JP2018127910A - Engine structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify work for coupling a flange part 3A of an exhaust manifold 3 and a flange part 4A of an EGR device 4 to a cylinder head 1.SOLUTION: On a sidewall 1A of the cylinder head 1, a first protruding flat part 1a to which the flange part 3A is coupled and a second protruding flat part 1b to which the flange part 4A is coupled are formed separately. Surfaces (mount surfaces) of both the protruding flat parts 1a, 1b are positioned on the same plane. A gasket 2 includes: a first seal part S1 which is mounted in the first protruding flat part 1a; and a second seal part S2 which is mounted in the second protruding flat part 1b. Both the seal parts S1, S2 are made to continue and are formed integrally. After the gasket 2 is mounted on the surfaces of both the protruding flat parts 1a, 1b, the flange part 3A is coupled to the first protruding flat part 1a by a fastening bolt 5, and the flange part 4A is coupled to the second protruding flat part 1b by the fastening bolt 5.SELECTED DRAWING: Figure 1

Description

The present invention relates to an engine structure, and more particularly, to an improvement in an exhaust manifold, an EGR (exhaust gas recirculation) device, and a connecting portion of a cylinder head to which they are connected.

Conventionally, an EGR device in which a part of exhaust gas is recirculated from an exhaust manifold to an engine is known (for example, Patent Document 1 and Patent Document 2).
A gasket for an exhaust manifold that is interposed between the flange portion of the exhaust manifold and the cylinder head and maintains a seal therebetween is known (for example, Patent Document 3), and the flange portion of the EGR device A gasket for an EGR device that is interposed between the cylinder head and maintains a seal between them is also known (for example, Patent Document 4).

JP2015-63910A JP2015-124729A JP 2013-76352 A JP-A-11-159621

By the way, conventionally, the mounting surface of the cylinder head to which the flange portion of the exhaust manifold is connected and the mounting surface of the cylinder head to which the flange portion of the EGR device are connected are arranged in different directions apart from each other. In relation to this, conventionally, the gasket for the exhaust manifold and the gasket for the EGR device are formed separately.
In such a conventional engine structure, the exhaust manifold gasket is mounted on the cylinder head mounting surface and then the flange portion of the exhaust manifold is connected to the cylinder head, and the EGR gasket is connected to the cylinder head. After attaching the EGR gasket to the mounting surface, it is necessary to perform the operation of connecting the flange portion of the EGR to the cylinder head from different directions at different positions, and such a connecting operation is complicated and takes time. there were.

In view of the circumstances described above, the present invention provides a cylinder head having a side wall in which a plurality of exhaust holes for exhaust and a suction hole for an EGR device are opened, and a first exhaust manifold connected to the position of the exhaust hole in the side wall. 1 flange part, the 2nd flange part of the EGR apparatus connected to the position of the suction hole of the side wall, and the cylinder head side wall and the both flange parts are interposed to maintain a seal therebetween. An engine structure with a gasket to perform,
A first projecting flat portion in which the exhaust hole is opened and the first flange portion is connected to the side wall of the cylinder head, and a second flange portion in which the suction hole is opened and the second flange portion is connected. The projecting flat part is formed apart from each other, and the surfaces serving as the mounting surfaces of the first projecting flat part and the second projecting flat part are located on the same plane at the same height,
The gasket is provided with an exhaust hole corresponding to the exhaust hole, a first seal portion interposed between the surface of the first projecting flat portion and the first flange portion, and the suction hole. A suction hole is provided, and a second seal portion interposed between the surface of the second projecting flat portion and the second flange portion is provided, and the first seal portion and the second seal portion are continuous. It is characterized by being integrally formed.

  According to such a configuration, the two mounting surfaces of the cylinder head are formed so as to be adjacent to each other on the same plane. Moreover, the gasket which was conventionally separated into two is continuously formed integrally. For this reason, the gasket can be interposed between the mounting surface of the cylinder head and the flange portion to simplify the operation of connecting them.

1 is a schematic perspective view showing an embodiment of the present invention. The front view of the principal part of FIG. The front view of the gasket of FIG. Sectional drawing of the principal part which follows the III-III line | wire of FIG. Sectional drawing of the principal part which follows the IV-IV line | wire of FIG. The enlarged view of the principal part of FIG. Sectional drawing which simplifies and shows the connection state of the component shown in FIG.

Hereinafter, the present invention will be described with reference to the illustrated embodiment. FIG. 1 shows a main part of an automobile engine, and a flange portion of an exhaust manifold 3 with a gasket 2 interposed on a side wall 1A (end surface) of a cylinder head 1. The flange portion 4 </ b> A of the 3 </ b> A and the EGR device 4 is connected by a plurality of fastening bolts 5. By sandwiching the gasket 2 between the side wall 1A and the flange portions 3A and 4A, the seal between the side wall 1A and the flange portions 3A and 3B is maintained.
The side wall 1A of the cylinder head 1 is formed with a trapezoidal first projecting flat portion 1a, and a second projecting flat portion 1b having a substantially circular shape is formed at an adjacent position. Both projecting flat portions 1a and 1b are formed so as to rise by the same height as the surface of the original side wall 1A. The surfaces (mounting surfaces) of both flat portions 1a and 1b are flat surfaces and are located on the same plane. Since the protruding flat portions 1a and 1b are formed apart from each other, a groove-like shape is formed between one end (left end in the drawing) of the first protruding flat portion 1a in the longitudinal direction and the second protruding flat portion 1b. A space 1C is formed.
Four exhaust holes 6 are opened in the first projecting flat portion 1a at equal pitches in the lateral direction (horizontal direction), and exhaust gas recirculated by the EGR device 4 is supplied to the second projecting flat portion 1b. A suction hole 7 for introduction is opened.
A total of five fastening bolts 5 are arranged in a staggered manner in the first projecting flat portion 1 a at positions adjacent to the exhaust holes 6. Further, a pair of fastening bolts 5 are disposed on both sides of the second projecting flat portion 1b with the suction hole 7 in between. The gasket 2 is attached to the surfaces (mounting surfaces) of the two protruding flat portions 1a and 1b, and the flanges 3A and 4A are brought into contact with the gasket 2 in this state, and then tightened with the fastening bolts 5.

As shown in FIGS. 1 and 2, the exhaust manifold 3 includes a substantially trapezoidal flange portion 3A, four branch pipes 3B connected to the flange portion 3A at an equal pitch, and those branch pipes 3B. And an exhaust pipe 3C to be joined together.
The flange portion 3A is formed in a trapezoidal shape according to the contour of the first protruding flat portion 1a, and the ends of the four branch pipes 3B are opened in the flange portion 3A according to the positions of the exhaust holes 6. doing. The surface (mounting surface) of the flange portion 3A is a flat surface, and five bolt holes 3D are formed in the flange portion 3A in accordance with the position of the fastening bolt 5 of the first protruding flat portion 1a. ing.
When the exhaust manifold 3 is connected to the first projecting flat portion 1a by the fastening bolt 5 through the gasket 2, the exhaust gas discharged from each exhaust hole 6 can be discharged to the outside through the branch pipe 3B and the exhaust pipe 3C. It is like that.
Next, the EGR device 4 includes a flange portion 4A adapted to the shape of the second projecting flat portion 1b, and a recovery tube 4B having one end connected to the exhaust pipe 3C and the other end opened to the flange portion 4A. And. The surface (mounting surface) of the flange portion 4A is a flat surface, and a pair of bolt holes 4C are formed in the flange portion 4A in accordance with the position of the fastening bolt 5 of the second protruding flat portion 1b. ing.
The flange portion 3A of the exhaust manifold 3 and the flange portion 4A of the EGR device 4 are separated from each other, but in the state before the connection to the both projecting flat portions 1a and 1b, the surfaces (mounting surfaces) of both flange portions 3A and 4A ) Are arranged on the same plane. The two flanges 3A, 4A positioned on the same plane as described above are opposed to the surfaces (mounting surfaces) of the two protruding flat portions 1a, 1b of the cylinder head 1.

Next, as shown in FIGS. 3 to 5, the gasket 2 of this embodiment has a horizontally long shape as a whole so that it can be mounted over the surfaces (mounting surfaces) of both projecting flat portions 1 a and 1 b on the cylinder head 1 side. It is formed in a substantially strip shape. The outline of the gasket 2 has a shape that follows the outline extending over both protruding flat portions 1a and 1b on the cylinder head 1 side.
The gasket 2 of the present embodiment is configured by superposing two metal substrates 2A and 2B having the same shape, and the upper and lower metal substrates 2A and 2B are integrally connected by caulking those required portions.

In the gasket 2, four exhaust holes 2C are formed in accordance with the positions and sizes of the four exhaust holes 6, and a position on one end side in the longitudinal direction (left end in FIG. 3). The suction hole 2D is formed in accordance with the position and size of the suction hole 7.
Bead portions 2a and 2b are formed at the overlapping positions of the upper and lower metal substrates 2A and 2B surrounding each exhaust hole 2C (FIG. 4). These bead portions 2a and 2b are formed so as to be inclined so that the inner peripheral edges are separated from each other when viewed in a radial cross section. Similarly to these, bead portions 2a and 2b are formed at the overlapping positions of the upper and lower metal substrates 2A and 2B surrounding the suction hole 2D (FIG. 5).
As described above, the bead portions 2a and 2b are formed so as to surround the exhaust holes 2C and the suction holes 2D, so that the gasket 2 is located between the protruding flat portions 1a and 1b and the flange portions 3A and 4A. When the bead portions 2a and 2b are in close contact with the mating member, the seal between the projecting flat portions 1a and 1b and the flange portions 3A and 4A is maintained. ing.

A region of the gasket 2 that contacts the surface of the first protruding flat portion 1a is the first seal portion S1 for the exhaust manifold 3, and a region of the gasket 2 that contacts the surface of the second protruding flat portion 1b is the EGR device 4. The second seal portion S2 is provided. That is, in the gasket 2 of the present embodiment, the first seal portion S1 for the exhaust manifold 3 and the second seal portion S2 for the EGR device 4 are configured continuously and integrally.
Bolt holes 2E are drilled in a total of five locations in the first seal portion S1 in accordance with the positions of the fastening bolts 5 of the first protruding flat portion 1a. These bolt holes 2E are formed in a staggered position across the exhaust hole 2C. In addition, a pair of bolt holes 2F are formed in the second seal portion S2 in accordance with the positions of the pair of fastening bolts 5 of the second projecting flat portion 1a. That is, a pair of bolt holes 2F is formed with the suction hole 2D interposed therebetween.

Furthermore, the gasket 2 according to the present embodiment has an elongated triangular hole in a direction intersecting the longitudinal direction of the entire gasket 2 at the boundary portion S3 that is a connecting portion between the first seal portion S1 and the second seal portion S2. A slit 2G is formed. The slit 2G is formed in the same shape at the overlapping position of the two metal substrates 2A and 2B.
The longitudinal direction of the slit 2G is a direction that intersects the longitudinal direction of the entire gasket 2. More specifically, the longitudinal direction of the slit 2G is a direction intersecting with a straight line connecting the centers of the exhaust hole 2C and the suction hole 2D adjacent to each other with the boundary portion S3 interposed therebetween.
Adjacent portions at both ends in the longitudinal direction of the slit 2G are left as residual connection portions that connect the first seal portion S1 and the second seal portion S2, and the residual connection portions at these two locations serve as crack allowable portions 2H. ing.
When the gasket 2 is mounted on and attached to the surfaces (attachment surfaces) of the both projecting flat surfaces 1a and 1b of the cylinder head 1, the boundary portion S3 of the gasket 2 is placed in the space 1C between the projecting flat surfaces 1a and 1b. And the slit 2G and the crack permissible part 2H there are located (refer FIG. 7).
Thereby, after the gasket 2 is attached to the cylinder head 1, when the internal stress is concentrated on the boundary portion S3 between the seal portions S1 and S2, the internal stress can be absorbed by the slit 2G, and a crack is generated in the crack allowable portion 2H. It has become. Thereby, when internal stress is concentrated on the boundary portion S3, it is possible to prevent the exhaust hole 2C and the bead portions 2a and 2b of the suction hole 2D adjacent to each other across the boundary portion S3 from being cracked or damaged. It is like that. As described above, in the gasket 2 of the present embodiment, the first seal portion S1 for the exhaust manifold 3 and the second seal portion S2 for the EGR device 4 are integrated, and the boundary portion S3 thereof is also formed. A feature is that a slit 2G and a crack allowing portion 2H are formed.

In the above configuration, the flange portions 3A and 4A are connected to the cylinder head 1 as follows.
First, as shown in FIG. 1, after the fastening bolt 5 is inserted into the bolt holes 2E and 2F of the gasket 2, the gasket 2 is superposed on the surfaces of the two protruding flat portions 1a and 1b of the cylinder head 1, and in this state, The flange portion 3A of the exhaust manifold 3 and the flange portion 4A of the EGR device 4 are superposed on the gasket 2 from the outside, and then both flange portions 3A, 4A are connected to both projecting flat portions 1a, 1b by fastening bolts 5.
Accordingly, the gasket 2 is sandwiched between the projecting flat portions 1a and 1b and the flange portions 3A and 4A so as to maintain a seal therebetween.
As shown in a simplified cross-sectional view in FIG. 7, the boundary portion S3 of the gasket 2 and the slit 2G and the crack-allowing portion 2H provided therein are formed on both protruding flat portions of the cylinder head 1 in a state after the attachment is completed. It is located in the space 1C between 1a and 1b.

As described above, in the engine structure of the present embodiment, the two protruding flat portions 1a and 1b of the cylinder head 1 are formed adjacent to each other, and their surfaces (mounting surfaces) are located on the same plane. . In addition, the gasket 2 is configured such that the first seal portion S1 and the second seal portion S2 are continuous and integrated. Furthermore, in the state before connection, both flange parts 3A and 4A are comprised so that it may be located on the same plane.
Therefore, the single gasket 2 can be mounted from the same direction with respect to the surfaces (mounting surfaces) of both projecting flat portions 1a and 1b on the same plane. Both flange portions 3A and 4A can be polymerized. Therefore, according to the present Example, the connection operation | work of both the flange parts 3A and 4A with respect to both the protrusion flat parts 1a and 1b can be simplified compared with the past.
Further, in the gasket 2 of this embodiment, the first seal portion S1 for the exhaust manifold 3 and the second seal portion S2 for the EGR device 4 are configured integrally in a continuous manner. Therefore, compared with the conventional product in which the first seal portion S1 and the second seal portion S2 are separated, the number of parts can be reduced by one, and also in this respect, the gasket 2 is attached to the cylinder head 1. The work effort can be reduced.
Furthermore, after the gasket 2 and the flange portions 3A and 4A are attached to the cylinder head 1, the engine 2 is repeatedly operated and stopped, whereby the gasket 2 is mainly attached to the first projecting flat portion 1a. The seal portion S1 repeats thermal expansion and contraction in the longitudinal direction. At this time, as shown in FIG. 6, the fastening bolt 5 for the EGR device 4 is located next to the boundary portion S3, so that the elastic deformation in the longitudinal direction of the first seal portion S1 is restrained. . For this reason, the internal stress is concentrated on the boundary portion S3 facing the space 1C. However, the internal stress is absorbed by the slit 2G in the boundary portion S3, and a crack is generated in the crack allowing portion 2H. Thereby, it is possible to prevent the bead portions 2a and 2b of the exhaust hole 2C and the suction hole 2D adjacent to the boundary part S3 from being cracked or damaged by internal stress acting on the boundary part S3. Thereby, it is possible to effectively suppress the occurrence of seal leakage in the gasket 2.

In addition, in the said Example, although both flange parts 3A and 4A are comprised on the same plane in the state before a connection, if the collection | recovery pipe | tube 4B is provided with flexibility, the EGR apparatus 4 of FIG. The flange portion 4A does not necessarily have to be positioned on the same plane as the flange portion 3A of the exhaust manifold 3 in a state before connection.
Further, as shown in FIG. 7, the slit 2G of the present embodiment has an elongated triangular shape, but the shape of the slit 2G may be a wide linear shape or a square shape.
Further, in the above embodiment, the gasket 2 is formed by polymerizing two metal substrates 2A and 2B. However, a gasket may be formed by polymerizing three or more metal substrates.

DESCRIPTION OF SYMBOLS 1 ... Cylinder head 1A ... Side wall 1a ... 1st protrusion flat part 1b ... 2nd protrusion flat part 2 ... Gasket 2C ... Exhaust hole 2D ... Intake hole 3 ... Exhaust manifold 3A ... Flange part 4 ... EGR device 4A ... Flange part 6 ... Exhaust hole 7 ... Suction hole S1 ... First seal part S2 ... Second seal part

Claims (2)

A cylinder head having a side wall in which a plurality of exhaust holes for exhaust and a suction hole for an EGR device are opened, a first flange portion of an exhaust manifold connected to the position of the exhaust hole in the side wall, and a suction hole in the side wall The engine structure includes a second flange portion of the EGR device connected to the position of the EGR device, and a gasket that is interposed between the side wall of the cylinder head and the flange portions to maintain a seal therebetween. And
A first projecting flat portion in which the exhaust hole is opened and the first flange portion is connected to the side wall of the cylinder head, and a second flange portion in which the suction hole is opened and the second flange portion is connected. The projecting flat part is formed apart from each other, and the surfaces serving as the mounting surfaces of the first projecting flat part and the second projecting flat part are located on the same plane at the same height,
The gasket is provided with an exhaust hole corresponding to the exhaust hole, a first seal portion interposed between the surface of the first projecting flat portion and the first flange portion, and the suction hole. A suction hole is provided, and a second seal portion interposed between the surface of the second projecting flat portion and the second flange portion is provided, and the first seal portion and the second seal portion are continuous. The engine structure is characterized by being integrally formed. 2. The engine structure according to claim 1, wherein the first flange portion and the second flange portion are located on the same plane in a state before the cylinder head is connected to the both projecting flat portions.

Images