JP3140639B2 - Apparatus for detecting ignition timing in internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the timing of ignition timing with respect to the movement of a piston in an internal combustion engine.

[0002]

2. Description of the Related Art In general, the detection of the ignition timing with respect to the movement of a piston is carried out by mounting a mark on a crankshaft or providing a mark on the outer peripheral surface of a rotating body rotating in conjunction with the crankshaft to indicate the position of the optimum ignition timing. On the other hand, a pointer for the mark is provided on a fixed portion on the side of the internal combustion engine.
By irradiating a flashing timing light with a current to the ignition plug in the specific cylinder, whether or not the mark that appears stationary when the timing light flashes matches or deviates from the pointer on the fixed side. Or to detect.

In this conventional ignition timing detection device, for example, as described in Japanese Utility Model Laid-Open Publication No. 59-58776, the pointer on the fixed side is made of a thin metal plate, and this is used as a cylinder block. Alternatively, it is configured to be attached to an internal combustion engine side such as a timing chain cover by a bolt or the like.

[0004]

However, as described above,
If the fixed side pointer is made of a thin metal plate and is attached to the internal combustion engine side such as a cylinder block or a timing chain cover, not only the number of parts increases but also the It requires a lot of trouble to attach to the surface, and since the fixed side pointer is a thin metal plate, the mark on the outer peripheral surface of the rotating body can be seen through the pointer even if the line of sight is inclined. However, there is a problem that an error easily occurs in the detection.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem by simultaneously forming a fixed-side pointer when casting a cast cylinder block or a timing chain case of an internal combustion engine. It is.

[0006]

SUMMARY OF THE INVENTION In order to achieve this technical object, the present invention relates to a method for mounting an optimum ignition timing on an outer peripheral surface of a rotating body which is attached to a crankshaft or rotated in conjunction with the crankshaft. While the mark shown is provided, a projection constituting a pointer on the fixed side with respect to the mark is integrally provided on the cylinder block or the timing chain cover made of casting so as to project toward the outer periphery of the rotating body. In the portion, a wide groove opening on the tip end surface of the projection, and a narrow groove opening in the wide groove at the center in the width direction of the wide groove, furthermore, the inner width dimension in the wide groove And the ignition timing is set within the allowable range. "

[0007]

In this configuration, when a mark that appears to be stationary due to the flash of the timing light is viewed through the wide groove and the narrow groove in the projection, the mark is inserted into the narrow groove of the two grooves. When the mark is positioned, it is determined that there is no shift in the timing of the ignition timing, and when the mark is located in the wide groove out of the narrow groove of the two grooves, the shift in the timing of the ignition timing is determined. It is possible to know that the ignition timing is out of the allowable range when the mark is out of the wide groove of the two grooves. is there.

In this case, the wide groove in the projection is provided so as to open at the tip end surface of the projection,
By providing the narrow groove so as to open in the wide groove, the protrusion provided with the wide groove and the narrow groove can be simultaneously formed when the cylinder block or the timing chain cover made by casting is cast. It can be formed in a form in which a wide groove and a narrow groove are provided in the portion.

In addition, by forming the projection by casting in a form in which a wide groove and a narrow groove are provided, the thickness of the projection can be increased, so that the mark on the outer peripheral surface of the rotating body is formed. When looking through the wide groove and the narrow groove in this protrusion, the mark cannot be seen unless the line of sight is directed straight in the thickness direction of the protrusion,
In other words, when the mark is seen through the wide groove and the narrow groove, and the line of sight is in a substantially straight state, it is possible to reliably reduce the occurrence of an error in detection.

[0010]

Therefore, according to the present invention, it is possible to accurately detect whether the timing of the ignition timing is correct and whether or not the deviation of the timing of the ignition timing is within an allowable range. This has the effect of preventing an increase in the number of assembling steps.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this figure, reference numeral 1 denotes a cast cylinder block in a multi-cylinder internal combustion engine;
Indicates a crankshaft supported by a bearing 3 in the cylinder block 1;
A timing chain cover 5 made of a casting, which covers the entirety of the timing chain 4 described later, is joined to the side surface of the cylinder with a plurality of bolts. Bread 6 is joined.

The shaft end 2a of the crankshaft 2 is
A pulley 7 for transmitting power to an engine accessory such as a cooling water pump (not shown) is fitted to the protruding end of the shaft end. A sprocket 8 is fitted to a portion of the inside of the timing chain cover 5 of 2a,
A timing chain 4 for transmitting power to a camshaft (not shown) is wound around the sprocket 8. Reference numeral 9 denotes a lubricating oil pump provided at a portion where the shaft end 2a penetrates the timing chain cover 5.

A mark 10 is provided on the outer peripheral surface of the pulley 7 to indicate the timing of the optimal ignition timing in a specific cylinder among the cylinders, while a projection 11 is provided on the outer surface of the timing chain cover 5. The protrusion 11
Are integrally provided so as to protrude toward the outer periphery of the pulley 7.
1a, a wide groove 12 having an appropriate inner width dimension L1 and a narrow groove 13 having an appropriate inner width dimension L0 opening in the wide groove 12 at the center of the wide groove 12 in the width direction. The inner width dimension L1 of the wide groove 12 is set to be within an allowable range of deviation of the ignition timing.

The slope 11b formed on the upper surface of the projection 11 is marked with a zero point (0) indicating that there is no shift in ignition timing. In this configuration, when the mark 10 that appears to be stationary with the flash of the timing light is viewed through the wide groove 12 and the narrow groove 13 in the protrusion 11, the mark 10
When the mark 10 is positioned within the narrow groove 13 of the two grooves 12 and 13, it is determined that the ignition timing does not deviate from the narrow groove 13 of the grooves 12 and 13. When it is located in the wide groove 12, it is possible to know that the deviation of the ignition timing is within the allowable range, and the mark 10 is positioned between the wide groove 12 and the wide groove 12. When it is farther out, it is possible to know that the timing of the ignition timing is out of the allowable range.

In this case, the wide groove 12 in the protrusion 11 is provided so as to open on the tip end surface 11a of the protrusion 11, while the narrow groove 13 is provided so as to open in the wide groove 12. Thus, the projections 11 having the wide grooves 12 and the narrow grooves 13 can be simultaneously formed when the timing chain cover 5 is cast.
1 can be formed in a form in which a wide groove 12 and a narrow groove 13 are provided.

The protruding portion 11 is provided with the wide groove 1.
2 and the narrow groove 13 are formed by casting, so that the thickness dimension T of the projection 11 can be increased, so that the mark 10 on the outer peripheral surface of the pulley 7 can be increased.
The wide groove 12 and the narrow groove 13 in the protrusion 11
When viewed through, as shown by the arrow A in FIG. 2, the mark 10 cannot be seen unless it is directed straight in the thickness direction of the protrusion 11, in other words, the wide groove 12 and the narrow groove When the mark 10 is visible through 13,
Because the line of sight is almost straight,
The occurrence of an error in the detection can be reliably reduced.

In the above-described embodiment, the mark 10 is provided on the pulley 7 for transmitting power to the engine accessory, while the protrusion 11 serving as a pointer on the fixed side with respect to the mark 10 is provided.
Is shown integrally with the timing chain cover 5, but the present invention is not limited to this, and the mark 10 is provided on a flywheel (not shown) attached to the output end side of the crankshaft 2. On the other hand, the projection 11 which is a pointer on the fixed side with respect to the mark 10 may be provided integrally with the cylinder block 1.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a side view taken along the line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view showing a main part of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Crankshaft 2a Shaft end part of crankshaft 3 Bearing part in cylinder block 4 Timing chain 5 Timing chain cover 7 Power transmission pulley 10 Mark 11 Projection 11a Tip surface of projection 12 Wide groove 13 Narrow groove

Continuation of the front page (56) References JP-A 62-90985 (JP, U) JP-A 64-13270 (JP, U) JP-A 3-68532 (JP, U) (58) Fields surveyed (Int .Cl. ⁷ , DB name) F02P 17/06

Claims (1)

(57) [Claims] 1. A mark indicating an optimum ignition timing position is provided on an outer peripheral surface of a rotating body which is attached to a crankshaft or rotates in conjunction with the crankshaft, while a mark is provided on a cast cylinder block or a timing chain cover. A protrusion that constitutes a pointer on the fixed side with respect to the mark is integrally provided so as to protrude toward the outer periphery of the rotating body. The protrusion has a wide groove that opens on the tip end surface of the protrusion, At the center in the width direction of the wide groove, a narrow groove that opens into the wide groove is provided.
An ignition timing detection device for an internal combustion engine, wherein the ignition timing is set within an allowable range of the deviation of the ignition timing.