Ignition device

Abstract

The ignition coil is positioned closer to the spark plug while maintaining sufficient fuel tank capacity. [Solution] In the saddle-type vehicle, the fuel tank is supported on the upper side of a pair of left and right tank rails (12) of the vehicle frame (10), and the engine (40) is supported on the lower side of the pair of left and right tank rails. The ignition system (50) of the saddle-type vehicle is provided with spark plugs (52, 55) installed in the engine to ignite the fuel-air mixture, an ignition coil (51) that applies an ignition voltage to the spark plugs, and plug wires (54, 57) that connect the spark plugs and the ignition coil. The ignition coil is located below the tank rails and, in a top view, to the side of the cylinder head cover (44) of the engine.

Description

Technical Field

[0001] The present invention relates to an ignition device.

Background Art

[0002] As an ignition device for a saddle-type vehicle, one in which an ignition coil is supported below the main frame above the engine is known (for example, see Patent Document 1). In the engine described in Patent Document 1, a pair of support portions protrude from the cylinder head cover, and a pair of flanges protruding from the ignition coil are screwed to the pair of support portions. Further, a plug cap of an ignition plug is installed on one side surface in the vehicle width direction of the cylinder head, and the plug cap is connected to the ignition coil via a plug cord. Thus, by supporting the ignition coil above the engine, the ignition coil is brought close to the ignition plug.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the ignition device described in Patent Document 1, it is necessary to form a fuel tank so as not to interfere with the ignition coil. If the size of the fuel tank is reduced to avoid the ignition coil, there is a possibility that the capacity of the fuel tank cannot be sufficiently ensured. Although the capacity can be ensured by expanding the fuel tank in the height direction or the vehicle width direction, as the vehicle becomes larger, it becomes difficult for the rider to take an appropriate riding position because the fuel tank interferes with the rider's legs.

[0005] In view of this point, the present invention has been made, and an object thereof is to provide an ignition device that can bring an ignition coil close to an ignition plug while ensuring the capacity of a fuel tank. [Means for solving the problem]

[0006] An ignition system according to one aspect of the present invention is an ignition system for a saddle-type vehicle in which a fuel tank is supported on the upper side of a pair of left and right tank rails of the vehicle frame, and an engine is supported on the lower side of the pair of left and right tank rails, and comprises a spark plug installed in the engine for igniting the fuel-air mixture, an ignition coil for applying an ignition voltage to the spark plug, and a spark plug cord connecting the spark plug and the ignition coil, wherein the ignition coil is located below the tank rails and, in a top view, to the side of the cylinder head cover of the engine, thereby solving the above problem. [Effects of the Invention]

[0007] According to one embodiment of the present invention, the ignition coil is positioned below the fuel tank, thereby ensuring sufficient fuel tank capacity without reducing the size of the fuel tank or increasing its height and width. Furthermore, by positioning the ignition coil to the side of the cylinder head cover, the ignition coil is brought closer to the spark plug installed in the engine. Thus, the ignition coil can be brought closer to the spark plug while ensuring sufficient fuel tank capacity. [Brief explanation of the drawing]

[0008] [Figure 1] This is a left side view of the saddle-type vehicle in this embodiment. [Figure 2] This is a left side view of the engine area in this embodiment. [Figure 3] This is a top view of the engine area in this embodiment. [Figure 4] This is a front view of the engine area in this embodiment. [Modes for carrying out the invention]

[0009] In one embodiment of the present invention, a saddle-type vehicle has a fuel tank supported above a pair of left and right tank rails on the vehicle frame, and an engine supported below a pair of left and right tank rails. In the ignition system of this saddle-type vehicle, a spark plug and an ignition coil are connected by a spark plug wire, and an ignition voltage is applied from the ignition coil to the spark plug to ignite the fuel-air mixture. The spark plug is installed in the engine, and the ignition coil is installed below the tank rails, to the side of the engine's cylinder head cover when viewed from above. By positioning the ignition coil below the fuel tank, sufficient fuel tank capacity is ensured without reducing the size of the fuel tank or increasing its height and width. Furthermore, by positioning the ignition coil to the side of the cylinder head cover, the ignition coil is brought closer to the spark plug. Thus, the ignition coil can be brought closer to the spark plug while ensuring sufficient fuel tank capacity. [Examples]

[0010] The saddle-type vehicle of this embodiment will be described below with reference to the attached drawings. Figure 1 is a left side view of the saddle-type vehicle of this embodiment. In the following figures, arrow Fr indicates the front of the vehicle, arrow Re indicates the rear of the vehicle, arrow L indicates the left side of the vehicle, and arrow R indicates the right side of the vehicle.

[0011] As shown in Figure 1, the saddle-type vehicle 1 is constructed by mounting various components such as the engine 40 and electrical systems on a vehicle frame 10. A pair of tank rails 12 extend diagonally downward and to the rear from the head pipe 11 of the vehicle frame 10, and a pair of body frames 13 extend downward from the rear of the pair of tank rails 12. A down frame 14 also extends downward from the head pipe 11, and a rearward-bent under loop 15 is connected to the lower part of the down frame 14. The rear end of the under loop 15 is connected to the lower part of the pair of body frames 13, forming the vehicle frame 10 in a cradle shape.

[0012] A steering shaft (not shown) supports a front fork 21 on the head pipe 11 so that it can be steered. A handlebar 22 is provided on the upper part of the front fork 21, and a front wheel 23 is rotatably supported on the lower part of the front fork 21. A fuel tank 24 is placed over a pair of tank rails 12, and the tank rails 12 and fuel tank 24 are covered from the sides by a front side cover 26. A seat 31 is installed behind the fuel tank 24, and a seat frame (not shown) that supports the seat 31 from below is covered from the sides by a rear side cover 32.

[0013] A swingarm 33 is pivotably supported on the body frame 13. The swingarm 33 extends rearward from the body frame 13, and a rear wheel 34 is rotatably supported at the rear end of the swingarm 33. The engine 40 is a four-stroke single-cylinder engine and is suspended inside the vehicle frame 10 via a suspension bracket (not shown). An air cleaner 35 is installed behind the cylinder head 43. Thus, in the saddle-type vehicle 1 of this embodiment, a fuel tank 24 is supported above a pair of tank rails 12, and the engine 40 is supported below a pair of tank rails 12.

[0014] Normally, engines are equipped with an ignition system to ignite the fuel-air mixture by creating a spark. The ignition coil of the ignition system is positioned close to the spark plug installed in the engine. However, if the ignition coil is installed inside the vehicle frame, it obstructs the space inside the frame that could be used for the fuel tank, resulting in a smaller fuel tank capacity. If the ignition coil is installed in front of the engine, the impact on the fuel tank is eliminated, but since there are heat sources such as the engine near the ignition coil, heat countermeasures must be taken for the ignition system, increasing costs.

[0015] Furthermore, the ignition coil is supported by brackets or the like on the tank rails and cylinder head cover. Since the ignition coil is heavy, the brackets need to be strong enough to prevent breakage, which increases costs. In the saddle-type vehicle 1 of this embodiment, there is dead space below the pair of tank rails 12 and to the side of the cylinder head cover 44. Therefore, in the ignition device 50 of this embodiment (see Figure 2), the dead space below one of the pair of tank rails 12 is utilized, and the ignition coil 51 is supported by a highly rigid bridge 16 (see Figure 2) of the vehicle frame 10.

[0016] The layout of the ignition system will be described with reference to Figures 2-4. Figure 2 is a left side view of the engine area in this embodiment. Figure 3 is a top view of the engine area in this embodiment. Figure 4 is a front view of the engine area in this embodiment. Note that in Figure 3, the fuel tank and tank cover are shown by dashed lines. Also, the radiator is omitted in Figure 4.

[0017] As shown in Figure 2, on the upper part of the vehicle frame 10, a pair of tank rails 12 extend diagonally downward and rearward from the upper rear side of the head pipe 11, and a single down frame 14 extends downward from the lower rear side of the head pipe 11. The middle sections of the pair of tank rails 12 and the middle section of the down frame 14 are connected via a pair of reinforcing bridges 16. The pair of tank rails 12 support a fuel tank 24, and the upper half of the fuel tank 24 is covered by a tank cover 25. The lower half of the fuel tank 24 is recessed inside the pair of tank rails 12, and the lower end of the fuel tank 24 is positioned below the bridges 16.

[0018] As shown in FIGS. 2 and 3, below the bridge 16, the engine 40 is suspended from the vehicle body frame 10 by a suspension bracket (not shown). A cylinder 42 is installed on the upper surface of the crankcase 41 of the engine 40, a cylinder head 43 is installed on the upper surface of the cylinder 42, and a cylinder head cover 44 is installed on the upper surface of the cylinder head 43. A magnet cover (engine cover) 46 and a sprocket cover 45 (see FIG. 1) are installed on the left side surface of the crankcase 41. A clutch cover (not shown), a water pump (not shown), etc. are installed on the right side surface of the crankcase 41.

[0019] In front of the cylinder head 43, radiators 36 are installed on both sides of the down frame 14 at the center of the vehicle. A radiator fan 37 is attached to the back of the radiator 36. Further, the saddle-type vehicle 1 is provided with an ignition device 50 that ignites and burns the air-fuel mixture by generating a spark during the start of the engine 40. The ignition device 50 is configured by connecting the first and second spark plugs 52, 55 and the ignition coil 51 with plug cords 54, 57. An ignition voltage is applied to the first and second spark plugs 52, 55 by the ignition coil 51, and the air-fuel mixture is ignited by the first and second spark plugs 52, 55.

[0020] The first and second spark plugs 52, 55 are installed in the engine 40. The first spark plug 52 is installed at the upper part of the cylinder head 43, and the plug cap 53 of the first spark plug 52 protrudes upward from the cylinder head cover 44. The second spark plug 55 is installed at the side part (left side part) of the cylinder head 43, and the plug cap 56 of the second spark plug 55 protrudes obliquely upward from the cylinder head 43. The first and second spark plugs 52, 55 are located on the same straight line (on the cylinder axis) in a side view. By adopting twin plugs in the engine 40, the exhaust gas is reduced and the fuel consumption is improved.

[0021] The ignition coil 51 is rectangular in side view and is positioned below the bridge 16 on one side (left side). A pair of support portions 17 protrude downward from the bridge 16, and the ignition coil 51 is supported by both of the pair of support portions 17. Although the ignition coil 51 is a heavy object, by being supported by the highly rigid bridge 16, brackets for the ignition coil 51 become unnecessary, reducing the vehicle body weight and cost. Plug cords 54 and 57 extend from the rear surface of the ignition coil 51 toward the first and second ignition plugs 52 and 55. A middle portion of one of the plug cords 54 is supported by a clamp 47 installed on the cylinder head 43, effectively suppressing the sway of the plug cord 54.

[0022] As shown in FIG. 2, in side view, the ignition coil 51 overlaps the fuel tank 24. In this case, the lower part of the fuel tank 24 bulges down to below the bridge 16, and the lower part of the fuel tank 24 overlaps the upper part of the ignition coil 51. The bulge of the fuel tank 24 increases the capacity while suppressing the expansion of the fuel tank 24 in the height direction and vehicle width direction, suppressing the enlargement of the vehicle. In side view, the ignition coil 51 overlaps the cylinder head cover 44. In this case, the lower part of the ignition coil 51 overlaps the protrusion 48 of the cam chain chamber of the cylinder head cover 44. By utilizing the dead space of the vehicle body frame 10 and the engine 40, design changes of the vehicle are suppressed.

[0023] Also, in side view, the ignition coil 51 is located above the first and second ignition plugs 52 and 55 on the axes of the first and second ignition plugs 52 and 55. By bringing the ignition coil 51 closer to the first and second ignition plugs 52 and 55, the plug cords 54 and 57 connecting the ignition coil 51 and the first and second ignition plugs 52 and 55 become shorter and the routing also becomes easier. By shortening the plug cords 54 and 57, the rotation of the plug caps 53 and 56 of the first and second ignition plugs 52 and 55 is suppressed. The plug cords 54 and 57 are curved so as to bulge rearward, and the plug cords 54 and 57 do not protrude outward in the height direction and vehicle width direction.

[0024] As shown in Figure 3, in a top view, the ignition coil 51 is positioned to the side (left) of the cylinder head cover 44, and is located inward in the vehicle width direction from the outer surface of the magneto cover 46. That is, the ignition coil 51 is located between the left side of the cylinder head cover 44 and the outer surface of the magneto cover 46. Because the ignition coil 51 does not protrude outward in the vehicle width direction, it does not interfere with the rider's legs, minimizing its impact on the riding position. When removing the cylinder head cover 44 for tappet adjustment or other purposes, it is not necessary to remove the ignition coil 51 from the vehicle frame 10, improving maintainability.

[0025] Furthermore, in a top view, the ignition coil 51 is positioned behind the front of the cylinder head cover 44 and in front of the rear. The ignition coil 51 overlaps the fuel tank 24 (see Figure 4), and the tank cover 25 covers the ignition coil 51 from above (see Figure 4). The tank cover 25 and magneto cover 46 are positioned outside the ignition coil 51 in the vehicle width direction, so that when the vehicle tips over, the tank cover 25 and magneto cover 46 hit the ground first, preventing damage to the ignition coil 51. The second spark plug 55 is located directly below the ignition coil 51, but the second spark plug 55 is also protected from damage when the vehicle tips over by the tank cover 25 and magneto cover 46.

[0026] In a top view, the ignition coil 51 is positioned on a straight line extending outward in the vehicle width direction from the center of the first spark plug 52, and in a side view, the ignition coil 51 is positioned on a straight line extending vertically from the center of the second spark plug 55. In a top view, the ignition coil 51 is positioned approximately to the side of the first spark plug 52, and in a side view, the ignition coil 51 is positioned approximately directly above the second spark plug 55, thus bringing the ignition coil 51 close to both the first and second spark plugs 52 and 55. By positioning the ignition coil 51 to the side of the cylinder head cover 44, the lower part of the fuel tank 24 is extended to the vicinity of the cylinder head cover 44, ensuring sufficient capacity.

[0027] As shown in Figure 4, in a front view, the ignition coil 51 overlaps the tank rail 12 on one side (left side). The ignition coil 51 is tilted so that the lower part is inward in the vehicle width direction rather than the upper part, and the ignition coil 51 extends inward in the vehicle width direction downward from the bridge 16 on one side (left side). By suppressing the protrusion of the ignition coil 51 below the bridge 16, the impact on the riding position and surrounding parts is reduced. In addition, since the ignition coil 51 is separated from the engine 40, which is a heat source, in the vehicle width direction and height direction, there is no need to implement heat countermeasures for the ignition coil 51, which reduces costs.

[0028] As described above, with the ignition device 50 of this embodiment, the ignition coil 51 is positioned below the fuel tank 24, ensuring sufficient fuel tank capacity without reducing the size of the fuel tank 24 or increasing its height and width. Furthermore, by positioning the ignition coil 51 to the side of the cylinder head cover 44, the ignition coil 51 is brought closer to the spark plug 52 installed in the engine 40. Thus, the ignition coil 51 can be brought closer to the spark plug 52 while ensuring sufficient fuel tank capacity.

[0029] In this embodiment, a twin-plug engine is used as an example, but a single-plug engine may also be used.

[0030] Furthermore, although a radiator is provided in the saddle-type vehicle in this embodiment, an air-cooled engine may be used in the saddle-type vehicle and a radiator may not be provided.

[0031] Furthermore, in this embodiment, the ignition coil overlaps the cylinder head cover in a side view, but the ignition coil may also overlap the cylinder head in a side view.

[0032] Furthermore, the ignition system of this embodiment may be used not only in the off-road type saddle-type vehicle described above, but also in other types of saddle-type vehicles. Note that the term "saddle-type vehicle" is not limited to all vehicles in which the driver sits straddling a seat, but also includes scooter-type vehicles in which the driver does not straddle a seat.

[0033] As described above, the first embodiment is an ignition system (50) for a saddle-type vehicle (1) in which a fuel tank (24) is supported above a pair of left and right tank rails (12) of a vehicle frame (10), and an engine (40) is supported below the pair of left and right tank rails. The ignition system (50) comprises spark plugs (first and second spark plugs 52, 55) installed in the engine to ignite the fuel-air mixture, an ignition coil (51) that applies an ignition voltage to the spark plugs, and spark plug wires (54, 57) connecting the spark plugs and the ignition coil. The ignition coil is located below the tank rails and, in a top view, to the side of the engine's cylinder head cover (44). With this configuration, by positioning the ignition coil below the fuel tank, sufficient fuel tank capacity can be ensured without reducing the size of the fuel tank or increasing its height and width. In addition, by positioning the ignition coil to the side of the cylinder head cover, the ignition coil is brought closer to the spark plugs installed in the engine. Therefore, the ignition coil can be placed closer to the spark plug while maintaining the fuel tank capacity.

[0034] In the second embodiment, as in the first embodiment, the ignition coil is positioned inward in the vehicle width direction from the outer surface of the engine cover (magneto cover 46) of the engine when viewed from above. With this configuration, since the ignition coil does not protrude outward in the vehicle width direction, the ignition coil does not interfere with the rider's legs, and its impact on the riding position is minimized. In addition, when removing the cylinder head cover for tappet adjustment or other purposes, it is not necessary to remove the ignition coil, improving maintainability.

[0035] In the third embodiment, the ignition coil overlaps the fuel tank in a side view, as in the first and second embodiments. With this configuration, the fuel tank fits inside the tank rail, increasing the fuel tank capacity while suppressing the increase in vehicle size.

[0036] The fourth embodiment is one of the first to third embodiments in which, in a side view, the ignition coil overlaps the engine's cylinder head cover or cylinder head (43). With this configuration, the design changes of the vehicle are minimized by utilizing the dead space of the vehicle frame and engine.

[0037] The fifth embodiment is one of the first to fourth embodiments in which the ignition coil is positioned on the axis of the spark plug in a side view. This configuration shortens the spark plug wire and simplifies its routing. Furthermore, it reduces the impact of the spark plug wire on surrounding components.

[0038] The sixth embodiment is one in which the spark plug wire is supported by a clamp (47) installed on the cylinder head of the engine, as in any one embodiment of the first to fifth embodiments. With this configuration, the spark plug wire is supported at an intermediate point by the clamp, and vibration of the spark plug wire is effectively suppressed.

[0039] The seventh embodiment is one of the embodiments from the first to the sixth, in which a down frame (14) of the vehicle frame is located in front of the engine, and the down frame and a pair of tank rails on the left and right are connected via a bridge (16), and the ignition coil is supported by a support part (17) that protrudes downward from the bridge. With this configuration, the fuel tank capacity can be easily secured by moving the ignition coil downward from the fuel tank. Since the ignition coil is supported by a highly rigid bridge, a bracket for the ignition coil is not required, which can reduce the vehicle weight and cost.

[0040] Although this embodiment has been described, other embodiments may include combinations of the above embodiment and its modifications, either entirely or partially.

[0041] Furthermore, the technology of the present invention is not limited to the embodiments described above, and may be modified, substituted, or transformed in various ways without departing from the spirit of the technical idea. Moreover, if the technical idea can be realized in a different way by advances in the technology or by other derived technologies, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea. [Explanation of Symbols]

[0042] 1: Saddle-type vehicle 10: Vehicle frame 11: Headpipe 12: Tank Rail 14: Down frame 16: Bridge 17: Support part 24: Fuel tank 25: Tank cover 40: Engine 43: Cylinder head 44: Cylinder head cover 46: Magneto cover (engine cover) 47: Clamp 50:Ignition device 51: Ignition coil 52: First spark plug (spark plug) 54: Spark plug wires 55: Second spark plug (spark plug) 57: Spark plug wires

Claims

1. An ignition system for a saddle-type vehicle in which a fuel tank is supported above a pair of tank rails on the left and right sides of the vehicle frame, and an engine is supported below the pair of tank rails, A spark plug installed in the aforementioned engine to ignite the fuel-air mixture, An ignition coil that applies an ignition voltage to the spark plug, The spark plug and the spark plug wire connecting the spark plug and the spark coil are provided, An ignition system characterized in that the ignition coil is located below the tank rail and, in a top view, to the side of the cylinder head cover of the engine.

2. The ignition device according to claim 1, characterized in that, when viewed from above, the ignition coil is located inward in the vehicle width direction from the outer surface of the engine cover of the engine.

3. The ignition device according to claim 1 or 2, characterized in that the ignition coil overlaps the fuel tank when viewed from the side.

4. The ignition device according to claim 1 or 2, characterized in that, in a side view, the ignition coil overlaps the cylinder head cover or cylinder head of the engine.

5. The ignition device according to claim 1 or 2, characterized in that the ignition coil is located on the axis of the spark plug when viewed from the side.

6. The ignition device according to claim 1 or 2, characterized in that the spark plug wire is supported by a clamp installed on the cylinder head of the engine.

7. The down frame of the vehicle body frame is located in front of the engine, and the down frame and the pair of left and right tank rails are connected via a bridge. The ignition device according to claim 1 or 2, characterized in that the ignition coil is supported by a support portion that protrudes downward from the bridge.

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