JP4312873B2 - Connection structure of connecting tube end and air cleaner case - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure between an end portion of a connecting tube and an air cleaner case suitable for improving sealing performance.
[0002]
[Prior art]
As a structure for connecting a connecting tube disposed on the upstream side of a carburetor of a vehicle and an air cleaner case, for example, Japanese Utility Model Publication No. 3-32778 “Intake Device” is known.
In the above technique, as shown in FIGS. 1 and 2, the annular groove having a U-shaped cross section provided on the outer periphery of the intake connecting tube 1 at the flat opening edge 15a of the outer plate 15 of the air cleaner 3 is used. The concave circumferential groove 16 is fitted.
[0003]
[Problems to be solved by the invention]
When the linear expansion coefficients of the intake connecting tube 1 and the air cleaner 3 are different from each other, a gap is generated between the concave circumferential groove 16 of the intake connecting tube 1 and the opening edge 15a of the air cleaner 3 due to temperature change. In order to maintain the property, a sealing agent must be applied to the concave circumferential groove 16 and the opening edge 15a, and the assembling property is deteriorated.
Accordingly, an object of the present invention is to provide a connection structure between an end portion of a connecting tube and an air cleaner case with improved sealing performance.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a connection structure between an end portion of a connecting tube and an air cleaner case when the air cleaner case and the intake passage of the engine are connected by a connecting tube. An opening is formed in the air cleaner case in order to insert the portion, and a claw-shaped ring portion extending substantially in the axial direction of the connecting tube is formed bulging at the edge of the opening, and the end portion of the connecting tube is formed in the claw-shaped ring portion. By fitting the outer circumferential groove formed on the outer circumference, the axial displacement and radial deviation of the connecting tube are suppressed, and the claw-shaped ring portion forms an opening and increases the inner diameter toward the outside of the air cleaner case. The inner tapered surface, the tip surface constituting the tip of the claw, and the end of this tip surface to the inside of the air cleaner case And an outer tapered surface with an increased selfish outer diameter, so as to be in close contact with the claw-shaped ring portion, is formed an outer peripheral groove corresponding to the outer shape, the connecting tube is connected to rush obliquely to the opening of the air cleaner case , the claw-shaped ring portion with respect to the extending direction of the cross wall of the connecting tube is characterized that you have to protrude in a direction crossing.
[0005]
By fitting the outer peripheral groove of the connecting tube to the claw-shaped ring portion of the air cleaner case, the axial and radial deviation of the connecting tube is suppressed, and the sealing performance between the air cleaner case and the connecting tube is improved.
[0006]
Claim 2 is that when the radial width of the distal end surface of the claw-shaped ring portion is E1, and the radial width of the outer circumferential groove distal surface facing the claw-shaped ring portion distal end surface of the outer circumferential groove is E2, E1 > characterized in that the E2.
[0007]
According to a third aspect of the present invention, the air cleaner case includes a case main body and a lid member attached to an upper portion of the case main body, and the opening is disposed in the vicinity of a joint portion between the case main body and the lid member.
[0008]
According to a fourth aspect of the present invention, a part of the portion of the connecting tube where the outer peripheral groove is formed is in contact with the fastening portion on the case body side provided in the joint portion.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a motorcycle provided with an air cleaner case and a connecting tube according to the present invention. A motorcycle 10 includes a vehicle body frame 11 as a vehicle body and a head pipe 12 attached to the front portion of the vehicle body frame 11. A handle 13 rotatably attached to the head pipe 12, a front fork 14 and a front wheel 15 integrally attached to a lower portion of the handle 13, a front fender 16 covering the upper portion of the front wheel 15, and a body frame 11 An oil tank 17 for dry sump type oil lubrication attached to the back side of the vehicle, a fuel tank 18 attached to the upper part of the vehicle body frame 11, and a power unit 23 comprising an engine 21 and a transmission 22 arranged below the fuel tank 18. Consists of.
[0010]
Further, the motorcycle 10 includes a carburetor 24, a connecting tube 25 and an air cleaner case 26 attached to the intake side of the engine 21, an exhaust pipe 27 and a muffler 28 attached to the exhaust side of the engine 21, and a rear lower part of the body frame 11. A swing arm 31 attached to the rear end of the swing arm 31, a rear wheel 32 attached to the rear end of the swing arm 31, a seat 33 disposed behind the fuel tank 16, and a body disposed below and behind the seat 33. It comprises a cowl 34 and a rear fender 35 attached to the rear part of the body cowl 34. In addition, 36 is a front cowl with a screen, 37 is a headlamp, 38 is a meter, 41 and 41 are shrouds which cover the front side surface of the vehicle body frame 11, and 42 is a side stand.
[0011]
FIG. 2 is a side view of a main part of a motorcycle provided with an air cleaner case and a connecting tube according to the present invention, that is, a view of the motorcycle 10 shown in FIG. It shows that the down tube 54 constituting the frame 11 is extended, the oil tank 17 is attached to the upper portion of the down tube 54, and the oil tank 17 and the engine 21 are connected by the first and second pipes 55 and 56. The shroud 41 on the front side of the oil tank 17 is indicated by an imaginary line for convenience of explanation.
[0012]
The first pipe 55 is for supplying oil from the oil tank 17 to the engine 21, and the second pipe 56 is for returning oil from the engine 21 to the oil tank 17. In addition, 57 and 58 are upper and lower brackets for attaching the oil tank 17 to the down tube 54, and 61 is an oil level gauge.
[0013]
The exhaust pipe 27 is a set for collecting the first exhaust pipe 62 and the second exhaust pipe 63 attached to each cylinder of the engine 21 (see FIG. 1), and the first exhaust pipe 62 and the second exhaust pipe 63. The pipe 64 and a muffler connecting pipe 65 that connects the collecting pipe 64 and the muffler 28 (see FIG. 1).
[0014]
FIG. 3 is a side view of the air cleaner case and the connecting tube according to the present invention, and shows that the air cleaner case 26 is connected to the downstream side of the connecting tube 25.
The connecting tube 25 is, for example, a rubber tube.
The air cleaner case 26 is, for example, a resin case, and includes a case main body 67, a lid member 68 attached to the upper portion of the case main body 67, and a suction duct 71 attached to the lid member 68. In addition, 72 is a blow-by recirculation hose connected to the engine 21 (see FIG. 1), and 73 is a drainage hose.
[0015]
FIG. 4 is a cross-sectional view of the connecting portion between the air cleaner case and the connecting tube according to the present invention. An opening 75 is formed in the case main body 67 of the air cleaner case 26, and the axial direction of the substantially connecting tube 25 is formed at the edge of the opening 75. A claw-shaped ring portion 76 extending in a direction (2) perpendicular to the radial direction (1) of the opening 75 is bulged and formed on the outer periphery of the end portion of the connecting tube 25 on the claw-shaped ring portion 76. It shows that the formed outer peripheral groove 77 is fitted.
[0016]
The claw-shaped ring portion 76 of the air cleaner case 26 is formed in a tapered shape so that the cross-sectional shape becomes thinner toward the outside of the case body 67, and the outer peripheral groove 77 of the connecting tube 25 is formed in the air cleaner case 26. The groove is brought into close contact with the claw-shaped ring portion 76 by making the dimension before fitting with the claw-shaped ring portion 76 smaller than the outer dimension of the claw-shaped ring portion 76.
[0017]
5A and 5B are enlarged cross-sectional views showing the claw-shaped ring portion and the outer peripheral groove according to the present invention.
The claw-shaped ring portion 76 shown in FIG. 6A includes an inner tapered surface 81 that forms an opening 75 and has an inner diameter that increases toward the outer side of the case body 67, a distal end surface 82 that constitutes the distal end of the claw, and the distal end. An outer tapered surface 83 having an outer diameter that increases from the end of the surface 82 toward the inside of the case main body 67 is provided. In addition, 84 is a front surface and 85 is a rear surface.
[0018]
In this claw-shaped ring portion 76, the minimum inner diameter of the inner tapered surface 81 is φA, the maximum inner diameter is φB, the width of the inner tapered surface 81 is C, the distance between the front surface 84 and the rear surface 85, that is, the thickness of the case body 67 is D. The width in the radial direction of the tip end surface 82 is E1, and the difference between the maximum outer diameter and the minimum outer diameter of the outer tapered surface 83 is F.
[0019]
The outer peripheral groove 77 shown in FIG. 5B includes a rear surface 91, an inner tapered surface 92, a tip surface 93, an outer tapered surface 94, and a front surface 95.
The dimension of the outer peripheral groove 77 is substantially equal to the dimension of the claw-shaped ring portion 76 of FIG.
That is, in the outer circumferential groove 77, the minimum outer diameter of the inner tapered surface 92 is φA, the maximum outer diameter is φB, the width of the inner tapered surface 92 is C, the distance between the front surface 95 and the rear surface 91 is D, and the radial direction of the front end surface 93 E2 and the difference between the maximum inner diameter and the minimum inner diameter of the outer tapered surface 94 is F.
In the above (a) and (b), different dimensions are E1 and E2, and E1> E2.
[0020]
Next, the operation of the claw-shaped ring portion 76 and the outer peripheral groove 77 shown in FIGS. 5A and 5B will be described.
6 (a) to 6 (c) are operation diagrams for explaining the connection state between the air cleaner case and the connecting tube. (A) is the present embodiment, and (b) and (c) are comparative examples.
In this embodiment of (a), as described with reference to FIGS. 5 (a) and 5 (b), by setting E1> E2, when the outer peripheral groove 77 is fitted to the claw-shaped ring portion 76, elasticity is achieved. The outer peripheral groove 77 of the connecting tube 25 having the inner tapered surface 92 and the outer tapered surface 94 fastens the inner tapered surface 81 and the outer tapered surface 83 of the claw-shaped ring portion 76 with the forces F1 and F2 and the inner tapered surface. A component force is generated in the direction in which the claw-shaped ring portion 76 extends by the surface 92 and the outer tapered surface 94, and the rear surface 85 is fastened by the rear surface 91 by a force F3 against the component force.
[0021]
In this way, by tightening the claw-shaped ring portion 76 at the three positions of the outer circumferential groove 77, the connecting tube 25 is substantially axial (direction (2) shown in FIG. 4) and radial direction (direction shown in FIG. 4). (1)) can be suppressed, and the sealing performance between the claw-shaped ring portion 76 and the outer peripheral groove 77, that is, the sealing performance between the air cleaner case 26 and the connecting tube 25 can be improved.
[0022]
Further, since the dimensions of E1 and E2 shown in FIGS. 5 (a) and 5 (b) are small, even if there is a difference in linear expansion coefficient between the air cleaner case 26 and the connecting tube 25, the temperature change expressed by the following equation The influence on the amount of expansion / contraction due to is small, and the sealing performance between the claw-shaped ring portion 76 and the outer circumferential groove 77 is not impaired.
[0023]
Expansion amount (or contraction amount) = α · Δt · d
Here, α represents a linear expansion coefficient, Δt represents a temperature change amount, and d represents a dimension. When the initial temperature is t1, the final temperature is t2, and Δt = t2-t1, the expansion amount is obtained if t2> t1, and the contraction amount is obtained if t2 <t1.
[0024]
In the comparative example (b), the opening 202 is opened in the flat wall surface 201 of the air cleaner case 200, and the outer peripheral groove 204 formed on the outer periphery of the end of the connecting tube 203 is fitted into the opening 202. Show.
In order to improve the sealing performance of the fitting portion between the air cleaner case 200 and the connecting tube 203, the groove width before fitting of the connecting tube 203 is made smaller than the plate thickness G of the air cleaner case 200, and the opening 202 is further closed. The groove bottom diameter of the outer peripheral groove 204 is increased with respect to the inner diameter φH of the inner diameter φH to generate the tightening forces F4, F4, F5.
[0025]
In the comparative example of (c), since the inner diameter of the opening 202 of the air cleaner case 200 is large, when there is a difference in the linear expansion coefficient between the air cleaner case 200 and the connecting tube 203, the amount of expansion / contraction due to temperature change is reduced. A large impact.
[0026]
For example, if the linear expansion coefficient of the air cleaner case 200 is larger than the linear expansion coefficient of the connecting tube 203 and the temperature rises, the expansion amount of the air cleaner case 200 becomes larger than the expansion amount of the connecting tube 203. The inner diameter of the opening 202 is larger than the groove bottom diameter of the outer peripheral groove 204, and a gap J is generated in the fitting portion, so that the wall surface 201 can be tightened only at two locations of the outer peripheral groove 204. The sealing performance with the tube 203 is lowered.
[0027]
7A and 7B are enlarged views of main parts of the exhaust pipe shown in FIG. 2, wherein FIG. 7A is a longitudinal sectional view and FIG. 7B is a perspective view.
In (a), the first and second exhaust pipes 62 and 63 are attached to the first and second bulging portions 101 and 102 on the upstream side of the collecting pipe 64 via the collars 103 and 104, and the downstream of the collecting pipe 64. It shows that the muffler connecting pipe 65 is attached to the straight pipe portion 105 on the side.
In (b), the collecting pipe 64 is formed by drawing a straight pipe.
[0028]
FIG. 8 is a perspective view showing a modified example of the collecting pipe. The collecting pipe 111 is formed by drawing a straight pipe and connecting it to the first and second exhaust pipes 62 and 63 (see FIG. 7A). The first and second bulging parts 112 and 113 and the straight pipe part 114 for connecting to the muffler connecting pipe 65 (see FIG. 7A) are formed. The straight pipe part 114 is arranged almost linearly, and the second bulging part 113 is offset with respect to the straight pipe part 114.
[0029]
Thus, by arranging the first and second bulging portions 112 and 113 with respect to the straight pipe portion 114, the exhaust characteristics according to each cylinder of the engine 21 (see FIG. 1) can be set. Engine performance can be changed.
[0030]
9 is a cross-sectional view taken along line 9-9 in FIG. 1 (a plan cross-sectional view of the left and right front forks). Fender mounting portions 123, 124 extending in the longitudinal direction of the vehicle body are respectively attached to the rod guide portions 121, 122 of the front fork 14. 125, 126 are provided, female screws 127, 128 are provided on the fender mounting portions 123, 125, convex portions 131, 132 are provided on the inner sides of the fender mounting portions 124, 126, and concave portions 134, It shows that the mounting holes 136 and 137 are opened in front of 135 and the mounting holes 141 and 142 are opened in the rear of the recesses 134 and 135.
[0031]
In order to attach the front fender 16 to the front fork 14, first, the width of the rear portion of the flexible front fender 16 is reduced, and the rod guide portions 121 and 122 of the front fork 14 are passed from the front to the rear to guide the rod guide. The concave portions 134 and 135 are aligned with the positions of the portions 121 and 122, and the mounting holes 141 and 142 of the front fender 16 are fitted into the convex portions 131 and 132 of the fender mounting portions 124 and 126.
[0032]
Next, the mounting holes 136 and 137 of the front fender 16 are aligned with the mounting female screws 127 and 128 of the fender mounting portions 123 and 125, and the screws 145 and 146 are passed through the mounting holes 136 and 137, respectively. Screw together.
As described above, the front fender 16 conventionally attached to the front fork 14 with the four screws is provided with the protrusions 131 and 132 on the front fork 14 and the mounting holes 141 and 142 are formed in the front fender 16. Thus, the front fender 16 can be easily attached to the front fork 14 with two screws.
[0033]
Although the claw-shaped ring portion 76 shown in FIG. 4 is protruded to the outside of the air cleaner case 26, it may be protruded to the inside of the air cleaner case 26.
Further, the dimensions of the claw-shaped ring portion 76 and the outer peripheral groove 77 described with reference to FIGS. 5A and 5B are not limited to this, and in short, the inner tapered surface 81 and the outer tapered surface of the claw-shaped ring portion 76 are important. The dimensions may be such that the surface 83 and the rear surface 85 are tightened at three locations of the inner tapered surface 92, the outer tapered surface 94 and the rear surface 91 of the outer peripheral groove 77 to improve the sealing performance.
Furthermore, the connection structure between the end of the connecting tube 25 and the air cleaner case 26 of the present invention is not limited to the motorcycle 10 shown in FIG. 1, and may be applied to vehicles such as a tricycle and a four-wheel vehicle.
[0034]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
The connection structure between the end of the connecting tube and the air cleaner case according to claim 1 is that an opening is formed in the air cleaner case, and a claw-shaped ring portion is bulged at the edge of the opening, and the connecting portion is connected to the claw-shaped ring portion. Since the outer circumferential groove of the tube is fitted, the axial displacement and radial displacement of the connecting tube can be suppressed, and the sealing performance between the air cleaner case and the connecting tube can be improved.
Therefore, the sealing agent conventionally applied to the connecting portion between the air cleaner case and the connecting tube becomes unnecessary, and it is possible to improve the assembling property and reduce the manufacturing cost.
[0035]
The connecting structure between the end of the connecting tube and the air cleaner case according to claim 2 is such that the radial width of the front end surface of the claw-shaped ring portion is E1, and the front end of the outer peripheral groove facing the front end surface of the claw-shaped ring portion of the outer peripheral groove. When the width in the radial direction of the surface is E2, E1> E2 .
[0036]
The connection structure between the end of the connecting tube and the air cleaner case according to claim 3 is such that the air cleaner case includes a case main body and a lid member attached to an upper portion of the case main body, and the opening includes the case main body and the lid member. It arrange | positions in the junction part vicinity.
[0037]
In the connection structure between the end portion of the connecting tube and the air cleaner case according to the fourth aspect , a part of the portion where the outer peripheral groove of the connecting tube is formed is in contact with the fastening portion on the case body side provided at the joint portion.
[Brief description of the drawings]
FIG. 1 is a side view of a motorcycle including an air cleaner case and a connecting tube according to the present invention. FIG. 2 is a side view of a main part of a motorcycle including an air cleaner case and a connecting tube according to the present invention. Side view of air cleaner case and connecting tube according to the present invention. FIG. 4 is a cross-sectional view of a connecting portion between the air cleaner case and the connecting tube according to the present invention. FIG. 6 is an operation diagram for explaining the connection state between the air cleaner case and the connecting tube. FIG. 7 is an enlarged view of the main part of the exhaust pipe shown in FIG. 2. FIG. 8 is a modification of the collecting pipe. FIG. 9 is a sectional view taken along line 9-9 in FIG. 1 (a plan sectional view of the left and right front forks).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 21 ... Engine, 25 ... Connecting tube, 26 ... Air cleaner case, 67 ... Case main body, 68 ... Cover member, 75 ... Opening, 76 ... Claw-shaped ring part, 77 ... Outer peripheral groove, 81 ... Inner taper surface, 82 ... Claw Tip end surface of the ring-shaped ring portion, 83 ... outer tapered surface, E1, E2 ... width, 93 ... tip end surface of the outer peripheral groove.

Claims (4)

In the connection structure between the end of the connecting tube and the air cleaner case when the air cleaner case and the intake passage of the engine are connected by the connecting tube,
An opening is opened in the air cleaner case to insert the end of the connecting tube, and a claw-shaped ring portion extending substantially in the axial direction of the connecting tube is formed at the edge of the opening, and the connecting portion is connected to the claw-shaped ring portion. By fitting the outer peripheral groove formed on the outer periphery of the end of the tube, so as to suppress the axial and radial displacement of the connecting tube,
The claw-shaped ring portion includes an inner tapered surface that forms the opening and has an inner diameter that increases toward the outer side of the air cleaner case, a tip surface that forms a tip of the claw, and an end portion of the tip surface. An outer tapered surface with an outer diameter increasing toward the inside,
The outer peripheral groove corresponding to the outer shape is formed so as to be in close contact with the claw-shaped ring portion ,
The connecting tube is connected to rush obliquely to the opening of the air cleaner case, the claw-shaped ring portion with respect to the extending direction of the cross wall of the connecting tube is characterized that you have to protrude in a direction intersecting connectin Connection structure between the tube end and air cleaner case. When the radial width of the tip surface of the claw-shaped ring portion is E1, and the radial width of the outer circumferential groove tip surface of the outer circumferential groove facing the claw-shaped ring portion tip surface is E2, E1> The connection structure between the end of the connecting tube and the air cleaner case according to claim 1, wherein E2 is used . The air cleaner case includes a case main body and a lid member attached to an upper portion of the case main body, and the opening is disposed in the vicinity of a joint portion between the case main body and the lid member. The connection structure of the edge part of the connecting tube of Claim 1 or Claim 2, and an air cleaner case. 4. The end of the connecting tube according to claim 3 , wherein a part of a portion of the connecting tube where the outer peripheral groove is formed is in contact with a fastening portion on the case body side provided in the joint portion. Connection structure with air cleaner case.

Images