JP2000248977A - Engine crank angle sensor - Google Patents

Abstract

(57) [Problem] To provide a crank angle sensor for an engine in which a clearance between a sensor plate and a sensor body can be accurately adjusted. SOLUTION: The crankshaft 2 is closest to a timing chamber.
Sensor plate 21 between No.1 journal and No.1 web
Install. The sensor body 22 is mounted on the side wall of the cylinder block 1 so as to face the sensor plate 21. The sensor main body 22 is disposed near the center of a region surrounded by the central axes of the crankshaft 2, the water pump 15, and the alternator 16, to effectively use the dead space between the engine accessories. A blow-by gas passage 45 is opened in the end wall of the cylinder block 1 on the timing chamber side so as to face the facing portion of the sensor plate 21 and the sensor body 22. In the engine assembling process, the opposing portions of the sensor plate 21 and the sensor main body 22 can be visually observed from the blow-by gas passage 45, so that the clearance therebetween can be accurately adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank angle sensor for detecting a rotational position of an engine crankshaft.

[0002]

2. Description of the Related Art When an engine of an automobile or the like is electronically controlled, it is necessary to accurately detect the rotational position of a crankshaft in order to use it as a base for fuel injection timing, ignition timing, cylinder discrimination, and the like. Therefore, conventionally, for example, an annular sensor plate provided with equally-spaced teeth on the outer peripheral portion is mounted so as to rotate integrally with the crankshaft, and a sensor main body such as a pickup coil is mounted facing the teeth on the outer peripheral portion of the sensor plate. Fixed,
2. Description of the Related Art There is known a crank angle sensor that obtains a rotational position of a crankshaft by detecting an electric pulse signal generated by rotation of a sensor plate.

[0003]

In such a crank angle sensor, the clearance between the sensor plate and the sensor body (usually about 0.8 mm to 1.3 mm) needs to be made accurately. In the case where the sensor body is fixed to the side wall of the cylinder block so as to be arranged in the crankcase so as to face the same, it is not possible to visually check the facing portion between the sensor plate and the sensor body. For this reason, the accuracy of the clearance depends on the mounting dimensions of the sensor plate and the sensor body, and there is a problem that it is difficult to control the accuracy of the clearance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an engine crank angle sensor in which a clearance between a sensor plate and a sensor plate can be visually checked after a sensor main body is assembled. Aim.

[0005]

According to a first aspect of the present invention, there is provided a sensor plate mounted on a crankshaft so as to rotate integrally therewith, and a sensor plate opposed to an outer peripheral portion of the sensor plate. A crank angle sensor of an engine for detecting a rotational position of a crankshaft having a sensor body fixed to a side wall of a cylinder block. An opening facing the portion is provided.

[0006] With this configuration, in the engine assembling process, the clearance between the sensor plate and the sensor main body can be visually observed through the opening provided in the partition of the crank chamber.

According to a second aspect of the present invention, in the configuration of the first aspect, the sensor plate is disposed at a position adjacent to the timing chamber in the crank chamber, and the sensor plate is provided on an end wall of the cylinder block on the timing chamber side. It is characterized in that the opening is provided.

With this configuration, the clearance between the sensor plate and the sensor main body can be visually checked through the opening provided in the end wall of the cylinder block.

According to a third aspect of the present invention, in the configuration of the first or second aspect, the opening is a blow-by gas passage.

[0010] Blow-by gas flows through openings provided in the partition in the crank chamber and the timing chamber.

According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the vicinity of the center of a region surrounded by a center axis of the crankshaft and an engine accessory driven by the crankshaft is provided. Wherein the sensor body is disposed.

With such a configuration, the dead space between the engine accessories can be effectively utilized.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. The first embodiment will be described with reference to FIGS. FIGS. 1 to 3 show the vicinity of the crankshaft on the timing mechanism side (opposite side of the flywheel) of the engine according to the present embodiment.
Is a cylinder block, 2 is a crankshaft, 3 is a bearing cap, 3A and 3B are bolts for attaching the bearing cap to the cylinder block 1, 4 is a cylinder liner,
Reference numeral 5 denotes a piston, 6 denotes a connecting rod, 7 denotes a water jacket, and 8 denotes an oil pan (only shown in FIGS. 2 and 3).

A timing sprocket 9 is attached to an end of the crankshaft 2 protruding from an end of the cylinder block 1. The timing sprocket 9 has a valve operating mechanism (not shown) of an intake / exhaust valve of a cylinder head. A timing chain 10 for driving the motor is wound. And
At the end of the cylinder block 1, there are a timing sprocket 9, a timing chain 10, and a timing chain.
A timing cover 11 that covers a timing mechanism formed by a cam sprocket (not shown) of a valve operating mechanism wound with 10.
(A part is cut away in FIG. 1) and is attached by a bolt 11A, and a timing chamber 12 is formed in the timing cover 11.

The distal end of the crankshaft 2 is inserted through the timing cover 11 to drive an oil pump 13 provided integrally with the timing cover 11. A crank pulley 14 is attached to a tip end of the crankshaft 2 protruding from the timing cover 11 to the outside. As shown in FIG. 1, a water pump 15 (engine accessory) is integrally provided on the side of the end face on the timing mechanism side of the cylinder block 1, and is provided on the side of the cylinder block 1 below the water pump 15. The alternator 16 (engine accessory) is mounted via a bracket 16A (only part of which is shown in FIG. 1). And crank pulley 1
4, water pump pulley 17 and alternator pulley 1
A V-belt 19 is wound around 8, and the water pump 15 and the alternator 16 are driven by the crankshaft 2.

Next, the configuration of the crank angle sensor 20 will be described. The crank angle sensor 20 includes a disc-shaped sensor plate 21 that rotates integrally with the crankshaft 2, and a sensor plate 21.
And a sensor body 22 for detecting the rotation of the sensor 21. In the crank chamber formed by the cylinder block 1 and the oil pan 8, the sensor plate 21 is a No. 1 journal 23 of the crankshaft 2 (the timing chamber 12).
At the position adjacent to the crankshaft 2, that is, between the No. 1 journal 23 and the No. 1 web 24 of the counterweight (the web closest to the timing chamber 12). It is designed to rotate together. The sensor plate 21 is a crankpin of the crankshaft 2
The outer peripheral portion extends to the vicinity of the inner wall of the crankcase with a diameter larger than that of the web of the counterweight 25 and the counterweight, and a plurality (eight in the illustrated case) of external teeth 26 project at predetermined intervals from the outer peripheral portion. A plurality of lightening holes 21a are provided for weight reduction.

The sensor body 22 of the crank angle sensor 20 has a pickup section 27 having a predetermined clearance (normally 0.8 mm).
(Approximately 1.3 mm) and into the mounting hole 28 provided on the side wall of the cylinder block 1 so as to face the outer peripheral portion of the sensor plate 21.
Installed by. Further, the sensor main body 22 is disposed substantially at the center of a region surrounded by the respective central axes of the crankshaft 2, the water pump 15, and the alternator 16. The sensor main body 22 can output an electric pulse signal in accordance with the rotation of the sensor plate 21 using, for example, a pickup coil or the like.

As shown in FIGS. 4 to 6, the crank chamber in the cylinder block 1 communicates with each cylinder bore by three partitions 31, 32, 33 (see FIG. 6).
It is partitioned into two crank chambers 34a, 34b, 34c, 34d. End wall 35 of cylinder block 1 on timing chamber 12 side
The (partition) is provided with a bearing portion 36 for supporting the No. 1 journal 21 of the crankshaft 2, and the partition walls 31, 32, 33
No. 2 to No. 4 bearings 37, 38, and 39 are provided to support No. 2 to No. 4 journals (not shown) of the crankshaft, respectively, and an end wall 40 on the flywheel side is provided. A No. 5 bearing portion 41 for supporting a No. 5 journal (not shown) of the crankshaft is provided.

The partition walls 31, 32, 33 of the cylinder block 1 are provided with blow-by gas passages 42, 43, 44 for communicating the crank chambers 34a, 34b, 34c, 34d with each other. The end wall 35 is provided with a blow-by gas passage 45 for communicating the crank chamber 34a with the timing chamber 12. The blow-by gas passage 45 in the end wall 35 is a sensor plate mounted on the crankshaft 2.
The sensor 21 is disposed at a position facing a facing portion of the sensor body 22 attached to the attachment hole 28. The blow-by gas passages 42, 43, 44, 45 are arranged on the same axis along the axial direction of the crankshaft 2.

Next, the operation of the embodiment constructed as described above will be described. When the crankshaft 2 rotates, the sensor main body 22 outputs an electric pulse signal in accordance with the rotation of the sensor plate 21 that rotates together with the crankshaft 2, and detects the rotational position of the crankshaft 2, that is, the crank angle based on the pulse signal. can do.

In the engine assembling process, the opposing portion of the sensor plate 21 attached to the crankshaft 2 and the sensor main body 22 attached to the cylinder block 1 are provided on the end wall 35 of the cylinder block 1 by blow-by gas. It can be seen from the outside through the passage 45. Thus, the clearance C between the sensor plate 21 and the sensor main body 22 can be easily checked visually or by using a gap gauge, and the clearance can be easily managed. And, for example, the mounting hole of the cylinder block 1
The clearance C between the sensor plate 21 and the sensor main body 22 can be accurately adjusted by adjusting the mounting position of the sensor main body 22 with respect to 28 using an adjusting screw or shim.

Further, since the sensor body 22 is disposed substantially at the center of the area surrounded by the central axes of the crankshaft 2, the water pump 15 and the alternator 16, the dead space between these engine accessories is effectively used. And space efficiency can be improved.
Also, the blow-by gas passages 42, 43, 44 and 45 are arranged on the same axis along the axial direction of the crankshaft 2,
The blow-by gas passages 42, 43, 44, 45 can be easily processed.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The second embodiment has substantially the same structure as the first embodiment except that the type of the cylinder block is different.
The same parts as those of the embodiment are denoted by the same reference numerals, and only different parts will be described in detail.

The engine according to the first embodiment uses a deep skirt type cylinder block, whereas the engine according to the second embodiment uses a half skirt type cylinder as shown in FIGS. The cylinder block is used. As shown in FIG. 7 and FIG.
In the engine according to the embodiment, a bearing 46a supporting the journal of the crankshaft 2 is provided below the cylinder block 1A.
A lower case 46 having a cylinder block 1A,
A crankcase is formed by the lower case 46 and the oil pan 8. With this configuration, the same operation and effect as those of the first embodiment can be obtained.

In the first and second embodiments,
The sensor plate 21 and the sensor body 22 of the crank angle sensor 20 are arranged in the crank chamber 34a closest to the timing chamber 12, but these are arranged in the other timing chambers 34b, 34c or 34d, and the partition walls 31, 32 Alternatively, the clearance C can be confirmed from the blow-by gas passages 42, 43, or 44 provided in the 33.

In the first and second embodiments,
Although the description has been given of the case where the water pump 15 and the alternator 16 are driven by the crankshaft 2, the present invention is not limited to this, and may be similarly applied to a case where other engine accessories are driven instead of these. it can.

[0027]

As described above in detail, according to the first aspect of the present invention, the partition wall in the crank chamber is provided with an opening facing the portion where the sensor plate and the sensor body face each other, thereby assembling the engine. In the process, the clearance between the sensor plate and the sensor main body can be visually checked through an opening provided in the partition wall of the crank chamber, so that the clearance between the sensor plate and the sensor main body can be easily checked visually or using a gap gauge or the like. And the clearance can be easily managed.

According to the second aspect of the present invention, in the configuration of the first aspect, the sensor plate is disposed at a position adjacent to the timing chamber in the crank chamber, and an opening is provided in an end wall of the cylinder block on the timing chamber side. Thus, the clearance between the sensor plate and the sensor body can be visually checked through the opening in the end wall of the cylinder block.

According to the third aspect of the present invention, in the configuration of the first or second aspect, the opening is a blow-by gas passage, so that the blow-by gas in the crank chamber and the timing chamber flows through the opening provided in the partition. Can be.

According to a fourth aspect of the present invention, in the configuration of any one of the first to third aspects, the vicinity of the center of the region surrounded by the central axis of the crankshaft and the engine accessory driven by the crankshaft is provided. By arranging the sensor body, the dead space between the engine accessories can be effectively used, and the space efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a front view of an engine according to a first embodiment of the present invention in which an end on a timing chamber side is partially cut away.

FIG. 2 is a longitudinal sectional view of a side surface near a timing chamber of the engine of FIG. 1;

FIG. 3 is a side view of the vicinity of the timing chamber of the engine of FIG. 1 on the opposite side to FIG. 2;

FIG. 4 is an end view of a cylinder block of the engine of FIG. 1 on a timing chamber side.

FIG. 5 is an enlarged view of a main part of FIG.

FIG. 6 is a bottom view showing a cylinder block of the engine of FIG. 1 with a part cut away.

FIG. 7 is a partially cutaway front view showing an end of the engine according to a second embodiment of the present invention on the timing chamber side.

FIG. 8 is a longitudinal sectional view of a side surface near a timing chamber of the engine of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder block 1A Cylinder block 2 Crankshaft 12 Timing chamber 15 Water pump (engine auxiliary equipment) 16 Alternator (engine auxiliary equipment) 20 Crank angle sensor 21 Sensor plate 22 Sensor body 35 End wall (partition wall) 45 Blow-by gas passage (opening) )

Claims (4)

[Claims] The present invention detects a rotational position of a crankshaft including a sensor plate mounted so as to rotate integrally with a crankshaft, and a sensor body fixed to a side wall of a cylinder block opposite to an outer peripheral portion of the sensor plate. An engine crank angle sensor according to claim 1, wherein an opening is provided in a partition partitioning a crank chamber so as to face an opposing portion between said sensor plate and said sensor main body. 2. The apparatus according to claim 1, wherein the sensor plate is disposed at a position adjacent to a timing chamber in the crank chamber, and the opening is provided in an end wall of the cylinder block on the timing chamber side. An engine crank angle sensor according to any of the preceding claims. 3. The crank angle sensor according to claim 1, wherein the opening is a blow-by gas passage. 4. The sensor body according to claim 1, wherein the sensor main body is disposed near a center of a region surrounded by a central axis of the crankshaft and an engine accessory driven by the crankshaft. An engine crank angle sensor according to any of the preceding claims.