JP2001193520A - Knock sensor mounting structure for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance rigidity of a sensor mounting boss so that vibration of knocking is easily transmitted for accurately detecting the knocking, and to easily detect vibration of knocking in a cylinder block of an open deck structure for preventing influence to a flow of cooling water inside a water jacket in regard to a knock sensor mounting structure for an engine. SOLUTION: The sensor mounting boss of the knock sensor is provided so as to bury it in a recessed part formed on a bottom outer face of the water jacket.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine knock sensor mounting structure, and more particularly to an engine knock sensor mounting structure for mounting a knock sensor to a cylinder block.

[0002]

2. Description of the Related Art In a vehicle engine, a knock sensor is mounted on an outer surface of a cylinder block in order to detect a knocking state.

That is, as shown in FIG. 8, a cylinder block 102 of a multi-cylinder engine has a plurality of cylinders 104 formed in series, and is substantially parallel to a cylinder center line C of the cylinders 104. Water jacket 106 around
Is provided. In this case, this water jacket 1
Reference numeral 06 is formed by the inner wall 108 and the outer wall 110, and a recess 112 is formed on the lower outer surface of the water jacket 106 so as to be depressed toward the cylinder 104 to form the upper water jacket 106. You. Also,
The outer wall 110 of the cylinder block 102 has a distance H2 downward from the deck surface 102D of the cylinder block 102.
A sensor mounting boss 114 is formed to protrude outward at the position. This sensor mounting boss 114 has a screw hole 1
A knock sensor 11 is formed in the screw hole 116.
Eight screw portions 120 are screwed and attached.

[0004] As a mounting structure of such a knock sensor, for example, Japanese Patent Publication No.
No. 64439 and Japanese Patent Publication No. 6-35843. In Japanese Patent No. 2751771, a knock sensor mounting seat is provided near a fluid passage on a side wall substantially at the center in the arrangement direction of cylinder bores. Japanese Unexamined Utility Model Publication No. 5-64439 discloses a knock sensor which is attached to a cylinder bore wall by penetrating a water jacket. Japanese Patent Publication No. 6-35843 discloses a V-type engine in which a knock sensor mounting seat is provided on a support jig insertion boss.

[0005]

By the way, conventionally, in the knock sensor mounting structure, the sensor mounting bosses are arranged at every place from the vicinity of the upper surface of the deck to the lower portion of the water jacket on the outer surface of the cylinder block. . For this reason, depending on the installation location, the space of the water jacket makes the transmission of knocking vibrations poor, making it difficult to detect knocking, or inadvertently detecting other vibrations as knocking vibrations. there were. Further, when the sensor mounting boss is disposed outside the water jacket, the rear surface of the sensor mounting boss is mounted so as to fill the water jacket, so that there is a disadvantage that the flow of cooling water in the water jacket is adversely affected. there were.

[0006]

SUMMARY OF THE INVENTION Accordingly, in order to eliminate the above-mentioned disadvantages, the present invention relates to a cylinder block having a plurality of cylinders formed in series, which is substantially parallel to the cylinder center line of the cylinder and is provided around the cylinder. In a knock sensor mounting structure for an engine in which a knock sensor is mounted on an outer surface of the cylinder block, a sensor mounting boss of the knock sensor fills a recess formed on a lower outer surface of the water jacket. Is provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, since the sensor mounting boss of the knock sensor is provided so as to fill a recess formed in the lower outer surface of the water jacket, the rigidity of the sensor mounting boss is increased, and Knocking can be detected accurately by facilitating the transmission of vibration, and knocking vibration in the cylinder block with open deck structure can be easily detected, and furthermore, the influence on the flow of cooling water in the water jacket is prevented. can do.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 4 show a first embodiment of the present invention. In FIGS. 1 to 3, reference numeral 2 denotes a multi-cylinder (for example, four cylinders) mounted on a vehicle (not shown).
# 1, # 2, # 3, and # 4) are cylinder blocks 2 of the engine. The cylinder block 2 has, for example, an open deck structure, and has a skirt portion 4 on the lower half side.
And an upper half 4 on the upper half side. In the cylinder block 2, first to fourth cylinders 8-1 to 8-4 are formed in series in the crankshaft direction X. The first to fourth cylinders 8-1 to 8-
4 is provided with first to fourth cylinder liners 10-1 to 10-4 fitted therein.

On the outer surface of the cylinder block 2, first to first
First to fourth cylinder center lines C1 to C4 of four cylinders 8-1 to 8-4
Are provided with first to fourth vertical ribs 12-1 to 12-4.

The cylinder block 2 includes first to fourth cylinders 8.
The water jacket 14 is provided with an outer peripheral surface 16 of each cylinder liner 10 substantially parallel to the first to fourth cylinder center lines C1 to C4 and around the first to fourth cylinders 8-1 to 8-4. And the outer wall 18. The water jacket 14 is formed within a vertical movement range of a piston (not shown) substantially downward from the deck surface 2D of the upper portion 6 of the cylinder block 2. For this reason, a recess 20 is formed on the lower outer surface of the water jacket 14 as in the related art.

The upper part 6 of the cylinder block 2 has
Around the space between the second and third cylinders 8-2 and 8-3 and inside the water jacket 14, the first and second fluid passages 2 are provided.
2-1 and 22-2 are formed. The first and second fluid passages 22-1 and 22-2 function as a breather and an oil dropper, and the first and second upper fluid passages 24-1 and 24-open in the deck surface 2 </ b> D of the upper part 6. 2 is formed of the first and second upper passage wall portions 26-1, 26-2, and
The first and second lower fluid passages 28-1 and 28-2 communicate with the lower portions of the first and second upper fluid passages 24-1 and 24-2 with a small step and extend downward. , The second lower passage wall 30-1 and 30-2. A fluid communication hole 32 is formed in the skirt portion 4 of the cylinder block 2.

On the outer surface of the cylinder block 2, for example, the third cylinder 8-
A sensor mounting boss 34 is provided so as to protrude outward at a position coinciding with the third cylinder center line C3 of No. 3 and filling the recess 20 on the outer surface below the water jacket 14.
The sensor mounting boss 34 is located at a distance H1 larger than the conventional distance H2 from the deck surface 2D of the upper part 6. A screw hole 36 is formed in the sensor mounting boss 34 from the end face.

The sensor mounting boss 34 is connected to the cylinder barrel 18A at the press-fitting portion connected to the outer wall 18 and is connected to the second lower passage wall 30-2. 3 and are provided continuously with the first to third oblique ribs 38-1 to 38-3 which are directed downward.

The screw portion 42 of the knock sensor 40 is screwed and fixed to the screw hole 36 of the sensor mounting boss 34. Thereby, knock sensor 40 is attached to the side surface of cylinder block 2.

Next, the operation of the first embodiment will be described.

The sensor mounting boss 34 is mounted on the cylinder block 2
Is provided so as to fill the concave portion 20 on the outer surface below the water jacket 14, so that knocking vibration generated in the cylinder 8 is easily transmitted, for example, by eliminating a space part. Knocking can be accurately detected.

A sensor mounting boss 34 is provided so as to fill the recess 20 below the water jacket 14 of the cylinder block 2, and the second lower passage wall 30-2 and the third vertical rib 12 are provided. -3 and the slanted ribs 38, the sensor mounting boss 34 is provided.
The surrounding rigidity is improved, and the knocking state can be detected more accurately.

FIG. 5 shows a special structure of the present invention.
It shows an embodiment.

In the following embodiment, portions having the same functions as those in the above-described first embodiment will be described with the same reference numerals.

The features of the second embodiment are as follows. That is, the mounting surface 34A of the sensor mounting boss 34 is arranged so that the knock sensor 40 is inclined at an angle θ with respect to the horizontal plane H and is directed toward a combustion chamber (not shown).
Was provided at an angle.

According to the structure of the second embodiment, since the knock sensor 40 is directed toward the combustion chamber, the knocking vibration can be detected satisfactorily, and the knock sensor 40 projects greatly outward. And the overhanging portion can be suppressed.

FIG. 6 shows a special configuration of the present invention.
It shows an embodiment.

The features of the third embodiment are as follows. That is, the sensor mounting boss 34 is provided at the same place as the conventional one, but a connecting portion 54 for connecting the inner side wall 52 and the sensor mounting boss 34 is provided at a portion inside the water jacket 14 facing the sensor mounting boss 34. .

According to the configuration of the third embodiment, even if the knock sensor 40 is arranged near the combustion chamber at the portion of the water jacket 14, the knock sensor 40 generates knocking vibration because the connecting portion 54 exists. It can detect well, and without changing the conventional structure drastically,
It can be inexpensive.

FIG. 7 shows a special structure of the present invention.
It shows an embodiment.

The features of the fourth embodiment are as follows. That is, the sensor mounting boss 34 is provided at the same place as the conventional one, but the sensor mounting boss 34 is
And the outer wall 18 including the connecting portion 54 penetrating the water jacket 14.

According to the structure of the fourth embodiment, even if the knock sensor 40 is arranged near the combustion chamber at the water jacket 14, the sensor mounting boss 34 comes close to the combustion chamber side. Knocking vibration can be detected more favorably, and the cost can be reduced without significantly changing the conventional structure.

[0028]

As is apparent from the above description, according to the present invention, the sensor mounting boss of the knock sensor is provided so as to fill the recess formed in the lower portion of the water jacket. The rigidity is increased, knocking vibration is easily transmitted, and knocking can be detected accurately.In addition, knocking vibration in the cylinder block of open deck structure can be easily detected, and the flow of cooling water in the water jacket Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a knock sensor mounting structure.

FIG. 2 is a side view of a cylinder block.

FIG. 3 is a partial plan view of a cylinder block.

FIG. 4 is a partial sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a sectional view of a knock sensor mounting structure according to a second embodiment.

FIG. 6 is a sectional view of a knock sensor mounting structure according to a third embodiment.

FIG. 7 is a sectional view of a knock sensor mounting structure according to a fourth embodiment.

FIG. 8 is a sectional view of a conventional knock sensor mounting structure.

[Explanation of symbols]

 2 Cylinder block 8 Cylinder 14 Water jacket 20 Recess 22 Fluid passage 34 Sensor mounting boss 40 Knock sensor

Claims (3)

[Claims] 1. An engine in which a water jacket is provided on a cylinder block in which a plurality of cylinders are formed in series and substantially parallel to a cylinder center line of the cylinder and around the cylinder, and a knock sensor is mounted on an outer surface of the cylinder block. The knock sensor mounting structure for an engine according to claim 1, wherein a sensor mounting boss of the knock sensor is provided so as to fill a recess formed on an outer surface below the water jacket. 2. The sensor mounting boss is provided on an outer surface of the cylinder block so as to be substantially orthogonal to a crankshaft direction, and is continuous with a passage wall of a fluid passage formed between adjacent cylinders. The knock sensor mounting structure for an engine according to claim 1, wherein the knock sensor mounting structure is provided. 3. The knock sensor mounting structure for an engine according to claim 1, wherein the sensor mounting boss is provided continuously with a rib on an outer surface of the cylinder block.