JP2522241B2 - Temperature control device for poppet type valve - Google Patents

Description

The present invention relates to an improvement of a temperature control device for a poppet type valve used in an internal combustion engine or the like.

[Conventional technology]

Many poppet valves used in internal combustion engines, industrial gas compressors, plant piping systems, etc. are used in a cooled state with a cooling system attached depending on the conditions of use.

For example, in a poppet type valve used in a large diesel engine, as shown in FIG. 3, a hollow portion 2 is formed in a valve head portion 1a and a valve stem portion 1b of a poppet type valve 1 and a cooling liquid 3 is contained therein. It is enclosed and cooled through a secondary cooler (not shown) provided on the outer periphery of the upper end of the valve rod portion 1b.

The temperature of the poppet valve 1 is controlled by changing the amount of cooling water in the secondary cooler, the temperature, the cooling area, and the like.

[Problems to be solved by the invention]

However, even if the amount of water or the temperature of the cooling water is changed by such a secondary cooler, the cooling liquid 3 enclosed in the hollow portion 2 of the poppet valve 1 is heated by the combustion gas or the like to become steam and transfer heat. On the other hand, in the secondary cooler, the temperature of the poppet valve 1 could not be significantly changed because the cooling water was always in the liquid phase and had a large amount of heat absorption.

That is, in terms of heat transfer conditions, the boundary conditions such as the heat transfer coefficient of the wall surface on the secondary cooler side are larger than the boundary conditions such as the heat transfer coefficient of the wall surface on the hollow portion 2 side of the poppet valve 1.

The present invention has been made in view of the above conventional technology,
An object of the present invention is to provide a temperature control device for a poppet-type valve, which can control the temperature of the poppet-type valve in a wide range, has good responsiveness, and can be easily controlled.

[Means for solving problems]

In order to solve the above problems, in the present invention, the boundary condition for heat transfer on the hollow portion side of the poppet type valve is changed contrary to the conventional case, and specifically, the poppet type valve and the outside are provided outside. A hollow portion, in which a primary cooling medium that exchanges heat with a secondary cooling medium is placed, is formed inside a poppet-type valve, and the primary cooling medium can be fed and discharged through the opening / closing valve in the hollow portion. On the other hand, there is provided a controller for opening and closing the on-off valve to control the amount of the primary cooling medium in the hollow portion to change the boundary condition for heat transfer on the primary cooling medium side to adjust the cooling temperature. It is characterized by that.

[Action]

The amount of cooling medium put in the hollow part of the poppet type valve is adjusted by controlling the opening / closing of the opening / closing valve provided in the supply / exhaust pipe, and the cooling medium is divided into a gas phase and a liquid phase depending on the heat load amount on the poppet type valve. The cooling temperature is adjusted by changing the boundary condition on the heat transfer by utilizing the change of.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings.

In the temperature control device for a poppet-type valve of the present invention, as shown in the schematic configuration of FIG.
Further, a hollow portion 12 for putting the cooling liquid C into the valve rod portion 11b is formed, and a supply / discharge pipe 13 for the cooling liquid C is inserted from the upper end portion of the valve rod portion 11b and sealed with a sealing 14. , So as to communicate with the hollow portion 12. A throttle valve type solenoid valve 15 is attached in the middle of the outside portion of the poppet type valve 11 of the supply pipe 13, and is connected to a cooling liquid supply device (not shown) via the solenoid valve 15.

Further, in order to secondarily cool the cooling liquid C in the hollow portion 12 of the poppet type valve 11, the cylindrical cooler 1 is provided on the outer periphery of the upper end portion of the valve rod portion 11b.
6 are arranged, sealed and attached by the seal rings 17 at both ends, and connected to a secondary cooling water supply device (not shown).

Furthermore, in order to control the temperature of the poppet valve 11, the hollow part
A temperature sensor 18 and a pressure sensor 19 for detecting the temperature of the cooling liquid C in 12 are provided, and the respective detection signals t _C and p _C are used for the controller 2
It is supposed to be input to 0.

In order to detect the heat load of the poppet type valve 11,
The valve temperature sensor 21 is embedded in 11a, and the detection signal t
_{When V} is input, the combustion flow rate signal is sent to the controller 20.
L, the rotational speed signal N, and the exhaust gas temperature signal H are electrically connected to the respective sensors, and the opening / closing operation signal V is output to the solenoid valve 15 based on these signals.

Poppet-type valve temperature controller 10 configured as described above
Then, the amount of the cooling liquid C supplied to and discharged from the hollow portion 12 of the poppet valve 11 is changed so that the state of the secondary cooling water in the cooler 16 is kept substantially constant, and the temperature control of the poppet valve 11 is performed.

Therefore, the relationship between the heat load and the amount of the cooling liquid C put in the hollow portion 12 of the poppet valve 11 will be described.

The amount of the cooling liquid C in the hollow portion 12 of the poppet type valve 11 is roughly classified into three states as shown in FIGS. 2 (a) to (c).

That is, a state in which a relatively large amount of cooling liquid C is put into the hollow portion 12 of the poppet valve 11 corresponds to FIG. 2 (a).
The portion of 12 corresponding to the valve head portion 11a is the cooling liquid C (liquid phase)
So that the saturated vapor S (vapor phase) of the cooling liquid C is located in the portion corresponding to the upper end of the uppermost valve rod portion 11b, and the vapor liquid phase W of the cooling liquid C is present in the middle portion. In this state, the poppet valve 11 is used for cooling when the heat load is large, and is cooled by the sensible heat of the liquid-phase cooling liquid C and the latent heat accompanying evaporation.

Further, in a normal heat load state, as shown in FIG. 2 (b), a slight amount of the cooling liquid C is present in the portion of the hollow portion 12 corresponding to the valve head portion 11a, and the dryout is also caused by evaporation. The saturated vapor S is condensed by the cooler 16 in the portion corresponding to the uppermost valve rod portion 11b, which is maintained in such a small amount, and by maintaining such a state, it is close to the ideal state. The poppet type valve 11 is cooled.

Further, when the heat load is extremely small and cooling is almost unnecessary, as shown in FIG.
The cooling liquid C (in the liquid phase) is not present in 12 and only the saturated steam S is in a dry-out state, and the heat transfer depends on the heat conduction by the metal body forming the poppet valve 11 and the amount carried by the saturated steam S. Done.

Each of these states occurs because the heat transfer coefficient of the wall surface of the hollow portion 12 largely changes depending on whether the cooling liquid C is in the liquid phase or the gas phase (saturated steam S). Further, although there is a change in the prosperity of each state depending on the state of the cooler 16 to which the secondary cooling water is supplied, it can be considered that it is almost constant as described above. It can be seen that responsiveness and excellent wide-range temperature control are possible.

Therefore, next, the temperature control of the poppet valve will be specifically described.

The temperature control of the poppet type valve 11 based on the detection signal T _V of the valve temperature sensor 21 embedded in the valve head 11a of the poppet type valve 11, compared the target temperature and the stored set in advance in the controller 20,
When the detected temperature is higher than the target temperature, the controller 20 outputs the valve opening operation signal V to the solenoid valve 15 to supply the coolant C,
For example, cooling is performed in a high cooling state as shown in FIG.

On the other hand, when the detected temperature is lower than the target temperature, conversely, the controller 20 outputs the valve opening operation signal V to the solenoid valve 15 to output the hollow portion.
The cooling liquid C in 12 is discharged, and FIG. 2 (b) or (c)
In such a state, cooling is suppressed.

In the temperature control device 10 for the poppet valve, when the pressure inside the hollow portion 12 becomes high, the detection signal P _{C of the} pressure sensor 19 is detected.
Based on the above, the valve opening operation signal V is output from the controller 20 to the solenoid valve 15 to open the hollow portion 12, and in this case, the cooling liquid C or vapor is piped so as to be discharged and recovered. is there.

Next, temperature control performed without detecting the temperature of the valve head portion 11a of the poppet valve 11 will be described.

For example, in the case of a diesel engine, since the heat load of the poppet type valve 11 can be known from the combustion flow rate L, the rotation speed N, and the exhaust gas temperature H, these detection signals L, N, which are input to the controller 20. Based on H, the temperature of the poppet valve 11 is calculated.

Then, the controller 20 compares the temperature of the poppet valve 11 obtained by this calculation with the preset target temperature, and outputs the valve opening operation signal V to the solenoid valve 15 in the same manner as in the above case. Take control.

As a drive device for such a poppet valve,
If the supply / discharge pipe 13 for the cooling liquid is attached to the side of the valve rod portion 11b and is capable of responding to the reciprocating movement of the valve, the conventional drive device can be used as it is, and the structure as shown in the figure is used. In this case, a hydraulic piston may be attached to the hollow portion of the valve rod portion 11b to reciprocate.

[Effects of the Invention] According to the present invention as specifically described in connection with the above embodiments, according to the present invention, a hollow portion is formed in the poppet type valve, and a supply / discharge pipe for a cooling medium is communicated with the hollow portion via an opening / closing valve. Since it is mounted so as to control the opening and closing of the on-off valve, temperature control of the poppet type valve can be performed by simply controlling the supply and discharge of the cooling medium amount in the hollow part, compared to the case of controlling the secondary cooler side. It is easy to control and has good responsiveness.

Further, depending on the amount of the cooling medium in the hollow portion, it is possible to control the temperature in a wide range from uncooled state to highly cooled state.

Furthermore, compared with controlling the temperature by controlling the state of the secondary cooling water of the primary cooling water sealed in the conventional hollow portion, since it controls the amount of the cooling medium in the hollow portion corresponding to the primary cooling water,
The equipment for the entire control system is simple and low cost, and the control accuracy is high.

Therefore, the temperature of the poppet valve can be maintained at the optimum temperature or a predetermined temperature range with respect to the fluctuation of the heat load, and the low temperature corrosion resistance and the high temperature corrosion resistance of the poppet valve as well as the high temperature strength can be increased. Its life can be greatly extended.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram according to an embodiment of a temperature control device for a poppet valve of the present invention, and FIGS. 2 (a) to 2 (c) are explanatory views of a cooling state depending on the amount of a cooling medium, and FIG. FIG. 6 is a sectional view of a conventional poppet valve. 10 ...... Temperature control device for poppet type valve, 11 ...... Poppet type valve, 12 ...... Hollow part, 13 ...... Supply and discharge pipe, 15 ...... Solenoid valve, 16 ...
… Cooler, 18 …… Temperature sensor, 20 …… Controller, C …… Coolant.

Claims (1)

(57) [Claims] Claim: What is claimed is: 1. A poppet-shaped valve is provided with a hollow portion in which a primary cooling medium that exchanges heat with a secondary cooling medium provided outside the poppet-shaped valve is inserted. A supply / discharge pipe capable of supplying / discharging the primary cooling medium is provided, while the opening / closing valve is opened / closed to control the amount of the primary cooling medium in the hollow portion to improve the heat transfer on the primary cooling medium side. A poppet-type valve temperature control device comprising a controller for adjusting a cooling temperature by changing boundary conditions.