Governor

Abstract

To provide a new standard governor capable of optimizing ignition timing after start of an engine and improving combustion efficiency of the engine.SOLUTION: A governor 1 is configured to adjust ignition timing of a two-cylinder, four-stroke engine. The governor 1 comprises: a mounting bolt 15 fixed to a camshaft 21 driven by the engine; and a governor weight 12 attached to the mounting bolt 15, advances the ignition timing of the engine after the engine starts and cancels the advance when the engine stops.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a governor for a two-cylinder four-stroke engine that is primarily mounted on a motorcycle or the like. [Background technology]

[0002] In recent years, efforts have been made on a global scale to promote the Sustainable Development Goals (2030 Agenda for Sustainable Development, adopted at the United Nations Summit on September 25, 2015, hereafter referred to as "SDGs"). Specifically, the SDGs include Goal 7: Affordable and clean energy, Goal 12: Responsible consumption and production, etc., and technological development aimed at achieving these goals is desired.

[0003] One known technology that can contribute to achieving these goals is that described in Patent Document 1. Patent Document 1 describes a governor controller for an ignition device that has a configuration in which "a large gap is provided between the drive shaft and the governor controller, and a pin to prevent rotation is provided between the two, so that vibrations from the engine (vibrations of the drive shaft) are absorbed by this gap."

[0004] The governor controller of the ignition device described in Patent Document 1 is said to "indirectly connect the drive shaft and governor shaft to prevent engine vibrations from being transmitted, thereby preventing the generation of vibration noise and vibration of the rotor shaft, and also ensuring that the two rotate together as a single unit, without any reduction in performance." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 55-36917 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the engine exhaust device described in Patent Document 1 can automatically adjust the ignition timing according to the engine rotation speed, it does not take into consideration the possibility of a misfire (burn) occurring when the engine is started due to a time lag between the engine's fuel injection timing and the ignition timing of the spark plug.

[0007] In particular, many older Harley-Davidson® motorcycles, such as those sold after 1970 and equipped with V-twin, four-stroke engines with gunner advance ignition, and which were released before the Evolution®, have a slow ignition timing when idling after starting the engine, causing the rear cylinder spark plug to misfire once every two times. This results in the three-beat exhaust sound that is often heard with this type of Harley-Davidson®.

[0008] However, if the rear cylinder spark plug misfires once every two times, the engine will become unstable after starting (e.g., while idling), resulting in a loss of power. This means that when the accelerator is gradually turned to start driving, the engine will not pick up speed steadily, putting a heavy load on the engine and potentially causing further engine failure.

[0009] The present invention has been made to solve the above-mentioned problems, and has as its object to provide a governor that optimizes ignition timing after engine start and improves engine combustion efficiency. [Means for solving the problem]

[0010] The governor of the present invention is a governor for adjusting the ignition timing of a two-cylinder four-stroke engine, and is characterized by comprising: a mounting bolt fixed to a camshaft driven by the engine; and an ignition timing advance device attached to the mounting bolt, which advances the ignition timing of the engine after the engine is started and cancels the advance when the engine is stopped. [Effects of the Invention]

[0011] According to the present invention, the ignition timing after starting the engine can be optimized, thereby improving the combustion efficiency of the engine. [Brief explanation of the drawings]

[0012] [Figure 1] 1A and 1B are diagrams showing a steady state of a governor according to an embodiment of the present invention, in which FIG. 1A is a front view and FIG. 1B is a side view. [Figure 2] The figure shows the advance state of the governor, (a) is a front view, and (b) is a side view. [Figure 3] FIG. 2 is a front view showing the governor attached to the engine case. [Figure 4] FIG. 4 is a side view showing the governor attached to the engine case. [Figure 5] The governor base of the above governor is shown, with (a) being a front view and (b) being a side view. [Figure 6] 1A and 1B show the governor advance member (governor body), with FIG. 1A being a front view and FIG. 1B being a side view. [Figure 7] 3 is a schematic view showing an elastic member (spring) of the gun bar. FIG. [Figure 8] The mounting bolts of the governor are shown, with (a) being a front view and (b) being a side view. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] (One embodiment) FIG. 1 is a schematic diagram showing a steady state of a governor 1 according to one embodiment of the present invention, with FIG. 1(a) being a front view and FIG. 2(b) being a side view. FIG. 2 is a schematic diagram showing an advanced state of the governor 1, with FIG. 2(a) being a front view and FIG. 2(b) being a side view. FIG. 3 is a front view showing the governor 1 attached to the engine case 2, and FIG. 4 is a side view thereof. FIG. 5 is a schematic diagram showing a governor base 11 serving as the main body of the governor 1, with FIG. 5(a) being a front view and FIG. 5(b) being a side view.

[0015] Figure 6 is a schematic diagram showing governor weight 12, which is the timing advance member of governor 1, with Figure 6(a) being a front view and Figure 6(b) being a side view. Figure 7 is a schematic diagram showing spring 13, which is the elastic member of governor bar 1. Figure 8 is a schematic diagram showing mounting bolt 15 of governor 1, with Figure 8(a) being a front view and Figure 8(b) being a side view.

[0016] <External configuration> The governor 1 according to this embodiment is a so-called new standard governor that is attached to a camshaft 21 driven by an engine of, for example, an older model motorcycle (not shown) equipped with a V-twin, four-stroke engine of the type that uses gunner advance ignition, such as a Harley-Davidson® pre-Evolution® model, to optimize ignition timing after engine start and improve engine combustion efficiency. As shown in Figures 3 and 4, the camshaft 21 is rotatably attached to the center of a governor mounting recess 22 with a concave cross section provided on the side of the motorcycle's engine case 2, protruding vertically (horizontally) from the governor mounting recess 22.

[0017] The governor 1 also includes a governor base 11. As shown in FIGS. 5(a) and 5(b), the governor base 11 has a plate portion 11a, which serves as a flat, plate-shaped main body formed by cutting opposing portions of a disk so that they are parallel to one another, and a shaft portion 11b, which serves as a slender, cylindrical shaft portion that protrudes vertically from the center of the front surface of the plate portion 11a. A bolt mounting hole 11c is provided in the center of the shaft portion 11b along the axial direction. A stepped portion 11d, which serves as a fitting recess for fitting the tip end of the camshaft 21, is concentrically provided in the center of the back surface of the plate portion 11a.

[0018] The plate portion 11a is provided with a pair of fixing holes 11e and a pair of fitting holes 11f as openings that penetrate the plate portion 11a in the thickness direction. These pairs of fixing holes 11e and pairs of fitting holes 11f are provided alternately in the circumferential direction of the plate portion 11a. In other words, the pair of fixing holes 11e are provided at positions facing each other with the shaft portion 11b as the center. The pair of fitting holes 11f are also provided at positions facing each other with the shaft portion 11b as the center.

[0019] A cylindrical pin 11g is inserted into each of the pair of fixing holes 11e and fixed therein. These pins 11g are attached so as to protrude from the side (front surface) of the plate portion 11a from which the shaft portion 11b protrudes. A gunner bar weight 12 is rotatably attached to each of the pins 11g. In short, the pair of governor weights 12 are attached to the gunner bar plate 11 so as to be concentrically opposed to the mounting bolt 15.

[0020] 6(a) and 6(b), each of the pair of governor weights 12 has a weight body 12a, which is a flat plate that is roughly crescent-shaped in plan view. One circumferential side (base end side) of each weight body 12a is provided with a mounting hole 12b through which a pin 11g is rotatably inserted and secured. Furthermore, a locking piece 12c that protrudes in the direction of the central axis of each weight body 12a is integrally formed on the inner circumferential side of one side of the weight body 12a.

[0021] Furthermore, a locking hole 12d is provided at the tip end of the other side (tip end side) of each weight body 12a as a spring locking portion for locking an arc-shaped locking portion 13a provided at one end of the spring 13. A pin fixing hole 12e is provided at the tip end side between the locking hole 12d and the mounting hole 12b of the weight body 12a, into which an end of a knock pin 14 serving as a pin body is inserted and fixed. With one end of the knock pin 14 protruding toward the governor base 11 side (rear side), the other end of the knock pin 14 is inserted and fixed in the pin fixing hole 12e.

[0022] 1 and 2, the pair of governor weights 12 are attached to the gunner bar base 11 with the locking pieces 12c of the pair of governor weights 12 facing each other in the direction of the central axis. The pair of gunner bar weights 12 are fitted together by inserting a knock pin 14 attached to each of the pair of governor weights 12 swingably into a fitting hole 11f of the governor base 11 from the side (front surface side) from which the shaft portion 11b of the gunner bar base 11 protrudes, and a pin material 11g fixed to the governor base 11 is rotatably inserted into the mounting hole 12b of each governor weight 12.

[0023] In short, the fitting hole 11f of the governor base 11 and the knock pin 14 function as a movement restricting portion that restricts the rotation angle (movement distance) of each gunner bar weight 12 about the mounting hole. The extension (stretching) of each gunner bar weight 12 against the elastic force of the spring portion 13c of the spring 13 caused by the rotational force of the camshaft 21 is restricted by contact between the knock pin 14 attached to each gunner bar weight 12 and the inner circumferential surface of the fitting hole 11f of the gunner bar base 11, thereby fixing the engine ignition timing in an advanced state.

[0024] A locking recess 11h is formed along the circumferential direction at the tip of the pin material 11g protruding from the mounting hole 12b of each governor weight 12. An arc-shaped locking piece 13b provided on the other end of the spring 13 is locked in this locking recess 11h. Also, a locking piece 13a provided on one end of each spring 13 is inserted into and fixed to a locking hole 12d of a governor weight 12 different from the governor weight 12 that locks the locking piece 13b on the other end of each spring 13. A restricting piece 11j is provided on the inner periphery of one fitting hole 11f of the governor base 11, restricting the rotation distance (angle) of the governor weight 12 inward around the pin material 11g as the center of rotation.

[0025] In this state, a substantially cylindrical governor shaft 16 serving as an advance cam is attached to the shaft portion 11b of the governor base 11. A pair of notched recesses 16a is provided on the base end of this governor shaft 16, into which the locking pieces 12c of each governor weight 12 are inserted and locked. The pair of notched recesses 16a are formed as grooves that open toward the base end of the governor shaft 16, and are provided at positions facing each other about the center position of the governor shaft 16, i.e., at positions 180 degrees apart in the circumferential direction.

[0026] The governor shaft 16 is attached by being inserted into the shaft portion 11b of the governor base 11, with the notched recesses 16a of the gunner bar shaft 16 fitting into and locking onto the locking pieces 12c of the governor weights 12. Furthermore, the shank 15b of the mounting bolt 15 is inserted into the tip end (surface side) of the shaft portion 11b of the governor base 11, and the threaded portion 15c at the tip end of the mounting bolt 15 is screwed into a tapped hole 21a provided at the center of the tip end of a camshaft 21 that protrudes into a gunner bar mounting recess 22 in the engine case 2. In short, the mounting bolt 15 secures the gunner bar base 11, governor weight 12, and governor shaft to the camshaft 21.

[0027] Governor 1 is configured such that, by adjusting the mass of each gunner weight 12, including knock pin 14, and the elastic force of spring 13, when the engine speed is between 800 ppm and 900 ppm, in other words, when the engine is idling, the rotation of camshaft 2 caused by the engine's drive causes governor shaft 16 to rotate (advance) in the rotational direction of camshaft 2, causing each governor weight 12 to rotate radially outward about pin material 11g, achieving maximum advance, thereby advancing the ignition timing of the engine. In other words, governor 1 is configured to advance the ignition timing when the engine is idling by increasing the mass of each governor weight, including knock pin 14, and reducing the elastic force of spring 13, compared to conventional governors 1. The rotation angle (e.g., 30 degrees) of these governor weights 12, in other words, the advance angle range, is configured to optimize the ignition timing of the engine to which it is attached, depending on the difference between the outer diameter of the knock pin 14 and the outer diameter of each fitting hole 11f of the governor base 11.

[0028] If the elastic force of the spring 13 in the gun bar 1 were too weak to maximize the timing advance when the engine is idling, the return force of the spring 13 when the engine is stopped would prevent the recovery of the timing advance of each governor weight 12. Therefore, the elastic force of the spring 13 is weakened (to make it easier to return) and the mass of each governor weight 12, including the knock pin 14, is increased so that each governor weight 12 can easily advance the timing, in other words, each governor weight 12 is adjusted to reliably advance the timing when idling.

[0029] <Assembly operation> Next, the assembly and installation operations of the governor 1 will be described with reference to the drawings.

[0030] First, two governor weights 12 are prepared, and the knock pins 14 are inserted and fixed into the pin fixing holes 12e of each governor weight 12 by press-fitting or the like so that each knock pin 14 protrudes from the back side (the side facing the governor base 11) of each of the two governor weights 12.

[0031] On the other hand, these pin materials 11g are inserted and fixed into each fixing hole 11e of the governor base 11 by press-fitting or the like so that the locking recess 11h side of the pin material 11g protrudes from the surface side of the governor base 11 (the side from which the shaft portion 11b protrudes).

[0032] In this state, these two governor weights 12 are paired, the locking pieces 12c of these governor weights 12 are placed facing each other, and the knock pins 14 fixed to these governor weights 12 are fitted into the fitting holes 11f of the governor weights 12. At the same time, the pin material 11g protruding from the gunner bar base 11 is rotatably inserted into the mounting holes 12b of these governor weights 12.

[0033] Furthermore, from this state, two springs 13 are prepared, and the locking portions 13a of these springs 13 are locked into the locking holes 12d of the governor weights 12. Furthermore, the locking pieces 13b of these springs 13 are locked into the locking recesses 11h of the pins 11g, the tip of which is inserted into the mounting holes 12b of the opposing governor weight 12, which is different from the governor weight 12 to which the locking portions 13a of the springs 13 are locked, and this pair of governor weights 12 is attached to the governor base 11.

[0034] Next, the gunner bar shaft 16 is inserted from the front surface (tip end) of the shaft portion 11b of the gunner bar base 11, with the notched recesses 16a of the gunner bar shaft 16 leading the way. Then, the notched recesses 16a of the gunner bar shaft 16 are fitted into the locking pieces 12c of the governor weights 12 to lock them in place.

[0035] As a result, by rotating the governor shaft 26 toward the other side of each governor weight relative to the governor base 11, the pair of governor weights 12 rotate radially outward around the pin material 11g against the elastic force of the coil-shaped spring portion 13c of each spring 13, thereby advancing the injection timing.

[0036] <Installation operation> Then, with the gunner bar base 11, pair of governor weights 12, and gunner bar shaft 16 assembled, the back side of the gunner bar base 11 is inserted into the governor mounting recess 22 of the engine case 2 of the motorcycle to which it is to be attached, and the stepped portion 11d of the governor base 11 is fitted onto the tip end of the camshaft 21 protruding from the gunner bar mounting recess 22.

[0037] In this state, the shank 15b of the mounting bolt 15 is inserted from the tip end (surface side) of the shaft portion 11b of the gunner bar base 11 into the center of this gunner bar shaft 16, that is, into the bolt mounting hole 11c of the shaft portion 11b of the governor weight 11. Then, the threaded portion 15c provided at the tip of the shank 15b of this mounting bolt 15 is screwed into the threaded hole 21a provided in the center of the camshaft 21 to secure it in place, completing the installation of the governor 1.

[0038] When the engine is started, the rotation of the camshaft 21 accompanying the start of the engine causes the governor shaft 16 to rotate in the rotational direction of the camshaft 21 from the attached (steady) state shown in Figures 1(a) and 1(b), as shown in Figures 2(a) and 2(b). As a result, the fitting recesses 16a of the governor shaft 16 press the locking pieces 12c of each governor weight 12 in the rotational direction of the camshaft 16.

[0039] This causes the spring portions 13c of the springs 13 to expand against their own elastic force, and the expansion of these springs 13 causes each governor weight 12 to rotate (advance) radially outward around the pin material 11g as the center of rotation. At this time, the advance angle of these governor weights 12 is fixed at a position where the knock pins 14 fixed to the governor weights 12 come into contact with the inner circumferential surfaces of the fitting holes 11g of the governor base 11.

[0040] Governor 1 is designed to advance the ignition timing of the engine when the engine speed reaches 800-900 ppm, i.e., when the engine is idling. When the motorcycle accelerator is rotated to increase the engine speed, governor 1 maintains the advanced state, maintaining the optimized ignition timing of the engine.

[0041] When the engine is stopped and the engine speed drops below 800 ppm, the speed of the camshaft 21 decreases as the engine speed decreases, causing the springs 13a of the governor 1 to recover (restore) from the extended state shown in Figures 1(a) and 1(b) due to the elastic force of each spring 13 of the governor 1.

[0042] As a result, the spring portions 13c of the springs 13 return to their original positions, causing each governor weight 12 to rotate inward about the pin material 11g as the center of rotation until one governor weight 12 contacts the restricting piece 11j of the governor base 11. This releases the advance state of the gunner bar 1 caused by the gunner bar weights 12, and the governor returns to its steady state.

[0043] <Action and effect> For example, many older Harley-Davidson® motorcycles sold after 1970 and equipped with V-twin, four-stroke engines, prior to the Evolution®, have a slow ignition timing when idling after starting the engine, causing the rear cylinder spark plug to misfire about once every two times. As a result, these types of Harley-Davidson® motorcycles currently suffer from the well-known triple-beat exhaust noise.

[0044] Furthermore, even with conventional gunbars, the timing is not advanced when the engine is idling, and the ignition timing is weak, typically around 5-10 degrees BTDC (Top Dead Center) when the engine is idling, which means that the rear cylinder spark plug tends to burn out about once every two times. This burnout effect results in the exhaust sound characteristic of older Harley-Davidson motorcycles, known as the "triple beat" sound.

[0045] However, if the rear cylinder spark plug goes out once every two times, the engine's original output performance cannot be achieved, and the engine will become unstable after starting (such as when idling), resulting in a loss of output.At the same time, when the accelerator is gradually turned to start driving, the speed will not rise steadily, which will place a heavy load on the engine and may lead to further engine failure.

[0046] Therefore, according to the governor 1 of the above embodiment, by attaching this gunner bar 1 to the camshaft 21 of a motorcycle, when the engine is started and the engine is idling, the rotation of the camshaft 21 accompanying the start of the engine causes the governor shaft 16 to rotate in the rotational direction of the camshaft 21, and each gunner bar weight 12 rotates (advances) in the outer diameter direction against the elastic force of the spring 13.

[0047] As a result, by fully advancing the engine ignition timing at an early stage, such as when the engine is idling, it is possible to prevent the previous phenomenon in which the rear cylinder spark plug would go out once every two times, stabilizing the idling state after engine start and preventing loss of engine power.

[0048] Furthermore, when the accelerator is turned from this idling state to increase engine speed, the advance state (maximum advance) of Gunner Bar 1 is maintained. This allows the engine ignition timing to be maintained in an optimized state, stabilizing speed gain when starting off and bringing out the engine's original output performance.

[0049] On the other hand, when the engine is stopped, the spring 13 returns to its original position due to the decrease in engine speed and the camshaft 21 rotation speed, thereby canceling the advance state set by each governor weight 12. As a result, the ignition timing itself is not advanced when starting the engine, allowing the engine to start properly, just as it was before the governor 1 was installed. In other words, if the advance state is maintained when starting the engine with a kick start, the engine ignition timing is too early, making the engine difficult to start and risking injury from the recoil of starting the engine. Furthermore, in the case of a self-start, the engine is forced to continue starting with the ignition timing being too early, which places a heavy load on the starter gear and may cause damage. This reduces the load on the engine and reduces the causes of engine failure. This improves engine combustion efficiency and enables complete combustion of exhaust gases, resulting in cleaner exhaust gases.

[0050] As a result, the governor 1 according to the present invention contributes to achieving the SDGs goals such as Goal 7: Affordable and clean energy, Goal 12: Responsible consumption and production, etc.

[0051] (others) It should be noted that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the described configurations.

[0052] In short, in the above embodiment, the governor 1 is designed to be attached to the camshaft of an older model motorcycle, released before the Harley-Davidson® Evolution®, that was sold after 1970 and was equipped with a V-twin, four-stroke engine that uses gunbar advance ignition. However, for engines such as the Shovelhead sold before 1969, the positions of the fitting hole 11f and the pin material 11g of the governor 1 can be reversed, and the knock pin 14 can be made to protrude in the opposite direction, resulting in a governor (not shown) that rotates in the opposite direction. This can then be attached to the camshaft of a Harley-Davidson® engine that was released before 1969 and is equipped with a V-twin, four-stroke engine, and can provide the same effects as the governor 1 according to the above embodiment.

[0053] Furthermore, even in the case of a so-called full-transistor ignition type V-twin four-cycle engine, the governor 1 according to the embodiment described above can be attached by modifying the engine to an engine that ignites with a gunner advance. [Explanation of symbols]

[0054] 1. Governor 11 Governor base (governor body) 11a Plate section 11b Shaft section 11c Bolt mounting holes 11d Stepped part 11e fixing hole 11f Fitting hole (opening, movement restriction part) 11g pin material 11h Locking recess 11j Regulation piece part 12 Governor weight (advance timing device) 12a weight body 12b mounting hole 12c Locking piece 12d locking hole 12e Pin fixing hole 13 Spring (elastic member) 13a Locking part 13b Locking piece 13c Spring part 14 Knock pin (pin body, movement restriction part) 15 Mounting bolts 15a head 15b Shaft 15c Threaded part 16 Gunner shaft 16a Notched recess 2 Engine case 21 Camshaft 21a screw hole 22 Governor mounting recess

Claims

1. A governor for adjusting ignition timing of a two-cylinder four-stroke engine, a mounting bolt fixed to a camshaft driven by the engine; an ignition timing advance device attached to the mounting bolt, which advances the ignition timing of the engine after the engine is started and cancels the advance when the engine is stopped; A governor comprising:

2. the advance device advances the ignition timing of the engine when the engine rotation speed reaches 800 ppm to 900 ppm; 2. The governor according to claim 1.

3. the advance device advances the ignition timing of the engine when the engine is idling, 2. The governor according to claim 1.

4. The advance angle device is a flat governor body fixed concentrically to the mounting bolt; a pair of timing advance members disposed concentrically opposite the mounting bolt and having base ends rotatably fixed to the governor body, a tip end side of each of the pair of timing advance members is attached to a base end side of the other timing advance member via an elastic member, The pair of timing advance members are configured such that the elastic members are stretched and expanded in diameter by the rotational force of the camshaft after the engine is started, thereby advancing the ignition timing of the engine.

2. The governor according to claim 1.

5. The advance angle device is a movement restricting portion that restricts movement of the tip end side of each of the pair of advance members, The pair of advance members have the movement restricting portion restricting extension of the elastic members due to the rotational force of the camshaft, thereby fixing the advance of the ignition timing of the engine.

5. The governor according to claim 4.

6. the movement restricting portion has a pair of openings formed in the governor body and a pin body fixed to a tip end of each of the pair of timing advance members, and the pin body is inserted into the openings to fix the advance of the ignition timing of the engine.

6. The governor according to claim 5.

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