JP2010174837A - Inlet pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inlet pipe directly connected to a throttle body and an engine while suppressing a thermal effect on the throttle body and having sufficient heat resistance. <P>SOLUTION: The inlet pipe 51 is connected between the throttle body 53 connected to an air cleaner 57 provided in a vehicle through a connecting tube 55 and the engine 20 of the vehicle, thereby forming an intake passage. The inlet pipe 51 is formed of resin composed of a polyphenylene sulfide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inlet pipe that is connected between a throttle body and an engine to form an intake passage.

Some vehicle engines employ an injector (fuel injection valve) instead of a carburetor (also referred to as a carburetor) from the viewpoint of improving the accuracy of fuel control or purifying exhaust gas.
This fuel injection type engine has a throttle body connected to an air cleaner via a connecting tube and connected to the engine via an inlet pipe (also referred to as an air inlet pipe), and connects the throttle body and the engine. There are pipes made of metal (for example, see Patent Document 1).
When the inlet pipe is made of metal, a female screw portion can be provided on the inlet pipe and a fastening member such as a screw or a bolt can be fastened. Therefore, the injector can be fixed to the inlet pipe by the fastening member.
JP 2004-183538 A

However, when the inlet pipe is made of metal, since the heat conductivity of the inlet pipe is high, a configuration for reducing the thermal influence on the throttle body by the heat of the engine is required, and the number of parts increases. For example, in the vehicle described in Patent Document 1, a rubber elastic connecting cylinder is provided at the upstream end of the inlet pipe, and the throttle body is connected via the elastic connecting cylinder, thereby reducing the thermal effect on the throttle body. Yes.
On the other hand, when the inlet pipe is formed of a general resin (such as polyamide (nylon) or polypropylene) that is applied to automobile parts, the heat of the throttle body is reduced because the resin has lower thermal conductivity than metal. The influence can be suppressed.

  However, conventional resins sometimes fail to satisfy the performance required for vehicles under severe thermal conditions. For example, a motorcycle has a limited part layout space compared to a four-wheeled vehicle such as an ordinary passenger car. For this reason, in the motorcycle, the layout of the inlet pipe is restricted, and other parts are arranged close to the periphery of the inlet pipe, so that the inlet pipe is easily affected by the heat of the engine. In particular, since motorcycles may be equipped with air-cooled engines that are rarely used in four-wheeled vehicles at present, the surroundings of air-cooled engines are more thermally than the surroundings of water-cooled engines that are normally installed in four-wheeled vehicles. In this case, it is difficult to apply an inlet pipe made of a conventional resin.

  The present invention has been made in view of the above-described circumstances, and provides an inlet pipe having sufficient heat resistance that can be directly connected to the throttle body and the engine while suppressing the influence of heat on the throttle body. It is an object.

In order to solve the above-mentioned problems, the present invention provides an inlet pipe that is connected between an air cleaner provided in a vehicle via a connecting tube and an engine of the vehicle to form an intake passage. The inlet pipe is formed of a resin made of polyphenylene sulfide.
According to the present invention, since the inlet pipe is formed of a resin made of polyphenylene sulfide, the inlet pipe can be directly connected to the throttle body and the engine while suppressing the thermal influence on the throttle body, and has sufficient heat resistance. Can be a pipe. In addition, the inlet pipe can be recycled.
Moreover, the said structure WHEREIN: You may make it the said inlet pipe form with resin which consists of polyphenylene sulfide containing an elastomer. According to this configuration, since the elastomer is included, it is possible to improve the fatigue strength and weld strength against the heat effect of the inlet pipe, and to make the inlet pipe more excellent in heat resistance.

In the above configuration, the inlet pipe is provided between the engine and the throttle body, and the inlet pipe supports the throttle body, and a pair of radially extending pipes is provided at one end of the inlet pipe. Flange is provided, and the engine may be connected via the flange. According to this configuration, the inlet pipe is required to have a strength against heat influence on the flange that is a connection portion with the engine. However, since the inlet pipe is formed of a resin made of polyphenylene sulfide, the required strength is required. Can be secured.
In the above configuration, a pair of flanges extending in the radial direction may be provided at the other end of the inlet pipe, and the throttle body may be supported via these flanges. According to this structure, even if the structure is connected to the engine via the flanges provided at both ends of the inlet pipe and supports the throttle body, the influence of the engine on the throttle body can be avoided and sufficient strength can be obtained. It can be secured.

In the above configuration, a collar may be inserted into the flange, and a bolt may be inserted through the collar. According to this configuration, the flange can be bolted to the engine or the throttle body with a configuration in which the bolt is inserted into the flange via the collar.
In the above configuration, in the step of resin molding the inlet pipe, the collar may be set in a mold, and the molten resin material may be poured into the mold from the gate and the collar inserted. According to this configuration, the collar can be easily inserted into the flange of the inlet pipe.
Further, in the above configuration, the inlet pipe is provided with an insertion port through which the injector is inserted, and includes a support portion that extends in a radial direction from the insertion port and supports a cover member that covers the injector. Also good. According to this configuration, it is possible to make it easy to attach other components (injector, cover member) with bolts or the like while using the resin inlet pipe.

In the present invention, since the inlet pipe is formed of a resin made of polyphenylene sulfide, the inlet pipe can be directly connected to the throttle body and the engine while suppressing the thermal influence on the throttle body, and has sufficient heat resistance. can do.
Moreover, since the inlet pipe is formed of a resin made of polyphenylene sulfide containing an elastomer, the inlet pipe can be made more excellent in heat resistance.
Also, the other end of the inlet pipe is provided with a pair of flanges extending in the radial direction, and the throttle body is supported via these flanges, so that the thermal influence of the engine on the throttle body is reduced. It can be avoided and sufficient thermal fatigue strength can be secured.
In addition, since the collar is inserted into the flange, and the bolt is inserted through the collar, the flange can be bolted to the engine or the throttle body with a configuration in which the bolt is inserted into the flange through the collar.
Further, at the stage of resin molding the inlet pipe, the collar is set in the mold, and the molten resin material is poured into the mold from the gate to insert the collar, so that the collar can be easily inserted. .
Further, the inlet pipe is provided with an insertion port through which the injector is inserted, and is provided with a support portion that extends in a radial direction from the insertion port and supports a cover member that covers the injector. While using a pipe, it is possible to make a structure in which other parts (injector, cover member) can be easily attached with a bolt or the like.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, directions such as front and rear, right and left, and up and down are directions seen from the occupant. In the figure, arrow F indicates the front of the vehicle body, arrow L indicates the left side of the vehicle, and arrow U indicates the upper side of the vehicle. .
FIG. 1 is a side view of a motorcycle according to an embodiment of the present invention.
A body frame 2 of the motorcycle 1 includes a head pipe 3 at the front of the vehicle body, a main frame 4 that extends rearward and downward from the head pipe 3, and a rear portion of the main frame 4 that extends downward. Between a pair of left and right pivot brackets 5 and 5 that protrudes, a pair of left and right rear frames 6 and 6 that are connected to the rear portion of the main frame 4 and extend rearward, and between the pivot brackets 5 and 5 and the rear frames 6 and 6 And a pair of left and right reinforcing frames 7 and 7 which are cross-linked to each other.
An occupant seat 8 is supported above the pair of left and right rear frames 6 and 6 so that the front end side can be opened and closed freely. A storage box 9 that opens upward is supported at the front of the rear frames 6 and 6, and a fuel tank 10 is supported at the rear of the rear frames 6 and 6. In other words, the occupant seat 8 is configured to also serve as a lid that covers the upper opening of the storage box 9 and the fuel filler opening provided above the fuel tank 10 so as to be exposed to the outside.

A handle 30 pivotally supported by the head pipe 3 is provided above the front part of the vehicle body, and front forks 11 and 11 extend below the handle 30 and a front wheel 12 is pivotally supported at the lower end thereof. A rear fork 14 is pivotally supported by pivot brackets 5 and 5 at the center of the vehicle body via a pivot shaft 13 so that the front end of the rear fork 14 can swing, and a rear wheel 15 is provided at the rear end of the rear fork 14. Is supported. A pair of left and right rear cushions 16 and 16 are interposed between the rear portion of the rear fork 14 and the rear frames 6 and 6.
An engine (also referred to as a power unit) 20 is suspended below the main frame 4 and in front of the pivot brackets 5 and 5. The upper part of the engine 20 is suspended by support brackets 17 and 17 suspended from the center of the main frame 4, and the rear part of the engine 20 is fixed to the upper and lower parts of the pivot bracket 5. That is, the engine 20 is supported at three points in such a manner that the engine 20 is suspended below the rear part of the main frame 4.

The body frame 2 is covered with a synthetic resin body cover 18 that is divided into various parts. The vehicle body cover 18 includes a pair of left and right main frame side covers 18A that covers both sides of the main frame 4, and a pair of left and right main frames that are fastened to the front portions of the main frame side covers 18A so as to cover the legs of the occupant from the front. The front shield 18B, the front top cover 18C connected to both leg shields 18B so as to cover the head pipe 3 from the front side, and the front top so as to cover the head pipe 3 from the rear side and the main frame 4 from the upper side. An upper cover 18D that is continuous with the cover 18C, an under cover 18E that is continuous with the lower portions of the main frame side covers 18A, and a pair of left and right rear side covers 18F that covers the rear portion of the vehicle body frame 2 together with the fuel tank 10 from both sides.
In FIG. 1, reference numeral 19A denotes a front fender that is attached between the front forks 11 and 11 and covers the upper side of the front wheel 12, and reference numeral 19B is attached to the rear frames 6 and 6 and extends above the rear wheel 15. It is a rear fender that covers it.

The engine 20 is a single-cylinder four-cycle air-cooled engine, and is a horizontal engine in which the cylinder portion 22 is largely tilted forward from the front surface of the crankcase 24 to a substantially horizontal state. As a result, the center of gravity of the vehicle body can be lowered, and as shown in the figure, the main frame 4 can be lowered to lower the straddling portion M on which the driver straddles when getting on, thereby improving boarding / exiting performance. The cylinder part 22 and the crankcase 24 of the engine 20 are formed by casting a metal material.
An output shaft 31 of the engine 20 is pivotally supported at the rear left side of the crankcase 24 of the engine 20 with its tip exposed, and a drive sprocket 32 is attached to the tip of the output shaft 31. A power transmission chain 34 is wound between the drive sprocket 32 and a driven sprocket 33 provided integrally with the rear wheel 15, whereby a power transmission chain 31 transmits the power of the output shaft 31 to the rear wheel 15. Is configured. Thereby, the power of the engine 20 is transmitted to the rear wheel 15 through this chain transmission mechanism.

As shown in FIG. 1, the vehicle body cover 18 has a cover shape that covers the vehicle body to the vicinity of the outer edge of the crankcase 24 in a side view of the vehicle body, so that the side surface and the lower surface of the crankcase 24 are exposed to the outside. ing.
The crankcase 24 exposed to the outside is provided with a pair of left and right steps 36 </ b> A and 36 </ b> A on which a driver puts his / her feet through a step bar 36 straddling the case 24 from below.
Further, a kick arm 39 that constitutes a part of a kick type starter that starts the engine 20 is pivotally supported on the left side of the crankcase 24, and a driver is provided rotatably at the tip of the kick arm 39. The engine 20 is started by depressing the kick pedal 40. In addition, a starter motor 41 is disposed at the front upper portion of the crankcase 24, and the starter motor 41 is rotationally driven by a driver operating a starter switch (not shown) to start the engine 20. That is, the motorcycle 1 includes a kick type and starter motor type starter, and is configured so that the driver can appropriately select the starter and start the engine 20.

FIG. 2 is a view showing the cylinder portion 22 of the engine 20 together with the peripheral configuration. As shown in FIG. 2, the cylinder portion 22 includes a cylinder block 25 coupled to the front surface of the crankcase 24 and a cylinder head 26 coupled to the front surface of the cylinder block 25. An exhaust port 22A is provided on the lower surface of the cylinder head 26).
An exhaust pipe 42 is connected to the exhaust port 22A. The exhaust pipe 42 extends downward, then bends and extends substantially horizontally rearward, and passes between the rear of the crankcase 24 and the rear wheel 15. It is connected to a muffler 43 (see FIG. 1) arranged on the right side of the rear wheel 15. That is, the exhaust pipe 42 constituting the exhaust system parts of the engine 20 is disposed on the lower side of the engine 20 and extends rearward, and does not protrude to the side of the engine 20.

As shown in FIG. 2, an intake port 22B is provided on the upper surface of the cylinder portion 22 (corresponding to the upper surface of the cylinder head 26), and the exhaust system of the engine 20 connected to the intake port 22B is a cylinder of the engine 20. It is laid out in a space between the portion 22 and the main frame 4 and inside the vehicle body cover 18 (particularly, the main frame side cover 18A (see FIG. 1)).
Specifically, the intake system of the engine 20 is connected to an intake port 22 </ b> B on the upper surface of the cylinder portion 22 of the engine 20, and is connected to the inlet pipe 51. A throttle body 53 and an air cleaner 57 which is connected to the throttle body 53 via a connecting tube 55 and whose upper end 57A is supported on the main frame 4 by bolts (hexagon flange bolts) 58. By laying out in sequence along the frame 4 in an upward order, the layout is made in the space.

  An injector (fuel injection valve) 60 that injects fuel in the fuel tank 10 is attached to the inlet pipe 51. That is, as shown in FIG. 1, the air purified by the air cleaner 57 is supplied to the inlet pipe 51 through an intake passage provided with a throttle valve (valve) (not shown) in the throttle body 53, and this inlet pipe 51 The fuel is supplied to the cylinder chamber formed in the cylinder portion 22 through the engine 51 and injected into the cylinder chamber in the engine 20 by the injector 60. In this case, the opening degree of the throttle valve is set according to the driver's throttle operation, and the fuel injection amount (actually the injection time) and the injection timing of the injector 60 are not shown in the figure. (ECU), and thereby the operating state of the engine 20 is controlled.

3 is a perspective view showing the inlet pipe 51 together with the throttle body 53, FIG. 4 is a view seen from the rear of the vehicle body, and FIG. 5 is a side view seen from the right side of the vehicle body. Note that the directions F, L, and U shown in the above-described drawings and the drawings that will be described later slightly vary depending on the expansion and contraction of the rear cushions 16 and 16.
The throttle body 53 includes a substantially tubular body main body 53C having a tube connecting portion 53A to which a connecting tube 55 is connected at one end and an inlet pipe connecting portion 53B to which the inlet pipe 51 is connected to the other end. A butterfly throttle valve (not shown) for adjusting the amount of intake air is rotatably provided in the intake passage in the body main body 53C. A valve shaft 53D (see FIG. 3) of the throttle valve is provided on the vehicle body 53C. Extending in the width direction and passing through the body main body 53C, a throttle drum 53E is fixed to the valve shaft 53D from the outside.
The throttle drum 53E is arranged on the left side of the body main body 53C in a state of being incorporated in the motorcycle 1, and a return spring for biasing the throttle valve toward the closing side is provided between the throttle drum 53E and the body main body 53C. The throttle valve is rotated and driven to the open side by pulling the throttle cable that is wound around the throttle drum 53E and connected in accordance with the throttle operation of the driver.

On the opposite side of the throttle drum 53E in the throttle body 53, that is, on the right side of the body main body 53C, a connector 53X for throttle opening output (valve opening output) is a bolt (hexagonal flange bolt). It is attached with 53Y. The connector portion 53X is electrically connected to a throttle sensor (not shown) provided in the body main body 53C, and a signal indicating the throttle opening (valve opening) detected by the throttle sensor is It functions as a wiring connection portion that outputs to the control unit via a wiring (harness) (not shown) connected to the connector portion 53X.
As shown in FIG. 5, the connector portion 53X extends rearward and downward substantially along the inlet pipe 51 from the throttle body 53 in a side view, and the extension end is opened. The portion 53X overlaps with the inlet pipe 51 and the throttle body 53 in a side view, so that the overall size can be reduced.
In addition to the throttle sensor described above, the throttle body 53 may include an intake air temperature sensor that detects the intake air temperature upstream of the throttle valve, an intake air pressure sensor that detects the intake air pressure, and the like. In this case, the connector part 53X is used as a common connector part connected to these sensors by changing to a connector having a large number of internal terminals.

Next, the inlet pipe 51 will be described.
6A is a left side view of the inlet pipe 51, FIG. 6B is a view seen from the back, and FIG. 7 is a view seen from the VII direction of FIG. 6A. . 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6B, FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 7, and FIG. 10 is viewed from the X direction in FIG. FIG. 11 is a bottom view, and FIG. 11 is a view seen from the XI direction of FIG.
The inlet pipe 51 forms an intake passage 51 </ b> A (see FIG. 8) and includes a bent pipe portion 61 having an opening 51 </ b> B (see FIG. 8) serving as an insertion port for the injector 60, and an upstream end portion of the bent pipe portion 61. A first flange portion (throttle body connecting portion) 62 provided to the throttle body 53 and a second flange portion provided at the downstream end of the bent pipe portion 61 and connected to the cylinder portion 22 of the engine 20. A flange portion (engine connection portion) 63 and an injector support portion 64 provided in the vicinity of the second flange portion 63 are provided.
The inlet pipe 51 of the present embodiment is formed of resin, that is, the bent pipe portion 61, the first flange portion 62, the second flange portion 63, and the injector support portion 64 are integrally formed of resin. Is formed into one part.

As shown in FIGS. 6 (A) and 6 (B), the bent pipe portion 61 has a tube shape that has a constant inner diameter and bends along a substantially arc, and is upstream of the injector support portion 64. Is formed with a substantially constant outer diameter, and a downstream pipe portion 61B including the injector support portion 64 is formed in a diameter-expanded portion that is larger than the outer diameter of the upstream pipe portion 61A.
More specifically, as shown in FIG. 6A, the bent pipe portion 61 is orthogonal to an axis (center line) L1 passing through the center of the intake passage 51A (see FIG. 8) of the bent pipe portion 61. The orthogonal surface M1 is set on the upstream side of the injector support portion 64, the upstream side is formed into a relatively thin-walled tube shape on the basis of the orthogonal surface M1, and the downstream side is formed into a tube shape that is thicker than the upstream side. It is formed by doing.
Thus, since the inlet pipe 51 is divided into the upstream side and the downstream side based on the axis L1 of the intake passage 51A, the upstream side and the downstream side of the intake passage 51A can be accurately divided into two. Here, since the upstream side of the intake passage 51A is a relatively thin diameter-reduced portion and the downstream side is a relatively thick-thickened diameter portion, the downstream flange is relatively strong, so the second flange The rigidity around the part 63 and around the injector support part 64 is improved, that is, the rigidity of the engine connection part and the injector support part can be increased.

As shown in FIGS. 6B and 11, the first flange portion 62 includes a pair of left and right extending portions (flange) 62 </ b> A extending in the left-right direction with respect to the upstream opening 51 </ b> A <b> 1 of the bent tube portion 61. 62A, and metal insert nuts 62B and 62B are fitted into the ends of the extending portions 62A and 62A. The first flange portion 62 is overlapped with the inlet pipe connection portion 53B of the throttle body 53. In this state, as shown in FIG. 5, a plurality of (two in this example) bolts (hexagons) from the throttle body 53 side. Flange bolts) 91 and 91 are inserted, and the bolts 91 and 91 are respectively fastened to the insert nuts 62B and 62B of the extending portions 62A and 62A, whereby the inlet pipe 51 and the throttle body 53 are connected by the bolt 91 and the nut 62B. Connected.
In this way, since the metal insert nuts 62B and 62B are used for bolt connection, the resin inlet pipe 51 can be fixed to the throttle body 53 with a sufficient connection force. In this case, since the inlet pipe 51 and the throttle body 53 are positioned by the bolts 91, 91, the intake passage 51A of the bent pipe portion 61 and the intake passage of the throttle body 53 can be easily communicated.

Further, one (left side) of the pair of left and right extending parts 62A and 62A is provided above the bent pipe part 61, and the other (right side) is provided below the bent pipe part 61 ( (See FIG. 4). As a result, a wide space can be secured between one (left side) extending portion 62 </ b> A and the lower side of the bent pipe portion 61, and this space projects sideways from the main body portion 60 </ b> A of the injector 60. It can be used for the layout space of the connector 60B (see FIG. 3).
Further, since the other extension portion 62A is provided below the bent tube portion 61, the other extension portion 62A is provided on the side (right side) of the throttle body 53 as shown in FIG. The connector portion 53X can be positioned below the connector portion 53X. For this reason, the bolt 91 can be visually recognized from the side, and the inlet pipe 51 can be bolted to the throttle body 53 without being obstructed by the connector portion 53X, and can be easily removed.
Further, a reinforcing rib 67 is integrally provided between the pair of left and right extending portions 62A and 62A and the bent tube portion 61 (see FIG. 6B). For this reason, the rib 67 improves the rigidity between the extending portions 62A and 62A and the bent tube portion 61, and the falling and twisting of the extended portions 62A and 62A with respect to the bent tube portion 61 can be avoided. Here, in the present embodiment, the rib 67 is provided so as to be orthogonal to the vertical direction and the horizontal direction, thereby improving both the longitudinal rigidity and the lateral rigidity of the extending parts 62A, 62A and the bent pipe part 61. be able to.

As shown in FIG. 10, the second flange portion 63 has a pair of left and right extending portions (flanges) 63A, 63A extending in the left-right direction with respect to the downstream side opening 51A2 of the bent pipe portion 61. Holes (fastening openings) 63B and 63B are formed at the ends of the extending parts 63A and 63A, and bolts (hexagon flange bolts) 92 and 92 (see FIG. 4) are respectively attached to the holes 63B and 63B from the outside. The inlet pipe 51 is connected to the engine 20 by being inserted and fastened to the engine 20.
More specifically, the pair of left and right extending portions 63A and 63A extend to the left and right along the vehicle width direction with respect to the downstream opening 51A2, and the ends of the extending portions 63A and 63A have a metal The insert collars 63C and 63C made of the insert collar 63C and 63C are used as the holes 63B and 63B through which the bolts 92 and 92 are inserted. Since the metal insert collars 63 </ b> C and 63 </ b> C are bolted in this way, the resin inlet pipe 51 can be fixed to the engine 20 with a sufficient coupling force.
Further, the second flange portion 63 is provided with an annular seal groove 63D around the downstream opening 51A2 (see FIG. 10), and the second flange portion 63 and the engine 20 are provided in the seal groove 63D. A sealing material for more reliably closing the gap between the two is disposed.

  As described above, in this configuration, the first flange portion 62 that is the throttle body connecting portion and the second flange portion 63 that is the engine connecting portion are each a pair of extending portions (flanges) 62A, 62A, 63A, 63A. These are respectively fastened to the throttle body 53 and the engine 20 by bolts 91, 91, 92, 92. In this case, the straight line LL passing between the fastening portions provided in the pair of extending portions 62A and 62A is inclined by a predetermined angle with respect to the straight line LM passing between the fastening portions provided in the pair of extending portions 63A and 63A. In the side view, as shown in FIG. 6A, the straight line LL is inclined at an angle θ1 (approximately 45 degrees). Accordingly, the fastening portions can be arranged apart from each other so that the bolts 91, 91, 92, 92 can be easily inserted, and can be easily attached to the throttle body 53 and the engine 20. In this configuration, the straight line LM passes through the axis L1 of the inlet pipe 51 (see FIG. 10), but it may be formed so as not to pass through the axis L1. Although not passing (refer FIG. 11), you may form so that it may pass along the axis line L1.

An opening portion (injector insertion port) 51B through which the injector 60 is inserted is formed in the pipe portion 61B on the downstream side of the bent tube portion 61, that is, the enlarged diameter portion (see FIGS. 7 and 8). More specifically, as shown in FIG. 8, a direction in which the bent pipe portion 61 is bent toward the upstream side (a direction along the axis L <b> 1) between the downstream pipe portion 61 </ b> B and the second flange portion 63. Is integrally provided with a projecting portion 71 projecting in the opposite direction, that is, in the rearward upward direction, and a through-hole is formed through the projecting portion 71 in a straight line and serving as the opening 51B.
The opening 51B is an axis L2 having an inclination angle intersecting with the axis L1 of the bending pipe portion 61 on the downstream side of the second flange portion 63 in a side view of the vehicle body (see FIG. 8), and is a rear view of the vehicle body. (Refer to FIG. 6B), it is formed in a through hole that becomes an axis L2 that overlaps the axis L1.
For this reason, fuel is injected from the injector 60 along the axis L2 by inserting the injector 60 into the opening 51B from its tip, and the fuel can be injected into the cylinder head 26 of the engine 20.
Since the axis L2 of the opening 51B coincides with the axis of the injector 60 inserted through the opening 51B, hereinafter, the axis of the injector 60 is also referred to as the axis L2.

In the present embodiment, the injector 60 is fitted into the opening 51B via a seal member (not shown) such as an O-ring, and the injector support 64 that supports the injector 60 is provided in the injector 60 through the opening 51B. A first extending portion 64A that extends to the right of the vehicle body in the radial direction with respect to the axis L2 is provided (see FIG. 7). Then, as shown in FIG. 4, a cover member 80 that covers the injector 60 from above is fixed to the first extending portion 64 </ b> A with a bolt (hexagon flange bolt) 94 and a nut 96, whereby the injector 60 is It is supported by the inlet pipe 51.
More specifically, the first extending portion 64A is a resin member formed integrally with the inlet pipe 51. As shown in FIGS. 7 and 9, the first extending portion 64A is a hole (fastened) through which the bolt 94 is passed. Opening) 64A1 is formed. Further, since the first extending portion 64A extends to the right of the vehicle body from the protruding end of the protruding portion 71 protruding from the second flange portion 63, the space H1 between the first extending portion 64A and the second flange portion 63 (see FIG. 9). ) Is provided. This interval H1, that is, the interval H1 between the lower surface 64A2 of the first extending portion 64A and the upper surface 63A1 of the second flange portion 63 can secure a sufficient mounting space for the nut 96 (see FIGS. 4 and 5). It is assumed that it is an interval. In this configuration, the first extending portion 64A is integrally provided via the step 64A3 (see FIG. 9) so as to be one step higher than the upper surface of the protruding end of the protruding portion 71. Therefore, the lower surface 64A2 of the first extending portion 64A is raised to widen the interval H1.

Further, as shown in FIG. 7, the injector support portion 64 has a second extension that extends in the rear direction, which is a radial direction different from the first extension portion 64 </ b> A, with respect to the axis L <b> 2 of the injector 60 from the opening 51 </ b> B. A protruding portion 64B is provided. The second extending portion 64B functions as a positioning member for positioning the cover member 80, and the second extending portion 64B is also a resin member formed integrally with the inlet pipe 51. FIG. And as shown in FIG. 8, it extends from the protrusion end of the protrusion part 71 to vehicle body back.
The second extending portion 64B has a recessed portion 64B1 that is recessed in a direction that coincides with the direction (right direction) in which the first extending portion 64A extends. As shown in FIG. The cover member 80 is positioned by fitting a protrusion 81 provided on the member 80.
Similarly to the first extending portion 64A, the second extending portion 64B has a step 64B2 (see FIG. 8) so as to be one step higher than the upper surface of the protruding end of the protruding portion 71 on the downstream side of the bent pipe portion 61. The second extending portion 64B and the first extending portion 64A are formed to be flush with each other. Further, as shown in FIG. 7, a reinforcing rib 64C is provided between the second extending portion 64B and the first extending portion 64A, whereby the second extending portion 64B and the first extending portion are provided. The rigidity of the portion 64A is improved efficiently.

The first extending portion 64A and the second extending portion 64B also function as a receiving portion for the cover member 80. That is, as shown in FIGS. 4 and 5, the cover member 80 has a flange portion 82 that substantially conforms to the outer shapes of the first extension portion 64 </ b> A and the second extension portion 64 </ b> B. Is superposed on the first extending portion 64A and the second extending portion 64B, a bolt 94 is inserted from the flange portion 82 side, and the tip of the bolt 94 is exposed below the first extending portion 64A. The cover member 80 can be bolted to the inlet pipe 51 by fastening the nut 96 to the tip of the bolt 94.
In this case, in this embodiment, the first extending portion 64A and the second extending portion 64B constituting the injector support portion 64 are formed on one side (substantially right side) with respect to the axis L2 of the injector 60, and vice versa. Since it is not formed on the side (substantially left side), the injector 60 can be viewed from the opposite side, and a space can be provided on the opposite side of the injector 60. For this reason, as shown in FIG. 4, this space can be utilized for the layout space of the connector part 60B which protrudes from the main-body part 60A of the injector 60 to the side.

As shown in FIG. 4, the cover member 80 described above extends from the cap portion 84 that covers the base end portion located above the main body portion 60 </ b> A of the injector 60 inserted through the inlet pipe 51 from above, and the cap portion 84. And a fuel hose connecting pipe portion 86. When the cover member 80 is bolted to the injector support portion 64, the cap portion 84 holds the injector 60 in the state where the injector 60 is inserted into the inlet pipe 51 while pressing the injector 60 toward the second flange portion 63.
In this embodiment, the cover member 80 is also formed by integrally molding with resin. Here, the cap portion 84 has a base end portion of the injector 60 fitted in an airtight state via a sealing member such as an O-ring, and fuel is supplied via a fuel hose (not shown) connected to the fuel hose connection pipe portion 86. This is a component for supplying the fuel supplied from the tank 10 to the injector 60. Further, since the fuel hose connection pipe portion 86 extends from the cap portion 84 to the rear of the vehicle body, the fuel hose between the fuel tank 10 and the fuel hose connection pipe portion 86 disposed at the rear of the vehicle body is laid out without being greatly bent. Can do.
A reinforcing rib 88 is provided between the cap portion 84 and the flange portion 82 at intervals in the circumferential direction to enhance the connection strength between the cap portion 84 and the flange portion 82.

  Further, as described above, as shown in FIG. 3, the cover member 80 is fitted into the concave portion 64 </ b> B <b> 1 of the second extending portion 64 </ b> B that constitutes a part of the injector support portion 64 to form the positioning portion of the cover member 80. A protrusion 81 is provided, and the protrusion 81 protrudes downward from the end of the flange portion 82 so that the fitting state between the protrusion 81 and the recess 64B1 can be seen from the left side of the vehicle body. For this reason, when attaching the cover member 80, the operator can easily fit the protrusion 81 and the recess 64B1 visually, and the attachment work of the cover member 80 can be facilitated.

Next, the attachment structure of the cover member 80 and the injector support part 64 will be described. Here, FIGS. 12 (A) to 12 (C) are diagrams for explaining the mounting structure. The cover member 80 and the injector support portion 64 are connected to the bolts 94 from the projecting portion 81 and the recessed portion 64B1. It is the figure which showed typically the cross section cut | disconnected so that the part to let it pass may be crossed.
As shown in FIG. 12A, the cover member 80 includes a hole (fastening opening) 80A communicating with the hole 64A1 of the injector support 64. A cylindrical collar 101 having a through hole into which the bolt 94 can be inserted is press-fitted into the hole 80A, and the collar 101 is held by the cover member 80 in a state where the upper end of the collar 101 slightly protrudes from the upper surface of the cover member 80.
The collar 101 has a cylindrical shape that is longer than the depth of the hole 80A (the thickness of the cover member 80), and the cover member 80 is superimposed on the injector support portion 64 as shown in FIG. Thus, it is inserted into the hole 64A1 of the injector support 64. In this case, the collar 101 passes through the hole 64A1 and, when the cover member 80 and the injector support 64 are in close contact, the lower end of the collar 101 protrudes downward from the lower surface of the injector support 64 (FIG. 12B). )reference).
The hole portion 64A1 of the injector support portion 64 is formed to have an inner diameter slightly larger than the outer diameter of the collar 101. That is, the collar 101 is loosely fitted in the hole portion 64A1 of the injector support portion 64.

As shown in FIG. 12 (B), the cover member 80 and the injector support portion 64 are stacked one above the other, and the bolt 94 is inserted into the collar 101 from above and the nut 96 is fastened. 101 is sandwiched so that the cover member 80 is not detached from the injector support portion 64.
In this case, since the collar 101 is loosely fitted to the injector support portion 64, the cover member 80 can be moved up and down via the collar 101. That is, the cover member 80 is integrated with the bolt 94, the nut 96, and the collar 101, and this integrated component can move up and down with respect to the injector support portion 64. Therefore, when a downward force (gravity direction) is applied during traveling, the cover member 80 comes into contact with the support surface 64X of the injector support portion 64 as shown in FIG. When an upward force is applied during traveling, the cover member 80 moves upward as shown in FIG. 12C, and a nut 96 that moves integrally with the cover member 80 is provided as an injector. It moves to a position where it comes into contact with the support portion 64. That is, the cover member 80 moves up and down by the distance (gap) S shown in FIGS.
Thus, by making the cover member 80 movable up and down, vibration transmitted from the outside can be released by the vertical movement of the cover member 80 and the like, and vibration transmission to the bolt 94 and the like can be suppressed.

FIG. 13 shows a state in which the cover member 80 and the injector 60 are assembled.
As shown in this figure, the main body 60A of the injector 60 is provided with a recess 60G that is recessed in the radial direction of the injector 60, and the cover member 80 is provided with an overhang 95 that enters the recess 60G. Thus, the cover member 80 and the injector 60 are configured to engage with each other.
More specifically, the hollow portion 60G of the injector 60 is a pair of left and right first wall portions formed by a step between the outer peripheral portion of the main body portion 60A in the circumferential direction of the injector 60 by being recessed in the radial direction of the injector 60. (Step part) It has 60G1 and 60G1, and it is a hollow shape opened in the extraction direction (upward direction) of the cover member 80, so that the outer peripheral part is on the opposite side (corresponding to the tip side of the injector 60). 2nd wall part (step part) 60G2 made by the level | step difference between them.

The overhanging portion 95 of the cover member 80 is formed integrally with the cover member 80 with resin, and when the cover member 80 is appropriately covered from above the injector 60, the overhanging portion 95 enters the recess portion 60G and enters the first wall. It is formed in a shape facing the parts 60G1, 60G1 and the second wall part 60G2. As a result, the projecting portion 95 of the cover member 80 and the recess portion 60G of the injector 60 are engaged in both the circumferential direction and the insertion direction of the injector 60, thereby restricting free rotation of the injector 60 with respect to the cover member 80 and the injector 60. The insertion depth can be regulated. That is, the mounting position of the injector 60 with respect to the cover member 80 can be positioned.
According to this, the position (rotational position and insertion position) of the injector 60 can be positioned by positioning the cover member 80 on the inlet pipe 51 via the injector support portion 64, and the injector 60 can be freely rotated and disconnected. Can be prevented.

In the intake structure of the engine 20 described above, the inlet pipe 51 is formed of resin, and the second flange portion 63 that is a connection portion with the engine 20 is provided with a pair of extending portions (flange extending in the radial direction of the inlet pipe 51. ) 63A, 63A, and the injector support portion 64 that supports the cover member 80 that covers the injector 60 from above is the first extension portion 64A that extends to the right of the vehicle body in the radial direction with respect to the axis L2 of the injector 60. The first extending portion 64A is provided with an opening through which the bolt 94 is passed, and the cover member 80 is supported by the bolt 94 passed through the opening and the nut 96 fastened to the bolt 94. 51 can be easily attached to the engine 20 and the cover member 80, and the injector support portion can be As compared with the case where than data insertion opening provided on the upstream side, the pipe length of the inlet pipe can be shortened, it is possible to support the injector 60 in a space-saving.
Further, in this configuration, since the cover member 80 and the injector 60 are supported by the fastening force of the bolt 94 without forming the female thread portion in the resin inlet pipe 51, the mounting position of the injector 60 is not limited, and the engine 20 It is possible to dispose fuel at an optimal position in the engine 20 at a position where fuel can be injected, and fuel injection can be efficiently performed. In addition, since the resin inlet pipe 51 has lower thermal conductivity than the case where it is made of metal, the heat of the engine 20 is prevented from being transmitted to the throttle body 53 between the inlet pipe 51 and the throttle body 53. There is no need to provide separate parts, and the number of parts is reduced.

  Therefore, in this configuration, other parts (the engine 20, the cover member 80, etc.) can be easily attached while using the resin inlet pipe 51, and the overall size can be reduced. Further, the heat effect on the throttle body 53 can be reduced while suppressing the number of parts, and the resin is lighter than metal, so that the weight of the intake system can be reduced. Furthermore, since the configuration around the injector 60 is closer to the engine 20, the center of gravity of the intake system is closer to the engine 20, contributing to the concentration of the mass of the vehicle.

In this configuration, the injector support portion 64 extends in the same direction (to the right of the vehicle body) as one of the pair of extension portions (flanges) 63A, 63A, so that the injector support portion 64 and the extension portion can be saved in a space-saving manner. 63A and 63A can be arranged.
The inlet pipe 51 includes an enlarged diameter portion (corresponding to the downstream pipe portion 61B) that expands between the injector support portion 64 and the second flange portion 63 that constitutes the engine connection portion. Since the first extending portion 64A is extended from the opening 51B (see FIGS. 6B and 7), the rigidity of the engine connection portion and the injector support portion is increased. Can be high.
Further, in this configuration, the injector 60 is inserted into an opening 51B (insertion opening) provided in the inlet pipe 51, and a cover member 80 is provided to cover the injector 60 from above, and the cover member 80 is provided with an injector support portion 64. The first extending portion 64A extending in the radial direction overlaps with the first extending portion 64A, and the overlapping portion includes a hole portion (fastening opening) 80A communicating with the hole portion 64A1 provided in the injector support portion 64, and communicates with each other. A single bolt 94 is inserted into the holes 64A1 and 80A, the cover member 80 is attached to the injector support 64 by the bolt 94 and a nut 96 fastened to the bolt 94, and the injector 60 is connected to the cover member 80 and the inlet pipe 51. Therefore, the bolt 94 and the nut that connect the cover member 80 and the injector support portion 64 are connected. 96 can support the injectors 60 by use of, it is possible to mount the injector 60 to ensure that the inlet pipe 51 with a simple configuration.

Furthermore, since the cover member 80 is provided with a protruding portion 81 that forms a positioning portion, and the injector support portion 64 is provided with a recess 64B1 that receives the protrusion 81 (see FIG. 3), the cover member 80 and the injector support portion are provided. 64 can be positioned and attached. According to this, since the cover member 80 is positioned on the injector support portion 64 by the positioning portion, the bolt member can be compared with the structure in which the cover member 80 and the injector support portion 64 are positioned by multi-point support using a plurality of bolts. The number can be reduced, and the cover member 80 can be attached with a single bolt 94. That is, when the single bolt 94 is removed, the cover member 80 and the injector 60 are removed. Therefore, the attaching / detaching operation of the cover member 80 and the injector 60 is easy, and the operation time can be shortened.
The main body portion 60A of the injector 60 is provided with a dent portion 60G that is recessed in the radial direction, and the cover member 80 is provided with an overhang portion 95 that enters the indentation portion 60G. The overhang portion 95 of the cover member 80 is The injector 60 is disposed so as to face the first wall portion (step portion) 60G1 and the second wall portion 60G2 which are step portions formed between the hollow portion 60G and the outer peripheral portion of the injector 60 (see FIG. 13). Can be easily positioned.

In this configuration, the throttle opening output connector 53 </ b> X provided on the throttle body 53 is located between the throttle body 53 and the downstream pipe 61 </ b> B, which is the enlarged diameter portion of the inlet pipe 51, in side view. (Refer to FIG. 5).
For this reason, the portion between the downstream pipe portion 61B and the throttle body 53 corresponds to a portion where the upstream pipe portion 61A is narrower than the downstream pipe portion 61B, and therefore the upstream pipe portion 61A. Because of the thinness, it is easy to secure a layout space around it.
In this configuration, since the connector portion 53X is arranged in this layout space, a space can be secured around the connector portion 53X, and supplementary items such as wiring components connected to the connector portion 53X from the vehicle side can be easily arranged. .

  Further, in this configuration, as shown in FIG. 7, the axis L3 of the bolt 94 inserted through the hole 64A1 provided in the injector support portion 64 and the axis L2 of the injector 60 are parallel to each other. The insertion direction of the injector 60 can be made to coincide with each other so that the assembling directions can be made uniform, and the attaching / detaching work can be facilitated. In this configuration, as shown in FIGS. 6A and 8, the axes L2 and L3 overlap in the side view of the vehicle body, but may not overlap in the side view of the vehicle body.

Furthermore, in this structure, the connection part with the engine 20 of the inlet pipe 51 is a pair of extension part (flange) 63A, 63A extended in radial direction from the axis line L1 of the inlet pipe 51, and one extension part 63A and the other extending portion 63A extend in different directions, and the extending portions 63A and 63A are provided with holes (fastening openings) 63B and 63B. As shown in FIG. The support surface (injector support surface) 64X of the injector support portion 64 to be supported is a surface inclined downward by a predetermined angle θA with respect to the engine connection surface 63X of the pair of extension portions 63A and 63A. The mounting direction (fastening direction) of the injector 60 and the mounting direction (fastening direction) to the engine 20 can be made different from each other. In this case, as shown in FIG. 6B, the injector support surface 64X and the engine connection surface 63X of the inlet pipe 51 extend in the same direction (right direction) when viewed from the rear of the vehicle body (the same applies to the front view). The attachment part (fastening part) of the injector 60 and the attachment part (fastening part) to the engine 20 are arranged close to each other.
Accordingly, the mounting portion (fastening portion) of the injector 60 and the mounting portion (fastening portion) to the engine 20 are arranged close to each other, and the mounting direction (tightening direction) is changed to save space and mounting workability. It can be compatible.

Further, in this configuration, the injector support surface 64X of the injector support portion 64 is a surface inclined by a predetermined angle θB with respect to the connection surface (throttle body connection surface) 62X to the throttle body 53 as shown in FIG. Therefore, it is possible to secure the space of the cover member 80 connected to the injector support portion 64 and facilitate the attachment work (fastening work).
Further, as shown in FIG. 8, the throttle body connecting surface 62X is a surface inclined upward by a predetermined angle θC with respect to the engine connecting surface 63X, so that the mounting direction to the throttle body 53 (fastening direction). And the mounting direction (fastening direction) to the engine 20 can be made different from each other, and the mounting direction (fastening direction) of the injector 60 can be made different.
In other words, in this configuration, the mounting direction (fastening portion) to the throttle body 53, the mounting portion (fastening portion) of the injector 60, and the mounting portion (fastening portion) to the engine 20 are arranged close to each other, and the mounting direction ( The tightening direction) can be varied forward and backward, and both space saving and mounting workability can be achieved.

Next, the resin material constituting the inlet pipe 51 will be described.
In this configuration, the resin material constituting the inlet pipe 51 is polyphenylene sulfide (PPS resin) containing an elastomer. In addition, this PPS resin may be called polyphenylene sulfide.
PPS resin has a heat distortion temperature of 260 ° C. or higher, has a high continuous use temperature, and has higher heat resistance than general resins (for example, polyamide (nylon) or polypropylene) used for automobile parts. ing.
In this embodiment, the engine 20 is an air-cooled engine, and the engine case (cylinder portion 22 and the like) is hotter than the water-cooled engine. However, by using polyphenylene sulfide (PPS) resin, the inlet pipe 51 is directly connected. Can be connected to the engine 20. In addition, since this PPS resin is a thermoplastic crystalline plastic, it can be easily re-molded and recycled.

Further, since the PPS resin contains an elastomer, the inlet pipe 51 is given rubber properties (the property of returning to the original shape when the weight is removed after applying a certain load to the material and then deforming (rubber elasticity)). be able to.
As a result, the fatigue strength against vibration is improved, the thermal fatigue strength of the inlet pipe 51 is improved, and the strength of the weld portion (the portion generated when the melted materials collide with each other) is improved. it can.
Further, when the engine 20 and the throttle body 53 are bolted together, the inlet pipe 51 side is elastically deformed and comes into close contact with the engine 20 and the throttle body 53, so that it has a seal (or packing) property that closes the gap between these members. It can also be made.

  In particular, in this vehicle, the air cleaner 57 on one end side (upstream side) of the intake system of the engine 20 is supported by the front portion of the vehicle body frame 2 (main frame 4), and the other end side (downstream side) of the intake system is connected. The engine 20 is fixed to a position away from the front part of the vehicle body frame 2 (intermediate part, rear part of the main frame 4, and the pivot bracket 5), so that one end side (upstream side) and the other end side ( The throttle body 53, which is one part between them, is formed in a rigid body because it has a throttle valve (valve) inside, so that the inlet pipe 51 is required to have a certain degree of flexibility. It is the composition which becomes. Further, in general, the motorcycle 1 itself is more frequently driven in a place with more irregularities such as rough terrain than a four-wheeled vehicle, so that vibration resistance is required.

The inlet pipe 51 is resin-molded by pouring the molten resin material injected from a nozzle of an injection molding machine into a mold from a gate serving as an inlet and solidifying by cooling. Insert collars 63C and 63C and insert nuts 62B and 62B are inserted into the inlet pipe 51. These insert parts (63C and 62B) are molded with resin as shown in FIGS. 14 (A) to (C). At this stage, it is set in advance in a mold and inserted by pouring molten resin material into the mold from the gate. 14A to 14C, the flow of the resin material is indicated by a broken line, the gate is indicated by G, and the weld portion is indicated by W.
As for the position of the gate G, when it is provided in the bent pipe part 61 which is the pipe part of the inlet pipe 51 (see FIG. 14A), the flange part of the inlet pipe 51 (first flange part (throttle body connecting part) 62). Alternatively, it may be provided in the second flange part (engine connection part) 63) (see FIGS. 14B and 14C). Here, FIG. 14B shows a case where the gate G (side gate) is set on the side of the second flange portion (engine connection portion) 63 away from the insert collars 63C, 63C. ) Shows a case where a gate G (side gate) is set on the side portion in the vicinity of the insert collar 63C.
As shown in these drawings, in any case, the molten resin material poured from the gate G wraps around the insert collar 63C, so that a weld portion W is generated. For this reason, it is necessary to ensure the strength of the weld portion W.
Further, since the present inlet pipe 51 supports the throttle body 53 and the like, the hot fatigue strength at the connection portion with the engine 20 and the like is also required.

表１に示すように、フェノール樹脂とＰＰＳ樹脂とが、エンジン２０に接続した場合の引張強度の低下が２０％程度であり、十分な熱疲労強度を備えている、との良好な結果が得られた。また、フェノール樹脂とＰＰＳ樹脂とは、アルミニウム合金に比してコストが低いため、コスト低減に有利でもある。
これに対し、６６ナイロンは、エンジンに接続した場合の引張強度の低下が６０％程度であり、良好な熱疲労強度は得られなかった。 Next, the performance evaluation of the PPS resin will be described by comparison with other resins.
Samples to be compared are 66 nylon and phenol resin, which are known as resin materials having heat resistance. Moreover, each evaluation with respect to PPS resin, 66 nylon, and a phenol resin described below was performed in the state which mix | blended glass fiber 30% with respect to the total weight.
<Evaluation of thermal fatigue strength>
In this evaluation, in order to evaluate the thermal fatigue strength when connected to the engine 20, the test conditions are caused to undergo thermal degradation after passing 1000 h (hours) under an environment of 200 degrees Celsius, and the tensile strength after thermal degradation is determined. The percentage of decrease from the tensile strength before thermal degradation was determined.
Table 1 shows the tensile strength reduction rate for each sample.

As shown in Table 1, when the phenol resin and the PPS resin are connected to the engine 20, the decrease in the tensile strength is about 20%, and a good result is obtained that sufficient thermal fatigue strength is provided. It was. Moreover, since the cost of the phenol resin and the PPS resin is lower than that of the aluminum alloy, it is advantageous for cost reduction.
In contrast, 66 nylon had a decrease in tensile strength of about 60% when connected to the engine, and good thermal fatigue strength was not obtained.

表２に示すように、フェノール樹脂は、成形サイクルが長く、かつ、リサイクル性も難である。これはフェノール樹脂が熱硬化性樹脂であることに起因するものである。
これに対し、ＰＰＳ樹脂は、成形サイクルが短く、かつ、リサイクル性も容易である。つまり、ＰＰＳ樹脂は、成形サイクルおよびリサイクル性のいずれもフェノール樹脂に対して優位である。これはＰＰＳ樹脂が熱可塑性であるため、成形性に優れることに起因するものである。 <Difference from phenolic resin>
In order to compare and examine the difference between the phenol resin and the PPS resin, an evaluation of the time required for a molding cycle when manufacturing a molded product and an evaluation of recyclability were performed.

As shown in Table 2, the phenol resin has a long molding cycle and is difficult to recycle. This is because the phenol resin is a thermosetting resin.
On the other hand, PPS resin has a short molding cycle and is easy to recycle. That is, the PPS resin is superior to the phenol resin in both molding cycle and recyclability. This is because the PPS resin is thermoplastic and therefore has excellent moldability.

表３に示すように、ＰＰＳ樹脂は、エラストマーを入れた方が衝撃強度が高くなる結果が得られた。これはエラストマーが衝撃を吸収する作用を及ぼすためと考えられる。 <Evaluation of elastomer 1>
In this evaluation 1, an impact test with a Charpy notch was performed and the impact strength was determined for each case in order to compare and examine the case where the elastomer was added to the PPS resin and the case where the elastomer was not added.

As shown in Table 3, the result that the impact strength of the PPS resin was higher when the elastomer was added was obtained. This is presumably because the elastomer acts to absorb impact.

表４に示すように、ＰＰＳ樹脂は、エラストマーを入れた場合の平面曲げ疲労強度が、一般部で４．０ＭＰａ、ウエルド部で１．２ＭＰａであり、また、エラストマーを入れない場合には、一般部で３．４ＭＰａ、ウエルド部で０．８ＭＰａであるという結果が得られた。 <Evaluation 2 of elastomer>
In this evaluation 2, the hot fatigue strength when connected to the engine was compared with and without the elastomer after being subjected to plane bending 10 ⁷ times in an environment of 200 degrees Celsius. The fatigue strength of was determined. The fatigue strength was determined for each of the weld portion and a portion other than the weld portion (referred to as a general portion).

As shown in Table 4, the PPS resin has a plane bending fatigue strength of 4.0 MPa in the general part and 1.2 MPa in the weld part when the elastomer is added. The result was 3.4 MPa in the part and 0.8 MPa in the weld part.

From the above, it is clear that PPS resin is superior to 66 nylon and phenol resin from the viewpoint of thermal fatigue strength, molding cycle and recyclability.
In addition, by including an elastomer in the PPS resin, the impact strength and hot fatigue strength are increased, and the strength of the weld portion is sufficiently ensured. Therefore, it can be said that it is suitable for the inlet pipe 51 of the motorcycle.

Moreover, the flexibility required for the inlet pipe 51 can be satisfied by this elastomer. In other words, the elastomer has a content that can correspond to at least vibration (vibration amount, vibration frequency range) between one end side (upstream side) and the other end side (downstream side) of the intake system.
In addition, the elastomer includes both thermoplastic elastomer (TPE) and rubber, but the inlet pipe 51 can be plastically deformed by pressurizing at a high temperature by using the thermoplastic elastomer. Therefore, re-molding is easy and recycling is possible.

As described above, in the present embodiment, since the inlet pipe 51 is formed of a resin (PPS resin) made of polyphenylene sulfide, the throttle body 53 and the engine 20 are directly connected to the throttle body 53 while suppressing the thermal influence on the throttle body 53. The inlet pipe can be connected and has sufficient heat resistance. In addition, since the resin of the inlet pipe 51 contains an elastomer, the weld pipe strength of the inlet pipe 51 and fatigue strength against thermal influence can be improved, and the inlet pipe 51 suitable for a vehicle such as a motorcycle is obtained. be able to.
In addition, a pair of extending portions (flanges) 63A and 63A extending in the radial direction are provided at one end of the inlet pipe 51, and are connected to the engine 20 via the extending portions 63A and 63A. For this reason, the extension portions 63A and 63A, which are the connecting portions with the engine 20, are required to have strength against heat influence. However, since the inlet pipe 51 is formed of a resin made of polyphenylene sulfide, the required strength can be ensured.
A pair of extending portions (flanges) 62A and 62A extending in the radial direction are also provided at the other end portion of the inlet pipe 51, and the throttle body 53 is supported via the extending portions 62A and 62A. Therefore, even if it is connected to the engine 20 via the extending portions 62A and 63A provided at both ends of the inlet pipe 51 and supports the throttle body 53, the thermal effect of the engine 20 on the throttle body 53 can be avoided. In addition, sufficient strength can be secured.
Further, in the stage of resin molding the inlet pipe 51, the insert collars 63C and 63C are set in the mold, and the molten resin material is poured into the mold from the gate to insert the collars 63C and 63C. 63C can be inserted easily.

As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this, A various design deformation | transformation can be performed.
For example, in the above-described embodiment, the injector support portion 64 has the first extension portion 64A extending in the radial direction with respect to the axis L2 of the injector 60 from the opening portion 51B through which the injector 60 is inserted. The cover member 80 that covers the injector 60 from above is fixed to the outlet 64A with bolts 94 and nuts 96, and the injector 60 is supported by the inlet pipe 51. However, the present invention is not limited to this, and the diameter of the injector 60 is important. A configuration in which the injector 60 is supported using the first extending portion 64A extending in the direction (excluding the configuration in which the female thread portion is resin-molded on the first extending portion 64A) is widely applicable.
That is, since the injector 60 is supported by using the first extending portion 64A extending in the radial direction of the injector 60, a wide space for supporting the injector can be secured, and various support structures can be used by using this space. It is possible to support the injector. For example, it is easy to embed a metal nut (insert nut) in the first extension portion 64A and fix the injector 60 to the nut via a bolt. An engaging member such as a claw may be provided, and the injector 60 may be hooked and fixed to the engaging portion.

Moreover, although the said embodiment demonstrated the case where the inlet pipe 51 was formed with resin which consists of polyphenylene sulfide (PPS resin) containing an elastomer, it is not restricted to this. In short, the base material of the inlet pipe 51 may be a resin made of polyphenylene sulfide (PPS resin) having high heat resistance, and other materials may be used within that range.
In the above embodiment, the case where the present invention is applied to a single-cylinder four-cycle air-cooled engine has been described. However, the present invention is not limited to this, and the present invention may be applied to known engines such as a multi-cylinder engine and a water-cooled engine. Good. Further, the case where the present invention is applied to the motorcycle shown in FIG. 1 has been described. However, the present invention is not limited to this, and the present invention is not limited to this. The invention may be applied.

1 is a side view of a motorcycle according to an embodiment of the present invention. It is a figure which shows the cylinder part of an engine with a periphery structure. It is a perspective view which shows an inlet pipe with a throttle body. It is the figure which looked at an inlet pipe from the vehicle body back with a throttle body. It is the figure which looked at the inlet pipe with the throttle body from the vehicle body right side. (A) is the left view of an inlet pipe, (B) is the figure seen from the back surface. It is the figure seen from the VII direction of FIG. 6 (A). It is VIII-VIII sectional drawing of FIG. 6 (B). It is IX-IX sectional drawing of FIG. It is the bottom view seen from the X direction of Drawing 6 (B). It is the figure seen from the XI direction of FIG. 6 (A). (A)-(C) is a figure with which it uses for description of the attachment structure of a cover member and an injector support part. It is the elements on larger scale of the state which assembled the cover member and the injector. (A)-(C) is a figure where it uses for description of resin molding of an inlet pipe.

1 Motorcycle (vehicle)
2 Body frame 20 Engine 22 Cylinder part 24 Crankcase 51 Inlet pipe (intake pipe)
51A Intake passage 51B Opening (Injector insertion opening)
53 Throttle body 53Y, 58, 91, 92, 94 Bolt (fastening member)
53X, 60B Connector 55 Connecting tube 57 Air cleaner 60 Injector (fuel injection valve)
60A body part 60G hollow part 60G1, 1st wall part (step part)
60G2 second wall (step)
61 Bent pipe part 61A Upstream pipe part (reduced diameter part)
61B Downstream pipe part (expanded part)
62 1st flange (throttle body connection)
63 2nd flange part (engine connection part)
64 Injector support part 64A 1st extension part 64B 2nd extension part 64B1 Recess 80 Cover member 81 Projection part 95 Overhang part 96 Nut

Claims (7)

In an inlet pipe that is connected between a throttle body connected to an air cleaner provided in a vehicle via a connecting tube and an engine of the vehicle to form an intake passage,
The inlet pipe is formed of a resin made of polyphenylene sulfide.   The inlet pipe according to claim 1, wherein the inlet pipe is made of a resin made of polyphenylene sulfide containing an elastomer.   The inlet pipe is provided between the engine and the throttle body. The inlet pipe supports the throttle body, and a pair of flanges extending in the radial direction are provided at one end of the inlet pipe. The inlet pipe according to claim 2, wherein the inlet pipe is connected to the engine via the flanges.   4. The inlet pipe according to claim 3, wherein a pair of flanges extending in a radial direction are also provided at the other end of the inlet pipe, and the throttle body is supported via the flanges.   The inlet pipe according to claim 3 or 4, wherein a collar is inserted into the flange, and a bolt is inserted through the collar.   6. The inlet pipe according to claim 5, wherein in the step of resin-molding the inlet pipe, the collar is set in a mold, the molten resin material is poured into the mold from a gate, and the collar is inserted.   The inlet pipe is provided with an insertion port through which the injector is inserted, and includes a support portion that extends in a radial direction from the insertion port and supports a cover member that covers the injector. Inlet pipe as described.

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