JPS60228749A - Auto choke apparatus for engine - Google Patents

Abstract

PURPOSE:To obtain a choke valve which possesses the characteristic of slow opening at low temperature and of speedy opening at high temperature by utilizing, as the opening pressure for the choke valve, the hydrogen pressure liberated from a metal hydride which liberates hydrogen as the heating at a cooling-water temperature proceeds. CONSTITUTION:A pressure generator 30 having metal hydrides 32 is installed into cooling water 3, and the hydrogen gas generated at high temperature is allowed to act onto a piston 23 through a pipe Z, and a choke valve 7 is opened against a spring 25 by the pressure. As for the metal hydride having hydrogen adsorbed, the rate of increase of the liberated hydrogen gas is low at a constant temperature variation rate at a low temperature, and therefore, the choke valve 7 is not opened so much in comparison with the rate of rise of the cooling-water temperature. As the cooling-water temperature rises, the rate of the pressure increase of the liberated hydrogen gas from the metal hydride increases, and the opening speed of the choke valve increases.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application in M industry) The present invention relates to an automatic engine filler device that controls the opening of a filler valve depending on the warm-up state of the engine. It is.

(Prior art) Conventional automatic engine tightening devices include a bimetallic automatic tightening device that uses bimetal (for example, Japanese Utility Model Publication No. 1120111) and a wax-type automatic tightening device that uses thermowax. A device (for example, Japanese Utility Model Application Publication No. 1111333/1983) is known.

However, among these known automatic reset devices, the bimetal type ones do not operate the check valve at engine temperature due to variations in the accuracy of the bimetal or variations in the performance of the heater that heats the bimetal. There were problems in that it was difficult to accurately control the process, and the structure was complicated due to the large number of parts.

In addition, in the case of wax-type products, the hysteresis of the thermowax is large, so even if a return spring with a large suppressing force is used, it is difficult to accurately contract the thermowax as the engine temperature falls, and the control of the Chirok valve according to the engine temperature is difficult. There was a problem that it became inaccurate.

(Object of the Invention) In view of the problems of the conventional automatic checker as described above, the present invention has a simple structure and an easy opening of the check valve by effectively utilizing the characteristics of metal hydrides. The purpose of this invention is to provide an automatic engine check device that accurately controls the engine temperature in accordance with the engine temperature to improve the startability and warm-up performance of the engine. .

(Structure of the Invention) The engine auto-chiloft device of the present invention has a built-in metal hydride that releases hydrogen gas when heated and stores hydrogen gas when cooled, in a position convenient for engine temperature detection. A pressure generator is provided to obtain a hydrogen gas pressure that corresponds to the engine temperature, and a pressure generator is provided to generate a hydrogen gas pressure that corresponds to the pressure of the hydrogen gas generated in the pressure generator. An actuator that acts to control the opening degree of the valve is installed, and the characteristics of the metal hydride, that is, the release of hydrogen gas starts from an extremely low temperature, and the rate of increase in the equilibrium dissociation pressure of the hydrogen gas is controlled by the metal hydride. By effectively utilizing the characteristic that the temperature increases as the temperature rises, the check valve is controlled to open within a wide temperature range from lower temperatures, and while accelerating the opening speed as the engine temperature rises. , the control characteristics of the check valve are permanently brought closer to the ideal control characteristics required from the driveability of the engine, thereby improving engine startability and @-like characteristics. It is something.

C Embodiment) Hereinafter, the engine auto-tilof device of the present invention will be described based on the embodiments shown in the accompanying drawings. FIG. 1 shows a system diagram of the auto-chill-off device 2 according to the embodiment of the present invention. This automatic checking device 2 includes a pressure generating device 30 (described later) attached to the cylinder head 2 of the engine body, and a checking valve 7 installed upstream of the venturi 6 of the carburetor. An actuator 20, which will be described later, is attached to the clever bar 10 and a gas pressure introduction pipe t.

It is connected and configured.

The pressure generating device 30 is constructed by accommodating a metal hydride 32 in a closed container-like case 3/. Incidentally, the surplus space 33 in case 3/ is used for metal hydrogenation 111J3.
It acts as a gas chamber that temporarily stores the hydrogen gas released from the case 31, and faces the gas communication port 3II provided in the case 31. In addition, in this example, a lanthanum-nidium alloy (
Adopts tc&nti.

This pressure generation *@30 is caused by case 3/3 as shown in Figure 1.
Attach it to the cylinder head with the tip (C opposite gas flow port end) 37G side protruding into the water jacket 3, which is convenient for detecting engine temperature.

Can be attached. Therefore, when the case 31 is warmed by the engine cooling water, the metal hydride 1m32 housed in the case 31 is also warmed, and hydrogen gas is released from the three metal hydrides until the equilibrium dissociation pressure corresponding to the temperature is reached. released. This hydrogen gas is led from the gas flow port 3'l of the case 3/ through the gas pressure introduction pipe II0 to the actuator 20, which will be described later, as an operating gas for the actuator 20.

In addition, Fig. 2 shows the temperature C (temperature of the metal hydride 32) and gas pressure C (equilibrium dissociation pressure of hydrogen gas) when a lanthanum-nickel alloy (t6Ni5) is used as the metal hydride 32.
showed a correlation with From the temperature-pressure diagram of this N2 diagram, it can be seen that metal hydride 3.2 starts releasing hydrogen gas from an extremely low temperature region around 0°C. It can be seen that C (second characteristic) increases as the temperature of the metal hydride 3.2 increases.

These two properties of the metal hydride 32 act very effectively in controlling the chimney valve 7, as will be described later.

The actuator 20 is housed in a sealed case 2/.
It is configured to house a piston 23 provided with an operating rod 2tI. A pressure chamber 22 is provided at one end of the piston 23.
is formed. This pressure main 22 is connected to the gas pressure introduction pipe qO via a gas flow port 26.

Further, the piston 23 is applied with pressure M2 by the spring 2j.
It is constantly biased toward the second side. Therefore, piston 2
3 (that is, the operating rod itt) is displaced in the axial direction by the balance between the spring force of the spring 25 and the gas pressure of the hydrogen gas introduced into the pressure N22.
One end 2≠C of t is engaged with the eye-clever 10.

Therefore, when the piston 23 moves in the direction indicated by the arrow, the choke valve 7 is rotated in the valve opening direction by the moving force of the piston 23 against the spring force of the return spring //, and conversely, the choke valve 7 is rotated in the valve opening direction by the moving force of the piston 23. When the choke valve 7 moves in the direction of arrow B, the restricting force of the piston 23 on the choke valve 7 is released, and the check valve 7 is rotated in the valve closing direction by the spring force of the return spring //. In FIG. 1, the reference numerals indicate fuel nozzles.

Next, to explain the operation of this daily valve control device 2, when the engine temperature (cooling water temperature) is low, the balance of hydrogen gas released from the metal hydride 3.2 of the pressure generator 30 is The dissociation pressure is low (C, that is, the gas pressure applied to the piston 23 of the actuator 20 is low), and therefore,
The piston 23 moves in the direction of arrow B and closes the check valve 7 nearly to the fully closed position. Therefore, a rich air-fuel mixture is supplied to Nissin, and its startability is improved.

After the engine starts, as the engine temperature gradually increases,
Along with this, the equilibrium dissociation pressure of the hydrogen gas released from the metal hydride 1m32 increases, so the piston 23 of the actuator 〇 receives the hydrogen gas pressure and gradually moves in the direction of the arrow, opening the hydrogen discharge valve 7. temperature gradually approaches the fully closed position (in this embodiment, the actuator is set so that the check valve 7 is fully open when the cooling water temperature is about 70°C, and half open when the cooling water temperature is about 20°C. The spring force, etc. of Spring Co. 20 is set).

By the way, in general, in an automatic check system, after the engine is cold started, until the cooling water temperature reaches approximately 20°C, it is necessary to supply a rich mixture to the engine in the engine cold region. Therefore, as the cooling water temperature rises, the daily valve slowly returns to the fully open position N (@inclination angle with respect to the airway road j = , 2) without increasing the opening speed too much.
0”) to half-open position C intake passage = jJ□
6), and then the cooling water temperature increases from about 20℃ to about 7℃.
During the temperature rise to 0°C (C engine condition range), as the cooling water temperature approaches 70°C, the choke valve increases its opening speed as the cooling water temperature rises and changes from the half-open position to the fully open position (the angle of inclination relative to the intake passage). = 90'), and beyond that, the choke valve can be controlled so that it is held in the fully open position until the cooling water temperature drops below 70°C (ideal MA characteristics). Although it is requested,
In the auto-start date device 2 of this embodiment, since the choke valve 7 is controlled by the gas pressure of the hydrogen gas released from the metal hydride 3.2, no special device or mechanism is required. The control characteristics of the choke valve 7 can be brought as close as possible to the ideal control characteristics as described above without providing such a control characteristic. That is, the metal hydride 3.2 has the above-mentioned second characteristic, that is, the rate of increase in the equilibrium dissociation pressure of hydrogen gas released from the metal hydride 32 increases as the temperature of the metal hydride 32 increases. Therefore, if the actuator 20 is actuated by the pressure of the hydrogen gas released from the metal hydride 3.2, the engine will open the valve 7 at a slow opening speed. In the cold region, the gas pressure is low and has a small rate of pressure increase, so the cooling water valve 7 can be opened slowly as the cooling water temperature rises without increasing the opening speed too much. In engine temperature ranges where it is desired to open the check valve 7 while rapidly accelerating the opening speed, the check valve 7 is opened at high pressure due to the pressure of hydrogen gas, which increases at a high rate. The valve can be opened while rapidly increasing the opening speed.

The spring force of the spring 23 of the actuator 20 is
Amount of movement of the piston 23 (i.e., opening degree of the check valve 7) K
(In other words, as the chill valve 7 approaches the fully open position from the fully closed position, the suppressing force increases). However, as in this example, the three metal hydrides include lanthanum nickel, When an alloy (LaNi3) is used, the temperature of the metal hydride 3 is 20% as shown in Figure 2.
The gas equilibrium dissociation pressure was about /3 atm when the temperature reached 70°C, but when the temperature reached 70°C, the gas equilibrium dissociation pressure increased to about 70 atm. In other words, the spring force of the spring 2j and its increase (The pressure and pressure rise rate are negligible), so even though the spring 25 is provided, the tick valve 7 can be ideally controlled as described above.

Furthermore, since this metal hydride 32 has the above-mentioned first characteristic C, that is, the characteristic that it starts releasing hydrogen gas from an extremely low temperature range, the control of the choke valve 7 is performed at an extremely low temperature around 0°C. (In other words, the controllable temperature range is wide.)
- The performance of the equipment can be improved.

In addition, with conventional bimetal type auto choke devices or thermowax type auto choke devices, their operation becomes more uncertain in low temperature ranges, and if you try to operate them from low temperature ranges, the controllable temperature range is relatively narrow. There is a problem in which the choke valve opens fully before the engine temperature rises sufficiently.

In the above embodiment, the pressure generator 30 and the actuator 20 are connected to the gas pressure introduction pipe 110''c to guide hydrogen gas to the vaporizer q side, but in other embodiments of the present invention, For example, a pressure generating device and an actuator may be integrated and provided on the engine side, and the actuator and choke valve may be connected by means such as a wire cable or a link.
10 omission).

Further, in the above embodiment, only the choke valve 7 is controlled, but in other embodiments of the present invention, for example, as shown in FIG.
l and throttle valve! 2 are connected to each other in a predetermined relationship via the retention lever S3 and the first idle cam Sll, and the first idle cam SII is rotated by the actuator 55 to control the choke valve 51 and the throttle valve S at the same time. ■You can also do this.

It goes without saying that the present invention can also be applied to LPG vehicles.

1 Effects of the Invention) The engine auto-choke device of the present invention controls the actuator that controls the opening and closing of the choke valve by using a metal hydride that releases hydrogen gas when heated and stores hydrogen gas when cooled. Since it is activated by the gas pressure of hydrogen gas generated from the equipped pressure generator, hydrogen gas release starts from an extremely low temperature, and as the temperature increases, the rate of increase in the equilibrium dissociation pressure of hydrogen gas increases. By blindly utilizing the unique properties of metal hydrides to control the choke valve over a wide temperature range from extremely low temperatures to high temperatures, the choke valve can be controlled while increasing the valve opening speed as the engine temperature rises. The effect is that it is possible to open the valve, and to accurately and ideally control the opening degree of the check valve according to changes in engine temperature, improving engine startability and warm-up performance. There is.

Furthermore, since this auto choke device consists of a pressure generator containing a metal hydride and an actuator, it is better than a bimetal auto choke device that requires a large number of components such as bimetals and heaters. The structure is simple and the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an auto choke device according to an embodiment of the present invention, JlZ diagram is a characteristic diagram of metal hydride, and 21g3.
The figure shows another embodiment of the auto-check date device. /・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・STOCK VENTURY 7 ...Actuator 23...Piston! ≠...Operating rod 30...Pressure generator 32...Metal hydride 110...Gas pressure introduction pipe/LX) 1030/30

Claims (1)

[Claims] 1. An auto choke device that controls the opening degree of the choke valve installed upstream of the venturi according to the warm-up state of the engine, and cools by releasing hydrogen gas when heated. A pressure generating device containing a metal hydride for storing hydrogen gas is provided at a position convenient for detecting the temperature of the engine, and the check valve is further provided with a pressure generating device containing a metal hydride that stores hydrogen gas. An auto choke device for an engine, comprising an actuator that receives gas pressure and operates to control the opening degree of the day valve in response to the pressure.