JP3157078U - Vehicle frame and motorcycle including the same - Google Patents

Abstract

The present invention provides a vehicle frame made of a magnesium-based material that hardly causes solidification cracking during casting. A rear frame is a cast product made of an aluminum alloy. The rear frame 20 includes a side surface portion 21A and a fastening portion 80 in which a through hole 23 through which a bolt is inserted is formed. Around the one end side and the other end side of the through hole 23 of the fastening portion 80, a seat surface 81 is formed so as to overlap the main frame. A recessed portion 82 that is recessed toward the through hole 23 is formed on the outer side of the through hole 23 in the fastening portion 80 in the radial direction and in the middle of the through hole 23 in the axial direction. [Selection] Figure 5

Description

  The present invention relates to a vehicle frame and a motorcycle including the same.

  In recent years, for the purpose of reducing the weight of automobiles and the like, it has been proposed to use a magnesium-based material such as a magnesium alloy for vehicle structural parts (for example, see Patent Document 1). Therefore, for example, in order to reduce the weight of the motorcycle, it is conceivable to form the rear frame of the motorcycle with a magnesium-based material.

  As shown in FIG. 19A, the main frame 101 and the rear frame 102 are usually fasteners such as bolts and screws in a state in which a part of each other is overlapped in the vehicle width direction (in other words, the left-right direction). 103 is fastened. The main frame 101 and the rear frame 102 are formed with insertion holes 101a and 102a through which the fasteners 103 are inserted.

JP 2002-188616 A

  By the way, the magnesium-based material is a material having a small specific heat. For this reason, if the rear frame 102 is to be cast with a magnesium-based material, cracks called so-called solidification cracks may occur in portions where the thickness is locally large.

  However, since the main frame 101 and the rear frame 102 are parts that form the frame of the vehicle, they must be firmly fixed. Therefore, a relatively large seating surface 102b is required at the fastening portion of the rear frame 102. However, as shown in FIG. 19B, when the seating surface 102b is made large, the thickness B around the insertion hole 102a becomes larger than the thickness C of the other portions. For this reason, there is a problem that solidification cracks are likely to occur around the fastening portion of the rear frame 102.

  The present invention has been made in view of such points, and an object of the present invention is to provide a vehicle frame made of a magnesium-based material, which is less prone to solidification cracking during casting. .

  In addition, said description is only an example for demonstrating the subject of this invention, and the flame | frame for vehicles which concerns on this invention is not limited to the rear frame of a motorcycle.

  A vehicle frame according to the present invention includes a main body portion, a fastening portion that is continuous with the main body portion and has an insertion hole through which a fastener is inserted, and is cast by a magnesium-based material. A seating surface is formed around at least one of the one end side and the other end side of the insertion hole of the fastening portion, and a seating surface is formed on the fastening portion in the radial direction of the insertion hole. A recess that is recessed toward the insertion hole is formed on the outer side and in the middle of the insertion hole in the axial direction.

  A motorcycle according to the present invention includes the vehicle frame.

  According to the present invention, it is possible to realize a vehicle frame made of a magnesium-based material that hardly causes solidification cracking during casting.

1 is a side view of a motorcycle. 1 is a plan view of a motorcycle. It is a side view of a body frame. It is a top view of a rear frame. (A) is the sectional view on the Va-Va line of (b), (b) is a side view of the front side part of a rear frame. It is a top view of a main frame and a rear frame. It is a perspective view near the fastening part on the upper side of the rear frame. It is a perspective view near the fastening part on the lower side of the rear frame. It is a side view of a bolt in the state where a washer and a collar are assembled. It is a color front view. It is sectional drawing of the fastening structure of a main frame and a rear frame. Fig. 2 is a plan view of a rear frame and an inner portion thereof in the motorcycle. It is a top view of a battery box. It is a side view of a battery box. (A) is a top view of a tool band, (b) is the XVb-XVb sectional view taken on the line of (a). It is a side view of a seat lock device. It is a perspective view of a part of the seat lock device. It is sectional drawing of a bearing structure. (A) is a figure which shows the fastening structure of the conventional main frame and a rear frame, (b) is an enlarged view of the fastening part in the conventional main frame.

<< Overall structure of motorcycle >>
As shown in FIGS. 1 and 2, a motorcycle 1 according to an embodiment includes a body frame 10, an engine 2 supported by the body frame 10, a front wheel 3, a rear wheel 4, a handle 5, and a fuel tank. 6, a main seat 7, and a tandem seat 9. A tail lamp unit 8 is provided on the rear side of the motorcycle 1. The motorcycle 1 according to the present embodiment is a so-called motorcycle type motorcycle. However, the type of the motorcycle according to the present invention is not particularly limited, and may be a so-called motocrosser type, moped type, scooter type motorcycle or the like. In the following description, the front, rear, left and right directions refer to the front, rear, left and right directions as viewed from the rider seated on the main seat 7.

<< body frame >>
As shown in FIG. 3, the vehicle body frame 10 includes a head pipe 11, a main frame 12 that extends rearward and downward downward from the head pipe 11, and a rear frame 20 that extends rearward and diagonally upward from a middle portion of the main frame 12. Yes. Although details will be described later, in the present embodiment, the rear frame 20 is formed of a magnesium alloy.

"main frame"
The main frame 12 is made of a material that is more potential than the material of the rear frame 20. In the present embodiment, the main frame 12 is made of an aluminum alloy. The main frame 12 is provided with a bracket 13 for attaching the rear frame 20.

《Rear frame》
FIG. 4 is a plan view of the rear frame 20. As shown in FIG. 4, the rear frame 20 includes a pair of left and right seat rails 21L and 21R, and a cross member 22 that connects both the seat rails 21L and 21R.

  The rear frame 20 is made of a material containing 50% by weight or more of magnesium, that is, a magnesium-based material. The rear frame 20 is preferably formed of a material containing 90% by weight or more of magnesium. Here, the rear frame 20 is formed of a magnesium alloy.

  The surface of the rear frame 20 is covered with an insulator. The insulator may be an insulating material added to the surface of the rear frame 20, and by modifying the surface of the base material (that is, magnesium alloy) of the rear frame 20 to have insulating properties. It may be formed. That is, the insulator may be a part of the modified base material. In the present embodiment, the rear frame 20 is subjected to surface treatment to prevent electrolytic corrosion. Although the kind of surface treatment is not specifically limited, For example, surface treatments, such as chromium chromate treatment (chromate treatment), chromium phosphate treatment, manganese phosphate treatment, can be suitably used. In addition, an insulating film may be formed on the surface of the rear frame 20 by vapor deposition or the like, or an insulating paint may be applied. Thus, the electric corrosion of the rear frame 20 can be suppressed by covering the surface of the rear frame 20 with the insulator.

  As shown in FIG. 4, a recess 25 recessed downward is formed in the rear portion of the seat rail 21 </ b> L of the rear frame 20. In addition, screw holes 26 are formed in front of and behind the recess 25, respectively.

  As shown in FIG. 3, fastening portions 80 that are fastened to the bracket 13 of the main frame 12 are provided at the upper and lower portions of the front end of the seat rail 21 </ b> L. In FIG. 3, the right seat rail 21 </ b> R is not shown, but a similar fastening portion 80 is also provided on the right seat rail 21 </ b> R. Hereinafter, only the fastening portion 80 of the left seat rail 21L will be described.

  As shown in FIGS. 5 (a) and 5 (b), the fastening portion 80 is continuous with the side surface portion 21A of the rear frame 20 (strictly speaking, the seat rail 21L), but is wider than the side surface portion 21A (that is, , Width in the left-right direction). A through hole 23 is formed in each of the upper fastening portion 80 and the lower fastening portion 80. A seat surface 81 is formed around the through hole 23 on one end side and the other end side in the left-right direction of the fastening portion 80. As shown in FIG. 5A, the fastening portion 80 has a recess 82. The recessed part 82 is formed in the radially outer part of the through hole 23 in the fastening part 80 and is recessed toward the through hole 23 side. Moreover, the recessed part 82 is formed in the middle part of the axial direction (left-right direction in Fig.5 (a)) of the through-hole 23 in the fastening part 80. FIG.

  In the present embodiment, the upper fastening part 80 in the seat rail 21L is located on the left side of the side part 21A, and the lower fastening part 80 is located on the right side of the side part 21A. Although illustration is omitted, the upper fastening part 80 in the seat rail 21R is located on the right side of the side part 21A, and the lower fastening part 80 is located on the left side of the side part 21A. That is, the upper fastening portion 80 is located outside the vehicle, and the lower fastening portion 80 is located on the center side of the vehicle. However, the positions of the upper fastening portion 80 and the lower fastening portion 80 are not particularly limited. The upper fastening portion 80 and the lower fastening portion 80 may be located on opposite sides of the side surface portion 21A as in the present embodiment, or may be on the same side with respect to the side surface portion 21A. May be located.

  As shown in FIG. 5A, the thicknesses B1 and B2 of both side portions of the concave portion 82 of the fastening portion 80 are substantially equal to the thickness C of the side surface portion 21A of the seat rail 21L. Here, “the wall thickness is substantially equal” means that the solidification cracking does not occur during casting. For example, one thickness is about 0.5 to 2 times the other thickness. Say. The thickness of the side surface portion 21A of the seat rail 21L varies depending on the location of the side surface portion 21A. Here, the average thickness at the front end portion of the seat rail 21L is considered as the thickness C of the side surface portion 21A. I will do it. In the present embodiment, the radial thickness of the through hole 23 in the fastening portion 80 (specifically, the thickness between the bottom surface of the recess 82 and the inner peripheral surface of the through hole 23) B3 is also the thickness of the side surface portion 21A. Substantially equal to C.

  As shown in FIG. 5B, if the corner 80b is present at the end of the fastening portion 80, the corner 80b becomes a useless portion (so-called sagging). However, in the present embodiment, the end portion 80a of the fastening portion 80 has a rounded shape, and the corner portion 80b is excluded. Thus, by eliminating the corner portion 80b, the occurrence of a thick portion in the fastening portion 80 can be suppressed. Therefore, in this embodiment, not only the recess 82 is formed but also the corner portion 80b is excluded, so that solidification cracking during casting of the rear frame 20 is less likely to occur.

  Although details will be described later, as shown in FIGS. 6, 7, and 8, the fastening portion 80 of the rear frame 20 is fixed to the bracket 13 of the main frame 12 by a bolt 71. That is, the rear frame 20 is fastened to the bracket 13 of the main frame 12 by the bolt 71 that passes through the through hole 23 (see FIG. 5A) of the fastening portion 80.

《Fastening structure between main frame and rear frame》
Next, a fastening structure 70 between the main frame 12 and the rear frame 20 will be described with reference to FIGS. 9, 10, and 11. Since the upper fastening structure 70 and the lower fastening structure of the rear frame 20 are the same, only the upper fastening structure 70 will be described below.

  As shown in FIGS. 9 and 11, the fastening structure 70 has a bolt 71, a washer 72, and a collar 73. As described above, the through hole 23 is formed in the fastening portion 80 of the rear frame 20 (see FIG. 11). A fastening hole 15 is formed in the bracket 13 of the main frame 12. In the present embodiment, the fastening hole 15 is a hole into which a shaft portion 71a of a bolt 71 described later is screwed. A screw groove (not shown) is formed in the fastening hole 15 of the present embodiment. However, the fastening hole 15 may be a hole in which no thread groove is formed. The shape of the fastening hole 15 can be appropriately set according to the fastener. The inner diameter of the through hole 23 is larger than the inner diameter of the fastening hole 15.

  The bolt 71 is made of a material different from the magnesium-based material, and is made of iron in the present embodiment. However, the material of the bolt 71 is not limited to iron, and may be another material such as stainless steel. The bolt 71 has a shaft portion 71a provided with a screw 71c on a part of the tip end side, and a head portion 71b provided on the base side of the shaft portion 71a and having a larger diameter than the shaft portion 71a.

  The collar 73 is made of an aluminum-based material, and is formed of an aluminum alloy in the present embodiment. The collar 73 is interposed between the shaft portion 71 a and the inner peripheral surface of the through hole 23 of the rear frame 20 by covering a part of the periphery of the shaft portion 71 a of the bolt 71. Although the specific shape of the collar 73 is not particularly limited, in this embodiment, the collar 73 is formed in a C-shaped cross section as shown in FIG. In a state where the collar 73 is not fitted in the shaft portion 71a of the bolt 71, the inner diameter of the collar 73 is smaller than the outer diameter of the shaft portion 71a. On the other hand, since the collar 73 is formed in a C-shaped cross section, it can be easily expanded in diameter by human force, and after the expansion, a restoring force is generated in the direction of reducing the diameter. Thus, according to the present embodiment, by forming the collar 73 in a C-shaped cross section, it is easy to fit the collar 73 into the shaft portion 71a. That is, when the collar 73 is fitted into the shaft portion 71a, the collar 73 can be easily inserted into the shaft portion 71a by expanding the diameter of the collar 73 with a finger. Further, after the collar 73 is inserted into the shaft portion 71a, the collar 73 is reduced in diameter by its own restoring force and is fixed to the shaft portion 71a by releasing the collar 73 from the finger. In the present embodiment, the collar 73 is only fitted into the shaft portion 71a, and no adhesive or the like is used. That is, the collar 73 and the shaft portion 71a are not joined. However, it is also possible to join the collar 73 and the shaft portion 71a.

  The washer 72 is made of an aluminum-based material, and is made of an aluminum alloy in the present embodiment. As shown in FIG. 9, the washer 72 is passed through the shaft portion 71 a of the bolt 71 and is disposed between the head portion 71 b of the bolt 71 and the collar 73. As shown in FIG. 11, the washer 72 is interposed between the head 71 b and the rear frame 20 after the bolt 71 is fastened. The washer 72 is a separate body from the collar 73. That is, the washer 72 can be separated from the collar 73 and can be rotated independently of the collar 73.

  When the rear frame 20 is fixed to the bracket 13, the through hole 23 of the rear frame 20 and the fastening hole 15 of the bracket 13 are aligned, and then the bolt 71 having the washer 72 and the collar 73 assembled in advance is attached to the through hole 23. And screwed into the fastening hole 15. At this time, since the washer 72 and the collar 73 are separate bodies, the washer 72 rotates together with the bolt 71 even when the bolt 71 and the collar 73 rotate together. There is no. Therefore, since the bolt 71 and the washer 72 rotate relative to each other when the bolt 71 is tightened, a loss in tightening torque can be reduced.

《Battery box》
As shown in FIG. 12, a battery box 40 is disposed inside the rear frame 20. FIG. 13 is a plan view of the battery box 40, and FIG. 14 is a side view of the battery box 40. The battery box 40 is formed of a material that does not substantially cause electrolytic corrosion even when it comes into contact with the magnesium-based material. The material of the battery box 40 is preferably a non-metallic material. In the present embodiment, the battery box 40 is integrally formed of synthetic resin.

  As shown in FIG. 13, the battery box 40 according to the present embodiment has a length in the front-rear direction that is longer than the length in the left-right direction. The battery box 40 includes a battery support 41 that supports the battery 60 (see FIG. 12). The battery box 40 includes left and right side plates 42L and 42R extending in the front-rear direction. The side plates 42L and 42R stand upright from the bottom plate 43. The left side plate 42L extends rearward from the left side of the battery support portion 41. The right side plate 42 </ b> R extends in the front-rear direction behind the battery support portion 41. In the present embodiment, the left side plate 42 </ b> L is located at the left end of the battery box 40, and the right side plate 42 </ b> R is located at the right end of the battery box 40. The battery box 40 of the present embodiment does not have a portion protruding to the left side from the left side plate 42L, and does not have a portion protruding to the right side from the right side plate 42R. However, the shape of the battery box 40 is not particularly limited.

  As shown in FIG. 12, the battery box 40 is disposed above the cross member 22 (see FIG. 4) of the rear frame 20 and inside the seat rails 21L and 21R. The right side plate 42R covers the left side of the right seat rail 21R. On the other hand, the left side plate 42L covers the right side of the left seat rail 21L. That is, the side plates 42L and 42R are arranged so as to cover the side of the seat rails 21L and 21R on the vehicle center side, and extend in the front-rear direction along the seat rails 21L and 21R.

  As shown in FIG. 13, the battery box 40 according to the present embodiment has an ECU support portion 44 that supports an ECU (Electric Control Unit) 62 (see FIG. 12). The ECU support portion 44 is provided on the rear side of the battery support portion 41. In other words, the rear side portion of the battery support portion 41 extends rearward to constitute the ECU support portion 44.

  In addition, a tool box portion 45 that divides a space (hereinafter referred to as a tool storage space) 45a in which a tool is stored is provided on the rear side of the ECU support portion 44 in the battery box 40. The tool box portion 45 is recessed downward, and various tools are stored in the tool box portion 45. As described above, in this embodiment, the rear portion of the battery support portion 41 is further extended rearward to constitute the tool box portion 45.

《Tool Band》
Reference numeral 90 shown in FIG. 12 is a tool band. The tool band 90 is fixed by pressing a tool or the like accommodated in the tool box portion 45. As shown in FIGS. 15A and 15B, in this embodiment, the tool band 90 is integrally formed of rubber. That is, the tool band 90 is entirely formed of rubber. The tool band 90 includes a first retaining ring 91, a second retaining ring 92, and a connecting portion 93 that couples the first retaining ring 91 and the second retaining ring 92.

"Harness"
As shown in FIG. 12, a plurality of harnesses 61 are connected to the battery 60. A part of the harness 61a extends in the front-rear direction along the seat rail 21L inside the left seat rail 21L. The harness 61 a extends from the battery 60 toward the tail lamp unit 8.

  In this specification, “extending in the front-rear direction” means extending in the front-rear direction as a whole. For this reason, even if there is a curved or bent portion in part, if it extends in the front-rear direction as a whole, it “extends in the front-rear direction”. Further, not only when extending in the front-rear direction in a strict sense, but also when part or all of the portion extends in the front-rear direction is included in the “extending in the front-rear direction” herein.

  Thus, although the harness 61a is arrange | positioned along the seat rail 21L, according to this embodiment, since the side plate 42L of the battery box 40 is interposed between the seat rail 21L and the harness 61a, Contact between the harness 61a and the seat rail 21L is prevented.

<Seat lock device>
The tandem sheet 9 (see FIG. 1) is formed so as to be removable. As shown in FIGS. 16 and 17, the motorcycle 1 is provided with a seat lock device 50 that locks the tandem seat 9. The seat lock device 50 includes a rotating shaft 51 extending in the left-right direction, a hook 52 attached to the rotating shaft 51 so as to rotate together with the rotating shaft 51, and a bearing structure that rotatably supports the rotating shaft 51 on the seat rail 21L. 53 and a lock bar 54 that engages with the hook 52. Although not shown, the lock bar 54 is fixed to the inside of the tandem seat 9. Therefore, the hook 52 is indirectly engaged with the tandem seat 9 via the lock bar 54. However, the hook 52 may be engaged with a part of the tandem seat 9, in other words, directly engaged with the tandem seat 9.

  As shown in FIG. 16, one end of a lever 55 that rotates with the rotation shaft 51 is attached to the rotation shaft 51. An engaging element 56 is rotatably engaged with the other end of the lever 55. The seat lock device 50 includes a cable 57 having an inner wire 57a and an outer tube 57b. One end of the outer tube 57b is fixed by a stopper 58. One end of the inner wire 57a protrudes from one end of the outer tube 57b. The engaging element 56 is fixed to one end of the inner wire 57a. As shown in FIG. 12, the other end portion of the outer tube 57 b (that is, the front end portion) is also fixed by the stopper 58. The other end of the inner wire 57a protrudes from the other end of the outer tube 57b. A lever 59 is locked to the other end of the inner wire 57a.

  When unlocking the tandem seat 9, the inner wire 57 a is pulled to the other end side (that is, the front side) by rotating the lever 59. Then, as shown in FIG. 16, the engaging element 56 fixed to one end side of the inner wire 57a is pulled to the other end side, and the lever 55 rotates in the clockwise direction in FIG. As a result, the rotating shaft 51 also rotates in the clockwise direction. Thereby, the hook 52 attached to the rotating shaft 51 is also rotated in the clockwise direction, the hook 52 is detached from the lock bar 54, and the lock of the tandem seat 9 is released. As shown in FIG. 17, a spring 69 that biases the hook 52 toward the lock position is attached to the hook 52. The lock position is a position where the hook 52 engages with the lock bar 54 (that is, a position shown in FIG. 16). When the hand is released from the lever 59 (see FIG. 12), the hook 52 is returned to the locked position by the spring 69. Accordingly, the inner wire 57a is pulled to one end side, and the lever 59 returns to the initial position.

<< Bearing structure >>
As shown in FIGS. 12 and 17, the left end portion of the rotating shaft 51 is rotatably supported by a bearing structure 53. The right end portion of the rotating shaft 51 is rotatably supported by the bearing 37. Next, a bearing structure 53 that rotatably supports the rotating shaft 51 of the seat lock device 50 will be described with reference to FIG.

  As described above, the seat rail 21L of the rear frame 20 is formed with a recess 25 that is recessed downward (see also FIG. 4). In addition, screw holes 26 are formed in front of and behind the recess 25, respectively.

  A bearing member 31 is fitted in the recess 25. The bearing member 31 is formed of a material that does not substantially generate electrolytic corrosion even when in contact with the magnesium-based material. Note that the material that does not substantially generate electrolytic corrosion even when in contact with the magnesium-based material refers to a material having a small potential difference from the magnesium-based material or an insulating material (for example, resin, rubber, anodized film, paint film, etc.). . In the present embodiment, the bearing member 31 is made of a non-metallic material, in particular, a resin material. However, it is needless to say that the material of the bearing member 31 is not limited to the resin material. The lower portion 31a of the bearing member 31 is fitted in the recess 25 of the seat rail 21L. In this embodiment, the cross section of the recess 25 is formed in an inverted trapezoidal shape, and the lower portion 31 a of the bearing member 31 has an inverted trapezoidal cross section corresponding to the cross sectional shape of the recess 25. The upper portion 31b of the bearing member 31 has a substantially trapezoidal cross-sectional shape that is vertically symmetrical with the lower portion 31a, and an arcuate recess 32 is formed on the upper surface of the upper portion 31b.

  The rotating shaft 51 is supported by the recess 32 of the bearing member 31. The rotating shaft 51 is made of a metal material that is more noble than magnesium, and in this embodiment, the rotating shaft 51 is made of an iron-based material.

  A pressing member 33 made of an aluminum-based material is disposed on the upper side of the rotating shaft 51. In this embodiment, the pressing member 33 is formed of an aluminum alloy. The central portion 33a of the pressing member 33 is formed in an arch shape. An arcuate recess 34 that is recessed upward is formed below the central portion 33a. The upper portion of the rotating shaft 51 is fitted into the recess 34. Thereby, the rotating shaft 51 is sandwiched between the recess 34 of the pressing member 33 and the recess 32 of the bearing member 31 and is rotatably supported. On both front and rear sides of the pressing member 33, flat portions 33b in which screw holes 35 are formed are provided. The lower surface of the flat portion 33b is in contact with the upper surface of the seat rail 21L. In addition, although the pressing member 33 and the seat rail 21L are in direct contact, since the pressing member 33 is formed of an aluminum alloy, substantially no electrolytic corrosion occurs in the seat rail 21L.

  A screw 36 is inserted into the screw hole 35 of the pressing member 33 and the screw hole 26 of the seat rail 21L. The presser member 33 is fixed to the seat rail 21L by these screws 36. Then, by fixing the pressing member 33 to the seat rail 21L, the rotating shaft 51 and the bearing member 31 are sandwiched between the pressing member 33 and the seat rail 21L. In other words, the rotating shaft 51 is rotatably supported by the bearing member 31 in a state where the rotating shaft 51 is pressed against the bearing member 31 by the pressing member 33.

<< Effects of the Embodiment >>
As described above, the rear frame 20 according to the present embodiment is a magnesium alloy casting, and includes the fastening portion 80 in which the through hole 23 into which the bolt 71 is inserted is formed. On one end side and the other end side of the fastening portion 80, a seating surface 81 that is overlapped with the bracket 13 of the main frame 12 is formed. A recess 82 is formed in the middle portion of the fastening portion 80. Thus, according to the rear frame 20 of this embodiment, since the recessed part 82 is formed in the middle part of the fastening part 80, it is thick in the fastening part 80, ensuring the seat surface 81 of the fastening part 80 large. Generation of the portion can be prevented. Therefore, although the rear frame 20 is a magnesium alloy casting, solidification cracking during casting can be suppressed.

  In the rear frame 20 according to the present embodiment, fastening portions 80 are respectively provided above and below the front side of each side surface portion 21A of the left and right seat rails 20L and 20R. According to the present embodiment, as described above, since solidification cracking during casting is less likely to occur, the preferred rear frame 20 having the fastening portion 80 arranged as described above can be stabilized without significantly reducing the yield. Can be manufactured.

  5A, in the rear frame 20 according to the present embodiment, the thickness C of the side surface portion 21A of the seat rail 20L and the thickness B2 and B3 of both side portions of the concave portion 82 of the fastening portion 80. Is substantially equal. Therefore, there is no portion where the wall thickness changes rapidly between the side surface portion 21 </ b> A and the fastening portion 80. Therefore, it is possible to further suppress the occurrence of solidification cracks when the rear frame 20 is cast.

  Further, according to the rear frame 20 according to the present embodiment, the concave portion 82 of the upper fastening portion 80 and the concave portion 82 of the lower fastening portion 80 are positioned on opposite sides with respect to the side surface portion 21A. . In other words, one of the concave portion 82 of the upper fastening portion 80 and the concave portion 82 of the lower fastening portion 80 is provided on the left side of the side surface portion 21A, and the other is provided on the right side of the side surface portion 21A. By thus arranging the fastening portions 80 in a balanced manner, the coupling strength between the main frame 12 and the rear frame 20 can be improved.

<< Definition of terms etc. in this specification >>
In this specification, “magnesium-based material” refers to a material containing 50% by weight or more of magnesium, and typically a material containing 90% by weight or more of magnesium.

  "Coated with an insulator" means not only the case where another insulating material is added to the surface of the base material, but also that the surface of the base material is insulated by applying a surface treatment to the base material. Cases are also included.

  “The thickness of the main body and the thickness of both sides of the concave portion of the fastening portion are substantially equal” means that the thickness of both is equal to the extent that solidification cracking does not occur during casting. Is about 0.5 to 2 times the thickness of the other.

  A “fastener” is a member that fastens a plurality of members, and includes, for example, bolts and screws.

  The present invention is useful for a vehicle frame and a motorcycle including the same.

1 Motorcycle 10 Body frame (vehicle frame)
12 Main frame (second frame)
20 Rear frame (first frame)
21L, 21R Seat rail 21A Side surface (main body)
23 Through hole (insertion hole)
71 bolts (fasteners)
80 Fastening portion 81 Seat surface 82 Recessed portion B1, B2 Thickness of both side portions of the recessed portion of the fastening portion C Thickness of the side surface portion

Claims (6)

A main body part, and a fastening part that is continuous with the main body part and has an insertion hole through which a fastener is inserted, and includes a first frame cast from a magnesium-based material,
Around at least one of the one end side and the other end side of the insertion hole of the fastening portion, a seating surface that is overlapped with another frame is formed,
A vehicle frame in which a recessed portion recessed toward the insertion hole is formed in a radially outer portion of the insertion hole in the fastening portion and in an intermediate portion in the axial direction of the insertion hole. The vehicle frame according to claim 1,
A second frame fastened to the first frame;
The first frame has a pair of left and right side portions as a main body portion, and is provided with a fastening portion that is fastened to the second frame above and below the front side of each side portion. The vehicle frame according to claim 2,
The first frame is a rear frame of a motorcycle;
The second frame is a vehicle frame that is a main frame of a motorcycle fastened to a front end portion of the rear frame. The vehicle frame according to claim 2,
One of the concave portion of the upper fastening portion and the concave portion of the lower fastening portion is provided on one side of the side portion, and the other is provided on the other side of the side portion. The vehicle frame according to claim 1,
The thickness of the main body and the thickness of both side portions of the recess of the fastening portion are substantially equal to the vehicle frame.   A motorcycle comprising the vehicle frame according to any one of claims 1 to 5.

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