JPS6262072A - Method of controlling temperature of poppet valve - Google Patents

Abstract

PURPOSE:To easily adjust the temperature of a poppet valve by sealing a cooling refrigerant in a hollow chamber of the poppet valve, and controlling the pressure in the hollow chamber to vary the vaporizable temperature of the sealed-in refrigerant. CONSTITUTION:A hollow chamber 4 in which a refrigerant is sealed is formed in the interior of a poppet 1, and a condenser is connected to the hollow chamber 4. An air supply pipe 13 and an air discharge pipe 15 are connected to the condenser 10 through solenoid valves 12, 14, and both solenoid valves 12, 14 are controlled to open and close, whereby the pressure in the condenser 10 and the hollow chamber 4 can be adjusted. If the solenoid valves 12, 14 are controlled to open and close by a control device 24 for detecting a thermal load, and the pressure in the condenser 10 and the hollow chamber 4 is controlled, the temperature of the poppet valve 1 can be easily adjusted.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a poppet valve used in the exhaust section of an internal combustion engine or a throttle section of high-temperature piping, and particularly relates to a poppet valve in which a hollow chamber is formed in the poppet valve. The present invention relates to a temperature control method for a poppet valve that can control the temperature of the poppet valve according to changes in heat input to the poppet valve when the poppet valve is cooled by sealing a refrigerant in a hollow chamber.

[Prior Art] Conventional heat siphon poppet valves have a hollow chamber formed within the poppet valve and a refrigerant sealed in the hollow chamber.The heat input to the poppet valve is recovered by the heat of evaporation of the refrigerant. The evaporated refrigerant is cooled and condensed in a condenser connected to the poppet valve, and the condensed refrigerant is returned to the heat input part of the hollow chamber to cool the poppet valve.

The temperature control of this poppet valve is performed by controlling the amount and temperature of the cooling water supplied to the condenser, or by adjusting the water level of the cooling water header of the condenser to control the number of condensing pipes through which the cooling water passes, that is, the wettability of the cooling water. Temperature is controlled by adjusting the area.

[Problems to be solved by the invention] However, even if the amount of condensation of the refrigerant is controlled by controlling the cooling water, the temperature change of the refrigerant is small despite the large control m, and it is difficult to respond to changes in the heat input load to the poppet valve. It is difficult to maintain the temperature at an appropriate temperature, and there is a problem in that the poppet valve is susceptible to sulfuric acid corrosion due to low temperatures and fatigue due to changes in thermal stress.

[Object of the Invention] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a temperature control method for a poppet valve that can maintain the poppet valve at a substantially constant temperature despite heat input load fluctuations. purpose.

[Summary of the Invention] In order to achieve the above object, the present invention provides a condenser in which a refrigerant is sealed in a hollow chamber of a poppet valve, and the refrigerant evaporated in the hollow chamber is condensed and returned to the hollow chamber. In this method, the pressure inside the hollow chamber is controlled according to the heat input load to the poppet valve, and the evaporation temperature (condensation temperature) of the refrigerant is controlled by controlling the pressure inside the hollow chamber. By changing the temperature, the temperature of the poppet valve is controlled to a constant temperature.

[Embodiment] A preferred embodiment of the poppet valve temperature control method according to the present invention will be described below with reference to the accompanying drawings.

In the accompanying drawings, reference numeral 1 designates a poppet valve that opens and closes an exhaust port of an internal combustion engine, and is swung by a rocker arm (not shown).

Inside the poppet valve 1, a hollow v4 is formed from the valve head portion 2 to the valve stem 3, and water is contained in the hollow chamber 4.

A refrigerant 5 such as oil, silicone oil, Dansom A, etc. is sealed.

A telescopic tube 6 communicating with the hollow chamber 4 is connected to the upper part of the valve shaft 3, and a seal ring 7 is provided around the outer circumference of the telescopic tube 6.

A branch pipe 8 is connected to the upper part of the telescopic pipe 6, and a condenser 10 for cooling and condensing the evaporative refrigerant generated in the hollow chamber 4 is connected to the branch pipe 8 via a horizontal pipe 9.

This condenser 10 has a large number of condensing pipes (not shown) to cool the evaporative refrigerant introduced from the horizontal pipe 9. Cooling water is supplied into the condensing pipes, and the condensed refrigerant is cooled by the condensing pipes. is returned into the hollow chamber 4 from the horizontal pipe 9 via the branch pipe 8.

A gas-liquid separator 11 is provided in the upper part of the condenser 10, and an air supply pipe 13 is connected to the gas-liquid separator 11 via a pressurizing solenoid valve 12, and a discharge pipe is connected via a pressure reducing solenoid valve 14. 15 is connected to the condenser 10, and a refrigerant replenishment pipe 17 is connected to the lower part of the condenser 10 via an enclosed refrigerant replenishment valve 16.

The hollow chamber 4 is provided with a temperature sensor 18 such as a thermal lightning pair for detecting the temperature of the refrigerant, and a pressure sensor (not shown) for detecting the pressure inside the hollow chamber 4. The temperature sensor 18 may be provided not only in the illustrated hollow chamber 4 but also in the valve head portion 2 or the valve face portion 19 thereof.

The detection outputs of the temperature sensor 18 and pressure sensor are transmitted through the branch pipe 8.
Lead wire 22 from terminal 20.21 provided at the upper end of
．． 23 to a control device 24, and the control device 24 controls the pressurizing solenoid valve 12 and the pressure reducing solenoid valve 14.

Next, a method of controlling the temperature of a poppet valve according to the present invention will be explained.

First, the refrigerant 5 in the hollow chamber 4 evaporates due to heat input from the valve head portion 2, rises as shown by the arrow 25, and flows from the Telesph pipe 6 to the branch pipe 8. It flows into the condenser 10 through the horizontal pipe 9, where it is condensed in a condensing pipe (not shown) through which cooling water passes, and the condensed liquid is sent to the hollow chamber from the telescopic pipe 6 via the horizontal pipe 91 and the branch pipe 8. 4 as droplets 26' and returned.

In this case, the pressure inside the hollow chamber 4 (or inside the condenser 10) is detected by a pressure sensor, and the temperature of the hollow chamber 4 or the poppet valve 1 is detected by a temperature sensor 18, and the respective detection outputs are sent to the control I device 24.
Enter. The control device 24 performs arithmetic processing on the input signal, compares the detected temperature and pressure with a pre-stored temperature and pressure, and adjusts the pressurizing solenoid valve 1 accordingly.
2 and the pressure reducing solenoid valve 14 are opened and closed to supply air, argon gas, etc. into the condenser 10 and the hollow chamber 4 from the pressurizing solenoid valve 12 to increase the pressure, or to separate the refrigerant from the gas-liquid separator 11. The air is exhausted from the decompression solenoid valve 14 to lower the pressure, and the pressure inside the condenser 10 and the hollow chamber 4 is changed, and the evaporation temperature (condensation temperature) of the refrigerant therein is changed to adjust the temperature of the poppet valve 1. Control.

In other words, when the temperature of the poppet valve 1 is lower than the setting, the saturated vapor pressure of the refrigerant 5 increases by increasing the pressure in the hollow chamber 4, and the evaporation temperature increases, so the heat input to the poppet valve 1 accumulates accordingly. The temperature of the poppet valve 1 can be increased.

Conversely, if the temperature of the poppet valve 1 rises above the setting, the pressure reducing solenoid valve 14 is opened to release only air, thereby lowering the pressure inside the hollow chamber 4, lowering the saturated vapor pressure, and lowering the evaporation temperature. Therefore, the amount of evaporation of the refrigerant increases, and therefore the poppet valve 1 is cooled, and its temperature can be lowered.

Further, the refrigerant sealed in the hollow chamber 4 and the condenser 10 is supplied by opening the replenishment valve 16 as appropriate, and the refrigerant 1 is adjusted to match the heat input. This replenishment valve 16 is controlled to open and close by a control device @24.

When the poppet valve 1 is used in an internal combustion engine, the control device 24 inputs these values because the temperature of the poppet valve 1 is proportional to the fuel rack position (fuel supply amount) and rotation speed of the internal combustion engine. The temperature of the poppet valve 1 may be controlled by the fuel supply amount and rotation speed.

[Effects of the Invention] As is clear from the detailed description above, the present invention exhibits the following excellent effects.

(1) By controlling the pressure inside the hollow chamber of the poppet valve, it is easier to control the poppet valve temperature than conventionally controlling the cooling water temperature and water volume of the condenser, and the pressure and refrigerant inside the hollow chamber can be controlled more easily. Since it is almost linearly proportional to temperature, it can be controlled extremely sensitively to heat input load.

(Since the evaporation temperature of the refrigerant can be controlled, it is possible to prevent low-temperature corrosion due to overcooling of the poppet valve, which is susceptible to corrosion due to sulfur attack at temperatures below 250°C in internal combustion engines, for example, in internal combustion engines.)

(3) By controlling the evaporation temperature of the refrigerant, the thermal stress of the poppet valve can be greatly reduced, and the life of the poppet valve can be extended.

[Brief explanation of drawings]

The accompanying drawings are diagrams showing an example of an apparatus for implementing the poppet valve humidity control method of the present invention. In the figure, 1 is a poppet valve, 4 is a hollow chamber, 5 is a refrigerant, 10 is a condenser, and 24 is a control device.

Claims (1)

[Claims] In a temperature control method for a poppet valve, in which a refrigerant is sealed in a hollow chamber of the poppet valve, and the poppet valve is provided with a condenser that condenses the refrigerant evaporated in the hollow chamber and returns it to the hollow chamber, heat input to the poppet valve is performed. A method for controlling the temperature of a poppet valve, characterized by controlling the pressure inside a hollow chamber according to the load.