JPH076488B2 - Ignition signal generator for internal combustion engine - Google Patents

Description

The present invention relates to an ignition signal generator for an internal combustion engine, and more particularly to an ignition signal generator for an internal combustion engine that obtains a pulse signal input from a pulse pickup to an electronic ignition timing control device. It is about.

(Prior Art) Conventionally, in a non-contact type or a capacitor discharge type ignition device, as disclosed in Japanese Patent Application Laid-Open No. 59-57458 previously filed by the applicant, a pickup for ignition timing detection is disclosed. Is provided in the crankcase, a protrusion is provided on the crankshaft facing the pickup, and when the protrusion passes through the pickup, an AC pulse is generated in the pickup. For example, when the AC pulse is in the positive direction, a high voltage is applied to the ignition coil. It is supposed to occur.

By the way, in recent years, the ignition device is provided with an electronic ignition timing control device that determines the ignition timing from the operating state of the internal combustion engine, intake pipe pressure, warm-up, and the like.

An ignition signal generator for an internal combustion engine equipped with this kind of ignition device has, for example, gear-shaped irregularities at equal intervals formed on the entire circumference of a crankshaft and a plurality of projections formed on the side surface. Japanese Laid-Open Utility Model Publication No. 57-75505 discloses a structure in which a rotating disc is arranged and a pulse pickup is provided so as to face the outer periphery of the disc.

(Problems to be solved by the invention) By the way, in the above-mentioned conventional one, it is necessary to form gear-shaped concavities and convexities at equal intervals on the rotating disk over the entire circumference and also to form a plurality of protrusions on the side surfaces. Therefore, the processing is troublesome, and no special consideration is given to how to mount the pulse pickup.

The present invention has been made in view of such problems of the prior art, and an object thereof is to provide a workability that allows a pulse signal to be easily obtained by the rotation of the crankshaft. It is an object of the present invention to provide an ignition signal generator for an internal combustion engine, which has a good pulse pickup assembling property and is safe and reliable.

(Means for Solving the Problem) In order to achieve the above object, an ignition signal generator for an internal combustion engine according to the present invention divides a crankcase, in which bearing walls are arranged at predetermined intervals, into upper and lower parts, and A through hole is formed in the side wall of the upper case in the vicinity of the bearing wall, a case body of the pulse pickup is embedded in the through hole, and the through hole is provided in a crank shaft rotatably supported in the bearing wall through a bearing. On the outer circumference of the crank wave facing the bearing wall, gear-shaped irregularities at equal intervals are formed over the entire circumference, and a partial convex portion of the irregularities is cut out by a predetermined width, and the pulse is formed on the irregular portion. The magnetic pole pieces of the pickup are arranged so as to face each other at a predetermined interval, and the pulse signal to be inputted to the electronic ignition timing control device is obtained by the pulse pickup.

(Operation) According to the present invention, gear-shaped irregularities at even intervals are formed on the outer circumference of the crank wave provided on the crank shaft rotatably supported on the bearing wall via the bearing and facing the bearing wall. Formed by cutting a part of the projections and depressions of a predetermined width, and arranging the pole pieces of the pulse pickup to face the projections and depressions at a predetermined interval, and electronic ignition by the pulse pickup. Since the pulse signal input to the timing control device is obtained, the internal combustion engine is ignited by determining the optimum ignition timing for the operating state based on the input pulse signal. Further, the gear-shaped irregularities and the notches having a predetermined width in the convex portions for obtaining the pulse signal can be easily machined with a normal gear cutting tool.

Further, in the case body of the pulse pickup, a crankcase in which bearing walls are arranged at predetermined intervals is divided into upper and lower parts, and a through hole is formed in the side wall of the upper case near the bearing wall to form the through hole. Since it is embedded in the bottom case, the mounting seal of the pulse pickup can be facilitated without being affected by the oil sump on the lower case side and without paying special attention to the oil. Further, since the case body of the pulse pickup can be embedded in the through hole of the upper case in a state of being divided into the upper and lower parts, the pulse pickup can be easily assembled and the cord can be easily taken out from the pulse pickup. Further, since the through hole for the case body of the pulse pickup is formed in the side wall of the upper case in the vicinity of the bearing wall, the through hole exists in a rigid portion near the bearing wall to weaken the case side wall. Never.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing a state in which an upper case of an internal combustion engine crankcase is removed, and FIG. 2 is a side view showing an arrangement state of a pulse pickup and a crank gear.

In the figure, reference numeral 1 is a crankcase, and the crankcase 1 is constructed by joining and fixing an upper case 2 and a lower case 3. Bearing walls 4 are arranged at predetermined intervals inside the crankcase 1, and a crankshaft 5 is rotatably supported by a side wall 1a of the crankcase 1 and the bearing wall 4 via bearings 6. This bearing 6 is of a split type in which two semi-circular plate-shaped metals are combined.

The crank webs 7 provided on the crank shafts 5 are arranged in the crank chambers defined by the respective bearing walls 4, and the crank pins 8 formed between the crank webs 7 are not shown by the connecting rods 9. It is connected to the piston. Therefore, the linear movement due to the vertical movement of the piston is converted into the rotational movement via the connecting rod 9, and the crankshaft 5 is rotated.

The crankshaft 5 is provided with a gear 11 which is connected to a starter motor (not shown) by a chain 10. A gear 12 is provided in the vicinity of the gear 11, and is connected via a chain 13 to a cam shaft that opens and closes an intake / exhaust valve (not shown).

The crank gear 14 of the crank shaft 5 is formed on the crank web 7, and the crank gear 14 meshes with the clutch gear 15 to transmit the rotational force of the crank shaft 5 to the clutch mechanism 16. The teeth 14a of the crank gear 14 are composed of a large number of irregular portions arranged at equal intervals, and a notch 17 of a predetermined width is formed in one tooth 14b. I have come to know the dead point.

A pulse pickup 18 is provided on a side wall 2a of the upper case 2 constituting the crankcase 1 in the crankshaft direction. The pulse pickup 18 is a well-known one in which a pole piece 18b and a coil 18c are built in a case body 18a. The pulse pickup 18 is arranged at a position facing the crank gear 14 so as to be integrated with the side wall 2a of the upper case 2. That is, the through hole 19 is formed in the side wall 2a of the upper case 2,
The case body 18a of the pulse pickup 18 is inserted into the through hole 19.
Is embedded, and the tip of the pole piece 18b is crank gear 1
It faces 4 at a predetermined interval.

The pulse pickup 18 is configured so that when the unevenness formed by the teeth 14a of the crank gear 14 passes through the magnetic pole piece 18b, the output voltage changes and a pulse signal corresponding to the unevenness is generated. This pulse signal is used by the electronic ignition timing control device 20.
The ignition timing is determined from the pulse signal, the intake pipe pressure, etc., and a primary current cutoff signal is sent to the igniter 21 to ignite the ignition plug 22.

Next, the operation of this embodiment will be described.

The crankshaft 5 is rotated via the connecting rod 9 by the vertical movement of a piston (not shown), and the rotational force of the crankshaft 5 is transmitted from the crank gear 14 to the clutch gear 15. As the crank gear 14 rotates, its teeth 14a pass through the magnetic pole pieces 18b of the pulse pickup 18, and the unevenness of the teeth 14a changes the output voltage from the coil 18c, so that a pulse signal corresponding to the unevenness is output. Therefore, the pulse signal associated with the rotation of the crank gear 14 is input to the electronic ignition timing control device 20, and the microcomputer included in the electronic ignition timing control device 20 calculates the engine speed based on this pulse signal. The ignition timing according to the operating state is determined from the intake pipe pressure and the like, and a primary current cutoff signal is sent to the igniter 21.

3 to 4 show another embodiment in which a large number of uneven portions are arranged on the crank web of the crank shaft.

FIG. 3 shows a structure in which a large number of teeth 7a at equal intervals are integrally formed on the outer periphery of the crank web 7 of the crankshaft 5 to form a concavo-convex portion. A notch 17 is provided for positioning the dead point. The crank web 7 having the teeth 7a is located on the side walls 2b, 3a of the upper case 2 and the lower case 3 which pivotally support the crank shaft 5, and the pulse pickup 18 is a side wall of the upper case 2 in the crank axis direction. It is located at 2a.

FIG. 4 shows another embodiment in which the uneven portion is not directly formed on the crank web.

An annular step portion 7b is formed on the outer periphery of the crank web 7 on the side wall side that pivotally supports the crank shaft 5 by casting or cutting. An annular member 23 is press-fitted and provided in the step portion 7b, and teeth 23a at equal intervals are formed on the outer circumference thereof.

The pulse pickup 18 is arranged at a position facing the teeth 23a, and is provided on the side wall in the crankshaft direction.

(Effects of the Invention) As described above, the present invention provides gears with equal intervals on the outer circumference of the crank wave provided on the crank shaft rotatably supported by the bearing wall via the bearing and facing the bearing wall. -Shaped unevenness is formed over the entire circumference, a convex portion of a part of the unevenness is cut out by a predetermined width, and the magnetic pole pieces of the pulse pickup are arranged facing the uneven portion at a predetermined interval, Since the pulse pickup receives the pulse signal input to the electronic ignition timing control device, the internal combustion engine is ignited by determining the optimum ignition timing for the operating state based on the input pulse signal. And to get the pulse signal,
The gear-shaped concavo-convex and the notch of a predetermined width in the convex part of the gear can be easily machined by a normal gear cutting tool.

Further, in the case body of the pulse pickup, a crankcase in which bearing walls are arranged at predetermined intervals is divided into upper and lower parts, and a through hole is formed in the side wall of the upper case near the bearing wall to form the through hole. Since it is embedded in the bottom case, the mounting seal of the pulse pickup can be facilitated without being affected by the oil sump on the lower case side and without paying special attention to the oil. Further, since the case body of the pulse pickup can be embedded in the through hole of the upper case in a state of being divided into the upper and lower parts, the pulse pickup can be easily assembled and the cord can be easily taken out from the pulse pickup. Further, since the through hole for the case body of the pulse pickup is formed in the side wall of the upper case in the vicinity of the bearing wall, the weakening of the case side wall is prevented by the existence of the through hole in the rigid portion near the bearing wall. As a result, a safe and reliable ignition signal generator for an internal combustion engine is obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which an upper case of an internal combustion engine crankcase is removed, FIG. 2 is a sectional view showing an arrangement state of a pulse pickup and a crank gear, and FIG. FIG. 4 is a view showing an embodiment in which uneven portions are formed at equal intervals, and FIG. 4 is a view showing another embodiment in which the uneven portions are not directly formed on the crank web. 1 ... Crank case, 2 ... Upper case 2a, 2b ... Side wall, 3 ... Lower case, 4 ... Bearing wall 5 ... Crank shaft, 7 ... Crank web 7a ... Teeth, 7b ... Step section 14 …… Crank gear, 14a …… Tooth 17 …… Notch 18 …… Pulse pickup, 18a …… Case body, 19…
… Through hole 20 …… Electronic ignition timing controller 23 …… Ring member, 23a …… Tooth

Claims (1)

[Claims] 1. A crankcase, in which bearing walls are arranged at predetermined intervals inside, is divided into upper and lower parts, and a through hole is formed in the side wall of the upper case in the vicinity of the bearing wall. A case body is embedded, and gear-like irregularities at even intervals are provided on the entire circumference on the outer circumference of a crank wave provided on a crank shaft rotatably supported on the bearing wall via a bearing and facing the bearing wall. Formed by cutting a part of the projections and depressions of a predetermined width, and arranging the magnetic pole pieces of the pulse pickup so as to face the projections and depressions at a predetermined interval, and an electronic ignition timing by the pulse pickup. An ignition signal generator for an internal combustion engine that obtains a pulse signal input to a control device.