WO2015142297A1

WO2015142297A1 - Engine control unit mounting structure for a motorcycle

Info

Publication number: WO2015142297A1
Application number: PCT/TH2014/000010
Authority: WO
Inventors: Yasuyuki Maeda; Noriyuki Matsui; Ryohei Kitamura
Original assignee: Honda Motor Company Limited
Priority date: 2014-03-18
Filing date: 2014-03-18
Publication date: 2015-09-24
Also published as: CN106170435B; PH12016501815B1; MY191521A; JP2017507845A; CN106170435A; PH12016501815A1; JP6238329B2

Abstract

An electronic control unit (ECU) mounting structure for a motorcycle having an ECU and seat rails passing both sides of an under-seat utility box is characterized in that: the utility box includes a recess portion inward of the seat rails, and the ECU resides inward of the seat rails, between a given seat rail and the recess portion of the utility box. The ECU inwardly faces the utility box recess portion. The seat rail overlaps portions of the ECU from a side view. Other electric parts are installable outside of the seat rail, at positions overlapping portions of the ECU from a side view. Spatial gaps exist between the ECU and a) the seat rail, and b) the utility box recess portion. The ECU avoids overlapping the utility box from a front view. The ECU mounting structure eliminates the need for special ECU protection covers, and keeps the motorcycle body shape slim.

Description

ENGINE CONTROL UNIT MOUNTING STRUCTURE FOR A MOTORCYCLE TECHNICAL FIELD

This invention relates generally to a mounting structure for an engine control unit (ECU) for a motorcycle, such as an underbone-type motorcycle or a scooter, which includes a seat, a utility box disposed under the seat, and a seat rail that extends along and overlays portions of a lateral side of the utility box when observed from a lateral view. The ECU is positioned inwardly facing toward a recess portion of the utility box and inside of the seat rail.

BACKGROUND ART

Japanese patent JP 3868944 (corresponding to United States patent US 7, 140,458) describes a Hybrid-motorcycle having an engine 20 and a motor 21b disposed on one side of a longitudinal center line, adjacent to a utility box 100. A set of control units (Driver) 90, 91 is mounted on a left member 6a of a rear frame 6, which is called the seat rail frame. 32

DISCLOSURE / DESCRIPTION

Technical Problem

A problem associated with the control unit mounting arrangement disclosed in JP 3868944 is that the control unit is mounted on the outside of seat rail (left member of rear frame), and it's necessary for the control unit to have a special cover attached thereto on the outside for protection. The presence of the special cover on the side of the utility box also negatively affects the shape of the motorcycle's body and the motorcycle's resulting aerodynamics, and results in a motorcycle having a non-streamlined, less appealing visual appearance. Moreover, the structure of the utility box limits the size of the components, in particular the size of the control unit, which can be installed on the motorcycle. Recently, this applicant has adapted an "Idling Stop System (ISS)" for motorcycles because of improving fuel consumption. The ISS requires a brushless starter motor rotating a crankshaft directly, and also it's necessary to adapt the "brushless motor driver unit". Additionally, the motorcycle engine is usually equipped with a fuel injection and ignition controller, namely, an Engine Control Unit (ECU). Accordingly, a modern ECU can be larger in size than an earlier generation ECU, and it is necessary to integrate such brushless motor driver unit for providing idle stop function to customers. As a result, such a larger ECU is difficult to mount in the motorcycle without resulting in a wider body shape.

It is desired to provide a motorcycle ECU mounting structure that solves at least some of the aforementioned problems. For example, it is desired to provide an ECU mounting structure that enables ECU mounting in the motorcycle without any special protection covers, and which keeps the motorcycle's body size slim. Especially, it should allow a modern large size ECU to be easily mounted to the motorcycle without adversely affecting the motorcycle's streamlined body shape.

Technical Solution

This invention according to claim 1 is an engine control unit (ECU) mounting structure for a motorcycle comprising an ECU for controlling an engine of the motorcycle, which is located near a pair of seat rails passing both sides of a utility box mounted below a seat characterized in that: said utility box is formed to include a recess portion at an inward portion of said seat rail, and said ECU is positioned at an inside portion of said seat rail and inwardly facing said recess portion of said utility box, wherein another electric parts is installable outside of said seat rail at least one position that overlaps portions of said ECU in a side view of the motorcycle.

This invention according to claim 2 has, in the ECU mounting structure of claim 1, a characteristic in that said ECU controls fuel injection and ignition of the engine, and also controls an Idle Stop System which stops the engine under stopping conditions and starts the engine when the rider operates a throttle to start the motorcycle

This invention according to claim 3 has, in the ECU mounting structure of claim 1, a characteristic in that said recess portion of said utility box is formed to open at a lower side whereat a harness wire for a coupler of the ECU can pass and extend through said lower side of the recess portion. This invention according to claim 4 has, in the ECU mounting structure of claim 1 , a characteristic in that said other electric part includes at least an ignition coil.

This invention according to claim 5 has, in the ECU mounting structure of claim 1 , a characteristic in that said ECU is positioned above said seat rail, said seat rail overlaps a coupler of said ECU, and said other electric part is installable at a position that overlaps the coupler of the ECU.

This invention according to claim 6 has, in the ECU mounting structure of claim 1 , a characteristic in that said ECU is mounted in a spatial gap between an outer surface of said ECU and the inner surface of said seat rail.

This invention according to claim 7 has, in the ECU mounting structure of claim 1, a characteristic in that said ECU is mounted overlapping said seat rail in a side view.

This invention according to claim 8 has, in the ECU mounting structure of claim 1, a characteristic in that said recess portion is formed in a right side and a lower side of said utility box, and said ECU is positioned inwardly facing said recess portion. This invention according to claim 9 has, in the ECU mounting structure of claim 3, a characteristic in that said ECU is installed at a position that avoids overlapping with said utility box in a front view.

This invention according to claim 10 has, in the ECU mounting structure of claim 3, a characteristic in that said Edu is installed such that a spatial gap exists between an inner surface of said ECU and the recess portion of said utility box.

Advantageous Effects

According to the invention disclosed in claim 1, the ECU is positioned at inside portion of the seat rail and inwardly facing toward the recess portion of the utility box. As a result, the inside portion of the ECU is covered or protected by the utility box, and the outside portion of the ECU is protected by and the seat rail. Consequently, there is no need for the motorcycle to include additional cover parts for specifically protecting the ECU. Furthermore, the ECU can have a slim or thin profile or structure, which allows it to be advantageously disposed at the side of the motorcycle without affecting the lateral dimensions of the motorcycle. This arrangement allows for a compact ECU mounting structure, which in turn allows the body of the motorcycle to be freely designed. The compact mounting structure gives the motorcycle a more streamlined body, plus improved aerodynamics and visual appearance. Yet further, due to the positioning of the ECU between the seat rail and the utility box, other electric parts (and possibly non-electric parts) can be readily installed at particular positions outside of the seat rail (e.g., at or along the outer surface of the seat rail), even if the ECU has a large or relatively large lateral size or surface area.

According to the invention disclosed in claim 2, as the ECU controls three (3) functions of the engine, namely, fuel injection, ignition, and the idle stop system, the ECU becomes bigger than usual, and this invention enables mounting of such bigger ECU near the utility box without any special cover means or making larger body cover.

According to the invention disclosed in claim 3, at a lower spatial region of the utility box recess portion, a harness wire for an ECU coupler can pass and extend below the utility box because the recess portion is formed to open at a lower side. Water that enters into or permeates the ECU coupler will be drained downward; and at the position of the harness wire, water will not collect inside the coupler. Additionally, at an upper side of the utility box, above the recess portion, the utility box can include a partition wall that efficiently protects the upper side of the ECU from water.

According to the invention disclosed in claim 4, motorcycles such as scooters have their engines installed below the seat. For such motorcycles, an ignition coil can be installed at a position outside of the seat rail. This ignition coil installation position shortens electrical wiring length to the engine, which advantageously reduces ignition energy loss. According to the invention disclosed in claim 5, the ECU is positioned such that it can be readily seen or identified from a lateral view because it extends above the seat rail. Additionally, during a motorcycle assembly inspection procedure or a motorcycle maintenance procedure, the position of the ECU is easy to distinguish relative to the other electric parts (e.g., an ignition coil) disposed outside of the seat rail. Furthermore, with respect to an ignition coil, the separation distance between the ECU and the ignition coil, which is comparatively far, reduces, minimizes, or eliminates the effect of ignition coil noise on the ECU. According to the invention disclosed in claim 6, the spatial gap between the outer surface of the ECU and the inner surface of the seat rail, provides a ventilation space through which air can easily flow when the motorcycle is running. This improved airflow across the outer surface of the ECU improves the rate of ECU heat dissipation. According to the invention disclosed in claim 7, the ECU is substantially protected by the seat rail, thereby eliminating the need for a specific ECU protection structure such as a separate ECU cover. Furthermore, the positioning of the ECU between the seat rail and the recess portion of the utility box avoids an increase in the width or lateral span of the motorcycle due to the ECU, thereby avoiding increased costs associated with wider body sizes.

According to the invention disclosed in claim 8, the recess portion is formed in a particular section of the lateral side of the utility box, for instance, the lower rear of the right side of the utility box. The recess portion can be formed at or along only one portion or part of surface of the utility box, especially a lower rear region of the right side, thereby increasing or maximizing the total storage capacity of the utility box.

According to the invention disclosed in claim 9, frontal or forward facing surfaces of the ECU are exposed to wind flowing from the front of the motorcycle toward the rear of the motorcycle as the motorcycle is running, which improves the rate of ECU heat dissipation. According to the invention disclosed in claim 10, the spatial gap between the inner surface of the ECU and the recess portion of the utility box provides a ventilation space through which wind can readily flow when the motorcycle is running. This ventilation space improves the rate of ECU heat dissipation.

Brief Description of the Drawings

FIG. 1 is a right view of a partial section of a motorcycle having an engine control unit (ECU) mounting structure in accordance with an embodiment of the present disclosure. FIG. 2 is a perspective view of a portion of the motorcycle of FIG. 1, illustrating the ECU mounting structure in accordance with an embodiment of the present disclosure.

FIG. 3 is a front view of a portion of the motorcycle of FIG. 1, illustrating the ECU mounting structure in accordance with an embodiment of the present disclosure.

FIG. 4 is a top plan view of a portion of the motorcycle of FIG. 1, illustrating the ECU mounting structure in accordance with an embodiment of the present disclosure.

FIG. 5 (a) and (b) show two perspective views of the ECU, and (c) shows a silhouette lateral view (right side view) of the ECU mounting structure in accordance with an embodiment of the present disclosure.

FIG. 6 shows a magnified lateral view (right side view) of the ECU in accordance with an embodiment of the present disclosure.

FIG. 7 shows a cross-sectional view of the ECU for the motorcycle along the line AA of FIG. 6, in accordance with an embodiment of the present disclosure.

FIG. 8 shows a cross-sectional view of the ECU for the motorcycle along the line BB of FIG. 6, in accordance with an embodiment of the present disclosure. Detailed Description of Example Embodiments

Hereinafter, embodiments of the present disclosure of an engine control unit (ECU) mounting structure for a motorcycle according to the present disclosure will be described, with reference to the drawings of FIG. 1 to FIG. 8.

FIG. 1 is a right view of a motorcycle or motorbike 10 that includes a mounting structure for an ECU 12 in accordance with an embodiment of the present disclosure. With reference to FIG. 1, in several embodiments, the motorcycle 10 is, or exhibits structural elements or features corresponding to, an underbone type or scooter type motorcycle, or a generally similar type of saddle-ride or straddle-ride type vehicle, in a manner understood by one having ordinary skill in the relevant art. The motorcycle 10 includes an underlying structural frame that is formed from a set of frame elements, tubes, or pipes. For easier understanding of the present disclosure and the internal parts and components of the motorcycle described herein, the external body covers of the motorcycle are omitted from the drawings.

In the embodiment shown in FIG. 1, the motorcycle 10 is equipped with a swing type engine unit 14, so called Scooter, and having an underlying frame through which a rider / driver can step through, and a step floor (not shown) having an upper surface for supporting the rider's feet in a manner understood by one having ordinary skill in the art. The motorcycle 10 additionally includes a seat 1 1 that can be opened and closed via a hinge 66 for seating the rider and an optional passenger. A pair of pillion steps 18L,R disposed on each side of the motorcycle 10 can support the passenger's feet; and a grab rail 20 disposed behind the seat 1 1 at the rear of the motorcycle 10 is configured for grasping by the passenger's hand(s).

The motorcycle's engine unit 14 is positioned below the seat 1 1. The engine unit 14 is swingably mounted to the motorcycle's structural frame, and includes a crank case 15, a cylinder with cylinder head 16a, and a cylinder head cover 16b in a manner readily understood by one having ordinary skill in the relevant art. The engine unit 14 is configured to generate a propulsion or driving force deliverable to a rear axle of the motorcycle 10 by way of a transmission, for instance, a Continuously Variable Transmission (CVT, such as a belt-CVT) that is disposed within a CVT case (not shown) on the left side of the Scooter. The engine unit 14 includes an air intake system connected to an air cleaner 22 on the same side as the CVT case, which filters and removes particulate matter from air prior to the delivery of filtered air into the engine unit 14. The air intake system also includes a fuel injection unit controlled by the ECU 12. The engine unit 14 additionally includes an exhaust port and exhaust pipe coupled to a muffler, which reduces the sound output of the engine unit 14. The fuel to the engine unit 14 is supplied to the fuel injection unit from a fuel tank 24 disposed above the engine unit 14 and under the seat 1 1. An ignition coil 26 controlled by the ECU 12 creates an electric spark in the spark plug 28 to thereby ignite the air-fuel mixture for starting the engine unit 14.

While the motorcycle 10 includes an electronic mechanism (e.g., a starter motor) for starting the engine unit 14, the motorcycle 10 typically additionally includes a kick-start mechanism, as illustrated with additional reference to FIG. 4. The starter motor is a brushless starter motor connecting to a crank shaft of engine unit 14, and enables the crank shaft rotate directly, quickly, and speedily. The ECU 12 also controls the brushless starter motor in accordance with the motorcycle's current running condition. The ECU 12 makes the engine stop when the scooter has been stopped, for instance, at a traffic signal, and restarts the engine to activate the starter motor when the rider operates the throttle, such as when the rider intends to go forward. Such a system is called "Idle Stop System" (ISS) and enables improved fuel consumption. Such a brushless motor requires the incorporation of a controller or driver including semiconductor bridges in the ECU 12 so as to control the current, and that causes the ECU 12 bigger than usual. In Fig. 4, the kick-start mechanism 56 comprises a kick-start aim 56a connected to a kick-start pedal 56b„ by which the rider can manually supply rotation to the engine unit 14 such that an air-fuel mixture therein is ignited to start the engine unit 14.

A rear wheel 30 equipped circumferentially with a rear tire 32 is mounted to the motorcycle's rear axle, for communicating the engine unit's driving force to an underlying surface or ground plane on which the motorcycle 10 can be driven (e.g., a paved roadway or other generally planar surface). A rear cushion or suspension 33 on the rear left side of the motorcycle absorbs the swing motion of the rear tire 32 caused by bumps and vibrations to provide improved ride and motorcycle handling characteristics while limiting the distance across which the engine unit 14 and the seat 1 1 are displaceable relative to each other. The rear cushion or suspension 33 may comprise springs, dampers, and/or shock absorbers to achieve this function. Alternatively or additionally, other components may be used to achieve the same or to complement the effect, as readily understood by one having ordinary skill in the art.

A rear fender 34 is disposed above the rear tire 32 and below and rearward of the seat 1 1, for substantially preventing mud, debris, and water that has been picked up from the motorcycle's underlying surface and directed upward and rearward as a result of rotation of the rear tire 32 from traveling above and behind the fender 34. A front fender (not shown) is positioned above the front tire (not shown), to serve a corresponding purpose to that of the rear fender 34. The motorcycle 10 includes a plurality of covers or cover members configured for concealing internal structural and mechanical portions of the motorcycle 10, such as the motorcycle's underlying frame, and forming portions of the motorcycle's exterior surfaces. A tail light unit 38 is installed beneath the grab rail 20, which includes a pair of winkers 36L,R at both sides of tail light unit 38, and the tail light unit 38 is configured for directing tail light illumination rearward and outward.

As further described hereinafter for the embodiment shown, the underlying structural frame of the motorcycle 10 comprises a pair of seat rails or seat frames 40L,R under the seat 1 1 supporting the fuel lank 24 and a utility box 44.. The pair of seat rails 40L,R are connected via a central structural beam or cross pipe 42. The connection therebetween can be by means of permanent welds and/or non-permanent fasteners. The cross pipe 42 includes a pair of brackets 42a of the utility box 44. Other types of connection can also be used, as readily understood by the person having ordinary skill in the art. In this embodiment shown in FIG. 1, the seat rail 40R is a metallic structural beam, which can have a rectangular hollow cross-section. So, it's easy to mount the ECU 12 because the seat rail's rectangular shape provides flat surfaces. However, other types of structural beams or components can be used, as readily understood by the person having ordinary skill in the art. The seat rails 40L,R extend from a lower portion of the utility box 44 to an upper rear portion of both sides of the fuel tank 24. . The seat rails 40L, R are mounted or mountable to the underlying structural frame of the motorcycle 10, such that the seat 1 1 is supported or supportable by the seat rails 40L, R. Further, as described in detail below, the seat rail 40R is configured relative to the ECU 12 in a manner that at least (a) shields or protects portions of the ECU 12 from external environmental factors by overlapping the ECU 12 in a side view; (b) enables a large ECU to be carried by the motorcycle 10 without impacting the motorcycle's lateral dimensions or visual appearance; and (c) allows ease of access to the ECU 12 for installing other electric and/or non-electric parts or components to the motorcycle 10.

The ECU 12 is an electrical component of the motorcycle 10 for electronically controlling the engine unit 14, especially the fuel injection and ignition units, also the brushless starter motor, and for ensuring optimal engine performance and controlling the "Idle Stop System". The ECU 12 reads data values from multiple engine unit sensors, interprets these data values, and adjusts the engine performance, for example, deciding the fuel injection amount and ignition timing, operating the brushless motor and rectifying the generating voltage of the brushless motor after operating the starter motor, accordingly. In this embodiment, the brushless starter motor operates as a generator after starter motor function, which is called an "AC Generator and Starter". As the result, the ECU 12 is typically a moderately large or large electrical component because of cheaper cost realized by integrally forming all ECU control functions in a single unit, and is important in terms of controlling the engine unit 14. Thus, secure protection and reliable operation of the ECU 12 is necessary.

In various modern motorcycle designs or models, the ECU 12 is large in size and it is not necessarily easy to set at a mounting position. As mentioned in more detail about "Idle Stop System", a motor control module or driver is merged with the ECU, resulting in an increased ECU size. Sensors around the motorcycle, such as engine sensors, delect conditions such as stopping of the motorcycle, engine temperature, throttle opening, engine revolutions, seating of the rider, etc. During cold starts of the engine unit 14, the ECU automatically prevents activation of the "Idle Stop System" until the engine unit 14 becomes warm, and during "Idle Stop", the ECU 12 restarts the engine unit 14 when the throttle is opened by rider. Such "Idle Stop System" was introduced by this applicant in motorcycles more than 10 (ten) years ago, and the applicant has been increasing the number of such motorcycles equipped with the "Idle Stop System".

FIG. 2 shows a perspective view of the mounting structure for an ECU 12 in accordance with an embodiment of the present disclosure. As illustrated in FIGs. 1 and 2, a utility box, storage box, or storage compartment 44 is disposed under the seat 1 1. The utility box 44 functions as utility space for storing, for example a helmet, luggage, and/or other personal equipment. As indicated with additional reference to FIG. 3, the utility box 44 is mounted or mountable to the motorcycle 10 via a pair of front mounting portions 48a and 48b which are front mounting points of the utility box 44. As illustrated with further reference to FIG. 4, the utility box 44 is disposed such that a longitudinal centerline 46 of the motorcycle 10 divides or bisects a top opening of the utility box 44 into right and left portions. The longitudinal centerline 46 additionally divides the motorcycle 10 between the motorcycle's right and left sides, in a manner readily understood by one having ordinary skill in the relevant art.

The ECU 12 is disposed or installed between the seat rails 40L,R and a lateral side of the utility box 44. Additionally, in several embodiments, the ECU 12 resides substantially at a lower-rear portion of the utility box 44. In the embodiment shown, with reference towards the front of the motorcycle 10, the ECU 12 is positioned such that the seat rail 40R is on the right side of the ECU 12, and the utility box 44 is on the left side of the ECU 12.

FIG. 3 is a front view showing a portion of the motorcycle of FIGs. 1 and 2, illustrating the mounting structure for the ECU 12 in accordance with an embodiment of the present disclosure. As illustrated in FIG. 3 and FIG. 6, the utility box 44 includes a recessed portion or indent portion 52 formed on its right side (e.g., its lower right rear side). In several embodiments, the ECU 12 is positioned and facing such that its lateral spatial area substantially or entirely sits within, occupies, or overlays the spatial area defined by the recess portion 52 of the utility box 44. Still more particularly, in a number of embodiments, the ECU 12 is positioned between an inner or inward surface of the seat rail 40R (defined relative to the motorcycle's center line 1 8) and the recess portion 52 of the utility box 44.

The positioning of the ECU 12 between the seat rail 40R and the utility box 44 and the ECU's facing toward the recess portion 52 shields or protects the ECU 12 from the motorcycle's external environment, and can provide a certain degree of impact protection to the ECU 12. Furthermore, in this embodiment, the utility box 44 includes an upper portion or a partition wall 54 that substantially overlaps the ECU 12. This further shields or protects the ECU 12 at its upper side in a manner similar to that as disclosed above. As the ECU 12 is protected at its lateral and upper sides, there is no need for any additional and/or redundant ECU protection and coverage parts. The elimination of the need for additional protective parts reduces the size of the body of the motorcycle 10, in particular the motorcycle's lateral size, and thus minimizes the effect on the cost of construction.

Furthermore, although the ECU 12 can have a large lateral size or significant lateral dimensions, the ECU 12 has a slim structure or profile (as illustrated in FIGs. 3, 4, and elsewhere) that allows it to be advantageously positioned at the right side of the motorcycle 10 without protruding from the right side of the motorcycle 10. This arrangement allows for a compact ECU mounting structure, which in turn allows the body of the motorcycle 10 to be freely designed. In addition, the compact ECU mounting structure gives the motorcycle 10 a more streamlined body and the advantage of improved aerodynamics and visual appearance.

In view of the foregoing, the recess portion 52 of the utility box 44 advantageously provides or creates a space for accommodating portions of the ECU 12, such that the ECU 12 can be disposed or installed between the seat rail 40R and the utility box 44 without compromising the overall compact structure of the motorcycle 10. The recess portion 52 of the utility box 44 need only be present on one lateral side of the utility box 44, thereby enhancing or maximizing the storage capacity of the utility box 44, or equivalently, minimizing the impact that the recess portion 52 has on the storage capacity of the utility box 44. The utility box 44 can be manufactured in various manners such that it includes the recess portion 52 and the upper partition wall 54. For example, the utility box 44 can be made of a plastic material and through a process of injection molding. Other types of materials and manufacturing processes may be utilized, as readily known by the person having ordinary skill in the art.

In FIGs. 6-8, the recess portion 52 comprises rear side wall portion 52a and front slant wall portion 52b. Each such wall portion 52a, 52b faces toward a rear portion 12a and a front portion 12b of the ECU 12. The front portion 12b is thinner than rear portion 12b. Accordingly, front slant wall 52b is inclined and keeps maximum capacity of the utility box 44.

Due to the position of the ECU 12 at the right external lateral side of the motorcycle 10, it is relatively easier to provide spatial area for accommodating other electric parts 50 for the motorcycle 10. Such other electric parts can include an ignition coil 26 and an electric regulator of generator's output. As the ECU 12 is positioned near the right outer side of the motorcycle 10, the other electric parts 50 are installable from outside of the seat rail 40R (e.g., at or along an outer surface of the seat rail 40R). Further, due to the position of the engine unit 14, the installation of the ignition coil 26 from the outside of the seat rail 40R provides the advantage of shorter wires because the engine is located under the utility box 44 like as shown in FIG. 1 and the spark plug 28 is close to the lower portion of the utility box 44, thereby leading to a short(er) length of a high tension cord or cable 27 from the ignition coil 26 and a reduction in the loss of ignition energy.

FIGs. 3 and A also show the positioning of the ECU 12 with respect to the seat rail 40R and the utility box 44, illustrating the aforementioned overlaps and shielding of the ECU 12.

As illustrated in FIG. 5(a) - (c), the ECU 12 is mounted or mountable to the seat rail 40R via at least mounting points 58a and 58b. The ECU 12 comprises a pair of couplers 60a and 60b for receiving connections from wires and other electrical parts of components of the motorcycle 10, such as electric parts 50 including the ignition coil 26. The ECU 12 is positioned in such a way that the couplers 60a and 60b are substantially overlapped, overlaid, or covered by the seat rail 40R and ignition coil 26, when the seat rail 40R and the ECU 12 are seen from a lateral view. As discussed above, such coverage provides protection to the couplers 60a and 60b which can be more delicate because of the wiring and electric components connected thereto. Additionally, the position of the couplers 60a and 60b at the lateral side of the motorcycle 10 allows ease of access to the couplers 60a and 60b from the lower side during motorcycle maintenance and/or assembly inspection.

As indicated above, in multiple embodiments the lateral extent or surface area of the ECU 12 overlays or is positioned within the recess portion 52 of the utility box 44 (e.g., when the ECU 12 and the utility box 44 are observed from a lateral view). Additionally, in accordance with an embodiment of the ECU mounting structure, a bottom portion of the ECU 12 remains uncovered or unobstructed by the utility box 44. The recess portion 52 of the utility box 44 can be formed to provide a lower spatial region, such as an L-shaped region, by which the bottom portion of the ECU 12 remains uncovered, in a manner indicated in FIG. 3. This exposure of the bottom portion of the ECU 12 allows a cable and/or wiring corresponding to a wiring harness 17 (e.g., indicated in FIGs. 1 and 2) to be readily coupled or connected to the couplers 60a and 60b of the ECU 12 (e.g., by the motorcycle manufacturer, maintenance personnel, and/or a motorcycle user). For instance, the wiring harness 17 can hold, couple, or connect to a wire or cable that passes and extends below the utility box 44 (e.g., beneath a bottom side of the utility box 44) as the wire / cable travels towards and to the ECU's couplers 60a and 60b. Additionally, in some embodiments, the seat rail 40R can shield or protect portions of the wiring harness 17 and/or wiring / cabling extending therefrom on the lateral side of the motorcycle 10.

Referring again to FIGs. 2 and 3, the upper portion or partition wall 54 of the utility box 44 also shields and effectively protects the couplers 60a and 60b from external environmental factors at the motorcycle's upper side. Furthermore, the ECU's couplers 60a and 60b are directed downward. In conditions such as rain, rainwater that has reached or which has entered or permeated into the couplers 60a and 60b will inherently be drained away at the lower end of the couplers 60a and 60b, because of such downward direction of the couplers 60a and 60b (e.g., as shown in FIGs. 1, 5, and 6). Advantageously, water will not become lodged inside the couplers 60a and 60b under rainy conditions, thereby enhancing the ECU's electrical reliability.

In the embodiment shown in FIG. 6(a) - (b), the utility box 44 comprises a top ring portion 62 and a compartment body 64. The top ring portion 62 is connected to the seat bottom seal, and seals the utility box 44 from water and mud when the seat 1 1 has been closed via the hinge 66. Further, the utility box 44 comprises a pair of rear mounting portions 70L,R for securing the utility box 44 together with the front mounting portion 48a,b.

As illustrated in FIGs. 7 and 8, the position of the ECU 12 between the seat rail 40R and the utility box 44 additionally provides for a spatial gap or ventilation space 72, 74 to exist between (a) the ECU 12 and the seat rail 40R (e.g., between an outer surface of the ECU 12 and an inner surface of the seat rail 40R), and (b) the ECU 12 and the utility box 44 (e.g., between an inner surface of the ECU 12 and the recess portion 52 of the utility box 44). The ventilation spaces 72 and 74 allow airflow and/or wind to readily flow along ECU surfaces when the motorcycle 10 is ridden. The increased airflow around the ECU 12 improves the rate of ECU heat dissipation. The ECU 12 includes heat generating elements, more particularly, semiconductor devices (SCR, FET, etc..) that drive the brushless starter and generator. So, it's possible for the ECU 12 to dissipate the heat from such heat generating elements and cool effectively because of the ventilation spaces 72, 74. In other words, heat can be more readily removed from the ECU 12 when the motorcycle 10 is in motion, thereby assisting in the cooling of the ECU 12 and improving its durability and reliability, notwithstanding the ECU 12 is mounted so compactly.

Also as illustrated in FIGs. 7 and 8, a front portion 76 of the ECU 12 is substantially exposed to the environment when seen from a frontal view of the motorcycle 10 (e.g., when the ECU 12 and the utility box 44 are observed from a frontal view). Such frontal exposure of the ECU 12 results in airflow or around the front portion 76 of the ECU 12 when the motorcycle 10 is ridden, further improving the rate of heat dissipation from the ECU 12. Thus, heat can be more readily removed from the ECU 12 when the motorcycle 10 is in motion, thereby assisting in ECU cooling, further improving its durability and reliability.

FIGs. 7 and 8 further show the mounting positions corresponding to various components of an ECU mounting structure in accordance with the embodiment described in the present disclosure. The various components of the motorcycle 10 described above, such as the ECU 12, seat rail 40R, seat 1 1 , and utility box 44, can be attached, coupled, and/or integrated to the motorcycle 10 by any means known to the person having ordinary skill in the art. By way of non-limiting examples, such means include permanent attachments such as welds, and non-permanent attachments such as fasteners, screws, bolts and nuts.

The ECU 12 is mounted to the seat rail 40R via two mounting points 58a and 58b. More particularly, the ECU 12 is mounted to an inner surface or side of the seat rail 40R by such mounting points 58a,b. Although only two mounting points 58a and 58b are shown, another number of mounting points 58 can be used to secure the ECU 12 to the seat rail 40R, as will be readily understood by the person having ordinary skill in the art. In this embodiment, non-permanent fasteners such as bolts and nuts 80a and 80b are used at mounting points 58a and 58b. Other types of fasteners such as screws and rivets can also be used. In this embodiment, 80a,b are nuts welded to brackets of seat rail 40R and such brackets establish or facilitate the formation of the ventilation space 72.

The ignition coil 26 is mounted to the seat rail 40R via two mounting points 82a and 82b. More particularly, the ignition coil is mounted to an outer surface of side of the seat rail 40R by such mounting points 82a,b. Although only two mounting points 82a and 82b are shown, another number of mounting points 82 can be used to secure the ignition coil 26 to the seat rail 40R, as will be readily understood by the person having ordinary skill in the art. In this embodiment, welding nuts 84a and 84b are used at the mounting positions 82a and 82b. Other types of fasteners such as screws and rivets can also be used. In this embodiment, the cross pipe 42 is connected to the seat rail 40R via a U-shaped structure 86. The interfaces between the cross pipe 42, the U-shaped structure 86, and the seat rail 40R can be by way of permanent attachment such as welds, and/or non-permanent attachment such as bolts and nuts.

Aspects of particular embodiments of the present disclosure address at least one aspect, problem, limitation, and/or disadvantage associated with existing motorcycle mounting structures for an ECU. While features, aspects, and/or advantages associated with certain embodiments have been described in the disclosure, other embodiments may also exhibit such features, aspects, and/or advantages, and not all embodiments need necessarily exhibit such features, aspects, and/or advantages to fall within the scope of the disclosure. A non- limiting example would be that an ECU mounting structure in accordance with an embodiment of the present disclosure can be implemented on the left side of the motorcycle 10 instead of the right side of the motorcycle 10 as detailed for the embodiment described above. It will be appreciated by a person of ordinary skill in the art that several of the above- disclosed structures, components, or alternatives thereof, can be desirably combined into alternative structures, components, and/or applications. In addition, various modifications, alterations, and/or improvements may be made to various embodiments that are disclosed by a person of ordinary skill in the art within the scope of the present disclosure, which is limited only by the following claims.

Claims

1. An electronic control unit (ECU) 12 mounting structure for a motorcycle 10 comprising: an ECU 12 for controlling an engine 14 of the motorcycle 10, which is located near a pair of seat rails 40L, 40R passing both sides of a utility box 44 mounted below a seat 1 1 ,

characterized in that:

said utility box 44 is formed to include a recess portion 52 at an inward portion of said seat rail 40L, 40R, and

said ECU 12 is positioned at an inside portion of said seat rail 40L, 40R and inwardly facing said recess portion 52 of said utility box 44 ,

wherein other electric part 26 is installable outside of said seat rail 40L,40R at positions that overlap portions of said ECU 12 in a side view of motorcycle 10.

2. The ECU mounting structure of claim 1, wherein said ECU controls the fuel injection and ignition of the engine, and also controls an idle stop system which stops the engine under stopping conditions and starts the engine when the rider operates a throttle to start the motorcycle.

3. The ECU mounting structure of claim 1 , wherein said recess portion 52 of said utility box 44 is formed to open at a lower side whereat a harness wire 17 for a coupler 60a,60b of the ECU 12 can pass and extend through said lower side of the recess portion 52 .

4. The ECU mounting structure of claim 1 , wherein said other electric part includes at least an ignition coil 26.

5. The ECU mounting structure of claim 1, wherein

said ECU 12 is positioned above said seat rail 60L,60R,

and said seat rail 60L,60R, overlaps a coupler 60a,60b of said ECU 12, and

said other electric part26 is installable at a position that overlaps the coupler 60L,60R of said ECU 12.

6. The ECU mounting structure of claim 1 , wherein said ECU 12 is mounted in a spatial gap 72 between an outer surface of said ECU 12 and the inner surface of said seat rail 60L,60R.

7. The ECU mounting structure of claim 1 , wherein said ECU 12 is mounted overlapping said seat rail 60L,60R in a side view.

8. The ECU mounting structure of claim 1 , wherein said recess portion 52 is formed in a right side and a lower side of said utility box 44 and said ECU 12 is positioned inwardly facing said recess portion 52.

9. The ECU mounting structure of claim 3, wherein said ECU 12 is installed at a position that avoids overlapping with said utility box 44 in a front view.

10. The ECU mounting structure of claim 3, wherein said ECU is installed such that a spatial gap 74 exists between an inner surface of said ECU and the recess portion 52 of said utility box 44.