KR20080046976A - A piston having a control valve - Google Patents

Abstract

A piston equipped with a control valve of controlling compression ratio by combustion pressure is provided to control combustion pressure in a cylinder by moving the control valve up and down by a valve spring. A piston equipped with a control valve(30) of controlling compression ratio by combustion pressure comprises an installation hole(11) which allows a front end of a piston(10) to communicate with each other. An insert(20) is inserted into the insertion hole such that the control valve projects from the insertion hole toward a cylinder. The control valve is elastically supported by a valve spring(50) installed on a cover valve(40), which is fixed to the installation hole. The valve spring has a spring pressure higher than an idle-compression pressure and lower than a normal combustion pressure.

Description

A piston having a control valve}

1 is a view showing a conventional piston cross-sectional shape.

Figure 2 is a schematic diagram showing a piston configured with a compression ratio control valve according to the combustion pressure change of the present invention.

Figure 3 is a schematic diagram showing an exploded state of the piston configured compression ratio control valve according to the combustion pressure change of the present invention.

Figure 4a and Figure 4b is an operating state according to the pressure of the piston configured compression ratio control valve according to the combustion pressure change of the present invention.

5 is a graph showing the engine combustion pressure diagram.

 <Brief description of symbols for the main parts of the drawings>

1: piston 2: connecting rod mounting hole

10: piston 11: mounting hole

12: step 13: thread

14: connecting rod mounting hole 20: insert

30: control valve 31: spring groove

32: step 40: cover valve

41: spring groove 42: thread

43: control valve groove 50: valve spring

S: Stroke

The present invention relates to a piston configured with a compression ratio control valve according to a combustion pressure change, and more particularly, a compression ratio control valve according to a combustion pressure change to have a compression ratio increase effect in a cylinder during idling operation by installing a compression ratio control valve in a piston. To a configured piston.

In the case of automobiles, it is desirable to minimize the emission of environmental pollutants in accordance with the enhancement of emission (emission gas reduction) technology.

Nox emitted from automobiles is a compound of nitrogen and oxygen. N₂O nitrous oxide NO nitrogen monoxide NO₂ is nitrogen oxide N₂O₃ nitrogen trioxide N₂O nitrogen pentoxide and exists as a gaseous body. There is an environmental standard for O₃, which occurs when P is combined.

As a method of reducing NOx, it is a general method to suppress combustion activity by applying exhaust-gas recirculation (ERG) or retarding injection timing.

The EGR valve is an exhaust gas recirculation device that serves to reduce NOx (nitrogen oxide) in the exhaust gas. Nitrogen oxides are released a lot at high combustion chamber temperatures, so the exhaust gas is sent to the combustion chamber through the EGR valve. This reduces the intake of fuel and air due to the inflow of oxygen-deficient gas, which lowers the combustion chamber temperature. Thus, nitrogen oxides are reduced.

Traditionally, cars open the EGR valve mostly at the pressure of the intake manifold, i.e. open a lot as the ALPM rises. In recent years, the EGR valve and solenoid valve are opened, and the feedback value of the oxygen sensor is read by the ECU and the electric signal is sent to the solenoid valve according to the value, and the solenoid valve is opened to operate the EGR valve.

However, such a method may lead to combustion instability in the initial normal combustion state as the combustion temperature of the engine is lowered and the combustion temperature of the engine is lowered, especially when the vehicle is left for a long time at low speed and low load in the winter. have.

Particularly, in the case of live car, which is a special purpose car, it is very likely that white smoke will occur because the engine continues to be idling for a long time because the oxygen supply must be operated while waiting for a long time to receive live fish or waiting for delivery.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a variable compression control valve so that a combustion failure does not occur even when operated for a long time in an idle operation state.

The purpose is to prevent the generation of white smoke due to unburned to prevent environmental pollution.

And the purpose is to improve the idle fuel economy by the combustion activation.

In order to achieve the above object, the present invention has an installation hole formed so that the front end of the piston and the connecting rod mounting hole penetrate therethrough, and the control valve is inserted to protrude into the installation hole toward the cylinder through the insert, and the control valve is installed in the installation hole. It is elastically supported by a valve spring installed on the cover valve fixed to the, the valve spring is characterized in that the spring pressure is set higher than the idle combustion pressure and lower than the normal combustion pressure, and the stepped toward the front end of the installation hole, A thread is formed on the rear wall of the installation hole, a step is formed around the rear end of the control valve, one end of the valve spring is inserted into a spring groove formed at the rear of the control valve, and a screw thread engaged with the thread of the installation hole is formed on the outer diameter. A spring groove is formed in the valve so that the other end of the valve spring is inserted, and a control valve groove is formed around the top of the spring groove. Is formed and the end portion of the control valve can be mounted insert, the insert provides a piston the compression ratio control valve in accordance with the combustion pressure changes characterized in that the indentation touches the stepped mounting holes configured.

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

The terms or words used in the present specification and claims should not be interpreted as being limited to the ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain the invention of their own. Based on the principle, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Figure 2 is a schematic diagram showing a piston configured with a compression ratio control valve according to the combustion pressure change of the present invention, Figure 3 is a schematic diagram showing an exploded state of the piston configured with a compression ratio control valve according to the combustion pressure change of the present invention.

As can be seen in Figures 2 and 3, the present invention is provided with an installation hole 11 that penetrates the front end of the piston 10 and the connecting rod mounting hole 14, the installation hole in the elastic force of the valve spring 50 By installing the control valve 30 to move back and forth, the control valve 30 is elastically supported by the valve spring 50 supported by the cover valve 40 is screwed with the installation hole (11).

In detail, an installation hole 11 is formed to penetrate the front end of the piston 10 and the connecting rod mounting hole 14, and the control valve 30 faces the cylinder through the insert 20. Is inserted to protrude). When the pressure in the cylinder is low, the control valve 30 protrudes toward the cylinder by the elastic force of the valve spring 50 to increase the pressure in the cylinder.

The control valve 30 is located in the center of the piston 10 combustion chamber to move up and down by the valve spring 50 to adjust the combustion pressure in the combustion chamber, that is, the cylinder. When the temperature in the cylinder is increased and the pressure in the cylinder is increased, the control valve 30 moves backwards, overcoming the elastic force of the valve spring 50, and again widens as much as the space of the control valve 30 moved backward. As the original cylinder space is reduced, the pressure in the cylinder increases only during idling, and when the idling ends, the internal pressure is maintained again.

In addition, the control valve 30 is elastically supported by the valve spring 50 installed in the cover valve 40 fixed to the installation hole 11, the valve spring 50 has a spring pressure higher than the idle combustion pressure and normal combustion Use something lower than pressure.

The valve spring 50 is located between the valve cover 40 and the control valve 30, and the position of the control valve at the top dead center when the engine is stopped and idling to increase the compression ratio to increase the combustion pressure and increase the engine speed. When the combustion pressure is increased to serve to adjust the position of the control valve due to the pressure acting on the control valve (30).

In the detailed embodiment, the stepped portion 12 is formed toward the front end of the installation hole 11 of the piston 10 to be in contact with the stepped portion 32 formed around the rear end of the control valve 32 such that the control valve 32 is in the cylinder space. Do not enter completely.

A thread 13 is formed on the rear wall of the mounting hole 11 so that the thread 42 engaged with the thread 13 of the mounting hole 11 is coupled to the cover valve 40 formed at the outer diameter. One end of the valve spring 50 is inserted into the spring groove 31 formed at the rear of the control valve 32, and a spring groove 41 is formed in the cover valve 40 to insert the other end of the valve spring 50. The control valve 32 elastically moves to the support point of the cover valve 40 fixed to the installation hole 11.

The cover valve 40 has a control valve groove 43 formed around the top of the spring groove 41 to allow the end of the control valve 30 to be inserted and seated.

The insert 20 is press-fitted to contact the step 12 of the installation hole 11 to prevent direct contact with the piston during sliding of the control valve 30, thereby preventing deterioration in durability of the piston due to frequent contact.

FIG. 4A shows a control valve state during idle operation, FIG. 4B shows a control valve state during operation other than idle, and FIG. 5 is a graph showing an engine combustion pressure diagram.

In the idle operation, the elastic force of the valve spring is set higher than the idle combustion pressure on the upper surface of the control valve 30. The control valve 30 is increased by the stroke S to increase the compression ratio of the combustion chamber. As a result, the combustion is activated by the increased combustion pressure, so that the white smoke reduction effect is generated and the idle fuel economy is improved.

During the idle operation, when the engine ALMP goes up through the idle state, the engine combustion pressure increases, and the increased combustion pressure acts on the control valve to push the valve spring down by the stroke, thereby converting it into a normal combustion form.

As described above, according to the present invention, as shown in the combustion pressure diagram when the idling rotates by the variable compression ratio control valve, the combustion ratio can be increased about 2 to 3 in comparison with the existing compression ratio. This does not occur, there is an effect that the generation of white smoke is suppressed.

In addition, the generation of white smoke due to unburned is suppressed, thereby preventing the environmental pollution.

Since the compression ratio is increased, combustion is activated to improve fuel economy during idle rotation.

Claims (3)

An installation hole 11 is formed to penetrate the front end of the piston 10 and the connecting rod mounting hole 14, and the control valve 30 protrudes from the installation hole 11 toward the cylinder via the insert 20. Is inserted, the control valve 30 is elastically supported by the valve spring 50 is installed in the cover valve 40 is fixed to the mounting hole 11, the valve spring 50 has a spring pressure is higher than the idle combustion pressure A piston configured with a compression ratio control valve according to a combustion pressure change, characterized by using a lower setting than the normal combustion pressure. The method of claim 1, wherein the step 12 is formed in the front end of the mounting hole 11, the thread 13 is formed on the rear wall of the mounting hole 11, and the stepped around the rear end of the control valve (32) 32 is formed, and one end of the valve spring 50 is inserted into the spring groove 31 formed at the rear of the control valve 32, and the thread 42 engaged with the thread 13 of the installation hole 11 is A spring groove 41 is formed in the cover valve 40 formed at the outer diameter to insert the other end of the valve spring 50, and a control valve groove 43 is formed around the upper portion of the spring groove 41 to control the valve 30. Piston with a compression ratio control valve according to the combustion pressure change, characterized in that the end of the) can be inserted and seated. The piston according to claim 1, wherein the insert (20) is press-fitted to contact the step (12) of the installation hole (11).

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