JPH0447424Y2 - - Google Patents

Description

[Detailed explanation of the idea] Technical field The present invention relates to internal combustion engines.

BACKGROUND ART When controlling, for example, ignition timing in an internal combustion engine, it is already known to control the ignition timing by controlling the rotation angle of the crankshaft. A device often used to detect the rotation angle of a crankshaft is a rotary disk for ignition signal generation, which is attached to the end of the crankshaft coaxially with the crankshaft and has regular shape changes in the circumferential direction. , and a pickup coil for generating an ignition signal that cooperates with the rotary disk to generate an electric signal in response to the regular shape change.

As a rotation angle detecting device having such a configuration, for example, the applicant of the present application has disclosed Utility Model Application No. 57-152911.
In the internal combustion engine proposed as 58240), the end of the crankshaft was made to protrude outside the engine case, the rotary disk was attached to this protruding part, and the rotary disk was further installed in a small case provided separately from the engine case. The structure is such that it surrounds the pick-up coil. Therefore, there was a problem in that the overall size of the internal combustion engine was increased by the amount occupied by the small case.

On the other hand, in an internal combustion engine, a power transmission means is provided for driving a valve train including a camshaft in synchronization with the crankshaft. It consists of two toothed belt pulleys as rotation transmission members fixed to one end, and a toothed belt wrapped around both toothed belt pulleys. In such a configuration, in order to synchronize the operation timing of the valve train, it is necessary to set the mounting angular position of each toothed belt pulley with respect to each shaft with high precision. Note that this work becomes more complicated as the number of cylinders increases. In addition to this work, in order to adjust the timing of the ignition signal system, the mounting angle position of the rotary disk with respect to the crankshaft must be set with high accuracy.The internal combustion engine is capable of efficiently performing each of these tasks. development was desired.

Purpose of the invention The present invention was made in view of the above points, and its purpose is to easily achieve miniaturization and to perform timing setting work for the valve train and ignition signal system with high efficiency. The objective is to provide an internal combustion engine that can

Structure of the invention The internal combustion engine according to the invention has a plurality of cylinders provided in a direction perpendicular to the crankshaft and in both directions with the crankshaft as the center, and a shaft end on one side of the crankshaft. An internal combustion engine having a rotation transmission means for driving a valve train of the cylinders in both directions, and a rotation transmission means housing chamber housing the rotation transmission means, the rotation transmission means including a pair of rotation transmission members. the pair of rotation transmitting members and a rotary disk for starting an ignition signal disposed between the pair of rotation transmitting members are fixed coaxially to the end of the shaft, and the pickup coil for starting an ignition signal is fixed to the end of the shaft, and It is characterized in that it is housed in a transmission means storage chamber and is disposed facing the rotary disk from the outer circumferential side.

Embodiments Hereinafter, an internal combustion engine as an embodiment of the present invention will be described with reference to the accompanying drawings.

As is clear from FIGS. 1 to 3, the internal combustion engine is a horizontally opposed four-cylinder engine of the overhead camshaft type. As shown,
It has a total of four cylinders, two in each direction perpendicular to the crankshaft 1 and centered around the crankshaft.

As shown in the figure, one shaft end of the crankshaft 1 protrudes outside the crankcase 3 via an oil seal 2, and a pair of cylindrical rotation transmitting members are provided at the shaft end. Drive pulleys 4, which are toothed pulleys, are fitted and inserted one on top of the other. A timing belt 28, which is a toothed belt, is wound around each of these drive pulleys to drive a valve train including a camshaft, which will be described later. As is particularly clear from FIGS. 4 and 5 a and b,
Both drive pulleys 4 are molded to have the same shape and size, and have teeth 5 formed on their outer peripheries. A key portion 6 is protruded from the inner circumferential surface of the drive pulley 4, that is, the fitting surface with the crankshaft 1. By fitting these, rotation of the drive pulley 4 with respect to the crankshaft 1 is restricted. Note that an annular recess 8 is formed on both end surfaces of the drive pulley 4 for thinning.

Two disk members 10 are provided to sandwich the pair of drive pulleys 4 from both sides, and an ignition signal made of another magnetic material is sandwiched between the mutually opposing sets of both drive pulleys. A transmitting rotary disk 11 is provided. These disk member 10 and rotary disk 11 are connected to drive pulley 4, bolt 12 and washer 13.
are jointly tightened to the crankshaft 1 by the respective disc members 10 and rotary disc 11.
The movement of the crankshaft 1 in the axial direction is restricted. As shown in FIGS. 6a and 6b, the rotary disk 11 held between the two drive pulleys 4 has a key portion 15 at the fitting portion with the crankshaft 1.
is provided protrudingly, and the key portion engages with the keyway 7 of the crankshaft 1. That is, the rotary disk 11 rotates together with the crankshaft 1. On the outer peripheral edge of the rotary disk 11, projections 16 are formed at constant pitches, for example, at intervals of 45 degrees in the circumferential direction. Each of these protrusions 1
A pickup coil 17 for generating an ignition signal is disposed corresponding to 6, and is attached to the crankcase 3 via a predetermined fixing member (not shown). This pick-up coil 17 cooperates with the rotary disk 11 to generate an electric signal, in this case a pulse signal, in accordance with the regular shape change in the circumferential direction of the rotary disk due to the provision of the plurality of projections 16 described above. Incidentally, the pick-up coil 17 emits eight pulses per revolution, and the emitted pulse signals are transmitted to the control circuit section along with electric signals sent from other pick-up coils to be described later, and the control circuit receives these electric signals. For example, it is used to detect a crank angle for ignition timing control or fuel injection control.

On the other hand, a pair of camshafts 20 are disposed on both left and right sides of the engine body, and are rotatably held by a cylinder head 22 and a cylinder head cover 23. One end of both camshafts 20 is connected to a cylinder head 22 and a cylinder head cover 2.
Timing pulleys 25 each consisting of a toothed belt pulley are attached to the projecting portions by bolts 26 and washers 27, respectively.

A timing belt 28 consisting of a toothed belt is attached to the drive pulley 4 and the timing pulley 25 in order to rotate the camshaft 20 in synchronization with the crankshaft 1.
is being passed around. The above-mentioned disk member 10 is connected to the timing belt 2 together with the rotary disk 11.
It acts to prevent lateral slippage of the drive pulley 4 of 8. Further, a tensioner 29 and a tensioner spring 30 are provided between each drive pulley 4 and the timing pulley 25 for applying a predetermined tension to the timing belt 28. In addition, drive pulley 4, rotary disk 1
1, timing pulley 25, timing belt 2
8, tensioner 29, etc., are covered by a cover 33 that constitutes an engine case 32 together with the crankcase 3, cylinder head 22, cylinder head cover 23, and the like. This cover 33
The space defined by is called a rotation transmission means storage chamber.

Incidentally, the pick-up coil 17 is also housed in this rotation transmission means storage chamber, and the drive pulley 4
and are opposed to the outer periphery of the rotary disk 11.

As shown in FIG. 1, the other end of one of the pair of camshafts 20 is projected to the outside of the engine case 32 via an oil seal 35, and the projecting end has a A rotary disk 36 made of a magnetic material and having a predetermined shape change in the circumferential direction is attached coaxially to the camshaft with a screw. A pick-up coil 37 is arranged corresponding to the predetermined shape change. These are provided to detect compression top dead center and generate one rotation pulse. These rotary disk 36 and pick-up coil 37 are surrounded by a small case 40 formed by screwing together a pair of bowl-shaped members 38 and 39. Note that the small case 40 includes the cylinder head 22 and cylinder head cover 23.
is fixed with screws. As mentioned above, the control circuit controls the ignition timing or fuel injection based on the electric signals sent from the pickup coil 37 and the pickup coil 17 mentioned above.

In the figure, reference numbers 42, 43, 44 and 45 respectively indicate a piston, a connecting rod, an intake valve and an exhaust valve, and reference numbers 46,
Reference numerals 47, 48, 49 and 50 indicate a generator, a transmission, a clutch, an output shaft and an injector, respectively.

Further, in the above embodiment, the protrusions 16 are formed on the outer peripheral edge of the rotary disk 11 at a constant pitch in the circumferential direction, but as shown in FIGS. A disk 48 may be installed. This rotary disk 48 is used only for ignition timing control, and the width L of the protrusion determines the advance width. In this case, the rotary disk 36, pickup coil 37, etc. on the camshaft 20 side become unnecessary.

Effects of the invention As detailed above, in the internal combustion engine according to the invention, the pair of rotation transmission members for driving the valve train and the rotary disk for starting the ignition signal are fixed to the same end of the crankshaft. Moreover, since it is stored in one rotation transmission means storage chamber, the timing adjustment work of the valve train system and ignition signal system, that is, the work of positioning the rotation transmission member and the disk in the rotational direction with respect to the crankshaft can be carried out sequentially and efficiently. This allows you to shorten your work time.

In addition, in the internal combustion engine according to the present invention, the rotary disk and the pick-up coil are arranged in the rotation transmission member storage chamber to effectively utilize the storage chamber, so it is necessary to secure a special installation space for the ignition signal transmitter. This helps make the engine more compact.

Furthermore, in the internal combustion engine according to the present invention,
Since the disk is fixed to the end of the crankshaft in the storage chamber together with the rotation transmission member, and the pick-up coil is opposed to the rotation transmission member and the disk from the outer circumferential side, it is necessary to extend the crankshaft specially for the ignition signal transmitter. This means that the engine does not become larger.

Furthermore, by making the rotary disk for ignition signal transmission placed between the drive pulleys, which are a pair of rotation transmission members, also serve as a member to prevent the timing belt from slipping laterally, which is wrapped around each drive pulley, it can be used for the purpose of transmitting the ignition signal. Of course, it is possible to prevent wear and damage due to lateral displacement of the timing belt, and there is no need to provide separate lateral displacement prevention members between the pair of drive pulleys and the rotary disk for transmitting the ignition signal.
The number of parts is reduced, the end shaft length of the crankshaft can be correspondingly shortened, and the engine as a whole can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an internal combustion engine according to the present invention, FIGS. 2 and 3 are a left side view and a cross-sectional view including a partial cross section of FIG. 1, and FIG. 4 is a partial cross-sectional view of the internal combustion engine according to the present invention. Detailed views of main parts, Figures 5a and 5b are front sectional views and side views of the drive pulley, respectively.
Figures a and b are a front sectional view and a side view of the disc member, and Figures 7a and b are views showing other examples of the disc member. Explanation of symbols of main parts, 1...Crankshaft, 4
...Drive pulley (rotation transmission member), 11...
Rotary disk, 16...protrusion, 17...pickup coil, 20...camshaft, 25...timing pulley, 28...timing belt.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of cylinders are provided in a direction orthogonal to the crankshaft and in both directions with the crankshaft as the center, and a shaft end on one side of the crankshaft is provided. An internal combustion engine having a rotation transmission means for driving a valve train of the cylinders in both directions, and a rotation transmission means housing chamber housing the rotation transmission means, the rotation transmission means including a pair of rotation transmission members. the pair of rotation transmitting members and a rotary disk for transmitting an ignition signal disposed between the pair of rotation transmitting members are fixed to the end portion of the shaft by a moving shaft; An internal combustion engine, characterized in that a rotation transmission means is housed in a storage chamber and is disposed facing the rotary disk from the outer peripheral side. (2) The rotation transmitting means includes a pair of drive pulleys and belts each wrapped around the pair of drive pulleys, and the ignition signal transmitting rotary disk is held between the pair of drive pulleys. An internal combustion engine according to claim 1 of the utility model registration claim.