APPARATUS FOR AUTOMATIC CONTROL OF EXHAUST PRESSURE OF AN INTERNAL COMBUSTION ENGINE

Abstract

The present invention relates to an apparatus for automatic control of the exhaust pressure of an internal combustion engine. The apparatus includes: a body having an inlet and an outlet for exhaust gas; a pressure control plate, which is a thin plate placed between the inlet and outlet inside the body, designed to rotate along a vertical direction with respect to the ground, within a particular range of angles; a rotational shaft, which is a bar coupled to one side of the pressure control plate that allows it to have a substantial vertical-rotation movement; first and second side elements, attached on both sides of the body's exterior and affixed to the protruding part of the rotational shaft extending outward through the holes on both sides; a controlling pendulum coupled to the first side element for setting the initial gradient of the pressure control plate; and a pendulum blade, coupled to a lower portion of the controlling pendulum, which moves in vertical rotation within a particular range of angles by means of air resistance generated during the operation of a vehicle and which, interlocked with the vertical rotational movement, causes the pressure control plate to move in vertical rotation also.

Description

TECHNICAL FIELD

The present invention relates to an apparatus for automatically controlling the exhaust pressure of an internal combustion engine, more particularly to an apparatus for automatically controlling the exhaust pressure of an internal combustion engine that creates an optimal exhaust pressure environment according to the output of the internal combustion engine by automatically controlling how far the exhaust passage is opened and closed, by way of a pressure control plate configured to rotate within a particular range of angles in correspondence with the speed of the vehicle.

BACKGROUND ART

The general four-stroke cycle of an internal combustion engine consists of intake, compression, explosion, and exhaust, in that order. With reference to the stroke continuing from exhaust to intake, the inlet valve opens and the outlet valve closes at the time of intake; however, for a very short time before the outlet valve closes, there exists a valve overlap time during which both the inlet and outlet valves are open. This is because only with the valve overlap can residual gas be expelled quickly and a fresh intake of air flow in.

When an internal combustion engine is running at a low speed, increasing the exhaust pressure can conserve fuel and enhance output.

One reason for this is that, when the aforementioned valve overlap occurs, the combustion gas is not expelled quickly during the downward movement of the piston, and the residual gas applies a downward force and increases the rotational torque. The efficiency of the engine can be increased as any incompletely combusted fuel may be recombusted.

However, when an internal combustion engine is running at a high speed, because the piston is making an alternating motion at a very fast speed, a high exhaust pressure can actually be an obstacle to the lift of the piston in the last stage of the valve overlap.

Consequently, the internal combustion engine can be expected to increase engine efficiency and enhance output if the exhaust pressure is raised during low-speed rotation and lowered during high-speed rotation.

However, for the exhaust pipe of an internal combustion engine installed in general vehicles, the diameter of the exhaust pipe is determined on the basis of the engine displacement at the point of greatest output during the explosion stroke.

Accordingly, when the internal combustion engine is running at a low speed, the size of the exhaust pipe is larger than is necessary compared to the engine displacement, and therefore the exhaust pressure is lower. Thus, a great deal of fuel is incompletely combusted and exhausted during the valve overlap, causing the engine's output to decrease.

In other words, the exhaust system of an internal combustion engine according to the related art does not include a means to adjust the exhaust pressure to the output of the internal combustion engine in correspondence with the valve overlap, because it uses an exhaust pipe of a fixed size, and thus has the problem of consuming more fuel than is necessary and of decreasing the engine's output, especially during low-speed rotation.

Certain methods have been suggested in the related art aimed at resolving the problem above, such as of utilizing an exhaust pressure sensor, motor, and driving gear to automatically control the amount by which an exhaust valve is opened and closed according to the exhaust pressure detected by the sensor, or utilizing multiple exhaust pipes of differing sizes so as to vary the exhaust path according to exhaust pressure.

These methods, however, do not entail simple structures and require the replacement of the entire exhaust pipe for installation, and in particular, substantially increases cost due to additional attachments such as a detector sensor.

DISCLOSURE

Technical Problem

The present invention was conceived in order to solve such problems as the aforementioned, and its purpose is to provide an apparatus for automatic control of exhaust pressure that can automatically control the amount by which the exhaust passage is opened and closed in correspondence to the exhaust pressure, so as to increase the exhaust pressure during low-speed rotation and lower the exhaust pressure during high-speed rotation, and thereby enhance the efficiency of the engine.

Another purpose of the present invention is to provide an apparatus for automatic control of exhaust pressure that can be easily attached to and detached from an existing exhaust pipe installed in a vehicle, has a low rate of failure from having a simple structure, can be installed conveniently, and has a low cost of production.

Technical Solution

To achieve the objectives above, an embodiment of the present invention provides an apparatus for automatic control of exhaust pressure of an internal combustion engine. The apparatus includes: a body that is inserted into a middle region of an exhaust pipe, where the body includes an inlet formed on one side and an outlet formed on the other side opposite the inlet, with the inlet configured to receive exhaust gas emitted from the internal combustion engine and the outlet configured to expel the received exhaust gas to the outside; a pressure control plate shaped as a thin plate that is placed inside the body between the inlet and the outlet and configured to be capable of rotational movement within a particular range of angles along a vertical direction with respect to a ground surface; a rotational shaft shaped as a bar and coupled to an edge of the pressure control plate to enable a substantial vertical-rotation movement of the pressure control plate, where the rotational shaft has portions thereof protruding through holes formed in both sides of the body; a first side element and a second side element included on both sides of the exterior of the body and coupled to protruding portions of the rotational shaft that extend outward to the outside through the holes; a controlling pendulum coupled to the first side element so as to set an initial gradient of the pressure control plate; and a pendulum blade shaped as a wing to receive sufficient air resistance and coupled to a lower portion of the controlling pendulum, where the pendulum blade is configured to move within a particular range of angles in vertical rotation by way of air resistance generated during an operation of a vehicle, and the pendulum blade is configured to cause the pressure control plate to move in vertical rotation in linkage with the vertical rotation movement.

Advantageous Effects

With an apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention, the amount by which the exhaust passage is opened and closed can be controlled automatically, to increase exhaust pressure during low-speed rotation and lower exhaust pressure during high-speed rotation, and thus effectively correspond to the valve overlap, thereby optimizing the exhaust pressure by immediately responding to the change in output of the internal combustion engine, that is to say, the change in rotational speed. This can increase the efficiency of fuel combustion, thus substantially decreasing exhaust fumes and saving fuel costs, and can increase rotational torque not only during high-speed movement but also during low-speed movement, thus enhancing stability in movement.

The apparatus can also be easily attached to and detached from an existing exhaust pipe installed in a vehicle, has a low rate of failure from having a simple structure, can be installed conveniently, and has a low cost of production.

Also, according to an embodiment of the present invention, since the amount by which the exhaust passage is opened and closed is automatically controlled according to the running speed of the vehicle by using the drag generated by a pendulum blade, a driver may drive a vehicle with maximum engine efficiency without paying particular attention

Furthermore, an apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention also has the marked effect of creating an optimal exhaust pressure environment by conforming easily to various sizes of exhaust pipes installed in a variety of vehicles, as the initial gradient setting of the pressure control plate and the control of the vertical position of the pendulum blade can be easily handled.

DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view showing the structure of an apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is an assembly drawing of FIG. 1.

FIGS. 3 (a), (b) and (c) are sequence diagrams showing the sequence of movements of the apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention moving according to the running speed of the vehicle.

MODE FOR INVENTION

An apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention is designed to automatically control the amount by which the exhaust passage is opened and closed according to the exhaust pressure, automatically increasing the exhaust pressure during low-speed rotation and lowering the exhaust pressure during high-speed rotation, and thus effectively responding to the valve overlap.

FIG. 1 is an exploded perspective view showing the structure of an apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention, and FIG. 2 is an assembly drawing of FIG. 1.

With reference to FIGS. 1 and 2, the apparatus for automatic control of exhaust pressure according to an embodiment of the present invention includes: a body 10; a pressure control plate 20; a controlling pendulum 30; and a pendulum blade 40.

A core concept of the apparatus for automatic control of exhaust pressure according to an embodiment of the present invention is that the pressure control plate 20 is designed to rotate in correspondence with the speed of the vehicle within a particular range of angles, thus automatically controlling the degree to which the exhaust passage is opened and closed, thereby creating an optimal exhaust pressure environment according to the output of the internal combustion engine.

The body 10 according to an embodiment of the invention is designed to accommodate the pressure control plate 20 inside, and to be inserted into the middle of an exhaust pipe to vary the exhaust pressure. On one side of the body 10 is an inlet 11 into which exhaust gas emitted from the internal combustion engine is entered, and on the other side opposite to the inlet is an outlet 13 out of which the entered exhaust gas is expelled.

Preferably, the inlet 11 and the outlet 13 should be cylindrical in shape to correspond to the general shape of exhaust pipes, so as to allow easy coupling to exhaust pipes, or be frustoconical, i.e. have a shape like a cone with its pointed end cut off, so as to allow coupling to exhaust pipes of various sizes with greater flexibility.

The pressure control plate 20 according to an embodiment of the present invention is in the shape of a thin plate; one side of the pressure control plate 20 is attached to a bar-shaped rotational shaft 25, and it is located between the inlet 11 and outlet 13 of the body 10.

The pressure control plate 20 attached inside the body 10 is designed to rotate within a particular range of angles in a direction perpendicular to the ground surface, according to the pressure of the gas emitted from the internal combustion engine.

The rotational shaft 25, coupled to one side of the pressure control plate 20 to allow the pressure control plate 20 to rotate, is designed to have one or more portions protruding through holes 15a, 15b in both sides of the body 10.

The protruding portions 25A, 25B extending through the holes 15a, 15b are coupled with a first side element 50 and a second side element 60 included on both sides of the exterior of the body 10.

The first side element 50 and the second side element 60 make sure that the rotational shaft 25 placed through the holes 15a, 15b on both sides rotate securely in a fixed position without sliding sideways.

The first side element 50 according to an embodiment of the present invention has a stepped part 51 protruding in a stepped shape, for the purpose of connecting the controlling pendulum 30 to the rotational shaft 25 and of coupling the rotational shaft 25 to the first side element 50.

The stepped part 51 has two bolt-fastening holes 53, 55 and a holding hole 51a for taking in the protruding portion 25A of the rotational shaft 25.

The protruding portion 25A of the rotational shaft 25 held inside the stepped part 51 is affixed coupled to the first side element 50 by tightening a tightening-bolt 70, which is inserted and fastened in a bolt-fastening hole 53, 55 of the stepped part 51, in relation to the controlling pendulum 30.

The controlling pendulum 30, inserted through the bolt-fastening holes 53, 55 of the stepped part 51 and clamped there, is a full-thread bolt 30, with a helical screw formed into a bar-shaped element. The controlling pendulum 30 serves to couple the rotational shaft 25 to the first side element 50 and also makes it possible to control the position of the pressure control plate 20 (more specifically, to control the gradient of the pressure control plate 20).

The protruding portion 25B of the rotational shaft 25 affixed coupled to the second side element 60 according to an embodiment of the present invention can be coupled by forming the same kind of stepped part on the second side element 60 as on the first side element 50 and using two tightening bolts in the bolt-fastening holes of the stepped part, or by tightening a tightening cap 90 in relation to a tightening bolt inserted and fastened to the tightening cap 90.

The pressure control plate 20 according to an embodiment of the present invention is included inside the body 10 to be perpendicular to the ground or to be inclined at an angle to the ground (in other words, rotated vertically to a particular angle), and the degree of opening and closing of the inlet 11 will change according to the degree of its inclination, thus varying the exhaust pressure.

The degree of inclination has to be set differently according to the types of engine and exhaust pipe installed in each vehicle, and the initial gradient of the pressure control plate 20, that is to say, the degree of inclination of the pressure control plate 20 installed inside the body 10 when the internal combustion engine is in a stationary state is set through the following process. (Hereafter, the state in which the pressure control plate 20 rests as meant in the aforementioned sense will be referred to as the initial gradient.)

The setting of the initial gradient of the pressure control plate 20 is done on the basis of low-speed rotation of the internal combustion engine. A typical exhaust pipe equipped in vehicles is designed on the basis of the engine displacement at the time of the greatest output in the explosion stroke of the engine, and therefore, the efficiency of the engine may be substantially decreased during low-speed rotation.

The apparatus for automatic control of exhaust pressure according to an embodiment of the present invention can be attached to an exhaust pipe that is designed based on engine displacement during high-speed rotation as described above, with the purpose of creating an optimal exhaust pressure environment by way of the pressure control plate during low-speed rotation of the internal combustion engine.

Therefore, the exhaust pressure that yields optimal fuel efficiency and output enhancement during low-speed rotation of the internal combustion engine may be detected, and the initial gradient may be set as the degree of inclination that is determined to cause the lift of the pressure control plate 20 placed slantingly on the path of the exhaust gas to produce the optimal exhaust pressure during low-speed rotation, i.e. the exhaust pressure detected above.

Accordingly, once the value of the initial gradient for creating the detected exhaust pressure is computed, a controlling element is needed by which the pressure control plate 20 maintains a gradient corresponding to that value within the interior of the body 10.

The controlling pendulum 30 according to an embodiment of the present invention is the implement for fulfilling that need, and the full-thread bolt corresponds to this implement; more specifically, the state of the initial gradient of the pressure control plate 20 is maintained by the weight of the full-thread bolt 30.

In other words, the rotational shaft 25, the stepped part 51, and the full-thread bolt 30 are designed to move together as a whole, fastened by the tightening bolt 70.

Accordingly, if no external force is applied to the full-thread bolt 30, the full-thread bolt 30 will tend toward the direction of gravity due to its own weight.

Using the aforementioned characteristics, the pressure control plate 20 is first set such that it is located inside the body 10 with the optimal gradient computed through the detection process described above, by rotating the protruding portions 25A, 25B of the rotational shaft 25 extending outward from the body 10.

Once this process is completed, the first side element 50 is rotated so as to allow the full-thread bolt 30 to be fastened to the bolt-fastening holes 53, 55 of the stepped part 51 while the full-thread bolt 30 points toward the direction of gravity, then by inserting the full-thread bolt 30 and the tightening bolt 70 into the bolt-fastening holes 53, 55 respectively and tightening the protruding part 25A, the pressure control plate 20 is made to be located inside the body 10 while maintaining the initial gradient.

As described above, in an apparatus for automatic control of exhaust pressure according to an embodiment of the present invention, the pressure control plate 20 is set by a method of conforming the kinetic energy of the exhaust gas to the lift of the pressure control plate 20, and detecting the exhaust pressure that will achieve the greatest engine efficiency during low-speed rotation of the internal combustion engine. This can eliminate incomplete combustion and decreased explosive power during low-speed rotation.

Above, a method is suggested of increasing the efficiency of an engine during low-speed rotation by using the pressure control plate 20 according to an embodiment of the present invention to increase the exhaust pressure of the exhaust pipe.

However, while a vehicle is running at a high speed, the time for the valve overlap to occur decreases significantly and the piston is going through an alternating motion at a very fast speed. Because of this, a high exhaust pressure actually becomes an obstacle to the lift of the piston during the last stage of the valve overlap, and thus lowers the efficiency of the engine.

Consequently, in the case of high-speed running such as the aforementioned, an element for lowering the exhaust pressure is needed. In other words, according to an embodiment of the present invention, the pressure control plate 20, which is obstructing the inlet 11 of the body 10, needs to be removed from the inlet 11 as much as possible.

The pendulum blade 40 according to the present invention is an implement for fulfilling this need during a high-speed run, and by using the drag generated during the run to remove the pressure control plate 20 from the inlet 11 as much as possible, it ensures adequate exhaust passage area in the exhaust pipe installed in the vehicle, allowing smooth exhaust emission and lowering the exhaust pressure.

Below is a more detailed description.

The pendulum blade 40 according to an embodiment of the present invention is designed to move by using the air resistance that is increased during a high-speed run of a vehicle. Consequently, its structure is shaped like a wing or a plate placed perpendicular to the direction in which the vehicle is going.

Also, the pendulum blade 40 is equipped on an exterior surface of the body 10, and moves in vertical rotation within a particular range of angles according to the degree of air resistance generated during the run of the vehicle. The apparatus for automatic control of exhaust pressure according to an embodiment of the present invention is configured such that the pressure control plate 20 also moves in vertical rotation in linkage with the vertical rotational motion of the pendulum blade 40, automatically ensuring adequate exhaust passage area in the body 10 in corresponding manner during high-speed rotation.

In other words, the apparatus for automatic control of exhaust pressure according to an embodiment of the present invention is configured to have the rotational shaft 25, the stepped part 51, and the full-thread bolt 30 moving together as a whole by way of the tightening bolt 70, in order to have the movement of the pendulum blade 40 interlocked with the pressure control plate 20. The pendulum blade 40 is coupled to a lower portion of the full-thread bolt 30, so that the pressure control plate 20 also moves in vertical rotation in proportion to the degree of vertical rotational movement of the pendulum blade 40 according to the air resistance, thus immediately varying the amount of opening and closing of the exhaust passage.

As illustrated in FIG. 2, the pendulum blade 40 can have at least two plates adjoined at one edge to form a leveled structure and can be fastened to the full-thread bolt 30 through the hole 41 formed in one plate of the pendulum blade 40 and with the use of a pair of tightening nuts 80a, 80b. The position of the pendulum blade 40 can be changed up and down by allowing change in the tightening position of the full-thread bolt 30 and the nuts, thus allowing the setting of a suitable position of the pendulum blade 40 according to the type of the vehicle.

FIGS. 3 (a), (b) and (c) are sequence diagrams showing the sequence of movements of the apparatus for automatic control of exhaust pressure of an internal combustion engine according to an embodiment of the present invention moving according to the running speed of the vehicle.

FIG. 3(a) shows the arrangement of the pressure control plate 20, the controlling pendulum 30, and the pendulum blade 40 according to an embodiment of the present invention when an internal combustion engine is in a stationary state.

As illustrated in FIG. 3(a), the pressure control plate 20 is included inside the body 10, maintaining a particular gradient for creating a corresponding optimal exhaust pressure during low-speed rotation of the internal combustion engine installed with the apparatus for automatic control of exhaust pressure according to the present invention. The controlling pendulum 30 and the pendulum blade 40 are arranged facing the direction of gravity.

Afterwards, when the internal combustion engine is in operation and in low-speed rotation, as illustrated in FIG. 3(b), the pressure control plate 20 is moved in vertical rotation to a particular angle by the pressure of the gas entering through the inlet 11 of the body 10 and by the air resistance generated at the pendulum blade 40.

Here, the gradient of the pressure control plate 20 rotated vertically to a particular angle approaches the gradient detected in the aforementioned process for creating the optimal exhaust pressure in low-speed rotation.

FIG. 3(c) shows the arrangement of the pressure control plate 20, the controlling pendulum 30, and the pendulum blade 40 according to an embodiment of the present invention when the vehicle is in a high-speed run, or in other words, when the internal combustion engine is in high-speed rotation.

As illustrated in FIG. 3(c), the pendulum blade 40 is moved in vertical rotation to a substantially large angle by the air resistance generated at the pendulum blade 40 and increased by the high-speed run of the vehicle. Accordingly, the pressure control plate 20 is removed from the inlet 11 of the body 10 to a maximum degree, thus maximizing the opening of the exhaust passage.

Accordingly, as the exhaust pressure is automatically lowered again during a high-speed run (more accurately, as the exhaust pressure is returned to the original level in the existing exhaust pipe installed in the vehicle), an exhaust pressure environment appropriate to the maximum output of the vehicle is created.

The location for installing the apparatus for automatic control of exhaust pressure according to an embodiment of the present invention installed in an automobile is as follows.

In general, an automobile comprises the following parts: starting with an exhaust manifold for engine exhaust, an automobile catalyst, a middle muffler, and an end muffler are joined in assemblage in this order.

As regards the order of configuration of an exhaust pipe, the apparatus for automatic control of exhaust pressure according to an embodiment of the present invention is installed in the area between the automobile catalyst and the middle muffler, or in the area between the middle muffler and the end muffler, where it can automatically control the opening and closing of the exhaust passage, thereby creating the optimal exhaust pressure environment according to the output of the internal combustion engine.

While the spirit of the invention has been described with reference to particular embodiments using particular terms, the embodiments are for illustrative purposes only and do not limit the invention. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the invention as defined by the appended claims. All such variations must not be understood separately from the spirit and scope of the invention, and are encompassed by the scope of claims.

Claims

1-6. (canceled)

7. An apparatus for automatic control of exhaust pressure of an internal combustion engine, the apparatus comprising:

a body inserted into a middle region of an exhaust pipe, the body having an inlet formed on one side thereof and an outlet formed on the other side thereof opposite the inlet, the inlet configured to receive exhaust gas emitted from the internal combustion engine, the outlet configured to expel the received exhaust gas to the outside;

a pressure control plate shaped as a thin plate, the pressure control plate placed inside the body between the inlet and the outlet and installed such as to be capable of rotational movement;

a rotational shaft shaped as a bar and coupled to an edge of the pressure control plate to enable the rotational movement, the rotational shaft installed such that a portion thereof protrudes from within the body to without;

a first side element coupled to the portion of the rotational shaft protruding out of the body;

a controlling pendulum included outside the body to set an initial gradient of the pressure control plate; and

a pendulum blade shaped like a wing to receive sufficient air resistance and coupled to a lower portion of the controlling pendulum, the pendulum blade configured to move together with the controlling pendulum by way of air resistance generated during an operation of a vehicle and configured to generate the rotational movement of the pressure control plate in linkage with the vertical rotation movement.

8. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the inlet and the outlet are cylindrical in shape so as to allow easy coupling of the body to an exhaust pipe, or are frustoconical in shape so as to allow coupling to exhaust pipes of various sizes with flexibility.

9. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the first side element further comprises a stepped part for coupling the rotational shaft and the controlling pendulum.

10. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the controlling pendulum is a full-thread bolt having a helical screw formed in a bar-shaped element.

11. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 7, wherein the rotational shaft protrudes outward at both sides of the body, with the first side element coupled to the rotational shaft protruding outward at one side and a second side element coupled to the rotational shaft protruding outward at the other side.

12. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 10, wherein the pendulum blade has at least two plate-shaped elements adjoined on one edge to form a leveled structure,

and a hole for a full-thread bolt is formed in a surface of the pendulum blade, such that the full-thread bolt inserted in the hole is coupled with the pendulum blade by way of a pair of tightening nuts tightened from above and below, and the vertical position of the pendulum blade is adjustable by selecting the positions of the tightening nuts.

13. The apparatus for automatic control of exhaust pressure of an internal combustion engine according to claim 9, wherein the stepped part has a holding hole and two bolt-fastening holes formed therein, the holding hole for inserting a portion of the rotational shaft inside,

the portion of the rotational shaft inserted inside the stepped part is coupled to the first side element by way of tightening, in relation to the controlling pendulum, tightening bolts fastened respectively in the two bolt-fastening holes,

and the rotational shaft, the stepped part, and the controlling pendulum are configured to move together as a whole.