JP4715573B2 - Exhaust system - Google Patents

Description

  The present invention relates to an exhaust device, and more particularly, to an exhaust device that can efficiently perform intake and exhaust of an engine using a negative pressure wave of exhaust.

In an exhaust system of a conventional in-line four-cylinder internal combustion engine, four branch portions (exhaust manifolds) are joined to two intermediate pipes, and an intermediate part is located upstream of a part where these two intermediate pipes further join. By providing two communicating pipes that communicate with each other, it is possible to improve the full opening torque in the low and medium speed ranges and to prevent an increase in the back pressure in the high speed range (for example, see Patent Document 1). ).
JP-A-11-280458 (first page, FIG. 2)

  However, in a conventional exhaust system for an in-line four-cylinder internal combustion engine (see, for example, Patent Document 1), three independent control valves are provided in the upstream communication pipe and the downstream communication pipe, and the upstream communication pipe is further provided. Since the air fuel consumption sensor is provided, there is a problem that the apparatus becomes complicated and the manufacturing cost increases. In addition, although the three control valves are fully opened in the high-speed range, the engine output is not designed to efficiently suck out the combustion gas from the exhaust port using the negative pressure wave of the exhaust generated in the communication pipe. There was a problem of not being able to put out enough.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an exhaust device that can efficiently perform intake and exhaust of an engine with a simple configuration.

In the exhaust system according to the present invention, the exhaust discharged from the engine flows through the inside thereof, and the two intermediate conduits that merge with each other at the junction, and the two intermediate pipelines on the upstream side of the junction are connected to each other. Two communication pipes communicating at different positions, a valve provided inside each of the communication pipes so as to be openable and closable, a single valve link rod connected to each of the valves, and the valve link rod Actuators that open and close each of the valves by driving the valve, and the valves are both closed, one is open, the other is closed, one is closed, the other is open, and each state is switched. It is characterized by.

  The exhaust device according to the present invention includes a plurality of communication pipes that communicate with each other between the intermediate pipes, and a plurality of valves provided inside each of the communication pipes, and the plurality of valves are connected by a single valve link rod. Since this is driven by an actuator, the apparatus becomes simple and the manufacturing cost can be reduced. Further, by opening and closing two or more valves, it is possible to select at least three exhaust pipe lengths, and efficient intake and exhaust using exhaust negative pressure waves is possible in the entire rotation range.

  Hereinafter, an embodiment of an exhaust device according to the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing an overall configuration of an exhaust device according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing portions of the intermediate pipe 20 and the communication pipes 30 and 32 of the exhaust device of FIG.

  As shown in FIG. 1, the exhaust system according to Embodiment 1 of the present invention exhausts exhaust from a V-type 6-cylinder engine 10, and three cylinders 12 are arranged in the left and right banks of the engine 10. It is out. An exhaust manifold 14 is connected to each cylinder 12, and three exhaust manifolds 14 coming out of the cylinder 12 are gathered together on the left and right sides and connected to two upstream pipelines 16. In this embodiment, a V-type 6-cylinder engine is taken as an example. For example, four exhaust manifolds of a V-type 8-cylinder engine may be connected together to two pipe lines, or an in-line 4-cylinder Two engine exhaust manifolds may be connected together and connected to two pipe lines.

  Each upstream pipeline 16 is connected to the intermediate pipeline 20 via, for example, a catalytic converter 18. The catalytic converter 18 (three-way catalyst) has a function of changing harmful substances such as carbon monoxide, hydrocarbons and nitrogen oxides contained in the exhaust gas of the engine 10 into harmless substances such as carbon dioxide, water and nitrogen. . The catalytic converter 18 may be provided in the middle of the intermediate pipeline 20 on the downstream side of the position shown in FIG.

  The two intermediate conduits 20 are arranged substantially parallel to each other and relatively close to each other, and merge at the junction 22 on the downstream side to form one junction tube 24. The junction pipe 24 is connected to a muffler (not shown in FIGS. 1 and 2) on the downstream side, and the exhaust gas silenced by the muffler is discharged to the outside of the vehicle or the like.

  An upstream communication pipe 30 and a downstream communication pipe 32 that connect the two intermediate pipes 20 at different positions are provided on the upstream side of the junction 22 of the intermediate pipe 20. The upstream communication pipe 30 and the downstream communication pipe 32 are substantially orthogonal to the two intermediate pipes 20, and the upstream communication pipe 30 and the downstream communication pipe 32 are substantially parallel to each other. In the present embodiment, two communication pipes, that is, the upstream communication pipe 30 and the downstream communication pipe 32 are provided in the middle of the intermediate pipe 20. For example, three or more communication pipes are provided in the middle of the intermediate pipe 20. You may make it provide.

  An upstream valve 34 that can be opened and closed is provided inside the upstream communication pipe 30, and a downstream valve 36 that can be opened and closed is provided inside the downstream communication pipe 32. The upstream side valve 34 and the downstream side valve 36 have, for example, a flat plate shape, and allow exhaust to pass through the communication pipe when the valve is open, and prevent exhaust from passing through the communication pipe when the valve is closed.

  Further, the upstream side valve 34 and the downstream side valve 36 are connected to one valve link rod 40, and the valve link rod 40 is rotated by an actuator 42 composed of an electric motor or the like. The actuator 42 rotates the valve link rod 40 with its central axis as the rotation axis, and the upstream valve 34 and the downstream valve 36 rotate as the valve link rod 40 rotates to open and close. For example, in the exhaust device shown in FIGS. 1 and 2, the valve link rod 40 is rotated, the upstream valve 34 is opened, and the downstream valve 36 is closed. The structures and operations of the upstream valve 34, the downstream valve 36, and the valve link rod 40 will be described later. In this embodiment, the valve link rod 40 is rotationally driven to open and close the valve. However, the valve link rod 40 may be driven by other methods to open and close the valve.

  Here, the operation of the two communication pipes provided in the intermediate pipe 20 will be described. In a state where both the upstream valve 34 and the downstream valve 36 are closed, the pressure wave of the exhaust gas is reversed in direction at the merging portion 22 of the intermediate pipe line 20 and is directed to the exhaust valve (not shown) of the engine 10. It becomes. This is because the cross-sectional area of the pipe line becomes large at the junction 22. When the timing at which the negative pressure wave reaches the exhaust valve of the engine 10 coincides with the timing at which the piston (not shown) of the engine 10 reaches top dead center, the negative pressure wave efficiently removes the combustion gas in the cylinder 12 from the exhaust port. The amount of air that is sucked out and flows into the cylinder 12 from the intake port (not shown) is increased, and as a result, the intake efficiency is increased.

  However, it is necessary to advance the timing at which the negative pressure wave returns to the exhaust valve of the engine 10 as the engine speed increases. For this reason, as the engine speed increases, the downstream valve 36 and the upstream valve 34 are sequentially opened to adjust the position where the exhaust pressure wave is inverted and becomes a negative pressure wave. For example, in the state shown in FIGS. 1 and 2, since the upstream valve 34 is open, the cross-sectional area of the pipe line increases in the upstream communication pipe 30, and the exhaust pressure wave is generated in the upstream communication pipe 30. The negative pressure wave directed to the exhaust valve of the engine 10 is reversed. This is the case, for example, when the rotational speed of the engine 10 is high. In this way, by adjusting the length of the propagation path of the pressure wave of the exhaust gas according to the rotational speed of the engine 10, the intake / exhaust efficiency of the engine 10 can be improved.

  3, 4 and 5 are perspective views showing the upstream valve 34, the downstream valve 36 and the valve link rod 40 shown in FIGS. 1 and 2. 3 to 5, the length of the valve link rod 40 is different from that shown in FIGS. 1 and 2, and the upstream communication pipe 30, the downstream communication pipe 32, and the actuator 42 are omitted. . Hereinafter, the configurations and operations of the upstream side valve 34, the downstream side valve 36, and the valve link rod 40 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 3, the valve link rod 40 is composed of a core rod 40a and a peripheral rod 40b that rotate around the same axis and are slidable with respect to each other. The core rod 40a is fitted in, for example, a hollow portion provided in the peripheral rod 40b, and the core rod 40a and the peripheral rod 40b rotate about the central axis as a rotation axis. The peripheral rod 40b is rotated by the actuator 42.

  For example, a disk-shaped upstream valve 34 is attached to the core rod 40a, and for example, a disk-shaped downstream valve 36 is attached to the peripheral rod 40b. The core rod 40a is provided with a protrusion 50, and the peripheral rod 40b is provided with a protrusion 52. In the state shown in FIG. 1, the protrusion 50 of the core rod 40a and the protrusion 52 of the peripheral rod 40b are separated at an angle of 90 degrees. Note that the downstream valve 36 may be separated from the peripheral rod 40 b in the same manner as the upstream valve 34. In FIG. 3, the upstream valve 34 and the protrusion 50 are integrated, but the upstream valve 34 and the protrusion 50 may be formed at positions separated from each other.

  Further, the exhaust device according to the present embodiment includes a spring 54 that biases the upstream valve 34 in the closing direction. For example, one end of the spring 54 is attached to the protrusion 50, and the other end is attached to the upstream communication pipe 30. In the state of FIG. 3, since the protrusion 52 of the peripheral rod 40b does not press the protrusion 50 of the core rod 40a, the upstream valve 34 is closed by the spring 54, and the downstream valve 36 is also closed. For example, when the engine 10 is driven in a very low rotation range such as idling, the upstream side valve 34 and the downstream side valve 36 are both closed as shown in FIG. At this time, the pressure wave of the exhaust gas is reversed at the junction 22 and becomes a negative pressure wave directed to the exhaust valve of the engine 10.

  When the rotational speed of the engine 10 is higher than that shown in FIG. 3 but is driven in a predetermined low speed range, the peripheral rod 40b is rotated 90 degrees in the direction of the arrow in FIG. Open (Figure 4). At this time, the protrusion 52 of the peripheral rod 40b contacts the protrusion 50 of the core rod 40a but is not pressed, so the upstream valve 34 remains closed. In FIG. 4, the spring 54 is omitted. In the state of FIG. 4, the pressure wave of the exhaust gas is inverted mainly by the downstream side communication pipe 32 and becomes a negative pressure wave toward the exhaust valve of the engine 10.

  When the engine 10 is driven in a higher rotational range than the predetermined low rotational range in FIG. 4, the peripheral rod 40b is further rotated 90 degrees in the direction of the arrow in FIG. Then, the downstream valve 36 is closed (FIG. 5). At this time, the protrusion 52 of the peripheral rod 40b presses the protrusion 50 of the core rod 40a, causing the core rod 40a and the upstream valve 34 to rotate. In FIG. 5, the spring 54 is omitted. As apparent from FIGS. 4 and 5, when one of the upstream valve 34 and the downstream valve 36 is open, the other is closed. In the state of FIG. 5, the exhaust pressure wave is inverted mainly by the upstream communication pipe 30 to become a negative pressure wave directed to the exhaust valve of the engine 10.

  In the first embodiment, an upstream communication pipe 30 and a downstream communication pipe 32 communicating two intermediate pipes 20 with each other, and an upstream valve 34 and a downstream valve 36 provided inside each communication pipe are provided. Since the plurality of valves are connected by a single valve link rod 40 and driven by the actuator 42, the apparatus becomes simple and the manufacturing cost can be reduced.

  Further, by opening and closing the upstream side valve 34 and the downstream side valve 36 as shown in FIGS. 3 to 5, it becomes possible to select an exhaust pipe length corresponding to the rotational speed of the engine. Efficient intake / exhaust can be achieved using this.

(Embodiment 2.)
FIG. 6 is a perspective view showing portions of the intermediate pipe 20, the upstream communication pipe 31, and the downstream communication pipe 33 of the exhaust device according to Embodiment 2 of the present invention.

  The upstream communication pipe 31 and the downstream communication pipe 33 of the exhaust device according to the second embodiment are curved so as to be convex upward. Other components, operations, and the like are the same as those of the exhaust device according to the first embodiment, and the same components are denoted by the same reference numerals.

FIG. 7 is a diagram illustrating an internal configuration of a vehicle on which the exhaust device according to the second embodiment is mounted. 7A is a top view showing the internal configuration of the vehicle equipped with the exhaust device according to the second embodiment, FIG. 7B is a side view thereof, and FIG. 7C is FIG. 7A. A CC section is shown. The vehicle shown in FIG. 7 is an FR vehicle that drives the rear wheels. 7 also shows a muffler 70 connected to the downstream side of the merging pipe 24. In the vehicle shown in FIG. 7, a floor tunnel 62 curved upward is formed in the bottom floor metal 60. A fuel tank 64 is provided above. The propeller shaft 66 that transmits driving force from the engine 10 to the rear wheel side passes through the interior of the floor tunnel 62, and the upstream side communication pipe 31 and the downstream side communication pipe 33 are also inside the floor tunnel 62. The propeller shaft 66 passes through the upward curved portions of the upstream communication tube 31 and the downstream communication tube 33. As a result, the upstream communication pipe 31 and the downstream communication pipe 33 do not interfere with the propeller shaft 66, and a place where the propeller shaft 66 is installed can be secured. Other effects are the same as those of the exhaust device according to the first embodiment.

  Needless to say, the present invention is not limited to the above-described embodiment, and includes various modifications and improvements that can be made within the scope of the technical idea. For example, the shape of the communication pipe is not limited to that shown in FIGS. Further, the configuration and operation of the valve link rod 40 are not limited to those shown in FIGS.

It is the schematic diagram which showed the whole structure of the exhaust apparatus which concerns on Embodiment 1 of this invention. It is the perspective view which showed the part of the intermediate | middle pipe line and communication pipe | tube of the exhaust apparatus of FIG. It is the perspective view which showed the upstream valve | bulb shown in FIG. 1 and FIG. 2, a downstream valve | bulb, and the valve link rod. FIG. 4 is a perspective view of a state in which a peripheral rod of the valve link rod of FIG. 3 is rotated. FIG. 5 is a perspective view of a state in which a peripheral rod of the valve link rod of FIG. 4 is rotated. It is the perspective view which showed the part of the intermediate | middle pipe line of the exhaust apparatus which concerns on Embodiment 2 of this invention, an upstream communication pipe, and a downstream communication pipe. It is the figure which showed the internal structure of the vehicle carrying the exhaust device which concerns on Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine 12 Cylinder 14 Exhaust manifold 16 Upstream side pipe 18 Catalytic converter 20 Intermediate pipe 22 Junction part 24 Junction pipe 30, 31 Upstream side communication pipe 32, 33 Downstream side communication pipe 34 Upstream side valve 36 Downstream side valve 40 Valve link Rod 40a Core rod 40b Peripheral rod 42 Actuator 50 Projection 52 Projection 54 Spring 60 Bottom floor metal 62 Floor tunnel 64 Fuel tank 66 Propeller shaft 70 Muffler

Claims (8)

Two intermediate pipes where the exhaust discharged from the engine flows through the inside and merges with each other at the junction,
Two communication pipes for communicating the two intermediate pipe lines at different positions on the upstream side of the junction part;
A valve provided inside each of the communication pipes so as to be opened and closed;
One valve link rod connected to each of the valves;
An actuator for opening and closing each of the valves by driving the valve link rod;
Equipped with a,
An exhaust system characterized in that the valves are both closed, one is open, the other is closed, one is closed, and the other is open . The actuator closes both of the valves when the engine is driven in an idle state, and the intermediate pipe line when the engine is driven in a predetermined low rotation range having a higher rotational speed than the idle state. When the engine is driven in a higher rotation range than the predetermined low rotation range, the communication pipe provided in the upstream side of the intermediate pipe is opened. The exhaust device according to claim 1 , wherein the valve is opened . 3. The valve according to claim 1, wherein the valve allows the exhaust to pass through the communication pipe in an open state and prevents the exhaust from passing through the communication pipe in a closed state. Exhaust system. The exhaust device according to any one of claims 1 to 3, wherein the actuator rotates the valve link rod and each of the valves about a predetermined axis . The exhaust device according to claim 4 , wherein the plurality of valves have a flat plate shape . The exhaust device according to claim 4 or 5 , further comprising a spring that biases the valve inside the communication pipe provided on the upstream side of the intermediate pipe in a closing direction . The valve link rod has a core rod and a peripheral rod that rotate about the same axis and are slidable with each other, and a valve inside the communication pipe provided on the downstream side of the intermediate pipe is attached to the peripheral rod. And a valve inside the communication pipe provided on the upstream side of the intermediate pipe is attached to the core rod, the core rod and the peripheral rod are provided with a protrusion, and the protrusion of the peripheral rod is the intermediate pipe The exhaust device according to claim 6, wherein when the valve inside the communication pipe provided on the upstream side of the passage is opened, the projection of the core rod is pressed . The exhaust device according to any one of claims 1 to 7 , wherein the plurality of communication pipes are curved so as to be convex upward .

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