housing chamber with a configuration that maintains the accuracy of joining the rim cored bar, An object of the present invention is to provide a steering wheel capable of improving the insertability of an elastic member into a rim cored bar.

  In order to achieve the above object, the invention according to claim 1 is a rim cored bar formed of a pipe material and having an annular shape in a cross section perpendicular to an axis of a steering shaft and a cross section including a coaxial line, A weight housing chamber formed by a part of the rim cored bar and having an arc shape in a cross section orthogonal to the axis and having an annular shape in a cross section including a coaxial line, and an arc shape in a cross section orthogonal to the axis Prior to the insertion of the weight into the pipe material, and the weight for damping that is movably disposed in the weight housing chamber by being inserted from one open end of the pipe material. A steering wheel that is attached to a cylindrical adherend portion provided at an intermediate portion in the circumferential direction and that elastically supports the weight on an inner peripheral wall portion of the weight housing chamber by the elastic member. The elastic member is a cylindrical mounting portion that is mounted on the adherend portion by fitting, and of both ends of the mounting portion in the circumferential direction with respect to the rim cored bar. The gist is provided with a tapered elastic portion that is connected to an end portion on the front side in the insertion direction of the weight and that increases in diameter toward the rear side in the insertion direction.

  According to the above configuration, since the weight having an arc shape in the cross section perpendicular to the axis of the steering shaft is used, unlike the case of using an annular shape, the rim core is made of a pipe material. Can be used. Therefore, when forming the weight accommodating chamber, the joining accuracy can be maintained relatively easily.

  Further, when the weight and the elastic member are arranged in the weight housing chamber, the weight on which the elastic member is mounted is inserted from one opening end of the pipe member. Along with this insertion, the elastic member attached to the intermediate part in the circumferential direction of the weight is also inserted into the rim cored bar from the one opening end together with the weight. At this time, the elastic part has a taper shape whose diameter increases toward the rear side in the insertion direction, and has a smaller diameter on the front side in the insertion direction than the inner peripheral wall part of the rim cored bar. Therefore, there are few contact parts with an elastic member and the inner peripheral wall part of a rim | limb core metal, and an elastic member is easy to insert in a pipe material from the said opening end.

  Further, even if the elastic portion abuts against the inner peripheral wall portion of the rim core metal during the insertion, if the elastic member is further inserted into the rim core metal in this state, the elastic portion is elastic toward the mounting portion side. Deform (bend). Therefore, the elastic member is easily inserted into the rim cored bar.

  And if a weight and an elastic member are inserted to the predetermined location of a rim | limb part core metal, it will be in the state by which the weight was elastically supported by the inner peripheral wall part by the elastic member. Therefore, when the rim cored bar vibrates in the vertical direction, the weight is moved in the vertical direction while elastically deforming the elastic part of the elastic member along with the vibration, thereby suppressing the vibration.

The invention according to claim 2 is characterized in that, in the invention according to claim 1, at least the vicinity of the adherent portion of the weight is formed in a larger diameter than the adherent portion.
According to said structure, since the to-be-adhered part is formed in diameter smaller than the neighborhood at least in the weight, a level | step difference arises between both. For this reason, if a mounting part is fitted to the attaching part of a weight, an elastic member can be mounted in the desired location of an arc-shaped weight. In this state, the movement of the mounting portion in the circumferential direction is restricted by the step. For this reason, it is possible to suppress the elastic member from being detached from the mounting portion (attachment portion) after the elastic member is mounted on the weight (including when the weight and the elastic member are inserted into the rim core metal).

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the same weight is provided at both end portions of the weight in the circumferential direction, and the weight of the inner wall of the weight housing chamber is in the circumferential direction. The gist of the present invention is that a pair of second elastic members elastically supported on the inner end wall portions located at both ends are mounted.

  According to the above configuration, when the rim cored bar vibrates in the circumferential direction, both the second elastic members attached to both ends in the circumferential direction are elastically deformed or elastically restored according to the vibration. While moving in the same direction. Due to this moving weight, the circumferential vibration of the rim cored bar is suppressed.

The second elastic member is attached to both ends of the weight in the circumferential direction. For this reason, when the weight is inserted into the rim cored bar, the second elastic member is unlikely to hinder insertion.
According to a fourth aspect of the present invention, in the third aspect of the present invention, the second elastic member has an elastic portion whose outer surface is formed in a curved shape, and the weight is used for the inner end wall by the elastic portion. The gist is to elastically support the part.

  Here, when the rim cored bar vibrates in the vertical direction, the second elastic member slides on the inner end wall portion of the weight accommodating chamber, and the second elastic member and the inner member that accompany the sliding move. The frictional resistance between the end walls tends to prevent the weight from moving. In this regard, in the invention according to the fourth aspect, the outer surface of the second elastic member is formed in a curved shape, and is substantially in line contact with the inner end wall portion. For this reason, the frictional resistance generated between the elastic portion and the inner end wall portion is small, and the second elastic member moves the weight when the weight is about to move up and down in response to the vibration of the rim core metal. It is hard to get in the way.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the rim cored bar is connected to the steering shaft via a spoke cored bar formed by casting. The weight storage chamber is provided at a location away from the connecting portion of the rim cored bar with the spoke cored bar in the circumferential direction.

  According to said structure, when forming a spoke part core metal by casting, the heat | fever of the metal material (molten metal) made into the molten state is also transmitted to an elastic member and a 2nd elastic member through a rim part core metal. However, in the invention according to claim 5, the weight housing chamber is separated from the connecting portion of the rim cored bar with the spoke cored bar in the circumferential direction. Therefore, the heat is not easily transmitted to the elastic member or the second elastic member in the weight accommodating chamber, and the influence of heat is suppressed.

  In a general steering wheel, the spoke core metal is connected to the left and right side portions of the annular rim core, and the spoke core is not connected to the rim core above the upper side. Therefore, it is desirable that the weight accommodating chamber is provided in a region above the connecting portion (left and right side portions) of the rim cored bar with the spoke cored bar and away from the connecting portion. If it is provided in the above, the above-mentioned effect can be surely obtained.

  According to the present invention, since the rim cored bar is made of a pipe material, the weight is a circular arc, and the elastic member has a tapered elastic part, relatively easily, The weight housing chamber can be formed with a configuration that maintains the accuracy of joining the rim cored bar, and the insertion of the weight and the elastic member into the rim cored bar can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a steering shaft 11 is rotatably provided in front of the driver's seat of the vehicle so as to be inclined so as to be higher toward the rear side, and a steering wheel is provided at a rear end portion of the steering shaft 11. 12 is attached. The steering wheel 12 connects an annular rim portion (sometimes called a ring portion) 13, a pad portion 14 disposed in a space surrounded by the rim portion 13, and the rim portion 13 and the pad portion 14. A plurality of (three in FIG. 1) spoke portions 15 are provided.

  In this embodiment, in order to specify the circumferential position of the rim portion 13, “up”, “down”, “left”, “left”, “Right” shall be defined.

  A cored bar made of a metal material such as iron, aluminum, magnesium, or an alloy thereof is disposed inside each of the above-described components (the rim portion 13, the pad portion 14, and the spoke portion 15) of the steering wheel 12. ing. The cored bar forms a skeleton part of the steering wheel 12 and is located at the center of the annular rim cored bar 16 and the rim cored bar 16 as shown in FIG. A boss cored bar 17 that is rotatably attached, and a spoke cored bar 18, 19, and 20 that connect the rim cored bar 16 and the bossed cored bar 17 are provided.

  As shown in at least one of FIGS. 5, 13, and 14, the rim cored bar 16 is formed by processing an iron pipe material (round pipe) 21, and is orthogonal to the axis A <b> 1 of the steering shaft 11. The cross section has an annular shape (circular shape) (see FIG. 14). The rim cored bar 16 has an annular shape in a cross section including the axis A1 (see FIG. 5). As the pipe material 21, one having a relatively small plate thickness T1 (around 1 mm) is suitable. This is a necessary condition for surely plastically deforming an intended portion of the pipe material 21 into an intended shape when caulking described later is performed. Both open ends 21A and 21B in the circumferential direction of the pipe material 21 are joined to each other by welding, and the rim cored bar 16 has an endless shape.

  As a material for the rim cored bar 16, a so-called seamless pipe having a seamless cross section is suitable. This is because if there is a seam in the pipe material 21, there is a possibility that the sliding or elastic deformation of the first elastic member 35 described later may be hindered.

  As shown in FIG. 2, the spoke cores 18 to 20 are integrally formed by a casting method such as die casting, medium pressure casting, low pressure casting, etc., using a metal material having a relatively small specific gravity such as an aluminum alloy. At the outer end of each of the spoke cores 18 to 20 (the end far from the boss core 17), connecting portions 22, 23, and 24 having an arc shape are provided. These connecting portions 22 to 24 correspond to connecting portions of the rim cored bar 16 to the spoke cores 18 to 20 in the claims. Each of the spoke part cores 18 to 20 covers a part of the rim part core bar 16 at these coupling parts 22 to 24. Two of the coupling portions 22 to 24 (the coupling portions 22 and 23) cover both sides of the rim core metal 16 in the vehicle width direction, that is, cover the left side and the right side of the rim core metal 16. (Coupling portion 24) covers the lower portion of rim cored bar 16.

  Although not shown, the entire rim cored bar 16 and the coupling parts 22 to 24 are surrounded by a synthetic resin or the like rich in heat insulation, elasticity, etc., and a skin made of leather or the like is covered on the outside. ing.

  As shown by a two-dot chain line in FIG. 1, a vibration damping mechanism D composed of a dynamic damper is incorporated in a part of the rim cored bar 16. The vibration damping mechanism D is a mechanism for suppressing each vibration in the circumferential direction and the vertical direction of the rim portion 13. Here, when a rotational unbalance occurs in the tire due to a drop of the balance weight or the like while the vehicle is running, vibrations resulting from the rotational unbalance are transmitted to the steering wheel 12 via the steering shaft 11. The vibration generated in the rim portion 13 by this transmission is the vibration in the circumferential direction of the rim portion 13 (flutter vibration). Further, the vertical vibration of the rim portion 13 is vibration transmitted from the engine to the rim portion 13 via the steering shaft 11 or the like when the vehicle is idling.

  Possible places in the steering wheel 12 where there is room for incorporating the damping mechanism D are in the pad portion 14 (lower cover) and in the rim portion 13. However, if the inside of the pad portion 14 is the installation destination of the vibration damping mechanism D, a space for setting the vibration damping mechanism D must be secured in the pad portion 14, which adds value to the function of the steering wheel 12. The mounting of other members to be given is prevented. Therefore, in the present embodiment, the interior of the rim portion 13 where the mounting of the other members is not performed as much as the inside of the pad portion 14, more specifically, the interior of the upper portion of the rim portion 13 in the neutral state is set as the installation destination of the damping mechanism D. Yes.

  As shown in at least one of FIGS. 3 and 4, the vibration damping mechanism D includes a weight housing chamber 25. The weight housing chamber 25 is configured by a part of the internal space S of the rim cored bar 16. As shown in at least one of FIGS. 4, 6, and 8, in each of the diagonally upper left portion and the diagonally upper right portion of the rim core metal 16, on a cross section orthogonal to the central axis A <b> 2 of the rim core metal 16. Thus, inner end wall portions 28 and 29 projecting into the inner space S of the rim cored bar 16 are provided at a plurality of locations around the central axis A2. In the present embodiment, the inner end wall portions 28 and 28 (29, 29) are provided at two locations facing each other across the central axis A2 of the rim cored bar 16. Here, “two places” are a place that is closer to the inner peripheral side and a part that is closer to the outer peripheral side with respect to the central axis A2. Each inner end wall portion 28, 29 has a V-shaped cross section and has an inner wall surface parallel to the axis A <b> 1 of the steering shaft 11. The inner end wall portions 28 and 29 are located at both end portions in the circumferential direction on the inner wall of the weight accommodating chamber 25. Moreover, the location pinched | interposed into the circumferential direction by both the inner end wall parts 28 and 29 among the inner walls of the rim | limb metal core 16 comprises the inner peripheral wall part 31 which has circular cross-sectional shape. In other words, a portion between the inner end wall portions 28 and 29 and the inner peripheral wall portion 31 in the internal space S of the rim cored bar 16 is the weight accommodating chamber 25. Since the weight accommodating chamber 25 is constituted by a part of the pipe material 21, the weight accommodating chamber 25 has inner end wall portions 28, 28, 29, and 29 in a cross section orthogonal to the central axis A2 of the rim cored bar 16. Except for 29 parts, it has an annular shape (circular shape). The weight housing chamber 25 has a substantially arc shape in a cross section perpendicular to the axis A1 of the steering shaft 11 (see FIG. 4).

  As shown in at least one of FIGS. 4 and 9, a damping weight 32 is movably disposed in the weight housing chamber 25. The weight 32 has a shape that can move within the weight housing chamber 25. Here, the weight 32 has a cross-sectional shape corresponding to the weight housing chamber 25. That is, the weight 32 has a substantially arc shape in a cross section orthogonal to the axis A1 of the steering shaft 11 (see FIG. 4), and has a circular shape in a cross section orthogonal to the central axis A2 of the rim cored bar 16 ( (See FIG. 9). With such a configuration, an annular gap is formed around the weight 32 in the weight housing chamber 25.

  A plurality of portions different from both ends of the weight 32 in the circumferential direction (hereinafter referred to as “intermediate portion 32M”), here, three portions near the center portion and both end portions, have at least an outer diameter larger than their vicinity. A small cylindrical adherend 33 is formed. The diameter D1 of the adherend 33 is preferably set to 8 to 12 mm, and is set to 10 mm here (see FIG. 11).

  The weight 32 can be formed, for example, by casting, extruding and bending a metal material such as iron, lead, copper, or brass. In addition, the weight 32 may be formed of ceramic or the like.

  The weight 32 is elastically supported on the inner wall of the weight housing chamber 25 by a first elastic member 35 and a second elastic member 41 mounted at a plurality of locations. The first elastic member 35 and the second elastic member 41 are all various rubbers such as silicone rubber, natural rubber (NR), ethylene / propylene rubber (EPDM), styrene / butadiene rubber (SBR), and chloroprene rubber. (CR), butyl rubber (IIR), urethane rubber or the like.

  The first elastic member 35 corresponds to an “elastic member” in the claims, and is elastic to the inner peripheral wall portion 31 in a state where the weight 32 is separated from the inner peripheral wall portion 31 of the weight accommodating chamber 25. Play a supporting role. The first elastic member 35 includes a mounting portion 36 and an elastic portion 37. As shown in at least one of FIGS. 10 and 11, the mounting portion 36 has a cylindrical shape and is fitted to the adherend portion 33 on the outer peripheral surface of the weight 32. The elastic part 37 is connected to an end part 36F on the front side (left side in FIG. 11) of the weight 32 with respect to the rim cored bar 16 among both end parts in the circumferential direction of the mounting part 36, and in the same insertion direction. The rear side (the right side in FIG. 11) has a tapered shape with a diameter increasing. In the end portion 36F of the mounting portion 36, a surface 38R on the rear side in the insertion direction of the first elastic member 35 into the rim core metal 16 is formed in a curved surface shape. The first elastic member 35 is in surface contact with the adherend portion 33 of the weight 32 at the mounting portion 36, and is substantially in line contact with the inner peripheral wall portion 31 of the weight accommodating chamber 25 at the outer peripheral portion of the elastic portion 37.

  Here, the plate thickness T2 of the first elastic member 35 (the mounting portion 36 and the elastic portion 37) is preferably set to 0.8 to 1.6 mm. If the plate thickness T2 is thinner than 0.8 mm, it is difficult to mold the elastic portion 37. On the other hand, when the plate thickness T2 is larger than 1.6 mm, the elastic portion 37 is hardly elastically deformed.

  In a state before the first elastic member 35 is inserted into the rim cored bar 16, the diameter D2 at the portion having the largest outer diameter in the elastic portion 37 needs to be set to a value satisfying the following condition. For example, it is desirable that it is 14-20 mm.

(I) It is slightly larger than the inner diameter of the rim cored bar 16.
(Ii) The elastic part 37 can be inserted into the rim cored bar 16.
(Iii) The elastic part 37 can be elastically deformed in the rim cored bar 16.

The length L1 of the elastic portion 37 in the circumferential direction is desirably set to 4 to 10 mm.
The radius R1 of the surface 38R of the mounting portion 36 is preferably set to 0.2 to 0.6 mm. If the radius R1 is smaller than 0.2 mm, it will be difficult to ensure the required strength in the mold for molding the first elastic member 35. Further, when the radius R1 is larger than 0.8 mm, only the connection part of the elastic part 37 to the mounting part 36 becomes extremely thicker than the other parts, and the elastic part 37 becomes difficult to elastically deform.

  The angle α1 formed with the mounting portion 36 of the elastic portion 37 is preferably set to 20 to 60 °. If the angle α1 is smaller than 20 °, it is difficult to ensure the necessary strength in the mold for molding the first elastic member 35. When the angle α1 is larger than 60 °, the length L1 in the circumferential direction of the elastic portion 37 is shortened accordingly, and the elastic portion 37 is hardly elastically deformed.

  As shown in at least one of FIGS. 4, 12, and 16, each second elastic member 41 is mainly in a state in which the weight 32 is separated from the inner end wall portions 28 and 29 of the weight housing chamber 25 in the circumferential direction. The elastic member plays a role of elastically supporting the inner end wall portions 28 and 29, and includes an attachment portion 42, an elastic portion 43, and a connecting portion 44. The mounting portion 42 has a cylindrical shape, and one end thereof is closed by a lid portion 42C. The second elastic member 41 is placed on the end portion 32E in the circumferential direction of the weight 32 in the mounting portion 42 (see FIG. 7). The mounting portion 42 is fixed to the end portion 32E by means such as vulcanization adhesion, and is integrated with the same weight 32. The elastic portion 43 has a cylindrical shape, and is connected to the lid portion 42C of the mounting portion 42 by a connecting portion 44 having a rectangular parallelepiped shape. The central axis A3 (see FIGS. 6 and 8) of the elastic portion 43 is parallel to the axis A1 (see FIG. 3) of the steering shaft 11. The outer surface (outer peripheral surface) of the elastic portion 43 is in substantially line contact with the inner wall surface parallel to the coaxial line A1 at the inner end wall portions 28 and 29. Each elastic portion 43 is elastically deformable between the inner end wall portions 28 and 29 and the weight 32.

  The steering wheel 12 in the present embodiment is configured as described above. In this steering wheel 12, a rim cored bar 16 having a vibration damping mechanism D inside is manufactured through the following steps (I) to (VII).

  (I) As shown in at least one of FIGS. 13 and 14, a linear seamless pipe having an annular opening (hereinafter simply referred to as a pipe member 21) is bent into an annular shape with a predetermined curvature (diameter). To do. At the stage where the bending process has been performed, both open ends 21A and 21B of the pipe material 21 are close to each other.

(II) Separately from the step (I), the weight 32 having an arcuate shape with the same curvature as the pipe material 21 and having the adherend portion 33 is manufactured by forging, casting, cutting, or the like. To do.
(III) As shown in FIG. 15, the first elastic member 35 is attached to each adherend portion 33 of the weight 32 obtained through the step (II). At this time, the mounting portion 36 of the first elastic member 35 is covered with the outer periphery of the weight 32 from one end portion 32 </ b> E in the circumferential direction of the weight 32. By pushing the mounting portion 36 along the weight 32 in the circumferential direction, the mounting portion 36 is moved to the target attached portion 33. In the weight 32, the adherend portion 33 is formed to have a smaller diameter than other portions, and therefore a step 34 (see FIG. 11) occurs between them. Therefore, if the mounting portion 36 is moved to the attached portion 33 of the weight 32 and fitted on the attached portion 33, the first elastic member 35 is desired in the circumferential direction of the arc-shaped weight 32. Attach to the place. In this state, the movement of the mounting portion 36 in the circumferential direction is restricted by the step 34.

  Further, the second elastic member 41 is attached to both end portions 32 </ b> E in the circumferential direction of the weight 32. At the time of mounting, the mounting portion 42 of the second elastic member 41 is put on the end portion 32E of the weight 32. The mounting portion 42 is vulcanized and bonded to the end portion 32E.

  (IV) A pair of caulking tools (not shown) each having a triangular prism shape at a location that satisfies the following condition (location indicated by “+” in FIG. 14) in the pipe material 21 that has undergone the bending process of (I) above, It arrange | positions in the state which made those top sides oppose, and pressurizes the pipe material 21 with both caulking tools.

  Condition: The pipe material 21 is separated from the one open end 21A toward the other open end 21B by a circumference of the damping mechanism D (a circumference CL between the outer ends of the second elastic members 41) or more (see FIG. 15), and the vicinity of the inner peripheral side and the outer peripheral side of the pipe material 21.

  Due to the pressurization (caulking), as shown in FIG. 15, the center axis of the pipe material 21 (because it is substantially the same as the center axis A2 of the rim cored bar 16, it is expressed as “center axis A2”). Two places (two places every 180 °) having a point-symmetric relationship as the center undergo plastic deformation. By this plastic deformation, inner end wall portions 28 having a V-shaped cross section and having an inner wall surface parallel to the axis A1 of the steering shaft 11 are formed at the two locations.

  (V) The weight 32 to which the first elastic member 35 and the second elastic member 41 are respectively attached in the step (III) is attached to one end in the circumferential direction (left side in FIG. 15) as shown in FIG. The pipe material 21 is inserted from the opening end 21A on one side (right side in FIG. 15) of the pipe material 21 that has undergone the step (I) in order along the circumferential direction from the portion 32E. At the time of this insertion, of both ends of the first elastic member 35 in the circumferential direction of the mounting portion 36, the end portion 36F (see FIG. 11) to which the elastic portion 37 is connected to the mounting portion 36 is the front side in the insertion direction. Like that. As the weight 32 is inserted, the first elastic member 35 attached to the intermediate portion 32M also enters the rim core metal 16 from the one opening end 21A together with the weight 32. At this time, the elastic portion 37 has a taper shape whose diameter increases toward the rear side in the insertion direction, and has a smaller diameter than the inner peripheral wall portion 31 of the rim cored bar 16 on the front side in the insertion direction. Therefore, the first elastic member 35 is easily inserted into the rim cored bar 16 from the opening end 21A.

  Even if the elastic portion 37 abuts against the inner peripheral wall portion 31 of the rim core metal 16 during the insertion, if the first elastic member 35 is further inserted into the rim core metal 16 in this state, the elastic portion The first elastic member 35 can be further inserted into the rim cored bar 16 by the elastic deformation of the 37 toward the mounting part 36 side. At this time, the frictional resistance generated between the first elastic member 35 (elastic portion 37) and the inner peripheral wall portion 31 of the rim core metal 16 causes the first elastic member 35 to be solid (described in Patent Document 1). The cross-sectional shape is uniform in an annular shape, a cylindrical shape, or a cylindrical shape having a plurality of protrusions in the periphery, etc.). Therefore, the first elastic member 35 and the weight 32 are easily inserted into the rim cored bar 16.

  At this time, the inner end wall portion 28 on the front side in the insertion direction functions as a positioning portion for the second elastic member 41 and restricts the movement of the second elastic member 41 toward the opening end 21B (the front side in the insertion direction of the weight 32, etc.). To do.

  In addition, the cylindrical mounting portion 36 of the first elastic member 35 is fitted to the adherend portion 33 that has a columnar shape having a smaller diameter than other portions of the weight 32. Therefore, when the weight 32 moves in the circumferential direction, even if the first elastic member 35 moves relative to the weight 32, the weight 32 stops against the step 34 between the adherend portion 33 and another location. It is difficult for the mounting portion 36 to be detached from the adherend portion 33.

  The second elastic member 41 is attached to an end 32E in the circumferential direction of the weight 32. For this reason, when the weight 32 is inserted into the rim cored bar 16, the second elastic member 41 is unlikely to hinder insertion.

  Then, when the weight 32 is inserted to a position where the elastic portion 43 of the second elastic member 41 substantially contacts the inner end wall portion 28, the weight 32 is weighted by the first elastic member 35 and the second elastic member 41. It will be in the state elastically supported by each wall part of the storage chamber 25. FIG.

  (VI) As shown in FIG. 15, it is a location corresponding to the second elastic member 41 in the circumferential direction of the pipe material 21 that has undergone the step (V), and is near the inner circumference side and the outer circumference side of the pipe material 21. A pair of caulking tools (not shown) having a triangular prism shape are disposed in the vicinity (location indicated by “x” in FIG. 15) with their apexes facing each other, and the pipe material is used with both caulking tools. 21 is pressurized. Here, the “location corresponding to the second elastic member 41 in the circumferential direction of the pipe material 21” means that the pipe material 21 is slightly separated from one opening end 21A to the other opening end 21A side and caulked. This is a place where the left and right elastic portions 43 can be slightly elastically deformed by pressing in the circumferential direction.

  As shown in FIG. 4, the above pressurization (caulking) plastically deforms two points (two places every 180 °) having a point-symmetrical relationship with respect to the central axis A <b> 2 of the pipe material 21, resulting in a V shape. The inner end wall portion 29 having an inner wall surface parallel to the axis A1 of the steering shaft 11 is formed at the two locations. These inner end wall portions 29 function as positioning portions of the second elastic member 41 and restrict the movement of the second elastic member 41 toward the opening end 21A (the rear side in the insertion direction of the weight 32 and the like).

  (VII) Both the open ends 21A and 21B of the pipe material 21 that have undergone the step (VI) are matched, and both open ends 21A and 21B are joined by welding. By this joining, the pipe material 21 becomes endless.

  By going through the above steps (I) to (VII), the rim cored bar 16 having the inner end wall portions 28 and 29 is easily and reliably formed. A portion sandwiched between the inner end wall portions 28 and 29 in the inner space S of the rim cored bar 16 is a weight accommodating chamber 25. The weight accommodating chamber 25, the weight 32, the first elastic member 35, and the second elastic member 41 constitute a vibration damping mechanism D.

  In the above series of steps, since the rim cored bar 16 is formed of the pipe material 21, the rim cored bar 16 is divided into a pair of halves having a semicircular cross section. In contrast, after the weight 32 is disposed in one half, the other half does not have to be joined to this half. Accordingly, when the two halves are joined so as not to hinder the elastic deformation and sliding of the first elastic member 35, the weight housing chamber 25 can be formed relatively easily with high accuracy. . It is to be noted that the rim cored bar 16 can be formed by the pipe material 21 as described above for the first time by using the weight 32 having an “arc shape” in a cross section perpendicular to the axis A1 of the steering shaft 11. Become. In Patent Document 1 using an annular (endless) weight as the weight, the rim cored bar divided into halves cannot be incorporated into the rim cored bar 16 formed by the pipe material 21. I have to adopt it.

  The rim cored bar 16 in which the vibration damping mechanism D is incorporated as described above is set in the mold together with the boss cored bar 17 when the spoke cored bars 18 to 20 are formed. And the spoke part metal cores 18-20 which connect the boss | hub part metal core 17 and the rim | limb metal core 16 are formed by implementing a casting method, as shown in FIG. At this time, as described above, the connecting portions 22 and 23 of the two spoke cores 18 and 19 are on both sides of the rim core 16 in the vehicle width direction, that is, the left side and the right side of the rim core 16. It is formed with the part covered. The positions where these coupling portions 22 and 23 are formed are locations away from the inner end wall portions 28 and 29 at both ends of the weight housing chamber 25 in the circumferential direction.

  In addition, although the junction part of opening end 21A, 21B is also provided in the location away from the inner end wall part 29 about the circumferential direction, this junction part is the influence at the time of formation of the coupling part 23 (for example, When the joint portion 23 is formed by casting, it is desirable to provide it at a portion between the inner end wall portion 29 and the joint portion 23 if the unevenness caused by welding of the joint portion disturbs the flow of the molten metal. . However, if this point does not have to be taken into account, the heat conduction to the elastic members 35 and 41 at the time of welding of the joint portion is suppressed (distant from each other), so that the joint portion is joined to the joint portion. It is desirable to provide in the part covered with 23. Moreover, it is good also as a structure which suppresses the influence of an unevenness | corrugation, such as giving the process which levels the unevenness | corrugation of a junction part, and provides a junction part in the site | part covered with the coupling | bond part 23. FIG.

Next, the operation and effect of the present embodiment configured as described above will be described.
4, FIG. 16 (B) and FIG. 17 (B) show the state of the vibration damping mechanism D when the rim cored bar 16 is not vibrating in the circumferential direction and the vertical direction. The position of the weight 32 at this time is referred to as a “neutral position”. Thus, in the state where the weight 32 is in the neutral position, the elastic portion 37 of each first elastic member 35 is slightly elastically deformed toward the mounting portion 36, and the weight accommodating chamber is located at the largest outer diameter portion of the elastic portion 37. The 25 inner peripheral wall portions 31 are in substantially line contact in a pressed state. A gap G1n between the adherent portion 33 and the upper portion of the inner peripheral wall portion 31 is substantially the same as a gap G2n between the adherent portion 33 and the lower portion of the inner peripheral wall portion 31 (see FIG. 16B). Further, the elastic portion 43 of each second elastic member 41 is slightly elastically deformed, and the elastic portion 43 is in substantially line contact with the corresponding inner end wall portions 28 and 29 of the weight accommodating chamber 25 in a pressed state. The gap G3n between the inner end wall portion 28 and the weight 32 and the gap G4n between the inner end wall portion 29 and the weight 32 are approximately the same (see FIG. 4).

  Next, FIG. 16A shows a state of the vibration damping mechanism D when the weight 32 moves upward from the neutral position (FIG. 16B) in response to the vertical vibration of the rim cored bar 16. Is shown. In this state, the upper portion of each elastic portion 37 is pressed upward by the weight 32. The upper part of the elastic part 37 is compressed between the adherend part 33 and the upper part of the inner peripheral wall part 31 to be further elastically deformed. At this time, in each first elastic member 35, the space 45 (see FIG. 11) between the upper portion of the mounting portion 36 and the upper portion of the elastic portion 37 is used for elastic deformation. Compared to the case where the first elastic member 35 is formed of a solid body), the elastic portion 37 is easily elastically deformed, and the weight 32 is easily moved upward. With the movement of the weight 32, the gap G1 between the adherent portion 33 and the upper portion of the inner peripheral wall portion 31 becomes smaller than the gap G1n at the neutral position (FIG. 16B). The gap G2 with the lower part of the portion 31 is larger than the gap G2n at the neutral position. As the gap G2 expands, the lower portion of the elastic portion 37 compressed between the adherend portion 33 and the lower portion of the inner peripheral wall portion 31 is elastically restored.

  Thereafter, the weight 32 changes the moving direction from above to below. As the weight 32 moves downward, the gap G1 between the adherend portion 33 and the upper portion of the inner peripheral wall portion 31 increases, and the gap G2 between the adherent portion 33 and the lower portion of the inner peripheral wall portion 31 decreases. . The upward pressing force on the upper portion of the elastic portion 37 by the weight 32 decreases, and the upper portion of the elastic portion 37 starts to be elastically restored. And if the weight 32 moves to a neutral position, the damping mechanism D will return to the state shown in FIG.16 (B) mentioned above.

  Subsequently, when the weight 32 moves downward, the lower portion of the elastic portion 37 is pressed downward by the weight 32. The lower part of the elastic part 37 is compressed and elastically deformed between the adherend part 33 and the lower part of the inner peripheral wall part 31. At this time, since the space 46 (see FIG. 11) between the lower portion of the mounting portion 36 and the lower portion of the elastic portion 37 is used for elastic deformation, the lower portion of the elastic portion 37 is smaller than the case where the space 46 is not provided. It is easy to elastically deform and the weight 32 is easy to move downward. As shown in FIG. 16C, the gap G2 between the adherend portion 33 and the lower portion of the inner peripheral wall portion 31 is smaller than the gap G2n at the neutral position (FIG. 16B), and the adherend portion 33 and The gap G1 with the upper part of the inner peripheral wall portion 31 is larger than the gap G1n at the neutral position.

  Thereafter, the weight 32 changes the moving direction from below to above. As the weight 32 moves upward, the gap G2 between the adherend portion 33 and the lower portion of the inner peripheral wall portion 31 increases, and the gap G1 between the adherent portion 33 and the upper portion of the inner peripheral wall portion 31 decreases. . The downward pressing force of the weight 32 against the lower portion of the elastic portion 37 decreases, and the lower portion of the elastic portion 37 begins to be elastically restored. When the weight 32 moves to the neutral position, the vibration control mechanism D returns to the state shown in FIG.

  The weight 32 that moves in the vertical direction as described above and the first elastic member 35 that elastically deforms function as a dynamic damper of a spring-mass system having a predetermined resonance frequency (approximately 30 Hz). That is, when the rim cored bar 16 vibrates in the vertical direction in a specific frequency range, the weight 32 and the first elastic member 35 resonate with a phase angle opposite to the input vibration (the vertical vibration of the rim cored bar 16). . The vibration displacement due to the resonance is generated in the opposite direction to the displacement due to the input vibration, thereby providing a damping function. The vibration of the rim cored bar 16 is suppressed (damped) by exerting the damping mechanism D.

  Here, the weight 32 is elastically supported by the inner end wall portions 28 and 29 of the weight accommodating chamber 25 via the second elastic member 41, and is supported on the inner peripheral wall portion 31 of the weight accommodating chamber 25 via the first elastic member 35. Elastically supported. Therefore, when the weight 32 moves in the vertical direction as described above, frictional resistance is generated between the elastic portion 43 of the second elastic member 41 and the inner end wall portions 28 and 29. This frictional resistance tends to prevent the weight 32 from moving up and down.

  However, in the present embodiment, the elastic portion 43 of each second elastic member 41 is formed in a cylindrical shape, and its central axis A3 is parallel to the axis A1 of the steering shaft 11. The curved outer surface (outer peripheral surface) of the elastic portion 43 having a generatrix parallel to the axis A1 is in substantially line contact with the inner wall surface parallel to the axis A1 at the inner end wall portions 28 and 29. Therefore, when the weight 32 moves in the vertical direction, the second elastic member 41 slides with respect to the inner end wall portions 28 and 29, but the frictional resistance generated by the sliding is small.

  Therefore, when the weight 32 tries to move in the vertical direction in response to the vibration of the rim cored bar 16 in the vertical direction, the second elastic member 41 is unlikely to hinder the movement of the weight 32. The weight 32 easily moves according to the vibration of the rim portion 13 and exhibits high vibration damping performance.

  FIG. 17A shows a state of the vibration damping mechanism D when the weight 32 moves counterclockwise from the neutral position in response to the vibration of the rim cored bar 16 in the circumferential direction. In this state, the left elastic portion 43 positioned in front of the movement direction of the weight 32 is pressed counterclockwise by the weight 32. The left elastic part 43 is compressed between the weight 32 and the inner end wall part 28 of the weight accommodating chamber 25 and elastically deforms into a non-cylindrical shape. At this time, since the space 47 inside the left elastic part 43 is used for elastic deformation, when the space 47 is not provided, that is, when the left elastic part 43 is solid, for example, a cylindrical shape. In comparison, the left elastic part 43 is easily elastically deformed, and the weight 32 is easy to move counterclockwise. The gap G3 between the weight 32 and the inner end wall portion 28 is smaller than the gap G3n at the neutral position (FIG. 17B). Although not shown, at this time, the gap G4 between the weight 32 and the inner end wall 29 is larger than the gap G4n at the neutral position (see FIG. 4). The pressing force by the weight 32 against the right elastic portion 43 is reduced or eliminated.

  Thereafter, the weight 32 changes the moving direction from the counterclockwise direction to the clockwise direction. As the movement of the weight 32 in the clockwise direction proceeds, the gap G3 between the weight 32 and the inner end wall portion 28 increases, and the gap G4 between the weight 32 and the inner end wall portion 29 decreases. The pressing force in the counterclockwise direction by the weight 32 with respect to the left elastic portion 43 decreases, and the elastic portion 43 starts to be elastically restored. When the weight 32 moves to the neutral position, the vibration control mechanism D returns to the state shown in FIG. 17B, and the left elastic part 43 becomes substantially cylindrical.

  Subsequently, when the weight 32 moves in the clockwise direction, the elastic portion 43 on the front side (right side) in the movement direction is pressed in the clockwise direction by the weight 32. The right elastic part 43 is compressed between the weight 32 and the inner end wall part 29 and elastically deformed into a non-cylindrical shape (not shown). At this time, since the space 47 inside the right elastic portion 43 is used for elastic deformation, the elastic portion 43 is more easily elastically deformed than the case where the space 47 is not provided, and the weight 32 moves in the clockwise direction. It's easy to do. The gap G4 between the weight 32 and the inner end wall portion 29 is smaller than the gap G4n at the neutral position (see FIG. 4), and between the weight 32 and the inner end wall portion 28 as shown in FIG. The gap G3 is larger than the gap G3n at the neutral position (FIG. 17B). In this case, the second elastic member 41 maintains a cylindrical shape, or is further elastically deformed into a non-cylindrical shape due to inertia, as shown in FIG.

  Thereafter, the weight 32 changes the moving direction from the clockwise direction to the counterclockwise direction. As the movement of the weight 32 in the counterclockwise direction proceeds, the gap G4 between the weight 32 and the inner end wall portion 29 increases, and the gap G3 between the weight 32 and the inner end wall portion 28 decreases. The pressing force in the clockwise direction by the weight 32 against the right elastic portion 43 decreases, and the elastic portion 43 starts to be elastically restored. When the weight 32 moves to the neutral position, the vibration damping mechanism D returns to the state shown in FIG. 17B, and the right elastic portion 43 becomes substantially cylindrical.

  As described above, the weight 32 that moves in the clockwise direction and the counterclockwise direction and the second elastic member 41 that is elastically deformed include a spring-mass system having a predetermined resonance frequency (approximately 15 Hz). Functions as a dynamic damper. That is, when the rim cored bar 16 vibrates in the circumferential direction in a specific frequency range, the weight 32 and the second elastic member 41 resonate with a phase angle opposite to the input vibration (vibration in the circumferential direction of the rim cored bar 16). . The vibration displacement due to the resonance is generated in the opposite direction to the displacement due to the input vibration, thereby providing a damping function. By exhibiting this vibration damping function, the circumferential vibration (flutter vibration) of the rim portion 13 is suppressed (vibrated).

  Here, the cylindrical mounting portion 36 of the first elastic member 35 is fitted to a columnar attached portion 33 having a smaller diameter than other portions of the weight 32. Therefore, even when the first elastic member 35 moves relative to the weight 32 when it moves in the circumferential direction of the weight 32, it stops by hitting the step 34 between the adherend portion 33 and another location. It is difficult for the mounting portion 36 to be detached from the adherend portion 33.

  The weight 32 is supported on the inner peripheral wall portion 31 of the weight housing chamber 25 via the first elastic member 35. Therefore, when the weight 32 moves in the circumferential direction (clockwise direction and counterclockwise direction) of the rim portion 13 as described above, the elastic portion 37 of the first elastic member 35 and the inner peripheral wall portion 31 of the weight accommodating chamber 25 are formed. A frictional resistance is generated between them, and the movement of the weight 32 is hindered.

  However, in this embodiment, each first elastic member 35 is attached to the intermediate portion 32M in the circumferential direction of the weight 32, and the elastic portion 37 is formed in a tapered shape whose diameter increases toward the rear side in the movement direction of the weight 32. ing. Each first elastic member 35 is merely in line contact with the inner peripheral wall portion 31 in the elastic portion 37. For this reason, when the weight 32 moves, the first elastic member 35 moves in the circumferential direction while maintaining a substantially line contact state, and the frictional resistance generated between the inner circumferential wall portion 31 and the weight 32 is small. Therefore, when the weight 32 is about to move in the circumferential direction according to the vibration of the rim cored bar 16, the first elastic member 35 is unlikely to hinder the movement of the weight 32. The weight 32 is easy to move according to the vibration of the rim cored bar 16 and exhibits high vibration damping performance.

  Further, since the amplitude of the vibration in the circumferential direction (flutter vibration) is sufficiently small, there is no possibility that the elastic portion 37 is reversed (turned over) even if the first elastic member 35 reciprocates in the circumferential direction together with the weight 32.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Since the weight 32 has an arc shape in the cross section orthogonal to the axis A1 of the steering shaft 11, the rim cored bar 16 made of the pipe material 21 can be used. As a result, the weight housing chamber 25 can be formed relatively easily with high accuracy.

  (2) As the first elastic member 35 attached to the intermediate portion 32M in the circumferential direction of the weight 32, a member provided with a cylindrical attachment portion 36 and a tapered elastic portion 37 is used. Therefore, when the weight 32 is inserted into the rim cored bar 16, the first elastic member 35 can be easily inserted into the rim cored bar 16 together with the weight 32 by bending the elastic part 37.

  (3) Although related to (2) above, as one method for facilitating insertion of the first elastic member 35 into the rim cored bar 16, grease is applied to the first elastic member 35 prior to the insertion. To do. The grease reduces the friction between the first elastic member 35 and the inner peripheral wall portion 31 of the rim cored bar 16 and facilitates the insertion of the first elastic member 35. However, unless the grease is completely removed thereafter, the grease is controlled. This may affect the vibration damping performance of the vibration mechanism D and increase the variation in the vibration damping performance. In this regard, in the present embodiment, the shape of the first elastic member 35 is devised to facilitate insertion into the rim cored bar 16, thus eliminating the need for grease. For this reason, the above-mentioned concerns (instability of vibration damping performance and increase in dispersion) due to the use of grease are not caused.

  (4) The intermediate portion 32M in the circumferential direction of the weight 32 is provided with a cylindrical attached portion 33 having a smaller diameter than other portions, and the attachment portion 36 of the first elastic member 35 is fitted to the attached portion 33. I am letting. Therefore, after the mounting portion 36 is mounted on the weight 32 (including when the weight 32 and the first elastic member 35 are inserted into the rim core metal 16), the elastic portion 37 is prevented from being detached from the adherend portion 33. be able to.

  (5) A pair of second elastic members 41 are attached to both ends of the weight 32 in the circumferential direction. Therefore, when the rim cored bar 16 vibrates in the circumferential direction, the weight 32 is moved in the same circumferential direction while elastically deforming or restoring both the second elastic members 41 according to the vibration, and the rim cored bar is moved. Sixteen circumferential vibrations (flutter vibration) can be suppressed.

  (6) As the elastic portion 43 of the second elastic member 41, a cylindrical shape having an outer surface formed in a curved shape is used. Therefore, the elastic portion 43 is brought into substantially line contact with the inner end wall portions 28 and 29 of the weight housing chamber 25 on the curved outer surface, and the friction resistance when the second elastic member 41 slides in the substantially vertical direction is obtained. Can be small. When the weight 32 tries to move in the vertical direction in response to the vibration of the rim core metal 16, the elastic portion 43 can be prevented from obstructing the movement of the weight 32.

  In addition, as described above, the elastic portion 43 is formed in a cylindrical shape, thereby having a structure having a space 47 inside. Therefore, the elastic part 43 can be easily elastically deformed, and the weight 32 can be easily moved to further improve the vibration damping performance.

  (7) The weight housing chamber 25 is provided in the upper part of the rim cored bar 16 which is a part away from the connecting part (the coupling part 22-24) with the spoked cored bar 18-20. Therefore, when the spoke core metal 18 to 20 is manufactured by casting, the heat of the molten metal is hardly transmitted to the first elastic member 35 and the second elastic member 41 which are members having low heat resistance in the weight housing chamber 25, The influence of the heat of the elastic members 35 and 41 can be suppressed.

  (8) The existing rim cored bar 16 used as the skeleton part of the rim part 13 is used, and a part of the inner space S is used as a weight accommodating chamber 25, where the weight 32, the first elastic member 35, and the second The elastic member 41 is accommodated. Therefore, the weight storage chamber 25 can be secured without providing a case or the like, and the number of parts of the steering wheel 12 can be reduced.

  (9) Although related to (8) above, an inner end wall portion 28 protruding into the inner space S of the rim core metal 16 is provided, and spaced from the inner end wall portion 28 in the circumferential direction of the rim core metal 16. An inner end wall portion 29 that protrudes into the internal space S is provided at the location. A portion sandwiched between the inner end wall portions 28 and 29 in the internal space S is defined as a weight accommodating chamber 25. With these inner end wall portions 28 and 29, the weight accommodating chamber 25 and the other portion can be partitioned in the inner space S of the rim cored bar 16. In other words, both inner end wall portions 28 and 29 can constitute both ends of the weight housing chamber 25 in the circumferential direction.

  Accordingly, the movement of both first elastic members 35 in the direction of exiting the weight housing chamber 25 is regulated by the inner end wall portions 28 and 29, and the second elastic member 41 is elastically deformed or restored by the movement of the weight 32. Can be surely performed.

  (10) The inner end wall portion 28 (29) is provided at a plurality of locations in a cross section orthogonal to the central axis A2 of the rim core metal 16. Therefore, it is possible to easily secure a large number of projecting portions of the inner end wall portions 28 and 29 to the weight accommodating chamber 25, and to more reliably regulate the movement of the first elastic member 35 in the direction of coming out of the weight accommodating chamber 25. it can.

  (11) The mounting portion 36 of the first elastic member 35 is merely fitted to the attached portion 33 of the weight 32 and is not fixed. Therefore, the mounting portion 36 can rotate around the adherend portion 33. However, because the mounting portion 36 has a cylindrical shape and the elastic portion 37 has a tapered shape, the inner peripheral wall portion 31 of the weight accommodating chamber 25 is always provided even if the first elastic member 35 rotates. Since it can maintain the state of being substantially in line contact, there is no problem.

  (12) The mounting portion 42 of the second elastic member 41 is fixed to the end portion 32E of the weight 32. Therefore, the mounting portion 42 does not rotate around the end portion 32E, and it is possible to suppress a change in the contact mode between the elastic portion 43 and the inner end wall portions 28 and 29 due to the rotation.

Note that the present invention can be embodied in another embodiment described below.
<About spoke core metal 18-20>
The spoke core metal 18 to 20 may be manufactured separately from the rim core metal 16, and the spoke core metal 18 to 20 may be joined to the rim core metal 16 by welding. Also in this case, the heat of welding is transmitted to the first elastic member 35 and the second elastic member 41 through the rim cored bar 16 (weight housing chamber 25). Therefore, it is effective to provide the weight housing chamber 25 at a location away from the connecting portion of the rim cored bar 16 to the spoke cored metal 18-20. In this way, the same effect as (7) described above can be obtained.

<About the weight housing chamber 25>
-The position of the weight storage chamber 25 may be changed on the condition that it is a place away from the connection part (joining part 22-24) with the spoke part cores 18-20 among the rim part cores 16. .

The weight storage chambers 25 are provided at a plurality of locations in the circumferential direction of the rim cored bar 16, and the weights 32 on which the first elastic member 35 and the second elastic member 41 are mounted are stored in the respective weight storage chambers 25. Also good.
The number of inner end wall portions 28 (29) in the same cross section orthogonal to the central axis A2 of the rim core metal 16 may be changed to a single number or a plurality other than two. In the case of a single piece, the inner end wall portion 28 (29) may be formed over the entire circumference of the rim cored bar 16 having an annular shape in the cross section. Further, when a plurality of inner end wall portions 28 (29) are provided, the inner end wall portions 28 (29) are provided at locations that are point-symmetric with respect to the central axis A2 of the rim cored bar 16. It may be provided, or may be provided at a location that does not have a point-symmetrical relationship.

-Inner end wall part 28 and 29 may be formed in the cross-sectional shape different from the said embodiment.
It is desirable that the inner end wall portions 28 and 29 are in substantially line contact with the cylindrical elastic portion 43 of the second elastic member 41. As described above, the central axis A3 (see FIGS. 6 and 8) of the elastic portion 43 is parallel to the axis A1 (see FIG. 3) of the steering shaft 11. The bus of the elastic part 43 is also parallel to the coaxial line A1. In order to make a substantially line contact with the outer surface (outer peripheral surface) of the elastic portion 43, at least the surface related to the contact with the elastic portion 43 in the inner end wall portions 28 and 29 needs to be parallel to the axis A <b> 1. Examples of the shape that satisfies this condition include a quadrangular pyramid shape in addition to the V-shaped cross section adopted in the embodiment and the inner wall surface parallel to the axis A1. In this case, at least one surface of the inner end wall portions 28 and 29 is formed in parallel to the axis A1. Even the inner end wall portions 28 and 29 having such a shape can be easily formed by pressurizing the pipe member 21 using a caulking tool whose tip is pointed in a quadrangular pyramid shape and making it depressed.

  -You may form the surface of the inner peripheral wall part 31 in a smooth surface so that the elastic part 37 of the 1st elastic member 35 may slide easily when the weight 32 moves to the circumferential direction. If it does in this way, the frictional resistance between the 1st elastic member 35 and the inner peripheral wall part 31 at the time of inserting the weight 32 in the rim | limb part metal core 16 will be small, and there also exists a merit which becomes easy to insert. Similarly to the above, the surfaces of the inner end wall portions 28 and 29 are formed to be smooth so that the elastic portion 43 of the second elastic member 41 can easily slide when the weight 32 moves in the vertical direction. May be.

The caulking angle when forming the inner end wall portions 28 and 29 can be changed according to the FS (load-stroke) characteristics of the rim portion 13.
<About the rim cored bar 16>
-You may change the order of the manufacturing process of the rim | limb core metal 16 which incorporated the damping mechanism D within the range which satisfy | fills the following conditions.

Condition 1: After bending the pipe material 21 into an annular shape, the weight 32, the first elastic member 35, and the second elastic member 41 are inserted into the pipe material 21.
Condition 2: After satisfying Condition 1, both open ends 21A and 21B of the pipe material 21 are welded and joined.

Therefore, for example, the operation of forming the inner end wall portions 28 and 29 by caulking may be performed at a time different from the above embodiment.
<About the weight 32>
-A cross-sectional shape (a shape in a cross-section orthogonal to the axis A1 of the steering shaft 11) of the portion different from the adherend portion 33 of the weight 32 can be inserted from one open end 21A of the pipe-shaped rim cored bar 16. However, it may be changed to a non-circular shape on the condition that it can move in the weight storage chamber 25.

<About the first elastic member 35>
-You may change to the structure which arrange | positions the 1st elastic member 35 in four places or more places about the circumferential direction of the intermediate part 32M in the weight 32. FIG.

  The mounting portion 36 of the first elastic member 35 may be fixed to the adherend portion 33 of the weight 32 by vulcanization adhesion or the like. In this case, since the first elastic member 35 moves integrally with the weight 32, it is not necessary to attach the first elastic member 35 to the small-diameter adherend 33 as in the above embodiment.

  A plurality of ribs extending radially from the mounting portion 36 and connected to the elastic portion 37 may be formed in a space (including the spaces 45 and 46) between the mounting portion 36 and the elastic portion 37. By adding these ribs, the damping performance can be changed by adjusting the ease of elastic deformation of the elastic portion 37.

<About the second elastic member 41>
-You may mount | wear with the aspect which can rotate, without fixing the mounting part 42 with respect to the edge part 32E of the weight 32. FIG. For example, the mounting portion 42 may be merely fitted to the adherend portion 33.

The elastic part 43 of the second elastic member 41 may have a structure that does not have the space 47 inside, that is, a so-called solid structure.
-From the viewpoint of reducing the frictional resistance with the inner end wall portions 28 and 29, the elastic portion 43 of the second elastic member 41 desirably has a curved outer surface. As a shape satisfying this condition, there are a columnar shape and a spherical shape in addition to the cylindrical shape as employed in the above embodiment. When the elastic portion 43 is formed in a spherical shape, the elastic portion 43 substantially makes point contact with the inner end wall portions 28 and 29 on the spherical outer surface. By this form of contact, the frictional resistance generated between the elastic portion 43 and the inner end wall portions 28 and 29 becomes smaller than in the case of the above-described line contact. Therefore, when the weight 32 tries to move in the vertical direction in response to the vertical vibration of the rim portion 13, the second elastic member 41 is less likely to hinder the movement of the weight 32.

  Both the second elastic members 41 may be accommodated in the weight accommodating chamber 25 in a state where both the weights 32 are not elastically deformed when the weight 32 is in the neutral position. In this case, when the weight 32 starts to move to one side in the circumferential direction from the neutral position, the second elastic member 41 located on the rear side in the movement direction of the weight 32 temporarily moves from the inner end wall portion 28 (29). The phenomenon of leaving can occur. However, when the weight 32 starts to reciprocate in the circumferential direction due to the vibration of the rim core metal 16 in the circumferential direction, the second elastic member 41 located on the rear side in the movement direction of the weight 32 also causes the inner end wall portion 28 ( Since it expands and contracts in a state in contact with 29), there is no particular problem.

<About other matters>
-The present invention can be applied to a steering wheel of a type different from the above embodiment in terms of the number of spoke cores 18 to 20 and the connection position of the spoke cores 18 to 20 with the rim core 16. is there.

The front view which shows the steering wheel in one Embodiment which actualized this invention. The front view which shows the metal core in the steering wheel of FIG. Sectional drawing which shows the internal structure of the rim | limb core metal in FIG. Sectional drawing which expands and shows the upper part of FIG. Sectional drawing which shows the cross-section of the rim | limb core metal along the QQ line of FIG. Sectional drawing which shows the cross-section of the damping mechanism along the RR line | wire of FIG. Sectional drawing which shows the cross-section of the damping mechanism along the SS line | wire of FIG. Sectional drawing which shows the cross-section of the damping mechanism along the TT line | wire of FIG. FIG. 5 is a cross-sectional view showing a cross-sectional structure of the vibration damping mechanism along the line U-U in FIG. 4. Sectional drawing which shows the cross-section of the damping mechanism along the VV line | wire of FIG. Sectional drawing which shows the adhesion part and 1st elastic member of a weight. The perspective view which shows a 2nd elastic member. It is a figure which shows the manufacturing process of a steering wheel, and is a fragmentary sectional view which shows the state of the pipe material before bending to an annular | circular shape. Sectional drawing which shows the state after bending the pipe material of FIG. FIG. 15 is a partial cross-sectional view showing a state before the weight, the first elastic member, and the second elastic member are inserted into the pipe material after one inner end wall portion is formed by caulking the pipe material of FIG. 14. (A)-(C) are the fragmentary sectional views explaining an effect | action of the damping mechanism when a rim | limb core metal vibrates to an up-down direction. (A)-(C) are the fragmentary sectional views explaining an effect | action of the damping mechanism when a rim | limb core metal vibrates to the circumferential direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Steering shaft, 12 ... Steering wheel, 16 ... Rim part core metal, 18-20 ... Spoke part core metal, 21 ... Pipe material, 21A, 21B ... Open end, 22-24 ... Joint part (Rim part core metal 25) weight accommodating chamber, 28, 29 ... inner end wall portion, 31 ... inner peripheral wall portion, 32 ... weight, 32M ... intermediate portion, 33 ... adherent portion, 35 ... first Elastic member 36... Mounting portion 36 F. End portion 37. Elastic portion 41. Second elastic member A 1 Axis of steering shaft

Claims (5)

A rim cored bar formed of a pipe material and having an annular shape in each of a cross section perpendicular to the axis of the steering shaft and a cross section including the coaxial line;
A weight storage chamber that is configured by a part of the rim cored bar, has a circular arc shape in a cross section orthogonal to the axis, and has an annular shape in a cross section including a coaxial line,
A weight for vibration damping arranged in an arc shape in a cross section perpendicular to the axis and movably disposed in the weight accommodating chamber by being inserted from one opening end of the pipe member;
Prior to insertion of the weight into the pipe material, an elastic member attached to a cylindrical adherend provided at an intermediate portion in the circumferential direction of the weight, and the weight is attached to the weight by the elastic member. A steering wheel elastically supported on the inner peripheral wall of the storage chamber,
The elastic member is an insertion direction of the weight with respect to the rim cored bar out of both ends of the cylindrical mounting part to be fitted to the adherend part by fitting and the circumferential direction of the mounting part. A steering wheel comprising: a tapered elastic portion connected to a front end portion and having a diameter increasing toward a rear side in the insertion direction. 2. The steering wheel according to claim 1, wherein at least the vicinity of the adherend portion of the weight is formed to have a larger diameter than the adherend portion. At both ends of the weight in the circumferential direction, a pair of second elastic members that elastically support the same weight on inner end wall portions located at both ends in the circumferential direction among the inner walls of the weight receiving chamber. The steering wheel according to claim 1 or 2, wherein a member is mounted. 4. The steering wheel according to claim 3, wherein the second elastic member has an elastic portion whose outer surface is formed in a curved surface, and the weight is elastically supported by the inner end wall portion by the elastic portion. The rim cored bar is connected to the steering shaft via a spoked cored bar formed by casting,
The steering wheel according to any one of claims 1 to 4, wherein the weight housing chamber is provided at a location away from a connection portion with the spoke core metal in the rim core metal in the circumferential direction. .

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