JP4409752B2 - Engine exhaust structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an exhaust part that exhausts exhaust gas from a cylinder head of an engine.
[0002]
[Prior art]
Conventionally, the cylinder head and the exhaust manifold are attached via a gasket. And since an exhaust manifold is attached according to the end surface shape of a cylinder head, the attachment position of the attachment bolt will be limited by the shape of a cylinder head. For this reason, it is difficult to attach an exhaust manifold of an engine with the same output or the same output and different specifications to the cylinder head, or the cost increases because an exhaust manifold having a shape matched to the cylinder head is manufactured. Conventionally, an instrument mounting portion has been provided in the exhaust manifold for measuring the temperature, pressure, etc. of the exhaust gas.
[0003]
[Problems to be solved by the invention]
Since the exhaust manifold is a large component, it is difficult to process the measurement bolt so that it can be inserted into the exhaust manifold, resulting in an increase in cost. In addition, since it is separated from the engine body, the error becomes large and the accuracy is lowered.
[0004]
[Means for Solving the Problems]
The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.
[0005]
In the exhaust structure of the engine (10), the exhaust manifold (2) is connected to the cylinder head (1) via the exhaust manifold spacer (3), and the exhaust passages (11, 13, 12) are connected in communication. The fastening portion of the fastening member (4) for fastening the exhaust manifold (2) and the exhaust manifold spacer (3) is disposed near the end face of the exhaust manifold (2) on the side opposite to the cylinder head (1), and the exhaust A boss portion (4) of a fastening member (4) for fastening the exhaust manifold (2) and the exhaust manifold spacer (3) at a position outside the exhaust passage (12) formed in the manifold (2) and the cooling water passage (32). 22), cooling water passages (31, 32) are respectively formed in the cylinder head (1) and the exhaust manifold (2), and the cooling water passages communicated with the exhaust manifold spacer (3). The cooling water passages (31, 32) are separated from each other, and recessed portions (24, 25, 26) are provided on the end face of the exhaust manifold spacer (3) on the cylinder head (1) side, A mounting portion (19) for a measuring instrument (6) is formed in the exhaust manifold spacer (3) at the position of the recessed portion (24, 25, 26), and the instrument mounting portion (19) The mounting hole (19a) includes a mounting hole (19a) from the outer periphery of the manifold spacer (3) to the exhaust passage (13) of the exhaust manifold spacer (3) and a measurement hole (19b). Is formed so that the screw part provided in the meter (6) can be screwed, the measurement hole (19b) penetrates the exhaust manifold spacer (3), and the tip of the meter (6) is directly connected to the exhaust gas. It can be contacted .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, examples of the present invention will be described.
[0007]
FIG. 1 is a cross-sectional view showing an exhaust structure of an engine according to the present invention, and FIG. 2 is a view taken along an arrow A in FIG. 1 of an exhaust manifold spacer.
[0008]
3 is a view of the exhaust manifold spacer as viewed from the downstream side, and FIG. 4 is a cross-sectional view of the exhaust manifold spacer taken along line BB in FIG.
[0009]
FIG. 5 is a view of the exhaust manifold spacer as viewed from the upstream side, and FIG. 6 is a view taken along arrow C in FIG. 5 of the instrument mounting portion provided in the exhaust manifold spacer.
[0010]
As shown in FIG. 1, the cylinder head 1 and the exhaust manifold 2 of the engine 10 are connected via an exhaust manifold spacer 3. An exhaust passage 11 is formed in the cylinder head 1, an exhaust passage 12 is formed in the exhaust manifold 2, and an exhaust passage 13 is formed in the exhaust manifold spacer 3. These exhaust passages 11, 13, and 12 are connected in communication. Exhaust gas is discharged from the engine 10 through the exhaust passage 11. The exhaust manifold 2 is connected to the exhaust pipe 14 on the downstream side in the exhaust gas discharge direction. The exhaust gas that has passed through the exhaust passages 11, 13, and 12 is discharged to an exhaust passage formed in the exhaust pipe 14.
[0011]
In addition, when the engine 10 is a multi-cylinder engine, a plurality of cylinder heads 1. The exhaust manifold 2 is formed to branch from one main pipe so as to correspond to a multi-cylinder engine, and the front end side of each branch pipe faces the cylinder head 1 side. .. Are connected to each other through exhaust manifold spacers 3, 3... So that the cylinder heads 1, 1. FIG. 1 shows a cross section of the exhaust manifold 2 taken along a plane including a communication portion between the exhaust pipe 14 and the exhaust manifold 2. Exhaust gas discharged from the cylinder heads 1,... Other than those shown in FIG. 1 is discharged from the opening 15 of the exhaust manifold 2 to the exhaust passage 12. The exhaust gas joins on the downstream side of the exhaust passage 12 and is then discharged to the exhaust pipe 14. Of course, the configuration of the present invention is possible even in the case of a single-cylinder engine without providing the opening 15 in the exhaust manifold 2.
[0012]
The cylinder head 1 and the exhaust manifold spacer 3 are connected via a metal gasket 16 to prevent the exhaust gas from leaking from the connecting portion. Similarly, the exhaust manifold spacer 3 and the exhaust manifold 2 are connected via a gasket 17, and the exhaust manifold 2 and the exhaust pipe 14 are connected via a gasket 18 to prevent the exhaust gas from leaking.
[0013]
The exhaust manifold spacer 3 will be described with reference to FIGS. An instrument mounting portion 19 is formed from the outer periphery of the exhaust manifold spacer 3 toward the exhaust passage 13. The instrument mounting portion 19 is composed of a mounting hole 19a and a measurement hole 19b, and the mounting hole 19a is formed so that a screw portion provided in the meter 6 can be screwed together. Further, the measurement hole 19b and the mounting hole 19a pass through the exhaust manifold spacer 3 in a direction substantially perpendicular to the exhaust passage 13 so as to communicate with the exhaust passage 13, and the tip of the instrument 6 is in direct contact with the exhaust gas. I can do it. The instrument 6 can be equipped with a thermometer to measure the temperature of the exhaust gas in this embodiment, but the exhaust gas pressure, components such as oxygen, carbon monoxide, carbon dioxide, NOx, noise, etc. As an instrument for measuring vibration and vibration, it may be screwed into the mounting hole 19a.
[0014]
As shown in FIGS. 4 and 5, recessed portions 24, 25, and 26 are formed in the end face of the exhaust manifold spacer 3 on the engine 10 side (cylinder head 1 side), that is, in the range where it contacts the engine 10 side. Yes. In other words, the end face of the exhaust manifold spacer 3 on the engine 10 side has a narrow area corresponding to the size of the mounting portion of the cylinder head 1, and the exhaust manifold spacer 3 wider than the mounting portion on the cylinder head 1 side. These are the recessed portions 24, 25, and 26. Therefore, the amount of protrusion of the exhaust manifold spacer 3 on the cylinder head 1 side is reduced, and protrusions such as heat radiation fins and reinforcing ribs formed on the cylinder block 10a and the cylinder head 1 of the engine 10 are provided between the exhaust manifolds. It does not interfere with the seat 3. Moreover, the weight of the exhaust manifold spacer 3 can be reduced by reducing the amount of protrusion of the exhaust manifold spacer 3. Further, by forming a recessed portion in the exhaust manifold spacer 3, it is not necessary to provide a collar or the like to avoid interference with the engine 10 side, and the projecting dimension of the exhaust manifold 2 can be reduced.
[0015]
A fastening structure between the exhaust manifold spacer 3 and the cylinder head 1 using the mounting bolts 5, 5... Will be described. As shown in FIGS. 1, 3, and 4, bolt holes 28, 28,... Are formed in the exhaust manifold spacer 3, and the mounting bolts 5, 5,. Can be inserted and fastened. Similarly, a bolt hole is formed in the cylinder head 1 so that the threaded portion 5a of the mounting bolt 5 can be screwed from the exhaust manifold spacer 3 side, and the bolt hole and the mounting hole 28 are continuously formed. Yes. Then, the mounting bolt 5 is inserted into the mounting hole 28 and the screw portion 5a is fastened by the bolt hole so that the exhaust manifold spacer 3 and the cylinder head 1 can be fastened and fixed.
[0016]
Next, a fastening structure between the exhaust manifold 2 and the exhaust manifold spacer 3 will be described. .. Are formed on the outer periphery of the exhaust manifold 2, and bolt holes are formed in the boss parts 22, 22... In parallel with the exhaust passage 12, and exhaust on the extension of the bolt holes. Screw holes 23, 23... Are formed in the manifold spacer 3. Then, the fastening member 4 is used as a bolt, the shaft part 4b is inserted into the bolt hole, the screw part 4a of the fastening member 4 is screwed into the bolt hole 23, and the exhaust manifold 2 and the exhaust manifold spacer 3 can be attached and detached. It is trying to become. The boss portion 22 is configured such that a bolt head 4c serving as a tightening portion of the fastening member 4 is positioned as far as possible from the cylinder head 1 (engine 10) side and is detachable. That is, the length of the boss portion 22 in the axial direction is increased, and the fastening portion is disposed so as to be positioned near the end face of the exhaust manifold 2 on the side opposite to the cylinder head 1. For this reason, when the exhaust manifold 2 is fastened and fixed to the exhaust manifold spacer 3, the tightening portion of the fastening member 4 is tightened compared to the case where the boss portion is formed shorter than in the case of the present embodiment. It is easy to set the tool to be set, so that the tool or the like does not come into contact with the outer wall of the exhaust manifold 2 during the tightening operation. The fastening member 4 is easily attached and detached, and the exhaust manifold spacer 3 and the like can be easily disassembled from the exhaust manifold 2.
[0017]
As shown in FIG. 1, the boss portions 22, 22... For this reason, the bosses 22, 22... Are less affected by the exhaust gas and are not easily deformed. Further, when the boss portions 22, 22... Are formed inside the exhaust passages 12, 13 and the cooling water passage 31, a bypass path is provided so that the boss portion 22 does not contact the exhaust passages 12, 13 and the cooling water passage 31. It is necessary to provide it. At this time, the structure of the exhaust manifold 2 is complicated, and the fastening member 4 is surrounded by the outer wall of the exhaust manifold 2 when the fastening member 4 is fastened. Therefore, when attaching / detaching the fastening member 4, the tool that holds the fastening member 4 is likely to come into contact with the outer wall of the exhaust manifold 2, so that attachment / detachment becomes difficult. In this embodiment, this point is avoided by forming the boss portions 22, 22... Outside the exhaust passages 12, 13 and the cooling water channel 31.
[0018]
In the cylinder head 1, a cooling water passage 31 for cooling the exhaust gas is formed around the exhaust passage 11. Similarly, a cooling water passage 32 is formed around the exhaust passage 12 in the exhaust manifold 2. However, the cooling manifold is not formed in the exhaust manifold spacer 3. That is, the outer wall of the cylinder head 1 and the exhaust manifold 2 is provided with an inlet and an outlet for cooling water (not shown). The cooling water outlet 31 provided in the cylinder head 1 and the cooling water inlet provided in the exhaust manifold 2 are connected to a connection pipe (not shown) so that the cooling water passages 31 and 32 are communicated with each other. With this configuration, the exhaust manifold spacer 3 is separated from the cooling water passages of the cylinder head 1 and the exhaust manifold 2 and can cool the exhaust gas without providing a cooling water passage in the exhaust manifold spacer 3. The structure of the seat 3 is simplified.
[0019]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
An engine (10) in which an exhaust manifold (2) is connected to a cylinder head (1) via an exhaust manifold spacer (3) and the exhaust passages (11, 13, 12) are connected in communication. ), The fastening portion of the fastening member (4) for fastening the exhaust manifold (2) and the exhaust manifold spacer (3) is used as the end face of the exhaust manifold (2) on the side opposite to the cylinder head (1). Fastening members that are disposed in the vicinity and fasten the exhaust manifold (2) and the exhaust manifold spacer (3) at positions outside the exhaust passage (12) and the cooling water passage (32) formed in the exhaust manifold (2). The boss portion (22) of (4) is formed, cooling water passages (31, 32) are respectively formed in the cylinder head (1) and the exhaust manifold (2), and the exhaust manifold spacer (3) Has a structure in which the cooling water passages (31, 32) are separated without providing a communicating cooling water passage, and a recessed portion (24, 25) is formed on the end face of the exhaust manifold spacer (3) on the cylinder head (1) side. 26), and a mounting portion (19) for the measuring instrument (6) is formed in the exhaust manifold spacer (3) at the position of the recessed portion (24, 25, 26). (19) comprises a mounting hole (19a) from the outer periphery of the exhaust manifold spacer (3) to the exhaust passage (13) of the exhaust manifold spacer (3) and a measurement hole (19b); The mounting hole (19a) is formed so that a threaded portion provided in the meter (6) can be screwed, and the measurement hole (19b) penetrates the exhaust manifold spacer (3), and the meter (6) since the tip is made possible direct contact with the exhaust gases, collected meter to the exhaust manifold which is a large part Compared with the case of forming a part, the structure of the exhaust manifold simplifies the machining can be facilitated by manufacture.
Further , since the instrument mounting portion is provided in the vicinity of the cylinder head, the measurement location is close to the engine, and more accurate measurement of exhaust gas temperature, pressure, and the like can be performed.
[0020]
In addition , since the fastening part of the fastening member that fastens the exhaust manifold and the exhaust manifold spacer is arranged in the vicinity of the end face of the exhaust manifold on the side opposite to the cylinder head, a tool for fastening the fastening part of the fastening member is fully inserted. This is unnecessary, and the outer wall of the exhaust manifold does not obstruct the tightening operation, and the attaching / detaching operation of the fastening member is facilitated.
[0021]
In addition , since the boss part of the fastening member that fastens the exhaust manifold and the exhaust manifold spacer is formed at the position outside the exhaust passage and cooling water passage formed in the exhaust manifold, interference with the boss portion is caused in the exhaust passage and cooling water passage. There is no need to provide a detour to prevent it.
Also, compared to the case where the boss is provided inside the exhaust passage or the cooling water passage, the tool for holding the fastening member is less likely to come into contact with the outer wall of the exhaust manifold when attaching / detaching the fastening member. It will be a thing.
In addition, the heat effect of the exhaust gas on the boss portion is small, and the boss portion is difficult to deform.
[0022]
In addition , a cooling water passage is formed in each of the cylinder head and the exhaust manifold, and the exhaust manifold spacer is separated from the cooling water passage, so that the exhaust gas can be cooled without providing a cooling water passage in the exhaust manifold spacer. . For this reason, there is no need to provide a cooling water seal structure in the exhaust manifold spacer, the structure is simplified, and the manufacturing cost is reduced.
Further , since there is no cooling water channel in the exhaust manifold spacer, there is no possibility of water leakage.
[0023]
In addition , because the recessed part is provided in the end face of the exhaust manifold spacer on the cylinder head side, the protruding part of the cylinder head and the exhaust manifold spacer do not interfere with each other, and the exhaust manifold and the exhaust manifold spacer approach the cylinder head. Can be attached.
Further, the weight of the exhaust manifold spacer can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an exhaust structure of an engine according to the present invention.
FIG. 2 is a view of the exhaust manifold spacer as viewed in the direction of arrow A in FIG.
FIG. 3 is a view of an exhaust manifold spacer as viewed from the downstream side.
4 is a cross-sectional view of the exhaust manifold spacer taken along the line BB in FIG. 3;
FIG. 5 is a view of an exhaust manifold spacer as viewed from the upstream side.
6 is a view taken from the direction of arrow C in FIG. 5 of the instrument mounting portion provided in the exhaust manifold spacer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Exhaust manifold 3 Exhaust manifold spacer 4 Fastening member 6 Instrument 10 Engine 22 Boss part 24/25/26 Recessed part 31/32 Cooling water channel

Claims (1)

In the exhaust structure of the engine (10), the exhaust manifold (2) is connected to the cylinder head (1) via the exhaust manifold spacer (3), and the exhaust passages (11, 13, 12) are connected in communication. The fastening portion of the fastening member (4) for fastening the exhaust manifold (2) and the exhaust manifold spacer (3) is disposed near the end face of the exhaust manifold (2) on the side opposite to the cylinder head (1), and the exhaust A boss portion (4) of a fastening member (4) for fastening the exhaust manifold (2) and the exhaust manifold spacer (3) at a position outside the exhaust passage (12) formed in the manifold (2) and the cooling water passage (32). 22), cooling water passages (31, 32) are respectively formed in the cylinder head (1) and the exhaust manifold (2), and the cooling water passages communicated with the exhaust manifold spacer (3). The cooling water passages (31, 32) are separated from each other, and recessed portions (24, 25, 26) are provided on the end face of the exhaust manifold spacer (3) on the cylinder head (1) side, A mounting portion (19) for a measuring instrument (6) is formed in the exhaust manifold spacer (3) at the position of the recessed portion (24, 25, 26), and the instrument mounting portion (19) The mounting hole (19a) includes a mounting hole (19a) from the outer periphery of the manifold spacer (3) to the exhaust passage (13) of the exhaust manifold spacer (3) and a measurement hole (19b). Is formed so that the screw part provided in the meter (6) can be screwed, the measurement hole (19b) penetrates the exhaust manifold spacer (3), and the tip of the meter (6) is directly connected to the exhaust gas. Engine exhaust structure characterized by being able to contact .

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