JP2010058730A - Magnesium alloy seat frame for saddle-riding type vehicle and saddle riding type vehicle including the same - Google Patents

Abstract

The present invention provides a magnesium alloy seat frame that has a high strength of a mounting portion of a component and is easy to manufacture.
A magnesium alloy seat frame 30 relates to a magnesium alloy seat frame integrally formed by die casting. The magnesium alloy seat frame 30 includes a frame main body 30 a and component attachment portions 36 to 39, 51. The frame body 30a is formed in a substantially U-shaped cross section. The component attachment portions 36 to 39, 51 are formed in a concave shape in a cross section so as to protrude outward from the frame body 30a.
[Selection] Figure 4

Description

  The present invention relates to a magnesium alloy seat frame for a straddle-type vehicle and a straddle-type vehicle including the same.

In recent years, exhaust gas regulations for straddle-type vehicles are becoming stricter. Along with this, the demand for weight reduction of saddle-ride type vehicles is also increasing. Conventionally, as an effective method for reducing the weight of a straddle-type vehicle, for example, in Patent Document 1 below, it has been proposed to use a magnesium alloy seat frame. Magnesium alloys have a lower specific gravity than iron or aluminum. For this reason, it becomes possible to greatly reduce the weight of the seat frame by using the magnesium alloy.
JP 2006-264673 A

  By the way, it is necessary to attach components, such as a footrest, to which a heavy load is applied to the seat frame. Usually, in an iron seat frame or an aluminum seat frame, a portion to which a part to which a large load is applied is thickened. As a result, the strength of the portion to which the part to which a large load is applied is increased.

  However, as disclosed in Patent Document 1, the strength per unit thickness of the magnesium alloy cast member tends to decrease as the thickness of the cast member increases. For this reason, the magnesium alloy seat frame has a problem that sufficient strength cannot be obtained simply by thickening a portion requiring high strength.

  For example, as shown in FIGS. 11 and 12, in the seat frame 100 disclosed in the above-mentioned Patent Document 1, by forming a plurality of ribs 106, the strength of a mounting portion of a component that receives a large load is increased. Yes. Specifically, as shown in FIG. 11, the seat frame 100 is provided with pedestals 101 to 104 to which the foot steps 105 shown in FIG. 12 are attached. As shown in FIG. 11, the pedestals 101 to 104 are connected to each other by a plurality of ribs 106. By forming the rib 106, the strength of the pedestals 101 to 104 to which the foot steps of the seat frame 100 are attached is increased.

  However, in order to connect the pedestal portions 101 to 104 to each other by the rib 106, the pedestal portions 101 to 104 need to be thick to some extent as shown in FIG. For this reason, when manufacturing the seat frame 100 by die casting, the tolerance of manufacturing conditions tends to be reduced. Moreover, since it is necessary to provide the rib 106, the structure tends to be complicated. Therefore, the seat frame 100 has a problem that it is difficult to manufacture.

  This invention is made | formed in view of this point, The objective is to provide the strength of the attachment part of components, and to provide the magnesium alloy seat frame which manufacture is easy.

  The magnesium alloy seat frame for saddle riding type vehicles according to the present invention relates to a magnesium alloy seat frame integrally formed by die casting. A magnesium alloy seat frame for a saddle riding type vehicle according to the present invention includes a frame body and a component mounting portion. The frame main body is formed in a substantially U-shaped cross section. The component mounting portion is formed in a concave shape in a cross section so as to protrude outward from the frame body.

  A straddle-type vehicle according to the present invention includes the magnesium alloy seat frame according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the intensity | strength of the attachment part of components can provide the magnesium alloy seat frame which is easy to manufacture.

  Hereinafter, an example of a preferable embodiment in which the present invention is implemented will be described taking the motorcycle 1 as a motorcycle in a narrow sense shown in FIG. 1 as an example. However, the straddle-type vehicle according to the present invention is not limited to a motorcycle in a narrow sense. The straddle-type vehicle according to the present invention may be, for example, a motorcycle such as a moped, a scooter, or an off-road vehicle. The straddle-type vehicle according to the present invention may be, for example, an ATV (All Terrain Vehicle).

  In the following description, the front, rear, left and right directions refer to directions when viewed from the rider 8 seated on the main seat 9 shown in FIG.

  As shown in FIG. 1, the motorcycle 1 includes a body frame 10 and a cowl 7. At least a part of the front and side of the body frame 10 is covered with the cowl 7.

  The vehicle body frame 10 includes a head pipe 11, a main frame 12, and a magnesium alloy seat frame 30 shown in FIG.

  A steering shaft (not shown) is rotatably inserted into the head pipe 11. A handle 5 is provided at the upper end of the steering shaft. On the other hand, a pair of front forks 13 is connected to the lower end of the steering shaft. A front wheel 14 is rotatably fixed to the lower ends of the pair of front forks 13.

  As shown in FIG. 2, the main frame 12 includes a main frame main body 12a and a down frame portion 12b. The main frame body 12a extends obliquely downward from the head pipe 11 toward the rear. The down frame portion 12b is connected to a middle portion of the main frame main body 12a. The down frame portion 12b extends slightly obliquely rearward downward from the middle portion of the main frame main body 12a.

  As shown in FIG. 1, a pivot shaft 15 extending in the vehicle width direction is attached to the main frame body 12a. A rear arm 16 is swingably attached to the pivot shaft 15. A rear wheel 17 is rotatably attached to the rear end portion of the rear arm 16. The rear wheel 17 is driven by an engine 18 suspended on the main frame 12.

  An exhaust pipe 21 is connected to the engine 18. The exhaust pipe 21 is routed backward from the engine 18 via the right side of the vehicle body. A rear end portion of the exhaust pipe 21 is connected to the silencer 22. The silencer 22 is disposed above the rear wheel 17 and on the side of the magnesium alloy seat frame 30 along the magnesium alloy seat frame 30. A cover 23 is attached to the silencer 22. The cover 23 covers the top of the silencer 22.

  A magnesium alloy seat frame 30 is attached to the middle portion of the main frame body 12a. The magnesium alloy seat frame 30 extends slightly obliquely upward from the main frame body 12a toward the rear. On the magnesium alloy seat frame 30, a main seat 9 on which a rider sits and a tandem seat 6 on which a passenger sits are attached.

  As shown in FIGS. 1 and 5, at least a part of the side and lower side of the magnesium alloy seat frame 30 is covered with a cowl 20. As shown in FIG. 5, the cowl 20 is disposed between the magnesium alloy seat frame 30 and the silencer 22. The cowl 20 separates the magnesium alloy seat frame 30 and the silencer 22 from each other.

  Next, the magnesium alloy seat frame 30 of the present embodiment will be described in detail with reference to FIGS.

  The magnesium alloy seat frame 30 is integrally formed by die casting. As shown in FIG. 10, a plurality of peritoneum membranes are formed on the surface of the magnesium alloy seat frame 30. Specifically, in the present embodiment, a first peritoneum 30 b and a second peritoneum 30 c are formed on the surface of the magnesium alloy seat frame 30. The magnesium alloy seat frame 30 is protected by the first and second peritoneums 30b and 30c. In addition, the kind of 1st and 2nd peritoneum 30b, 30c is not specifically limited. For example, the first peritoneal membrane 30b is composed of an electrodeposition coating film. The second peritoneal membrane 30c is composed of an electrostatic coating film.

  As shown in FIGS. 5 and 6, the magnesium alloy seat frame 30 includes a bottom wall portion 31 and a pair of side wall portions 32 and 33. As shown in FIG. 5, the pair of side wall portions 32, 33 extends upward from the bottom wall portion 31. In the magnesium alloy seat frame 30, the bottom wall portion 31 and the pair of side wall portions 32 and 33 constitute a frame body 30a having a substantially U-shaped cross section.

  As shown in FIGS. 3 and 6, a pair of upper and lower parts mounting portions 34 and 35 are provided at the front end portions of the side wall portions 32 and 33. The magnesium alloy seat frame 30 is fixed to the main frame 12 by attaching the component attaching portions 34 and 35 to the attached portions 12c and 12d of the main frame main body 12a shown in FIG.

  As shown in FIGS. 3, 4, and 6, a foot step 40 that extends from the magnesium alloy seat frame 30 outward in the vehicle width direction is attached to the bottom wall portion 31 of the magnesium alloy seat frame 30. The foot step 40 includes a left foot step 41 and a right foot step 42. Specifically, as shown in FIGS. 6 and 7, the bottom wall portion 31 is provided with first to fourth component attachment portions 36 to 39. As shown mainly in FIGS. 4 and 7, the component attachment portions 36 to 39 are formed in a concave shape in a cross section so as to protrude outward from the frame body 30 a. In the present embodiment, specifically, each of the component attachment portions 36 to 39 is formed in a concave shape in a cross section so as to protrude downward from the frame main body 30a.

  As shown in FIG. 6, the left foot step 41 is attached to the first and second component attachment portions 36 and 37. The right foot step 42 is attached to the third and fourth component attachment portions 38 and 39. Specifically, as shown in FIG. 7, through holes 36 a to 39 a are formed in the component mounting portions 36 to 39. As shown in FIGS. 3 and 4, the right and left foot steps 41 and 42 are fixed to the magnesium alloy seat frame 30 by bolts 45 inserted into the through holes 36 a to 39 a.

  As shown in FIG. 4, the above-described cowl 20 is also fixed to the component attachment portions 36 to 39 together with the foot step 40. Specifically, the cowl 20 is fixed by being sandwiched between the component mounting portions 36 to 39 and the right and left foot steps 41 and 42.

  As shown in FIG. 3, a number bracket 50 to which a number plate (not shown) is attached is attached to the magnesium alloy seat frame 30. Specifically, as shown in FIG. 3, a component mounting portion 51 is provided on the bottom wall portion 31 of the magnesium alloy seat frame 30. As shown in FIGS. 3, 5, and 6, the component mounting portion 51 is formed in a concave shape in a cross section so as to protrude outward from the frame body 30 a. Specifically, the component mounting portion 51 is formed in a concave shape in a cross section so as to protrude downward from the frame main body 30a. As shown in FIG. 6, three through holes 51 a to 51 c are formed in the component mounting portion 51. As shown in FIG. 5, the number bracket 50 is fixed to the magnesium alloy seat frame 30 by bolts 52 inserted into the through holes 51a to 51c.

  In addition, an opening 51d is formed at a substantially central portion in plan view of the component mounting portion 51 shown in FIGS. The opening 51d is for discharging water that has entered the component mounting portion 51 formed in a concave shape, and for pulling the wire harness 56 shown in FIG. 8 downward from the magnesium alloy seat frame 30. is there. Specifically, as shown in FIG. 8, a battery box 53 is disposed inside the magnesium alloy seat frame 30. A battery (not shown) is arranged in the battery box 53. The wire harness 56 is connected to this battery. The wire harness 56 extends downward from the battery, and is pulled out into the number bracket 50 through the opening 53a of the battery box 53, the opening 54a of the washer 54, the opening 51d, and the opening 20a of the cowl 20. It is.

  In the present embodiment, the diameters of the opening 53a, the opening 20a, and the opening 54a are set smaller than the diameter of the opening 51d. For this reason, the movement of the wire harness 56 is regulated by the opening 53a, the opening 20a, and the opening 54a. Therefore, the contact between the wire harness 56 and the magnesium alloy seat frame 30 is suppressed. Therefore, wear of the magnesium alloy seat frame 30 due to contact between the wire harness 56 and the magnesium alloy seat frame 30 is suppressed.

  In addition, a damper 55 is disposed between the cowl 20 and the magnesium alloy seat frame 30 in order to suppress contact between the cowl 20 and the magnesium alloy seat frame 30.

  As described above, in the present embodiment, the component mounting portions 36 to 39, 51 are formed in a concave shape in a cross section so as to protrude outward from the frame body 30a. By doing in this way, the part attachment parts 36-39 and 51 can be provided with a part parallel to the attachment direction of components. Therefore, the strength of the component attachment portions 36 to 39, 51 is increased, and there is no need to separately provide ribs or the like. Moreover, since it is not necessary to provide a rib, unlike the seat frame 100 described in the said patent document 1, it is not necessary to thicken the component attachment parts 36-39,51. Thus, in this embodiment, it is not necessary to provide a rib, and it is not necessary to thicken the component attachment parts 36-39,51. Therefore, the high rigidity of the component attachment parts 36-39, 51 and the high freedom of manufacturing conditions and the ease of manufacturing of the magnesium alloy seat frame 30 are realized.

  By the way, in this embodiment, the component attachment parts 36-39 and 51 are formed in the concave shape in the cross section so that it may protrude below. For this reason, water tends to accumulate in the component mounting portions 36 to 39, 51. Especially, since the component attaching part 51 protrudes largely below, water tends to accumulate especially. However, in the present embodiment, an opening 51 d is formed in the component attachment portion 51. For this reason, it is suppressed effectively that water accumulates in the component attachment part 51.

  In this embodiment, no opening is formed in the component attachment portions 36 to 39 which are shallow and hardly collect water, but an opening may be formed also in the component attachment portions 36 to 39.

  In the present embodiment, as shown in FIG. 5, the cowl 20 is disposed between the magnesium alloy seat frame 30 and the silencer 22. For this reason, the magnesium alloy seat frame 30 can be effectively protected from the radiant heat of the silencer 22.

  In particular, in the present embodiment, an air layer 60 is formed between the cowl 20 and the magnesium alloy seat frame 30. For this reason, the magnesium alloy seat frame 30 can be particularly effectively protected from the heat of the silencer 22.

  As described above, the magnesium alloy seat frame 30 of the present embodiment is integrally formed by die casting. For this reason, as shown in FIG. 9, the extrusion pin trace part 57 is formed in the position corresponding to the die cutting pin in the magnesium alloy seat frame 30. As shown in FIG. 10, the extrusion pin mark portion 57 is normally formed in a convex portion having a rectangular cross section. For this reason, a sharp corner 57 a that is not chamfered in the R shape is formed in the extrusion pin trace 57.

  As a result of diligent research, the present inventors have found that the first and second peritoneums 30b and 30c are not formed thick on the corner 57a, and therefore, electrical corrosion occurs when water or the like comes into contact with the corner 57a. I found that there was a fear. In addition, when the shortest distance between a corner portion such as the extrusion pin mark portion 57 and a member made of a metal or an alloy that causes electric corrosion with a magnesium alloy is 6 mm or less, the present inventors have attached water. On the other hand, it was found that when the thickness is 6 mm or more, the electrolytic corrosion is not substantially generated even when water is attached. For this reason, in this embodiment, as shown in FIG. 10, between the magnesium alloy reinforcing member 60 (see also FIG. 9) attached to the magnesium alloy seat frame 30 and the corner 57 a of the extrusion pin mark portion 57. The distance l is set to be 6 mm or more. Thereby, the electric corrosion of the magnesium alloy seat frame 30 in the extrusion pin mark portion 57 can be effectively suppressed.

1 is a left side view of a motorcycle. It is a left view of a head pipe and a main frame. It is a left view of a seat frame. It is the IV-IV arrow line view in FIG. It is a VV arrow line view in FIG. It is a perspective view of a seat rail at the time of seeing from diagonally below. It is a perspective view of a part of a seat rail when viewed from obliquely below. It is a VIII-VIII arrow line view in FIG. It is a perspective view of the seat rail at the time of seeing from diagonally upward. It is sectional drawing showing a part of seat rail. 10 is a plan view showing a part of a seat frame disclosed in Patent Document 1. FIG. 2 is a cross-sectional view of a seat frame disclosed in Patent Document 1. FIG.

Explanation of symbols

1 Motorcycle (saddle-ride type vehicle)
20 cowl 22 silencer 30 magnesium alloy seat frame 30a frame main body 36-39, 51 parts mounting part 40 foot step 51d opening 60 air layer

Claims (6)

A magnesium alloy seat frame formed integrally by die casting,
A frame body formed in a substantially U-shaped cross section;
A component mounting portion formed in a concave shape in a cross section so as to protrude outward from the frame body;
A magnesium alloy seat frame for straddle-type vehicles. In the magnesium alloy seat frame for straddle-type vehicles according to claim 1,
The component mounting portion is formed in a concave shape in a cross section so as to protrude downward from the frame body,
A magnesium alloy seat frame for a saddle-ride type vehicle in which an opening is formed in the component mounting portion.   A straddle-type vehicle comprising the magnesium alloy seat frame according to claim 1. In the saddle riding type vehicle according to claim 3,
A silencer disposed on the side of the magnesium alloy seat frame and attached to the magnesium alloy seat frame;
Between the silencer and the magnesium alloy seat frame, a cowl attached to the component attachment portion,
Further comprising
A straddle-type vehicle in which at least a part of a side of the magnesium alloy seat frame is covered with the cowl. In the saddle riding type vehicle according to claim 4,
A straddle-type vehicle in which an air layer is formed between the cowl and the magnesium alloy seat frame. In the saddle riding type vehicle according to claim 3,
A straddle-type vehicle further comprising a foot step attached to the component attachment portion.

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