JP2021156169A - Internal combustion engine - Google Patents

Abstract

To improve the strength of a protector and the like in an internal combustion engine provided with a bracket for mounting a connector for a crank angle sensor or the like and a protector for heat-shielding the connector.SOLUTION: A crank angle sensor has a connector 16 for connecting harnesses 15, 17, which is mounted to a bracket 18 fixed to a rear flange 8 of a cylinder block 1. A protector 21 for heat-shielding the connector 16 and the harness 15 has an upper mounting portion 26 fixed to the bracket 18 with a bolt 27, and a lower mounting portion 30 fixed to the rear flange 8 with a bolt 31. The bracket 18 is formed with a stepped-up portion 18c on which the upper mounting portion 26 of the protector 21 overlaps. The protector 21 has no need of being excessively bent in a deep drawn shape, so that a stress concentration can be prevented and the strength can be improved.SELECTED DRAWING: Figure 4

Description

The present invention relates to an internal combustion engine for automobiles and the like.

Many sensors are used in the internal combustion engine, and along with this, many harnesses are stretched around the engine body. The harness is generally connected to the sensor via a connector. The connector consists of a movable part to which one end of the harness is connected and a fixed part to which this is connected. When the fixed part is attached to the sensor, and when the fixed part is connected to the harness (cable) pulled out from the sensor, the fixed part is connected. There are cases where it is done.

In any case, connectors and harnesses do not necessarily have high heat resistance, so if they are placed near hot parts such as exhaust manifolds and catalyst cases, they are covered with a protector to prevent heat damage (for example, patents). Documents 1 and 2).

Japanese Patent No. 6477809 Microfilm of Jitsukaihei No. 1-166243

As mentioned above, the connector consists of a fixed part and a movable part, and if the fixed part is connected to the harness pulled out from the sensor, it is necessary to attach the fixed part to the bracket fixed to the engine body. There is. Therefore, a bracket for attaching the connector and a heat shield protector for protecting the connector and the harness are required, and conventionally, these are separately fixed to the engine body (for example, a cylinder block).

The problem here is the shape of the protector, for example, if the connector is located on the exhaust side of the cylinder block, it is fixed to the cylinder block in order to properly cover the connector while allowing fastening to the cylinder block. The heights of the portion and the portion covering the connector (the dimension of protrusion from the side surface of the cylinder block) must be significantly different.

Then, the protector must be bent to a deep drawing state, and then the curvature of the bend becomes large (a sharply bent corner is formed), and when its own weight acts as a load due to the vibration of the engine. There is a problem that stress is concentrated on the corners and it is easy to break.

In addition, the protector will be fastened to the engine body such as the cylinder block with bolts, but since it is necessary to secure the fastening part of the protector on the engine body such as the cylinder block and machine a tap hole in this, the shape of the protector. And the mounting position must be designed while adjusting with the arrangement of other members, which causes a problem that the design takes time and effort. It is also troublesome to process tap holes.

On the other hand, Patent Document 2 discloses that the fixing portion of the connector is fixed to the bracket and the protector is attached to the connector with a spring-type clip body. There is a problem that the vibration of the protector may spread to the connector and the connection may be disconnected, or there is a problem that the heat received by the protector is transferred to the connector and the heat shield function of the connector is not sufficient, so the reality is questionable. be.

The invention of the present application has been made to improve such a situation.

The internal combustion engine of the present invention is
"A connector for connecting a harness is attached to a bracket fixed to the engine body, and a metal plate protector covering the connector is fixed to the bracket."
It is configured as.

In the present invention, the protector can be fixed only to the bracket, or a part of the mounting portions at a plurality of locations can be fixed to the bracket, and the other mounting portions can be fixed to the engine body. .. Further, the present invention can be applied to various connector attachment / protection structures, and can be applied to, for example, a connector connected to a crank angle sensor.

In the present invention, the bracket for attaching the connector is also used as the fixing member of the protector, but since both the bracket and the protector have high processing flexibility, the protector can be fastened to the bracket without being significantly bent. As a result, it is possible to prevent stress from concentrating on the bent portion when its own weight acts as a load on the protector, and to improve the strength and reliability of the protector.

Moreover, since the protector is not in contact with the connector, there is no problem with the protection function of the connector. Moreover, since the protector can be firmly fastened with bolts or the like, there is no problem of falling off due to vibration.

Further, since the fixed portion of the protector to the engine body can be eliminated or reduced, it becomes easy to adjust with the arrangement of other members, and the labor of design can be saved accordingly. Further, there is an advantage that the fastening strength of the bracket can be improved by reinforcing each other between the bracket and the protector.

It is a top view of the cylinder block which concerns on embodiment. It is a side view which looked at the cylinder block from the exhaust side. It is a side view in the state which the protector is arranged. It is a separated perspective view of a main part. (A) is a separated rear view seen from the VA-VA viewing direction of FIG. 3, and (B) is a side view of the clip.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following, the front-back and left-right terms are used to specify the direction, but the front-back direction is the crank axis direction, and the left-right direction is the direction orthogonal to the crank axis and the cylinder bore axis. Regarding the front and the back, the side where the timing chain is arranged is the front, and the side where the mission kens is arranged is the back. To be on the safe side, the direction is clearly shown in FIG.

(1). Outline As shown in FIG. 1, the internal combustion engine of the present embodiment has three cylinders, and the cylinder block 1 is formed with three cylinder bores 2 arranged side by side in the direction of the crank axis. A water pump 3 is attached to the front portion of the exhaust side surface of the cylinder block 1.

As shown in FIG. 2, ribs and boss portions are formed on the exhaust side surface of the cylinder block 1. That is, first, a hollow upper horizontally long boss portion 4 that returns the cooling water to the water pump 3 is formed on the upper portion so as to extend long in the front-rear direction. The rear end portion of the upper horizontally long boss portion 4 communicates with the cooling water return port 5 shown in FIG.

Further, vertically long hollow bosses 6 are formed at two portions on the exhaust side surface of the cylinder block 1 which are divided into three equal parts in the front-rear direction. The vertically long hollow boss 6 is for forming an oil return passage, and the upper end communicates with the oil drop port 7 shown in FIG.

Further, as clearly shown in FIG. 4, a rear flange 8 for fixing a mission case (not shown) is formed on the rear surface of the cylinder block 1 so as to protrude forward and backward. Therefore, a rear recess 9 is formed between the rear flange 8 and the vertically elongated hollow boss 6 at the rear portion, and a reinforcing rib 10 is provided in the rear recess 9. An intermediate recess 11 is formed between the vertically elongated hollow bosses 6 adjacent to each other, and a group of reinforcing ribs 12 is also formed in the intermediate recess 11. A lower flange 13 for fixing the oil pan is formed at the lower end of the cylinder block 1.

As shown in FIG. 2, a receiving seat 14 for mounting a crank angle sensor (not shown) is formed at the rear end of the exhaust side surface of the cylinder block 1. One end of the first harness 15 is connected to the crank angle sensor, the first harness 15 extends upward, and the other end (upper end) is connected to the fixing portion 16a of the connector 16. The connector 16 includes a movable portion 16b that can be freely inserted and removed from the fixed portion 16a, and one end of the second harness 17 is connected to the movable portion 16b. The second harness 17 is pulled out to the upper rear of the cylinder block 1.

(2). Bracket protector As shown in FIG. 4, the connector 16 is attached to the bracket 18, and the connector 16 and the first harness 15 are outside with a protector 21 made of a metal plate such as a stainless steel plate. Surrounded by. That is, since the catalyst case 19 for purifying the exhaust gas (see FIG. 3) is arranged on the side of the connector 16 and the first harness 15, the catalyst is prevented from being affected by the heat dissipated from the catalyst case 19. The protector 21 is arranged between the case 19, the connector 16, and the first harness 15.

Like the protector 21, the bracket 18 is also made of a metal plate such as a stainless steel plate, and has a base portion 18a having a portion overlapping the upper boss portion 22 provided on the rear flange 8 of the cylinder block 1 and a cylinder block 1 from the front end of the base portion 18a. It is provided with an inward facing portion 18b that is bent toward the surface, and a step-up portion 18c that is bent in a crank shape from the lower end of the base portion 18a to the outside of the cylinder block 1. The base portion 18a is fixed to the upper boss portion 22 of the rear flange 8 with one bolt 23. Therefore, a tap hole 22a is formed in the upper boss portion 22 of the rear flange 8.

Then, as shown in FIG. 4, the base portion 18a is provided with a mounting hole 24 having a square shape or the like, and the engaging claw 16c shown in FIG. 5 (A) is forcibly fitted into the mounting hole 24 to form a connector. 16 fixing portions 16a are attached.

On the other hand, as shown in FIG. 5, an elongated clip holding hole 25 is formed in the inward facing portion 18b of the bracket 18, and the first harness 15 is held by the clip 25a attached to the clip holding hole 25. ing. As shown in FIG. 5B, the clip 25a includes an engaging claw 25b that is elastically fitted into the clip holding hole 25, and a holding portion 25c that can forcibly fit the first harness 15. The holding portion 25c is rotatably attached to the engaging claw 25b.

As described above, in the cylinder block 1, the portion between the rear flange 8 and the vertically elongated hollow boss 6 at the rear portion is the rear recess 9, but the rear end portion and the upper portion of the rear recess 9 are: Since it is located behind the cylinder bore 2 at the rear end, it is a recessed portion 9a that penetrates deeply toward the inside of the cylinder block 1, and the inward facing portion 18b of the bracket 18 becomes a recessed portion 9a of the rear recessed portion 9. It's getting in.

The first harness 15 is held by the clip 25a attached to the clip holding hole 25 of the bracket 18 so as to be as close to the side surface of the cylinder block 1 as possible. Therefore, the influence of the heat dissipated from the catalyst case 19 is prevented as much as possible.

The protector 21 basically has a quadrangular shape in a side view, and is roughly formed in a stepped manner between a front portion 21a approached to the cylinder block 1 and a rear portion 21b separated from the cylinder block 1. ing. The staggered formation is to avoid the catalyst case 19, the front portion 21a is located on the back side of the catalyst case 19, and the front portion is located behind the catalyst case 19.

Then, as clearly shown in FIG. 4, an upper mounting portion 26 is formed on the rear portion 21b of the protector 21 so as to overlap the stepped portion 18c of the bracket 18, and the upper mounting portion 26 is connected to the stepped portion 18c of the bracket 18 by the upper bolt 27. It is fixed to. Therefore, as shown in FIG. 5, a nut 28 is welded to the back surface of the step-up portion 18c of the bracket 18.

Further, the protector 21 is formed with a lower mounting portion 30 that overlaps the lower boss portion 29 formed on the rear flange 8 of the cylinder block 1, and the lower mounting portion 30 is fixed to the lower boss portion 29 with a lower bolt 31. There is. Therefore, a tap hole 29a is formed in the lower boss portion 29. The lower mounting portion 30 is farther from the cylinder block 1 than the upper mounting portion 26, which is due to the shape of the rear flange 8 of the cylinder block 1.

That is, the rear flange 8 of the cylinder block 1 has a rear view shape corresponding to the shape of the mission case, but since the flange of the mission case is most widened in the front-rear direction at the lower boss portion 29, it is lower. The boss portion 29 is in the state farthest from the crankshaft center, and correspondingly, the lower mounting portion 30 of the protector 21 is located on the left and right outer sides of the upper mounting portion 26.

Since the upper and lower mounting portions 26 and 30 of the protector 21 are displaced in the left-right direction, the rear portion 21b of the protector 21 is bent in a stepped manner in the left-right direction and is inclined to connect the front portion 21a and the rear portion 21b of the protector 21. The width of the lower portion of the portion 21c is large. Due to such a three-dimensional shape, the protector 21 has a sturdy structure with high resistance to bending even if it is thin.

The portion of the rear portion 21b of the protector 21 above the upper mounting portion 26 is the connector protecting portion 32, but the connector protecting portion 32 has a stepped shape shifted from the upper mounting portion 26 to the outside of the cylinder block 1. ing. Reference numeral 33 shown in FIGS. 2 and 3 is a lower boss portion for fixing the bracket fixed to the catalyst case 19 (or the exhaust pipe) with bolts.

The protector 21 is fixed by the upper and lower mounting portions 26 and 30, but when the upper mounting portion 26 is fastened together with the bracket 18 to the upper boss portion 22 of the cylinder block 1, for example, the upper mounting portion is formed. 26 must be formed in a form that is largely extruded toward the cylinder block 1, and then the dimension in the left-right direction becomes large and a sharply bent portion is formed. Therefore, when the own weight acts as a load due to the vibration of the engine. , There is a concern that stress will be concentrated on the sharply bent part (corner part) and it will be easy to break.

On the other hand, in the present embodiment, since the upper mounting portion 26 is fixed to the bracket 18, the dimension for pushing and bending the upper mounting portion 26 toward the cylinder block 1 is small, and therefore, the presence of a sharply bent portion is required. Can be prevented from breaking due to. Further, it is easy to form the stepped-up portion 18c on the bracket 18, and the protector 21 and the bracket 18 can be freely designed while maintaining the required strength, so that the freedom of design can be improved.

The bracket 18 is fixed to the upper boss portion 22 of the rear flange 8 with one bolt 23, but since the inward facing portion 18b is inserted into the recessed portion 9a of the cylinder block 1, the inward facing portion 18b is prevented from rotating. The bracket 18 is held so as to be non-rotatable. Therefore, the bolt 23 does not run idle. Further, the bracket 18 receives a clockwise force even when the upper bolt 27 of the protector 19 is screwed in, but since the bracket 18 is stopped by the inward facing portion 18b, the upper bolt 27 must be screwed firmly into the nut 28. Can be done.

The bracket 18 and the protector 21 can be arbitrarily changed in shape based on the required functions. For example, in the embodiment, the lower mounting portion 30 of the protector 21 is fixed to the lower boss portion 29 of the rear flange 8, but instead of or in addition to this, the lower portion of the protector 21 is attached to the vertically elongated hollow boss 6 adjacent to each other. It is also possible to fix it to the lower boss portion 33 located between them via a bracket plate.

Further, the application target of the present invention is not limited to the bracket 1 protector related to the connector or harness for the crank angle sensor, but can also be applied to the bracket and protector related to other connectors and harnesses. Therefore, the bracket and protector can also be attached to the cylinder head or the timing chain cover.

The present invention can be embodied in an internal combustion engine including a bracket for a connector and a protector. Therefore, it can be used industrially.

1 Cylinder block 8 Rear flange 14 Crank angle sensor mounting seat 15 1st harness 16 Connector 16a Connector fixing part 16b Connector moving part 17 2nd harness 18 Bracket 18a Base 18b Inward facing part 18c Step-up part 19 Catalyst case 21 Protector 22 Upper boss part 26 Upper mounting part 28 Nut 29 Lower boss part 30 Lower mounting part

Claims (1)

A connector for connecting a harness is attached to a bracket fixed to the engine body, and a protector made of a metal plate covering the connector is fixed to the bracket.
Internal combustion engine.

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