JP2704644B2 - Engine starter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine starter, and more particularly to an engine starter used in a four-cycle gasoline engine started by a starter motor.

2. Description of the Related Art FIG. 19 schematically shows a conventional starting device for a four-cycle gasoline engine of this kind. Engine body (1)
A flywheel (4) integrally formed with a cooling fan (3) is attached to a more protruding crankshaft (2). A ring gear (5) is attached to the outer periphery of the flywheel (4). A starter motor (6) having a body part substantially the same length as the width of the engine body (1) is attached to a side surface part of the engine body (1), and a drive shaft () protruding from the starter motor (6). The drive gear (8) is fixed to 7). When the starter motor (6) is driven, the shaft (7) protrudes, the drive gear (8) meshes with the front ring gear (5), and rotates the crankshaft (2) via the flywheel (4). Let it. When the engine is started, the clutch structure is such that the drive shaft (7) retracts to its original state and disengages from the ring gear (5). The power for driving the starter motor (6) is supplied from the engine body (1).
A battery having a size of about half of is separately prepared and connected to the starter motor (6) for use.

Problems to be Solved by the Invention As described above, a conventional four-stroke gasoline engine requires a starter motor (6) having a main body having substantially the same width as the engine main body (1). When (6) is attached to the engine body (1), there is a disadvantage that the outer shape of the entire engine becomes very large. Further, in order to drive such a large starter motor (6), similarly, a large power supply battery is required, and conventionally, it is difficult to attach the battery to the engine body (1) as described above. However, there is a drawback that must be provided separately. Further, in the case of the engine for mounting the work machine, there are those of the recoil starter specification and those of the starter motor specification, but in the case of the starter motor specification, a special spacer for mounting the battery is required, Therefore, for example, it is difficult to easily mount an engine of a starter motor specification on a work machine of a recoil starter specification, and there is a disadvantage that wiring work between the battery and the starter motor is required.

In the case of a very small two-cycle engine of 50 cc or less, a small starter motor and a battery are attached to the engine body, but in a small four-cycle gasoline engine of about 50 cc to 250 cc, such a thing is not used. No, it was not possible.

The present invention solves the above-described inconvenience of the conventional four-stroke gasoline engine, so that even when a starter motor is mounted, the whole can be compactly incorporated into the engine body with a battery. It was made.

Means for Solving the Problems That is, in order to achieve the above object, in the present invention, 4
In the cycle gasoline engine, the starter motor is mounted on the recoil starter case on the same side of the engine body as the recoil starter and above the center of the horizontal crankshaft. And the battery may be arranged side by side. Further, the starter motor may be mounted such that its axis is in a direction orthogonal to the direction of the crankshaft.

According to the configuration of the present invention described above, by providing the starter motor above the center of the crankshaft, a general-purpose engine or the like can be protected from dust, dirt, mud and water below. Further, since the starter motor and the recoil starter are provided on the same side with respect to the engine main body, the entire engine can be made compact.

Embodiments FIGS. 1 and 2 show an elevational view of an entire engine showing an embodiment of the present invention, in which a cylinder center line Q is inclined with respect to a crankshaft center P in an oblique direction. 4
It is a cycle gasoline engine. The fuel tank (12) is located above the engine body (11) just above the center P of the crankshaft.
Is mounted, and an exhaust silencer (13) is mounted on an upper portion of the cylinder head on the side thereof. A fan case (19) is mounted on one side surface in the direction of the crankshaft center P, and a recoil starter (14) is mounted on a side surface of the fan case (19). An air cleaner (15) disposed above the crankshaft center P and on the side of the cylinder head on the same side as the recoil starter (14);
A starter motor (16) is attached to the recoil starter (14), and a battery (17) is attached below the starter motor (16). Also, on the upper side of the recoil starter (14),
The handle (18) for pulling the starting rope is protruding.

FIG. 3 shows the internal structure of the recoil starter (14) and the fan case (19). A flywheel (24) provided with a cooling fan (23) is attached to an end of a crankshaft (22) projecting from the engine body (11). A driven member (25) is fixed to a side surface of the flywheel (24) with a bolt (26) and protrudes into a dish-shaped recoil starter case (27). At the center of the ceiling of the recoil starter case (27), a starter wheel (30) around which a rope (29) is wound is rotatably fitted around a shaft (28) protruding from the ceiling. Further, the large deceleration gear (33) and the driving member (34) are rotated together with the shaft (32) fixed to the end surface of the shaft portion (28) via the screw (31) so as to rotate together. It is fitted. The driving member (34) and the driven member (25) are linked to each other via a first clutch (35). The large deceleration gear (33) and the starter wheel (30) are connected to each other via a second clutch (36). These first and second clutches (35)
An intermediate shaft (37) is pivotally supported on the side of (36), that is, at an obliquely upper part of the center P of the crankshaft, and the intermediate shaft (37) has a small diameter that constantly meshes with the large gear (33). The intermediate pinion (38) and another driven intermediate gear (39) are mounted so as to rotate together. Between the intermediate pinion (38) and the intermediate shaft (37), another third clutch (4
7) is provided. The starter motor (16) has a motor body (41) mounted inside a motor case (40) integrally formed with a recoil starter case (27), and a motor shaft (41) protruding from the motor body (41). 42)
A drive pinion (43) is attached to the end of the driven pinion (43), and the driven pinion (43) is supported between the motor case (40) and an extension of the recoil starter case (27).
4) meshes with the upper gear (45), and this driven shaft (44)
An upper pinion (46) meshes with the driven gear (39) on the intermediate shaft (37).

In the configuration shown in FIG. 3, when the starter motor (16) is driven, the gears (45) and (46) on the driven shaft (44) and the intermediate shaft ( 37)
In the order of the upper driven gear (39) and the pinion (38), rotation is transmitted while decelerating, and further transmitted from the pinion (38) on the intermediate shaft (37) to the large gear (33) while being greatly reduced. At the same time, rotation is transmitted to the crankshaft (22) side via the first clutch (35) between the driving member (34) and the driven member (25), and the engine is started. When the engine is started, the first clutch (35) is automatically disengaged, so that the drive member (3) is disengaged from the crankshaft (22) side.
4) The side is not rotated. Also, when starting by the starter motor (16), the third clutch (47) is in the connected state, but the second clutch (36) is engaged with the large gear (3).
3) Since the power is not transmitted from the side to the starter wheel (30) side, this starter wheel (30)
Does not rotate. On the other hand, if the puller (18) is pulled out to pull out the rope (29), the starter wheel (30)
The rotation is transmitted from the second clutch to the large reduction gear (30), and the crankshaft (22) side is further turned from the first clutch (35) to start. At this time, rotation is transmitted from the large gear (33) to the pinion (38) meshing therewith, and the pinion (38) and the intermediate shaft (37)
The third clutch (47) is a one-way clutch mechanism in which rotation is not transmitted to the intermediate shaft (37), and the starter motor (16) is turned when the recoil starter (14) starts. It is not turned.

A battery (17) for driving the starter motor (16) is charged into a roughly hexagonal cylindrical case (49) into a rechargeable dry battery (50) (50) (50 )
. Are inserted and mounted. As shown in FIG. 5, engagement grooves (51) and (51) are formed on both upper and lower sides thereof. An engagement projection (52) made of a leaf spring, which engages with the one groove (51), is attached to a side surface of the motor case (40), and a recoil starter case (27) is provided on the opposite side. The lever (53) is attached to the side surface of. The lever (53) is urged by a spring (not shown) so that the tip always projects inside the mounting member (54). When the battery case (49) is inserted between the projection (52) and the lever (53), they are engaged with the grooves (51) and (51) by a spring action to hold the case (49). It has become. At that time, the positive and negative terminals (55) and (55) are provided on both sides of the upper groove (51) in the battery case (49).
On the other hand, also on the motor case (40) side, correspondingly, the plasma side and the negative side terminal (56) are protruded in an exposed state, so that the battery case (49) as described above. When the terminal is mounted, these terminals come into contact with each other, and the battery (17) and the motor (16) are connected to each other. As mentioned above, batteries (50) (50)
Are rechargeable, and the lever (53) is rotated to take out the battery case (49), whereby charging can be easily performed using a commercial power supply.

As shown in FIGS. 2 and 3, the starter motor (16) has a drive shaft (42) oriented in the same direction as the crankshaft (22) so that the side of the recoil starter case (27) The width in the direction of the crankshaft (22) is substantially the same as the width of the recoil starter case (27), and the size in the left-right direction is the same as that of the air cleaner (15) and the recoil starter ( 14), and the battery (17) is also large enough to fit within the width of the recoil starter case (27). Thus, the starter motor (1
Since the battery 6) and the battery 17 are very small, they can be stored very compactly even when they are mounted on the engine.

As shown in FIG. 7, the starter motor (16) and the battery (17) are integrally mounted on a recoil starter case (27), and the recoil starter (14), the motor (16) and the battery (17) are provided. As an integrated unit, and bolts (5) as shown in FIG.
9) Fix it to the side of the fan case (19) with (59).
In this case, in FIG. 3, except for the driven member (25) integrated with the flywheel (24), members outside the driving member (34) are integrally formed. They are connected to each other through (35). FIG. 8 shows a normal recoil starter unit (61) having no such starter motor (16) and battery (17), and a recoil starter case (27) shown in FIG. A recoil starter wheel (30), a large reduction gear (33), a second clutch (36), and the like, which are obtained by removing the member on the starter motor (16) side from the intermediate shaft (37), are provided. By replacing the unit (60) with the starter motor specification in Fig. 7 on the side of the fan case (19), the engine from the starter motor specification to the engine with the recoil starter specification or from the engine with the recoil starter specification to the starter motor specification It can be easily changed and installed on other engines.

Fig. 9 shows the starter motor (16) connected to the motor shaft (42).
Is attached to the recoil starter case (27) in the same manner as described above so that the direction is perpendicular to the center P of the crankshaft. In addition, the battery (17) is also mounted sideways in accordance with this. Starter motor (16)
Is very small compared to conventional ones,
Its shape is such that the size in the direction of the motor shaft (42) is larger in the diameter direction, and when mounted in the direction of the crankshaft in the above-mentioned FIGS. Or slightly more than that. Thus, by mounting in a horizontal direction in this way, it is possible to use the dead space between the air cleaner (15) and the recoil starter (14) so as to prevent the air cleaner (15) from completely projecting. As shown in FIG. 10, accordingly, the drive pinion (43) of the motor shaft (42) and the driven gear (45) on the driven shaft (44) meshing with the drive pinion (43) both use bevel gears. . A worm and a worm gear can be used instead of such a bevel gear mechanism.

11 and 12 show another embodiment of the present invention,
The handle (18) of the recoil starter (14) is shown housed in a recoil starter case (27). In this way, when the starter motor (16) is driven, the foil (30) on the recoil starter (14) side can be rotated, and accordingly, the starter motor (16) and the recoil There is an advantage that the second clutch (36) between the starters (14) is not required. The handle (18) is folded inside the opening (63) formed on the side surface of the recoil starter case (27). When the starting operation is performed, the handle (18) is connected to the opening (63). 63) Take out and operate as shown in Fig. 13. In these embodiments, the motor shaft (42) of the starter motor (16) is
Although it is mounted so as to be orthogonal to the center P of the crankshaft as in FIG. 9, it may be mounted in the same direction as the center P of the crankshaft as shown in FIGS. .

Next, the starter motor (16) and the battery (17)
A description will be given of a means for enabling the engine to be started in a low rotation range of 350 rpm or less in order to reduce the size to a size that can be accommodated within the width of the recoil starter (14) as described above.

As is well known, in order to turn the crankshaft of the engine at the time of starting, it is necessary to survive the compression step near the top dead center of the piston, which requires a very large force. In order to solve this, the exhaust valve or the intake valve is forcibly opened to release the compression. In the case of the present invention, an automatic decompression device which automatically releases the compression at the time of so-called low-speed rotation is used. Thus, the required capacity of the starter motor (16) can be reduced. An example of such an automatic decompression device is a centrifugal automatic decompression device filed by the applicant of the present invention as Japanese Patent Application No. 59-1139 (Japanese Patent Application Laid-Open No. 60-155696). This device is a centrifugal weight that is displaced along with the rotation of a camshaft, and moves a pin in the diameter direction of the shaft, and pushes up the tappet in a direction of decompression by this pin. Because of the movement in the decompression direction, decompression at start can be obtained without any special operation.

Next, FIG. 14 shows an electric circuit of the ignition power supply device used in the present invention. In the figure, a secondary coil (66) of an ignition coil (65) and a spark plug (67) are connected in series. On the other hand, at both ends of the primary coil (68), the collector and emitter terminals of the transistor (69) are connected in parallel with the primary coil (68). Similarly, the anode and cathode terminals of the thyristor (70) are connected in parallel to both ends of the transistor (69).
Further, the anode side of the thyristor (70) is connected to the base of the transistor (69). Both terminals of the Zener diode (71) are connected in parallel to the anode / cathode terminal of the thyristor (70), and the anode side of the Zener diode (71) is also connected to the gate terminal of the thyristor (70). FIG. 15 shows a voltage waveform generated in the primary coil (68). The voltage generator used in this embodiment is of a flywheel magnet type that generates an AC voltage with the rotation of the flywheel.
When the operating voltage Vo is equal to or less than 1), the transistor (69)
Voltage is applied to the base side of the transistor (69)
A current flows between the collector and the emitter. When the generated voltage exceeds Vo, a voltage is applied to the gate terminal of the thyristor (70), so that a voltage flows between the anode and the cathode of the thyristor (70) (in the direction of the dashed arrow in the figure) and the base of the transistor (69). The voltage drops, this transistor (69)
The current flowing between the collector and the emitter is cut off. Therefore, a large secondary voltage is generated in the secondary coil (66), and the ignition plug (67) is ignited.

As shown in FIG. 15, the voltage generated in the primary coil (68) changes according to the engine speed. For example, when the engine speed is about 250 rpm, the generated voltage is equal to the Zener diode (71). Operating voltage Vo. Therefore, the current flowing through the transistor (69) is not interrupted,
A large voltage cannot be generated in the secondary coil (66). Therefore, in this embodiment, a capacitor (72) as shown in the figure is provided in parallel with the Zener diode (71), and a peak point P of a voltage due to conversion of charging and discharging of the capacitor (72) is detected by a detection circuit. By the detection, at the time of low rotation where only a voltage lower than the voltage V _O is generated,
At the peak point P of the voltage, the transistor (6
9) A signal to release conduction is generated, and the primary coil (6
8) The current is cut to enable ignition.

Next, in order to prevent reverse rotation (ketchin) at the time of low-speed start, in this embodiment, in the flywheel magnet type ignition device, the shape of the iron core (73) around which the ignition coil (65) is wound is defined by: As shown in FIG. 16, the ignition timing at the time of low-speed rotation is retarded. That is,
In Fig. 16, the magnet (7
Opposite the lip (7)
5) The U-shaped iron core (73) provided with (76) is fixed, and the ignition coil (65) is wound around the iron core (73). In this embodiment, the flywheel (24) The length l ₁ of the lip (75) located on the rear side in the rotational direction is made larger than the length l ₂ of the other lip (76),
The waveform of the voltage generated by the primary coil (68) is deformed as shown in FIG. 17, so that the amount of retard at the time of low rotation is made larger than that in FIG. As shown in FIG. 14 and FIG. 15, at a low rotation of about 250 rpm or less below the operating voltage Vo, the peak point P of the voltage is detected, thereby generating a cutoff signal. in the waveform of FIG. 17, two peak points of the first peak point P ₁ and the second peak point P ₂ appears. In this case, when the cut off at the first peak point P _1, not yet sufficient retard amount relative to the firing angle theta ₁ at the maximum rotation, it is necessary to take the cut-off signal at the second peak point P ₂ This makes it possible to take the low speed rotation of the retard amount [Delta] [theta] = theta ₂ to - [theta] ₁ is increased, a sufficient retard amount that does not cause a reverse rotation as described above with respect to the maximum rotation range. Such detection of the second peak point P ₂ is, for example, a determining means for peak point to determine whether the first or second peak point is a peak point, based on the determination result of the determination means , Can be easily realized by using a microcomputer having control means for generating a cutoff signal of the transistor at the second peak point. Note that the specific retardation amount Δθ with respect to the maximum rotation performed in the example was 7 degrees.

In order to improve the ignition performance at low revolutions, in this embodiment, the voltage of the secondary coil (66) for igniting the ignition plug (67) is further increased from the conventional 8KV / 250rpm. This improves the ignition performance.

By the way, even if it is possible to ignite at low rotation and without reverse rotation, if the carburetor cannot supply a fuel amount of an appropriate air-fuel ratio into the cylinder at the low rotation, , Cannot be ignited.
Therefore, in this embodiment, as shown in FIG. 18, the diameter D ₁ of the venturi section (79) of the carburetor (78) is set to obtain an appropriate air-fuel ratio sufficient to ignite at a low rotation speed of 350 rpm or less. By making it smaller than the conventional one, the inflow speed in this part is increased to ensure that the fuel is sucked up from the nozzle (80). In addition, an appropriate air-fuel ratio can be obtained at low rotation speed even when the combination of the extraction position of the air jet (81) and the shape of the nozzle (80) is properly selected. It becomes possible.

By using such means in combination with all or some of them as appropriate, it is possible to start with a small torque in a low rotation range of 350 rpm or less, and accordingly, the required capacity of the starter motor (16) is reduced. It is possible to make the battery much smaller than the conventional one and the battery as well.

Effect of the Invention As described above, according to the present invention, the starter motor is mounted on the upper side of the center of the crankshaft. It is protected from mud and water and requires less length maintenance. In general, this type of engine usually has a dead space around the cylinder head on the upper side of the crankshaft and the lower part of the fuel tank, and such a dead space can be used to effectively arrange the engine. it can. In particular, since the starter motor is on the same side as the engine body together with the recoil starter, by arranging it in the dead space beside the recoil starter, unlike the one that extends from the recoil starter part to the engine body side, The entire engine can be made compact without projecting to the side of the engine body.

Further, according to the second invention of this application, since the starter motor and the battery are mounted side by side on the case of the recoil starter, they can be connected only by contacting the two terminals, and there is an effect that the wiring itself is not required. .

Further, in the third invention, since the starter motor is attached to the recoil starter with the longitudinal direction being transverse to the crankshaft, a dead space on the side of the recoil starter can be reduced without protruding in the crankshaft direction. It can be stored compactly by using.

[Brief description of the drawings]

1 is a front view of the entire engine showing an embodiment of the present invention, FIG. 2 is a side view of the engine as viewed from the right in FIG. 1, FIG. 3 is a cross-sectional plan view of a recoil starter and a fan case,
FIG. 4 is a perspective view of the battery, FIG. 5 is a vertical sectional view of a main part showing the same state of mounting the battery, FIG. 6 is a vertical cross-sectional view of a main part of a terminal connecting portion between the battery and the starter motor, and FIG. Is a perspective view of a recoil starter having a starter motor and a battery, FIG. 8 is a perspective view of a conventional recoil starter, FIG. 9 is a front view of the entire engine showing another embodiment of the present invention, FIG. FIG. 9 is a cross-sectional view of the recoil starter and the starter motor portion, FIG. 11 is a front view showing another example of the recoil starter, FIG. 12 and FIG.
FIG. 14 is a cross-sectional plan view of a main part of the recoil starter shown in FIG.
FIG. 1 shows a power supply circuit of an ignition device according to an embodiment of the present invention,
FIG. 15 is a graph showing a change in a generated voltage of an ignition device for performing ignition by a flywheel magnet system, and FIG. 16 is a schematic explanatory view of a flywheel magnet type power generation unit also used in the embodiment of the present invention. Figure 17 shows the 16th
FIG. 18 is a graph showing a waveform of a generated voltage obtained by the power generation device shown in FIG. 18, FIG. 18 is a longitudinal sectional view of a main part of a carburetor used in the embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional plan view of a main part of the engine, showing (14) ... recoil starter, (16) ... starter motor, (17) ... battery, (22) ... crankshaft.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hisayuki Sakaguchi 1-32 Chaya-cho, Kita-ku, Osaka-shi, Osaka Yanmar Diesel Co., Ltd. (56) References JP-A-63-285263 (JP, A) JP-A Sho-59-34480 (JP, A) Sho-sho 63-1834777 (JP, U) Sho-sho 63-183476 (JP, U) Sho-sho 49-136704 (JP, U) Sho-sho 49-135306 (JP) , U) Japanese Utility Model Showa 57-120760 (JP, U) Japanese Utility Model Showa 59-141168 (JP, U) Japanese Utility Model Showa 57-39555 (JP, Y2)

Claims (3)

(57) [Claims] In a four-cycle gasoline engine, a starter motor is mounted on a recoil starter case on the same side of the engine body as the recoil starter and above the center of the horizontal crankshaft. Engine starting device. 2. The engine starting device according to claim 1, wherein a starter motor and a battery are arranged side by side in a four-stroke gasoline engine. 3. The engine starter according to claim 1, wherein in the four-stroke gasoline engine, the starter motor is mounted such that the motor shaft is in a direction orthogonal to the center of the crankshaft.