KR102429177B1 - Device and method for controlling engine brake device - Google Patents

Abstract

The present invention uses an eccentric mechanism that is eccentrically fastened to each rotation point of the exhaust rocker arm, and an actuator that elevates the eccentric mechanism to temporarily open the exhaust valve at the end of the compression stroke of the engine to relieve pressure increase in the cylinder By doing so, the engine brake can be operated, and in particular, a reset control method of the engine brake device is provided so that the reset process that must be performed every stroke of the engine is automatically performed so that more accurate control of the engine brake can be achieved. it was meant to be

Description

DEVICE AND METHOD FOR CONTROLLING ENGINE BRAKE DEVICE

The present invention relates to a reset control method of an engine brake device, and more particularly, to an actuator reset control method for a compression relief type engine brake device that allows the pressure increase in a cylinder to be relieved by opening an exhaust valve at the end of a compression stroke of an engine. it's about

Although hydraulic brakes are commonly used as a braking system for vehicles with internal combustion engines, engine brakes are used to prevent premature wear of brake pads during downhill driving or frequent sudden stops.

Although the generally known engine brake is known to apply braking to a vehicle in a manner of lowering the transmission ratio of a gear, this has a problem in that an excessive load is applied to each part of the engine, thereby shortening the life of the engine.

Therefore, in large vehicles such as trucks and buses, since the weight is large, a separate engine brake device is installed instead of a gear ratio downward adjustment method in order to reduce the burden of hydraulic brakes and improve driving stability.

That is, by temporarily opening the exhaust valve near the compression top dead center of the piston at the end of the compression stroke among the basic four strokes of the engine, and discharging the compressed air in the cylinder out of the cylinder, the engine brake effect through delay and relaxation of the compression stroke An engine brake system is being installed to achieve this.

However, the existing engine brake device has disadvantages in that the structure is complicated and the manufacturing cost is high.

The present invention was devised in view of the above points, and by using an eccentric mechanism that is eccentrically fastened to each rotation point of the exhaust rocker arm, and an actuator that elevates the eccentric mechanism, the exhaust valve is installed at the end of the compression stroke of the engine. An object of the present invention is to provide a method for controlling an actuator reset of a compression relief type engine brake device in which the engine brake can be operated by temporarily opening the cylinder to relieve pressure increase in the cylinder.

One embodiment of the present invention for achieving the above object includes: an exhaust rocker arm for opening and closing an exhaust valve of an engine, and a rotation center point that is eccentric with the rotation center point of the exhaust rocker arm and is formed on one surface of the exhaust rocker arm An eccentric mechanism to be fastened, an actuator connected to the front end of the eccentric mechanism to angularly rotate the eccentric mechanism around a rotation center point that is eccentric with the rotation center point of the exhaust rocker arm, and is fastened to the rear end of the exhaust rocker arm An apparatus for controlling a reset of an engine brake device including a roller contactable with a cam of a camshaft, comprising: an angle sensor for detecting a current rotation angle of the cam; a controller that turns on the actuator to operate the engine brake or turns it off to cancel the operation of the engine brake based on the sensed value of the angle sensor; It provides a reset control device of the engine brake device, characterized in that it comprises a.

Another embodiment of the present invention for achieving the above object includes: an exhaust rocker arm for opening and closing an exhaust valve of an engine, and a rotation center point that is eccentric with the rotation center point of the exhaust rocker arm on one surface of the exhaust rocker arm An eccentric mechanism to be fastened, an actuator connected to the front end of the eccentric mechanism to angularly rotate the eccentric mechanism around a rotation center point that is eccentric with the rotation center point of the exhaust rocker arm, and is fastened to the rear end of the exhaust rocker arm A reset control method of an engine brake device including a roller contactable with a cam of a camshaft, the method comprising: detecting a current rotation angle of the cam by an angle sensor; turning on the actuator to operate the engine brake or to turn off the operation of the engine brake based on the sensing value of the angle sensor in a controller; It provides a reset control method of the engine brake device comprising a.

Through the above-described problem solving means, the present invention provides the following effects.

By temporarily opening the exhaust valve at the end of the engine's compression stroke to relieve the pressure increase in the cylinder, it is possible to easily provide the engine braking effect according to the delay and relaxation of the compression stroke, and in particular, By allowing the reset process to proceed automatically, more precise control of the engine brake can be achieved.

1 is a schematic diagram showing a basic four-stroke cycle of the engine;
2 is a schematic diagram showing that compression relief is made at the end of the compression stroke for engine brake, among the basic four strokes of the engine;
3 is a view showing an engine brake device to which the present invention is applied;
4 and 5 are views showing the before and after operation of the engine brake device to which the present invention is applied, respectively;
6 is a view comparing the state before and after the operation of the engine brake device to which the present invention is applied;
7 and 8 are views for explaining that the reset operation is performed by the reset control device of the engine brake device according to the present invention;
9 is a flowchart illustrating a reset control method of the engine brake device according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1 attached, an engine is basically driven by repeating a four-stroke cycle such as intake, compression, expansion, and exhaust.

Among the basic four strokes of such an engine, as shown in FIG. 2, the exhaust valve is temporarily opened at the end of the compression stroke, that is, near the compression top dead center of the piston, and the compressed air in the cylinder is discharged out of the cylinder, thereby delaying the compression stroke. And through the relief, the engine brake effect can be obtained.

Here, in order to help the understanding of the present invention, an engine brake apparatus capable of providing an engine brake effect according to delay and relaxation of the compression stroke by temporarily opening the exhaust valve at the end of the compression stroke to relieve pressure increase in the cylinder let's take a look

3 shows an engine brake device to which the control method of the present invention is applied, and FIGS. 4 and 5 show a state before and after operation of the engine brake device to which the control method of the present invention is applied. Reference numeral 100 denotes an exhaust valve Instructs the exhaust rocker arm to open and close.

An element foot 104 is mounted on the front end of the exhaust rocker arm 100 , and the element foot 104 is in close contact with the valve bridge 106 connected to the exhaust valve 108 .

In addition, a roller 110 that is in contact with or not in contact with the cam 200 of the camshaft is mounted at the rear end of the exhaust rocker arm 100 .

Looking at the cam 200 for each profile section, it is divided into a round section 202 section and a nose section 204, and a predetermined position of the round section 202 is in contact with the roller 110 when the engine brake is operated and the roller A protrusion 206 for pushing up 110 is formed.

At this time, the leaf spring 120 is connected between the spring engaging end 105 formed at the rear end of the exhaust rocker arm 100 and the fixed shaft 102 as will be described later. The leaf spring 120 is the exhaust rocker arm An elastic restoring force is provided in a direction in which the front end of the exhaust rocker arm 100 is brought into close contact with the valve bridge 106 while lifting the rear end of the 100 .

Accordingly, referring to FIG. 4 showing a state before engine brake operation (at the time of basic engine stroke), the roller 110 mounted on the rear end of the exhaust rocker arm 100 by the elastic restoring force of the leaf spring 120 is It is always kept spaced apart from the round part 202 of the cam 200 and, of course, the roller 110 is pushed up by the nose 204 of the cam 200 during the exhaust stroke.

In particular, the eccentric mechanism 300 is mounted on one surface of the exhaust rocker arm 100 .

The eccentric mechanism 300 is angularly rotatably fastened to one surface of the exhaust rocker arm 100 while having a rotation center point P2 eccentric with the rotation center point P1 of the exhaust rocker arm 100 .

The eccentric mechanism 300 includes an eccentric disk body 310 having an insertion hole 312 through which the fixed shaft 102 is inserted, and an actuator 400 integrally extended from the disk body 310 to be described later. It is configured to include a lever 320 hinged with the plunger 422 of the, and an eccentric protrusion ring 330 protruding from the inner surface of the disk body 310 .

At this time, the fixed shaft 102 is inserted into the insertion hole 312 of the disk body 310 to serve as a support during each rotation of the eccentric mechanism 300 , and the exhaust rocker arm without interference with the exhaust rocker arm 100 . passing through the center of

In particular, the eccentric protrusion ring 330 is integrally formed on the inner surface of the disk body 310 while forming an eccentricity with the rotation center point P2 of the eccentric mechanism 300 , and is formed on one surface of the exhaust rocker arm 100 . By being slidably inserted and fastened in the circular groove 107 in the circumferential direction, the eccentric protruding ring 330 and the circular groove 107 of the exhaust rocker arm 100 have a concentric arrangement with the same center.

In addition, the eccentric protrusion ring 330 is formed integrally with the inner surface of the disk body 310 while forming an eccentricity with the rotation center point P2 of the eccentric protrusion ring 330, but the outer diameter of the eccentric protrusion ring 330 is a circular groove (107) will form a circle inserted in.

Accordingly, as shown in FIG. 6 , the center point of the eccentric protrusion ring 330 and the circular groove 107 , that is, the rotation center point P1 of the exhaust rocker arm 100 and the rotation center point P2 of the eccentric mechanism 300 are collinear are set eccentric to each other.

Accordingly, even when the eccentric protrusion ring 330 is inserted into the circular groove 107 of the exhaust rocker arm 100, since the outer diameter of the eccentric protrusion ring 330 is in a perfect state, the exhaust rocker arm 100 is It is in a state where it can freely angularly rotate around the rotation center point P1, and when the exhaust rocker arm rotates, the inner diameter of the circular groove 107 and the outer diameter of the eccentric protrusion ring 330 are in sliding contact.

On the other hand, the actuator 400 is adopted as a push/pull type solenoid valve. When the electrical signal is turned on, the plunger 422 is raised and lowered, and when the electrical signal is turned off, the plunger 422 is lowered.

At this time, the plunger 422 protruding to the upper portion of the actuator 400 is hinged with the lever 320 of the eccentric mechanism 300 by a hinge pin.

Here, an operation flow of the engine brake device configured as described above is as follows.

Engine basic stroke (engine brake not working)

The accompanying FIG. 4 shows the operating state during the basic stroke of the engine (the engine brake device is not in operation).

In a state in which the engine brake device is not operated, the engine is basically driven by repeating a four-stroke cycle of intake, compression, expansion, and exhaust.

When the engine brake switch (not shown) is in the off state, the actuator 400 is also maintained in the off state, so that the lever 320 of the eccentric mechanism 300 connected to the plunger 422 of the actuator 400 is also an eccentric mechanism. (300) is maintained in a lowered state around the center of rotation (P2).

At the same time, the rear end of the exhaust rocker arm 100 is lifted upward around the rotational center point P1 of the exhaust rocker arm 100 by the elastic restoring force of the leaf spring 120, so that the exhaust rocker arm ( The element foot 104 formed on the front end of the 100 is in a state of being in close contact with the valve bridge 106, and the roller 110 mounted on the rear end of the exhaust rocker arm 100 is 202) and is always kept apart.

Therefore, in the engine, when a four-stroke cycle such as intake, compression, expansion, and exhaust is performed, the roller 110 of the exhaust rocker arm 100 moves to the circular part 202 of the cam 200 in the intake, compression, and expansion strokes. ) and the protrusion 206 and the spaced apart state, and in the exhaust stroke, as the cam 200 rotates, the nose 204 of the cam 200 pushes up the roller 110 .

Accordingly, the front end of the exhaust rocker arm 100 descends around its rotational center point P1, and the element foot 104 of the exhaust rocker arm 100 presses the valve bridge 106, so that the valve bridge ( An exhaust stroke in which the exhaust valve 108 is opened is performed by the descending of the exhaust valve 108 connected to the 106 .

engine brake actuation

5 shows an engine brake operating state of the engine brake device.

When the engine brake is operating, the engine brake effect can be obtained through delay and relaxation of the compression stroke by temporarily opening the exhaust valve at the end of the compression stroke, that is, near the compression top dead center of the piston and discharging the compressed air in the cylinder out of the cylinder. have

To this end, when the engine brake switch (not shown) is turned on, an electrical signal is applied to the actuator 400 to move the plunger 422 up and down.

Then, when the plunger 422 is raised and lowered, the lever 320 rotates clockwise (based on the drawing) around the rotation center point P2 of the eccentric mechanism 300, and at the same time, the disk body of the eccentric mechanism 300 310 also rotates in the same direction (clockwise) around the rotation center point P2.

In addition, the eccentric protrusion ring 330 protruded from the inner surface of the disk body 310 of the eccentric mechanism 300, that is, the eccentric protrusion ring 330 formed eccentrically from the rotation center point P2 is also in the same direction (clockwise) makes each rotation.

At this time, since the eccentric protrusion ring 330 is slidably inserted and fastened in the circumferential direction in the circular groove 107 formed on one surface of the exhaust rocker arm 100, the eccentric protrusion ring 330 rotates the eccentric mechanism. At the same time as the eccentric angular rotation in the clockwise direction about the central point P2, the rear end of the exhaust rocker arm 100 is also angularly rotated in the same direction about the rotation central point P2 of the eccentric mechanism 300 together.

Therefore, before each rotation operation of the eccentric mechanism 300, the center point of the eccentric protrusion ring 330 and the circular groove 107, that is, the rotation center point P1 of the exhaust rocker arm 100, as shown in the left drawing of FIG. 6 . And, the rotation center point P2 of the eccentric mechanism 300 is set to be eccentric to each other on the same line, but on the other hand, after the clockwise angular rotation operation of the eccentric mechanism 300 as described above, as shown in the right view of FIG. The rotation center point P1 of the exhaust rocker arm 100 is lower than the rotation center point P2 of the eccentric mechanism 300 .

In addition, as the rotation center point P2 of the exhaust rocker arm 100 is lowered, the roller 110 mounted on the rear end of the exhaust rocker arm 100 is in close contact with the circular part 202 of the cam 200 . become in a state of being

At this time, even when the eccentric protrusion ring 330 is inserted into the circular groove 107 of the exhaust rocker arm 100 , the inner diameter of the circular groove 107 and the outer diameter of the eccentric protrusion ring 330 are in a perfect state. , during each rotation of the exhaust rocker arm 100, the inner diameter of the circular groove 107 and the outer diameter of the eccentric protrusion ring 330 are in slide contact, and eventually the exhaust rocker arm 100 rotates around the rotation center point P1. It becomes a state in which it can rotate freely angularly.

Accordingly, in the engine, when a four-stroke cycle such as intake, compression, expansion, and exhaust is performed, the roller 110 of the exhaust rocker arm 100 comes into contact with the protrusion 206 of the cam 200 at the end of the compression stroke. , the roller 110 is pushed up by the protruding thickness of the protrusion 206 .

Then, as the roller 110 mounted on the rear end of the exhaust rocker arm 100 is pushed up, the front end of the exhaust rocker arm 100 descends around the rotation center point P1, and then the exhaust rocker arm ( As the element foot 104 of 100 presses the valve bridge 106 and at the same time the exhaust valve 108 connected to the valve bridge 106 descends, the exhaust valve 108 is temporarily opened as shown in FIG. The internal pressure rise is relieved.

Accordingly, by reducing the pressure increase in the cylinder at the end of the compression stroke, it is possible to provide an engine braking effect according to the delay and relaxation of the compression stroke.

reset operation

Here, the reset refers to a process of releasing the engine brake operation at every stroke of the engine.

In more detail, the reset means lowering the plunger 422 of the actuator 400 to temporarily open the exhaust valve 108 again at the end of the next compression stroke to lower the plunger 422 of the actuator 400 to restore the eccentric mechanism 300 to its original state. It refers to the process of moving into position.

This reset should be performed every stroke of the engine. If the reset is not performed, as shown in FIG. 10 , the exhaust valve profile according to non-reset causes a larger vertical movement width (lift) of the exhaust valve compared to the profile when the engine brake is on. Therefore, there is a risk of collision between the exhaust valve and the engine piston, a separate release mechanism is needed to release the engine brake, and the internal oil pressure of the engine piston is continuously This is because piston lift delay and reduction in lift amount may occur.

If the reset is performed as above (eg, the portion indicated as 'reset' in FIG. 10), the solenoid valve, which is the actuator 400, is turned off to lower the plunger 422, and at the same time the eccentric mechanism 300 is moved to the original position. When braking, the profile can be matched with the general exhaust profile.

According to the present invention, as a configuration for automating the reset process as described above, the angle sensor 132 for detecting the current rotation angle of the cam or the current position or angle of the crankshaft, and the sensing value of the angle sensor 132 Based on the actuator 400 includes a controller 130 that controls to turn on for the operation of the engine brake or to turn off the operation of the engine brake.

Therefore, as shown in the flowchart of FIG. 9 , first, in a state in which the brake switch is turned on while the engine is running, the controller 130 receives the current rotation angle of the cam detected by the angle sensor 132 and sets a preset reset start cam angle ( W°) and reset end cam angle (X°) are compared.

As a result of comparison, the current rotation angle of the cam is less than the reset start cam angle (W°) (cam angle ≤ W°), or the current rotation angle of the cam is the reset end cam angle (X°) or more (cam angle ≥ X°) ), there is no need for the above reset yet, so the controller 130 keeps the actuator 400, that is, the solenoid valve on.

For example, assuming that the reset start cam angle (W°) is 45° and the reset end cam angle (X°) is 270°, the current rotation angle of the cam is 45° which is the reset start cam angle (W°). If it is less than or equal to or greater than 270°, which is the reset end cam angle (X°), the solenoid valve is kept on.

On the other hand, if the current rotation angle of the cam is greater than the reset start cam angle (W°) and less than the reset end cam angle (X°), that is, the current rotation angle of the cam is the reset start cam angle (W°) and the reset end cam angle (W°). If it falls within the range (W°<cam angle<X°) between the cam angles (X°), the actuator 400, ie, the solenoid valve, is turned off for the reset.

For example, assuming that the reset start cam angle (W°) is 45° and the reset end cam angle (X°) is 270°, the current rotation angle of the cam is 45° which is the reset start cam angle (W°). If it is larger than the reset end cam angle (X°), which is less than 270°, the solenoid valve is turned off. Preferably, the reset start cam angle (W°) turns off the solenoid valve when it exceeds 45° and then resets the reset end cam angle. Keep the solenoid valve off until (X°) 270° is reached.

At this time, the reset operation starts when the roller 110 of the exhaust rocker arm 100 comes into contact with the protrusion 206 of the cam 200 so that the roller 110 is pushed up by the protrusion thickness of the protrusion 206, and then the cam ( 200) is further rotated and the roller 110 is further pushed up by the portion where the nose 204 of the cam 200 starts (eg, the exhaust stroke starting point).

Therefore, when the nose 204 of the cam 200 starts to contact the roller 110 of the exhaust rocker arm 100 as shown in FIG. 7 , the cam 200 is reset starting cam angle (W°). Since 45° is reached, when the actuator 400, that is, the solenoid valve is turned off, the plunger 422 is lowered to its original position.

At the same time, the lever 320 of the eccentric mechanism 300 connected to the plunger 422 is also pulled downward, so that the eccentric mechanism 300 is returned to the position before the engine brake is applied.

On the other hand, when the cam reaches 270° or more, which is the reset end cam angle (X°), it is the brake-on time for engine brake operation, and when the solenoid valve is turned on again, the plunger of the actuator moves up and down as shown in the attached FIG. do.

As described above, since the process for operating the engine brake and the reset process are repeated during every stroke of the engine, it is possible to easily provide the engine braking effect according to the relaxation of the compression stroke.

In the embodiment described above, the current angle of the cam has been described by comparing the reset start cam angle (W°) and the reset end cam angle (X°). The same reset process as in the above-described embodiment can be implemented even by detecting the crankshaft rotation angle for elevating and comparing the crankshaft rotation angle with the reset start crank angle (Y°) and the reset end crank angle (Z°).

100: exhaust rocker arm
102: fixed shaft
104: element foot
105: spring engaging end
106: valve bridge
107: circular groove
108: exhaust valve
110: roller
120: leaf spring
200 : cam
202 : epicenter
204 : nose
206: protrusion
300: eccentric mechanism
310: disk body
312: insertion hole
320: lever
330: eccentric protrusion ring
400: actuator
422: plunger

Claims (6)

An exhaust rocker arm for opening and closing the exhaust valve of the engine, an eccentric mechanism fastened to one surface of the exhaust rocker arm while having a rotation center point eccentric with the rotation center point of the exhaust rocker arm, and connected to the front end of the eccentric mechanism An engine brake device comprising: an actuator for angular rotation of an eccentric mechanism about a rotation center point that is eccentric with a rotation center point of an exhaust rocker arm; A reset control device comprising:
an angle sensor for detecting the current rotation angle of the cam;
a controller that turns on the actuator to operate the engine brake or turns it off to cancel the operation of the engine brake based on the sensing value of the angle sensor;
consists of,
After the controller receives the current rotation angle of the cam detected by the angle sensor and compares the preset reset start cam angle (W°) and reset end cam angle (X°), the current rotation angle of the cam is the reset start cam The reset control apparatus of the engine brake device, characterized in that the actuator is maintained on when the angle (W°) or less or the current rotation angle of the cam is equal to or greater than the reset end cam angle (X°).
delete The method according to claim 1,
After the controller receives the current rotation angle of the cam detected by the angle sensor and compares the preset reset start cam angle (W°) and reset end cam angle (X°), the current rotation angle of the cam is the reset start cam When the angle (W°) is greater than the reset end cam angle (X°), the actuator is turned off to return the eccentric mechanism to the pre-engine brake operation position.
An exhaust rocker arm for opening and closing the exhaust valve of the engine, an eccentric mechanism fastened to one surface of the exhaust rocker arm while having a rotation center point eccentric with the rotation center point of the exhaust rocker arm, and connected to the front end of the eccentric mechanism An engine brake device comprising: an actuator for angular rotation of an eccentric mechanism about a rotation center point that is eccentric with a rotation center point of an exhaust rocker arm; A reset control method comprising:
detecting the current rotation angle of the cam by an angle sensor;
turning on the actuator to operate the engine brake or to turn off the operation of the engine brake based on the sensing value of the angle sensor in a controller;
including,
After the controller receives the current rotation angle of the cam detected by the angle sensor and compares the preset reset start cam angle (W°) and reset end cam angle (X°), the current rotation angle of the cam is the reset start cam The reset control method of the engine brake device, characterized in that the actuator is maintained on when the angle (W°) or less or the current rotation angle of the cam is equal to or greater than the reset end cam angle (X°).
delete 5. The method according to claim 4,
After the controller receives the current rotation angle of the cam detected by the angle sensor and compares the preset reset start cam angle (W°) and reset end cam angle (X°), the current rotation angle of the cam is the reset start cam When the angle (W°) is greater than the reset end cam angle (X°), the actuator is turned off to return the eccentric mechanism to the pre-engine brake operation position.

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