JP5023905B2 - Steering wheel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a steering wheel at least partially covered with a decorative member formed by welding a pair of divided bodies, and a method for manufacturing the same.

  In a vehicle steering wheel, a rim coated with a decorative member is known to improve its aesthetic appearance. As this decorative member, for example, there is a member made of a resin-made cylindrical covering portion having a wood grain pattern printed on the outer surface. In general, the cylindrical covering portion is formed by a pair of divided bodies that are divided in half, and is formed by joining and integrating the pair of divided bodies. And as a structure to join such a divided body, a part of the divided body is melted by frictional heat by applying vibration in a state where the parts to be joined are in contact, and the melted resin is cooled and cured. By doing so, what welds both division bodies is proposed (patent documents 1 and patent documents 2).

In Patent Document 1, a protrusion is formed on the end face to which one divided body is welded, and a concave groove is formed on the end face to which the other divided body is welded. The configuration to be performed is described. Moreover, in patent document 2, it vibrates in the state which contact | abutted the top surfaces of the convex part formed in both of the end surfaces to which a pair of division body is welded, and is made from the resin fuse | melted from the front end side of the same top surface The structure which welds both division bodies is described.
JP 2002-103451 A JP 2004-306671 A Japanese Utility Model Publication No. 5-36671

  By the way, when forming a decorative member by integrating a pair of divided bodies by welding as described above, it is necessary to finish the outer surface of the rim into a smooth curved surface so as not to impair the aesthetic appearance. For example, in the case where welding is performed in a state where the pair of divided bodies are displaced, not only the aesthetic appearance is impaired, but also the bonding area of both divided bodies is smaller than a predetermined bonding area, so that the bonding strength may be reduced. . Therefore, it is necessary to accurately position the pair of divided bodies in order to weld them at predetermined positions.

  Here, in Patent Document 1, as a configuration for positioning, a ridge and a groove for engagement are formed, but considering the ease of engagement between the ridge and the groove, a recess is formed. The opening width of the groove needs to be set slightly larger than the width of the ridge. For this reason, a convex line and a ditch | groove cannot be engaged without a clearance gap, and there exists a possibility that both may shift | deviate from a desired position.

  Moreover, in patent document 2, it has the structure which can melt | dissolve the resin fuse | melted from the top surface tip side by providing an avoidance part in the vicinity of the top surface pressed at the time of welding. However, in such a structure, since only the top surfaces are pressed, there is a possibility that both are displaced from a desired position.

  In addition, as what performs exact positioning of a pair of division body, as described in patent document 3, for example, while a protruding item | line is formed in the end surface to which one division body is welded, welding of the other division body is carried out. A configuration has been proposed in which a groove is formed on the end face, and only the tip of the ridge is supported by falling into the mouth end of the groove. However, according to the same structure, when the tip of the ridge is correctly brought into contact with the mouth end of the groove, accurate positioning can be performed, but both of the two are arranged so that the tip of the ridge falls to the mouth end of the groove. When it is not brought into contact, or when the tip of the ridge is pulled out from the mouth end of the groove due to a given vibration or the like, it is difficult to correct it to a predetermined position. This can be a particularly significant problem when joining relatively large segments for application to a steering wheel.

  This invention is made | formed in view of the said situation, The objective is to provide the steering wheel which can weld a pair of division body which forms a decoration member in an exact position, and its manufacturing method. is there.

To achieve the above object, a first aspect of the present invention, a pair of divided bodies in the steering wheel at least partially covered by a decorative member made by vibration welding, to one of the holder halves formed Ri and narrow grooves are formed in a narrow convex strip and the other as the front side width of a width as the bottom side the name is welded, the convex Article, at the base end side of the convex strip, the ridges And a first convex portion formed in a substantially rectangular cross section in a cross section perpendicular to the extending direction of the concave groove, and a second convex section formed in a substantially triangular shape in the cross section at the tip side of the ridge. And the concave groove on the mouth side of the concave groove, in the cross section, in the cross section, in the cross section, the first concave portion formed in a substantially rectangular cross section, and on the bottom side of the concave groove, in the cross section, It consists of a second recessed portion formed in a substantially triangular cross section, before In cross section, with the angle of both outer inclined surface of the second convex portion is formed smaller than the angle between both the inclined surfaces of the second recessed portion, said first convex portions in the cross The gist is that the width of the base end is formed smaller than the width of the mouth end of the first recessed portion .

According to the above configuration, the protrusions formed on one side of the pair of divided bodies are welded to the protrusions that are narrower toward the front side and the grooves that are formed on the other side and are narrower toward the bottom side. In a cross section perpendicular to the extending direction of the concave groove, an angle formed by both outer slopes of the second convex portion of the ridge is formed smaller than an angle formed by both inner slopes of the second concave portion of the concave groove . Therefore, it can be set as the state by which the front-end | tip of the protrusion was guide | induced to the bottom side of the ditch | groove. As a result, the pair of divided bodies can be brought into a welded state at an accurate position. Note that the angle formed by both outer slopes of the second convex portion of the ridge and the angle formed by both inner slopes of the second recessed portion of the groove are the angle formed by both outer slope portions of the ridge and the groove Of these, the angle between the two inner slopes shall be referred to.
The width of the base end of the first convex portion of the convex groove is smaller than the width of the mouth end of the first concave portion of the concave groove in a cross section perpendicular to the extending direction of the convex groove and the concave groove. Therefore, the tip of the ridge can be guided to the bottom side of the groove. As a result, the pair of divided bodies can be brought into a welded state at an accurate position.

Specifically, as described in claim 2, in the cross section perpendicular to the extending direction of the ridge and the groove, an angle formed by both outer slopes of the second protrusion is 50 to 90 °. There can be adopted a configuration in which an angle formed by both inner slopes of the second recessed portion is 110 to 160 °.

Specifically, as described in claim 3 , in the cross section perpendicular to the extending direction of the ridge and the groove, the width of the base end of the first protrusion is 0.8 to 1.1 mm. It is possible to adopt a configuration in which the width of the mouth end of the first recessed portion is 0.9 to 1.2 mm.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a steering wheel that is at least partially covered with a decorative member formed by welding a pair of divided bodies. a forming step of forming a narrow groove width as the bottom side to the other to form a strip, the step of engaging the said formed ridges and grooves, the vibration in at least one of the pair of split bodies A step of welding the engaged ridges and grooves to each other , and the molding step is substantially cross-sectional in a section perpendicular to the extending direction of the ridges and the grooves, on the one divided body. A first convex portion having a rectangular shape is formed, and a second convex portion having a substantially triangular cross section in the cross section is formed on the distal end side of the first convex portion, thereby forming the ridge. Process and said other divided body Forming a first recessed portion having a substantially rectangular cross section in the cross section and forming a second recessed portion having a substantially triangular cross section in the cross section on the bottom side of the first recessed portion. Forming the concave groove, and forming the molding step so that a width of a base end of the first convex portion is smaller than a width of a mouth end of the first concave portion in the cross section. together, the angle of the both outer inclined surface of the second convex portion, and summarized in that the a second recessed portion shaping so as to be smaller than the angle between both the inclined surfaces of the.

According to the molding step, a ridge that is narrower toward the front side is formed on one side of the pair of divided bodies, and a groove that is narrower toward the bottom side is formed on the other side. In the cross section perpendicular to the extending direction, the angle formed by both outer slopes of the second convex portion of the ridge is formed smaller than the angle formed by both inner slopes of the second recessed portion of the groove. In addition, in the cross section perpendicular to the extending direction of the ridge and the groove, the width of the base end of the first protrusion portion of the ridge is smaller than the width of the mouth end of the first recess portion of the groove. Is done. Then, the formed ridges and grooves are engaged, and vibration is applied to the pair of divided bodies so that the engaged ridges and grooves are welded. In this case, the tip of the ridge can be guided to the bottom side of the groove. As a result, a pair of divided bodies forming the decorative member can be welded at an accurate position.

Specifically, as described in claim 5 , in the forming step, an angle formed by both outer slopes of the second convex portion is set to 50 to 90 °, and a height of the both outer slopes is set to 0. .6 to 1.0 mm, the angle formed by the inner slopes of the second recessed portion is 110 to 160 °, and the depth of the inner slopes is 0.08 to 0.3 mm. can do. Note that the height of both outer slopes of the second convex portion and the depth of both inner slopes of the second concave portion are the same as that of both outer slope portions of the second convex portion with respect to the engaging direction of the ridges and grooves. The height and the depth of both inner slope portions of the second recessed portion are respectively referred to.

Specifically, as described in claim 6 , in the forming step, the width of the base end of the first convex portion is set to 0. 0 in a cross section perpendicular to the extending direction of the convex stripes and the concave grooves. The height of both outer slopes of the second convex portion is 0.6 to 1.0 mm and the width of the mouth end of the first concave portion is 0.9 to 1.2 mm. In addition, it is possible to adopt a configuration in which the depth of both inner slopes of the second recessed portion is 0.08 to 0.3 mm.

  In a steering wheel at least partially covered with a decorative member formed by welding a pair of divided bodies, the pair of divided bodies forming the decorative member can be welded at an accurate position.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a steering wheel 1 is rotatably attached to a steering shaft S located in front of the driver's seat of the vehicle. The steering wheel 1 is inclined at an appropriate angle so that the upper portion thereof is located on the front side of the vehicle. In the following description, it is assumed that the steering wheel 1 of FIG. 1 is in a non-operating state, and the upper side of FIG. 1 corresponds to the upper side of the vehicle. Further, the left-right direction coincides with the left-right direction when the vehicle moves forward.

The steering wheel 1 includes a substantially circular rim 2, a pad 3 disposed at the center thereof, and a plurality of (three in this embodiment) spokes 4 that connect the rim 2 and the pad 3.
Further, a core metal that forms the skeleton of the steering wheel 1 is disposed inside the rim 2, the pad 3, and the spoke 4. The core metal includes a boss 11 to which the steering shaft S is coupled, a substantially circular rim core metal 12 having the steering shaft S as its center, and a plurality of ( In the present embodiment, it is constituted by three (spoke) cored bar 14. Note that the boss 11, the rim core 12 and the spoke core 14 constituting the core are all integrally formed of an alloy of aluminum and magnesium.

  As shown in FIGS. 2A and 2B, the rim 2 includes a rim covering portion 20 as a covering portion that covers the outer surface of the rim core metal 12. The rim covering portion 20 includes a soft covering portion 21 that covers the entire outer surface of the rim core metal 12 and a cylindrical covering portion 22 that covers a part of the outer peripheral surface of the soft covering portion 21 (three locations in the present embodiment). (22a, 22b, 22c). Specifically, the cylindrical covering portion 22a is provided in the upper portion (between A and A), the cylindrical covering portion 22b is provided in the lower left portion (between BB), and the lower right portion (between CC). ) Is provided with a cylindrical covering portion 22c. These cylindrical covering portions 22 correspond to decorative members.

  For example, a sheet-like decorative board 23 having a wood grain or the like is attached to the outer surface of the cylindrical covering portion 22 (FIG. 2A). In addition, the cylindrical coating | coated part 22 can be used arbitrarily, such as what a predetermined pattern was printed on the outer surface. On the other hand, in the portion where the cylindrical covering portion 22 is not provided, the diameter of the soft covering portion 21 is set to be large by an amount substantially corresponding to the thickness of the cylindrical covering portion 22 (FIG. 2B). Thereby, the cylindrical covering portion 22 is formed so that both end portions (A portion, B portion, C portion) are in contact with the soft covering portion 21 and the entire circumference of the rim 2 has a substantially constant outer diameter. Yes. The soft covering portion 21 is made of a soft material such as foamed polyurethane, and the cylindrical covering portion 22 is made of, for example, ABS resin, polyamide (PA), polypropylene (PP), polycarbonate (PC), and ABS resin. It is comprised from hard resin materials, such as an alloy.

  The cylindrical covering portion 22 includes a pair of divided bodies 31 and 32, and is formed into a cylindrical shape by joining the joining end surfaces 31a and 32a of the divided bodies 31 and 32 to each other. In addition, the split body 31 is formed with ridges along the outer periphery of the rim 2 (the direction indicated by the one-dot chain line in FIG. 1), and the split body 32 is formed along the outer periphery of the rim 2 (the one-dot chain line in FIG. 1). (Direction indicated by) A concave groove is formed.

  FIG. 3 shows an enlarged view of the structure within the alternate long and short dash line A in the cross-sectional view shown in FIG. 2, and shows the shape of the ridge 33 before joining the divided bodies 31 and 32 with a two-dot chain line. The resin of the protrusion 33 in a portion surrounded by the two-dot chain line and both inner inclined surfaces 34c of the groove 34 is melted at the time of welding and spreads and hardens in the groove 34 and between the joining end faces 31a and 32a. 2 and 3 correspond to a cross section perpendicular to the extending direction of the ridge 33 and the groove 34.

  As shown in FIG. 3, the ridge 33 has a convex portion 33B extending perpendicularly from the joint end surface 31a at the base end 33b and having a substantially rectangular cross section, and the tip 33a is narrower at the tip side 33a. And a convex portion 33A having a substantially isosceles triangle cross section. Specifically, the extending length L1 of the convex portion 33B is formed to be 0.2 mm, and the angle θ1 formed by both outer inclined surfaces 33c of the convex portion 33A of the convex strip 33 is formed to be 65 °.

  The concave groove 34 is cut out perpendicularly from the joining end face 32a to form a substantially rectangular cross section, and the concave portion 34B is cut out so that the width of the bottom side 34a becomes narrower at the tip thereof to form a substantially isosceles cross section. 34A. Specifically, the depth L2 of the recessed portion 34B is set to 0.2 mm, and the angle θ2 formed by both inner inclined surfaces 34c of the recessed portion 34A of the recessed portion 34 is set to 145 °. That is, the angle θ1 formed by both outer inclined surfaces 33c of the ridge 33 is formed to be smaller than the angle θ2 formed by both inner inclined surfaces 34c of the groove 34.

  Further, the width W1 of the base end 33b of the ridge 33 is smaller than the width W2 of the mouth end 34b of the ridge 33 in a cross section perpendicular to the extending direction of the ridge 33 and the groove 34. Note that the width W1 of the base end of the ridge 33 and the width W2 of the mouth end of the groove 34 are the radial lengths of the steering wheel 1 orthogonal to the extending direction of the ridge 33 and the groove 34, that is, in FIG. It corresponds to the length in the left-right direction.

  Next, a method for manufacturing the steering wheel 1 will be described with reference to FIGS. 4 and 5 correspond to a cross section perpendicular to the extending direction of the ridge 33 and the groove 34. In the following description, members corresponding to those shown in FIGS. 1 to 3 are denoted by the same reference numerals.

  As shown in FIG. 4, the divided bodies 31 and 32 have a shape that can sandwich the soft covering portion 21, that is, a substantially arc along the rim 2 of the steering wheel 1 by a member having a substantially semicircular cross section. Each shape is formed by, for example, injection molding. That is, the substantially arc shape is a shape corresponding to each of AA, BB, and CC in FIG. Then, a protrusion 33 is formed on the joint end surface 31 a of one divided body 31, and a concave groove 34 is formed on the joint end surface 32 a of the other divided body 32.

  As shown in FIG. 5, the protrusion 33 has a protrusion 33B extending perpendicularly from the joint end surface 31a at the base end 33b and having a substantially rectangular cross section, and the tip 33a is narrower at the tip 33a. And a projecting portion 33A having a substantially isosceles triangle cross section. Specifically, the extended length L1 of the convex portion 33B is 0.2 mm, the angle θ1 formed by both outer slopes 33c of the convex portion 33A is 65 °, and the height H1 of the convex portion 33A is 0.8 mm. Formed to be. The height H1 corresponds to the extended length of the convex portion 33A in the direction perpendicular to the joining end surface 31a.

  Further, the concave groove 34 is cut out perpendicularly from the joint end face 32a to form a substantially rectangular cross section, and at the tip thereof, the bottom side 34a is cut so that the width thereof becomes narrower to form a substantially isosceles cross section. And a recessed portion 34A. Specifically, the depth L2 of the recessed portion 34B is 0.2 mm, the angle θ2 formed by both the inner slopes 34c of the recessed portion 34A is 145 °, and the depth H2 of the same portion 34A is 0.2 mm. The The depth H2 corresponds to the depth of the recessed portion 34A in the direction perpendicular to the joining end surface 32a.

  That is, the angle θ1 formed by the outer slopes 33c of the protrusion 33 whose width is narrower toward the front side 33a, and the angle θ2 between the inner slopes 34c of the groove 34 whose width is narrower toward the bottom side 34a. It is formed so as to be smaller. Here, the width corresponds to the length in the radial direction of the steering wheel 1 orthogonal to the direction in which the ridges 33 and the grooves 34 extend, that is, the length in the left-right direction in FIG. The angle formed by both outer slopes of the ridge and the angle formed by both inner slopes of the groove are the angle θ1 formed by the both outer slopes 33c of the ridge 33 and the both inner slopes 34c of the groove 34. The angles θ2 are respectively referred to. The heights of both outer slopes of the ridge and the depths of both inner slopes of the groove are the height H1 and the depression of the both outer slopes 33c of the ridge 33 with respect to the engaging direction of the ridge 33 and the groove 34. The depths H2 of both the inner slopes 34c of the groove 34 are respectively referred to.

In addition, the width W1 of the base end 33b of the ridge 33 is formed smaller than the width W2 of the mouth end 34b of the ridge 33 in a cross section perpendicular to the direction in which the ridge 33 and the groove 34 extend.
The ridges 33 and the grooves 34 are set to suitable shapes based on experiments and the like. Specifically, the extended length L1 of the convex portion 33B and the height H1 of the convex portion 33A are set so that the tip A of the convex strip 33 can contact the deepest B point on the bottom side of the concave groove 34. In addition, the depth L2 of the recessed portion 34B and the depth H2 of the recessed portion 34A are set. Here, the state of welding when the protrusion 33 and the groove 34 are engaged with the tip A of the protrusion 33 in contact with the deepest point B on the bottom side of the groove 34 is a pair of splits. The shapes of the ridge 33 and the groove 34 are set so that the bodies 31 and 32 are welded to each other at an accurate position, that is, the outer surface of the rim 2 is smooth without any step.

  In addition, the angle θ2 formed by both the inner slopes 34c of the groove 34 is such that the tip A of the ridge 33 extends to the bottom side 34a of the groove 34 along the inner slope 34c, that is, the bottom B point in the welding step described later. It is desirable to set the inclination suitable for being guided naturally so as to approach.

  Furthermore, it is desirable to set the shape of the ridge 33 and the groove 34 in consideration of the welding strength and the welding time between the divided body 31 and the divided body 32. Specifically, it is considered that the adhesive strength of the pair of divided bodies 31 and 32 is related to the volume of the resin that comes into contact with the inner wall of the groove 34 and melts from the tip portion of the ridge 33. For example, when the molten resin volume increases due to an increase in the angle difference between the angle θ1 of the ridge 33 and the angle θ2 of the groove 34, the adhesive strength between the two divided bodies 31 and 32 increases. However, along with this, the time required for welding the two divided bodies 31 and 32 is increased and the processing efficiency is deteriorated. Therefore, it is desirable to set the angle θ1 and the angle θ2 to appropriate angles at which a desired adhesive strength can be obtained. . In addition, it is good to consider that welding becomes quick and easy because ultrasonic energy concentrates on the tip part as the tip of the ridge 33 is thinner.

  On the other hand, the boss 11, the rim core 12 and the spoke core 14 are integrally formed by a well-known die casting method. Next, for example, using a foam molding method or the like, the soft covering portion 21 is formed on the integrally formed rim core metal 12 and the spoke portion covering portion 24 is formed on the spoke core metal 14. Subsequently, the rim cored bar 12 covered with the soft coating 21 is set at a predetermined position of the ultrasonic welding apparatus together with the boss 11, the spoke cored bar 14 and the like.

  And the soft coating | coated part 21 is inserted | pinched by the division bodies 31 and 32 which were previously shape | molded as mentioned above, and the decorative board 23 was affixed, and the front-end | tip A of the protruding item | line 33 falls straightly into the recess of the ditch | groove 34 And set at a predetermined position of the ultrasonic welding apparatus. Thereafter, ultrasonic waves are oscillated by the ultrasonic welding apparatus while applying a pressure of about 1000 kg in the direction in which the divided bodies 31 and 32 approach each other (the engagement direction of the ridges 33 and the grooves 34). This ultrasonic vibration is applied in the direction in which the joining end surfaces 31a and 32a of the two divided bodies 31 and 32 are pressed, that is, in the direction in which the ridge 33 and the groove 34 are engaged. In addition, suitable conditions are set for the output of the ultrasonic welding apparatus based on experiments and the like.

  When vibration is applied in this manner, friction is generated in the contact portion between the ridge 33 and the groove 34 to generate frictional heat, and the frictional heat causes the protrusion 33 that is in contact with the inner wall of the groove 34 to be generated. The resin melts from the tip A. Then, as the melting of the tip of the ridge 33 progresses, the two divided bodies 31 and 32 approach each other, and the resin melted between the joint end faces 31a and 32a or in the concave groove 34 is cooled and hardened to be divided into two. The bodies 31 and 32 are welded. This welding process is completed in a state where the inner peripheral surface 31b of the divided body 31 and 32b of the divided body 32 are in contact with the outer peripheral surface 21a of the soft covering portion 21 (see FIG. 4).

According to the embodiment described in detail above, the following operational effects can be obtained.
(1) In the steering wheel 1, the protruding strip 33 formed on one split body 31 of the pair of split bodies 31 and 32 and narrower on the front side 33a and formed on the other split body 32 and on the bottom side 34a is wider. The angle θ1 formed by the outer slopes 33c of the ridges 33 in the cross section perpendicular to the extending direction of the ridges 33 and the groove 34 is the angle of the inner slopes 34c of the grooves 34. Since the angle θ2 is smaller than the formed angle θ2, the tip A of the ridge 33 can be guided to the point B at the bottom of the groove 34. Therefore, the pair of divided bodies 31 and 32 covering the rim 2 can be welded at an accurate position.

  Further, a protruding line 33 formed on one divided body 31 of the pair of divided bodies 31 and 32 and having a width narrower toward the front side 33a, and a concave groove 34 formed on the other divided body 32 and having a width decreased toward the bottom side 34a, and Are formed, and the width W1 of the base end 33b of the protrusion 33 is smaller than the width W2 of the mouth end 34b of the groove 34 in a cross section perpendicular to the extending direction of the protrusion 33 and the groove 34. Therefore, it is possible to make the state where the tip A of the ridge 33 is led to the point B at the bottom of the groove 34. Therefore, the pair of divided bodies 31 and 32 covering the rim 2 can be welded at an accurate position.

  (2) In the method for manufacturing the steering wheel 1, the narrower protrusion 33 is formed on the one divided body 31 of the pair of divided bodies 31, 32 as the front side 33 a and the bottom side 34 a is formed on the other divided body 32. An angle θ1 formed by both outer inclined surfaces 33c of the ridge 33 in the cross section perpendicular to the extending direction of the ridge 33 and the groove 34 is formed by the narrow groove 34, and the angle formed by the both inner inclined surfaces 34c of the groove 34. Molded smaller than θ2. Then, the ridge 33 and the groove 34 are engaged, and vibration is applied to the pair of divided bodies 31 and 32, so that the engaged ridge 33 and the groove 34 are welded.

  Thus, when vibration is applied during welding, the tip A of the ridge 33 can be guided toward the bottom side 34a of the groove 34 so as to approach the bottom B point. That is, for example, when the ultrasonic wave is set in an ultrasonic welding apparatus or when vibration is applied, the tip A of the ridge 33 is displaced from the point B at the bottom of the groove 34 and is positioned on any of the inner slopes 34c. However, since both inner slopes 34c are narrower slopes on the bottom side 34a, the tip A of the ridge 33 can be naturally guided along the inner slope 34c to the bottom side 34a. Accordingly, since the pair of divided bodies 31 and 32 are welded in a state where the tip A of the ridge 33 is close to the point B at the bottom of the groove 34, the joint end surface 31 a of the divided body 31 and the divided body 32 are separated. It is possible to suppress welding at a position shifted from the joining end surface 32a. As a result, it becomes possible to weld the pair of divided bodies 31 and 32 forming the cylindrical covering portion 22 that is a decorative member to each other at an accurate position. That is, the outer surface of the rim 2 can be finished into a smooth curved surface.

  Further, a convex line 33 having a narrower width toward the front side 33a is formed on one divided body 31 of the pair of divided bodies 31 and 32, and a concave groove 34 having a smaller width toward the bottom side 34a is formed on the other divided body 32. In addition, the width W1 of the base end 33b of the ridge 33 is formed smaller than the width W2 of the mouth end 34b of the ridge 33 in a cross section perpendicular to the extending direction of the ridge 33 and the groove 34. Then, the ridge 33 and the groove 34 are engaged, and vibration is applied to the pair of divided bodies 31 and 32, so that the engaged ridge 33 and the groove 34 are welded. Thus, when vibration is applied during welding, the tip A of the ridge 33 can be guided toward the bottom side 34a of the groove 34 so as to approach the bottom B point.

  (3) Since the angle θ1 formed by both outer slopes 33c of the ridge 33 is an acute angle of 65 °, and the angle θ2 formed by both inner slopes 34c of the groove 34 is formed by an obtuse angle of 145 °, In the engagement process between the strip 33 and the concave groove 34, it can be easily engaged.

  (4) Since the ridge 33 is formed in a substantially isosceles triangular shape with a narrower width toward the tip 33a side, in the welding step, ultrasonic energy is concentrated on the tip and the pair of divided bodies 31 and 32. Can be quickly and easily welded.

Note that the present invention can be embodied in another embodiment described below.
In the steering wheel 1 of the above embodiment, the angle θ1 formed by the both outer inclined surfaces 33c of the ridge 33 is 65 °, and the angle θ2 formed by the both inner inclined surfaces 34c of the groove 34 is 145 °. It is only necessary that θ1 be smaller than the angle θ2, and these shapes can be changed as appropriate. Specifically, as a suitable condition for achieving the above object, for example, the angle θ1 can be formed in a range of 50 to 90 °, and the angle θ2 can be included in a range of 110 to 160 °.

  In addition, in the step of forming the ridge 33 and the groove 34 in the method of manufacturing the steering wheel 1, the angle θ1 formed by the both outer inclined surfaces 33c of the ridge 33 is 65 °, and the angle formed by both the inner inclined surfaces 34c of the groove 34 In the example, θ2 is 145 °, the height H1 of the ridge 33 is 0.8 mm, and the depth of the groove 34 is 0.2 mm. However, the angle θ1 may be formed smaller than the angle θ2. These shapes may be changed as appropriate. Specifically, as conditions suitable for achieving the above object, for example, the angle θ1 is included in the range of 50 to 90 °, the angle θ2 is included in the range of 110 to 160 °, and the height H1 is 0.6 to The ridges 33 and the grooves 34 can also be formed so that the depth H2 is included in the range of 0.08 to 0.3 mm in the range of 1.0 mm.

  In the steering wheel 1 of the above embodiment, the shapes of the ridges 33 and the concave grooves 34 are specified by the angle θ1 formed by the both outer inclined surfaces 33c of the ridge 33 and the angle θ2 formed by both the inner inclined surfaces 34c of the groove 34, respectively. Although an example was shown, it can also be specified by the width W1 of the base end of the ridge 33 and the width W2 of the mouth end of the groove 34. As a preferable condition in this case, specifically, the width W1 can be included in the range of 0.8 to 1.1 mm, and the width W2 can be included in the range of 0.9 to 1.2 mm. .

  In the step of forming the ridge 33 and the groove 34 in the method for manufacturing the steering wheel 1 of the above embodiment, the shape of the ridge 33 and the groove 34 is the angle θ1 formed by the two outer slopes 33c of the ridge 33, Although the example specified by the angle θ2 formed by both the inner slopes 34c of the groove 34 is shown, it can also be specified by the width W1 of the base end 33b of the ridge 33 and the width W2 of the mouth end 34b of the groove 34. As a suitable condition in this case, specifically, the protrusion 33 and the width W1 are included in the range of 0.8 to 1.1 mm, and the width W2 is included in the range of 0.9 to 1.2 mm. A step of forming the concave grooves 34 can be employed. Further, the height H1 of both outer slopes 33c of the ridge 33 is included in the range of 0.6 to 1.0 mm, and the depth H2 of both inner slopes 34c of the groove 34 is included in the range of 0.08 to 0.3 mm. As described above, a process of forming the ridge 33 and the groove 34 can be employed.

In the step of forming the ridge 33 and the groove 34, an example is shown in which the cross-sectional shapes of the ridge 33 and the groove 34 are formed into a substantially isosceles triangle. However, as long as the cross-sectional shape of the ridge is narrower toward the front side, the cross-sectional shape of the groove may be narrower toward the bottom side, and is not limited to a substantially isosceles triangle .

The example in which the ridge 33 and the groove 34 are formed at substantially the center of the joint end surfaces 31a and 32a of the pair of divided bodies 31 and 32 in the radial direction of the steering wheel 1 has been shown. it can. For example, as shown in FIG. 6 , it is possible to adopt a mode in which a ridge 63 is formed near the edge of the side surface 61 b of the divided body 61. Similar to the above-described embodiment, the protruding line 63 has a protruding part 63B that extends perpendicularly from the joint end surface 61a at the base end 63b and has a substantially rectangular cross section, and the width of the protruding side 63 becomes narrower toward the front side 63a. And a convex portion 63A having a substantially isosceles triangle cross section. And one side 63d of this convex part 63B is formed so that it may become the same plane as the side 61b of the division body 61. FIG.

  On the other hand, the concave groove 64 to be engaged with the ridge 63 is cut out so that the width of the concave portion 64B perpendicularly cut from the joining end face 62a and having a substantially rectangular cross section is narrower toward the bottom side 64a. And a recessed portion 64A having a substantially isosceles triangle cross section. Furthermore, a rib 65 is formed that is disposed along the side surface 61b of the divided body 61 or with a predetermined clearance when the ridge 63 and the groove 64 are engaged. One side surface 65a of the rib 65 is formed so as to be flush with the inner wall of the recessed portion 64B.

  In such a case, when the pair of divided bodies 61 and 62 are set in the ultrasonic welding apparatus, the mutual positioning of the both divided bodies 61 and 62 can be facilitated by the rib 65. Further, in the welding process, even when the tip A of the ridge 63 is displaced from the point B at the bottom of the groove 64 and is positioned on any of the inner slopes 64c, the inner slopes 64c are as wide as the bottom side 64a. Therefore, the tip A of the ridge 63 is naturally guided to the bottom side 64a along the inner slope 64c. Accordingly, since the pair of divided bodies 61 and 62 are welded in a state where the tip A of the ridge 33 is close to the point B at the bottom of the concave groove 64, the joint end surface 61 a of the divided body 61 and the divided body 62 are separated. It is possible to suppress welding at a position shifted from the joining end surface 62a.

  Note that the cross-sectional shape of each of the pair of divided bodies of the cylindrical covering portion does not need to be the same shape on the entire circumference, and for example, the ribs 65 may be formed at predetermined intervals. Moreover, you may employ | adopt the aspect which forms a rib in the division body 61 which forms the protruding item | line 63 contrary to the above.

  -Although the example which performs ultrasonic welding as a process of welding a pair of division bodies 31 and 32 was shown, what is necessary is just the method of giving a vibration and welding, for example, a vibration welding method etc. can also be employ | adopted.

  Also, as an example of the step of welding, the example in which vertical vibration is applied to the joining end faces 31a and 32a along the direction in which the two divided bodies 31 and 32 are pressed to each other has been shown. A method of applying vibration along the direction in which the ridge 33 and the groove 34 extend can also be adopted. At this time, only one of the divided bodies 31 and 32 may be vibrated, or both the divided bodies 31 and 32 may be vibrated so as to be displaced in different directions. Even in this case, when the tip A of the ridge 33 deviates from the B point at the bottom of the groove 34 which is a desired position due to vibration, both inner slopes of the groove 34 as in the present embodiment. The position of the tip A of the ridge 33 is naturally guided to the bottom B point along 34c, and the pair of divided bodies 31, 32 can be welded at an accurate position.

An embodiment which materialized the steering wheel concerning the present invention. (A) is the X1-X1 sectional view taken on the line of FIG. 1, (b) is the X2-X2 sectional view taken on the line of FIG. Sectional drawing which expands and shows the structure in the dashed-dotted line A in FIG. FIG. 3A is an exploded cross-sectional view showing the structure before the cylindrical covering portion is welded in FIG. (A) is sectional drawing which expands and shows the structure in the dashed-dotted line B of FIG. 4, (b) is sectional drawing which expands and shows the inside of the dashed-dotted line C of FIG. (A) (b) The elements on larger scale which show the modification of the steering wheel concerning this invention, and its manufacturing method .

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Steering wheel, 2 ... Rim, 3 ... Pad, 4 ... Spoke, 11 ... Boss, 12 ... Rim cored bar, 14 ... Spoke cored bar, 20 ... Rim covering part, 21 ... Soft covering part, 22 ... Tube 23, decorative plate, 24 ... spoke covering portion, 31, 32, 41, 42, 52, 61, 62 ... segment, 33, 43, 63 ... ridge, 34, 44, 54, 64 ... Recessed groove, 65... Rib, .theta.1... Angle formed by both outer slopes of ridges, .theta.2.

Claims (6)

In a steering wheel at least partially covered with a decorative member formed by vibration welding a pair of divided bodies,
Ri name and the pair of one to be formed in and narrow are formed in a narrow convex strip and the other as the front side width of a width as the bottom side groove of the divided body is welded,
The protruding line is a first protruding part formed in a substantially rectangular cross section in a cross section perpendicular to the extending direction of the protruding line and the recessed groove on the base end side of the protruding line, and a distal end of the protruding line And a second convex portion formed in a substantially triangular shape in the cross section, and the concave groove is a first portion formed in a substantially rectangular shape in the cross section on the mouth side of the concave groove. And a second recessed portion formed in a substantially triangular cross section in the cross section on the bottom side of the recessed groove,
Before Kidan surface, wherein with an angle of both outer inclined surface of the second convex portion is formed smaller than the angle between both the inclined surfaces of the second recessed portion, wherein in the cross section first convex A steering wheel characterized in that the width of the base end of the portion is smaller than the width of the mouth end of the first recessed portion . The steering wheel according to claim 1, wherein
Characterized in that before Kidan plane, the angle between the two outer inclined surfaces of the second convex portions is 50 to 90 °, the angle of both the slope of the second recessed portion is 110 to 160 ° And steering wheel. The steering wheel according to claim 1 or 2 ,
Before Kidan surface, the width of the base end of the first convex portion is a 0.8～1.1Mm, the width of the mouth end of the first recessed portion is 0.9~1.2mm Steering wheel characterized by In a method for manufacturing a steering wheel at least partially covered by a decorative member formed by welding a pair of divided bodies,
A forming step of forming a ridge that is narrower toward the front side on one side of the pair of divided bodies and a groove that is narrower toward the bottom side on the other side ;
Engaging the formed ridges and grooves,
A step of applying vibration to at least one of the pair of divided bodies to weld the engaged ridges and the grooves ,
The forming step forms, on the one divided body, a first convex portion having a substantially rectangular cross section in a cross section perpendicular to a direction in which the convex strips and the concave grooves extend, and the first convex portion A step of forming the convex line by forming a second convex portion having a substantially triangular cross section in the cross section on the tip side, and a first cross section having a substantially rectangular cross section in the cross section on the other divided body. And forming the recessed groove by forming a second recessed portion having a substantially triangular cross section in the cross section on the bottom side of the first recessed portion.
In the cross-section, the forming step is performed so that the width of the base end of the first convex portion is smaller than the width of the mouth end of the first concave portion , and both outer sides of the second convex portion are formed. angle of slope method of the steering wheel, characterized in that a molding which process <br/> be such that the smaller than the angle between both the inclined surfaces of the second recessed portion. In the manufacturing method of the steering wheel according to claim 4 ,
The forming step, before Kidan surface, the height of the both outer slope and 0.6~1.0mm well as the angle between the two outer inclined surfaces of the second convex portion and 50 to 90 °, the A method for manufacturing a steering wheel, characterized in that an angle formed by both inner slopes of the second recessed portion is 110 to 160 ° and a depth of both the inner slopes is 0.08 to 0.3 mm. In the manufacturing method of the steering wheel according to claim 4 ,
The forming step, before Kidan surface, the height of both outer inclined surface of the second convex portions with the width of the base end of the first convex portion and 0.8～1.1Mm 0.6 To 1.0 mm, the width of the mouth end of the first recess portion is 0.9 to 1.2 mm, and the depth of both inner slopes of the second recess portion is 0.08 to 0.3 mm. A method for manufacturing a steering wheel.