JPS5974358A - Automatic choke device in caburetter - Google Patents

Abstract

PURPOSE:To carry out appropriate choking operation with a simple structure by providing an electrical resistance heater for heating a temperature sensing drive element, a temperature sensor for detecting a cooling water temperature and an electrical control device for supplying a predetermined current to the electrical resistance heater. CONSTITUTION:An automatic choke device comprises a link mechansim 17 for associatingly rotating a choke valve 2 and a throttle valve 3 in opposite rotational directions, respectively, and a temprature sensing driving element 20. A temperature sensor 32 detects the temperature of cooling water around an engine manifold or engine cylinders, and an electrical controller 34 feeds a predetermined current to an electrical resistance heater 33 to heat the temperature sensing driving element 20. With this arrangement, no pipe lines such as, for example, bypass lines, are necessary for guiding cooling water, thereby appropriate chocking operation may be carried out with a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic choking device for a motor vehicle engine.

In an automatic choke device, in order to avoid the trouble of depressing the accelerator pedal while the engine is warming up and artificially reducing the throttle valve opening to correspond to the increase in the choke valve opening, the throttle valve will not throttle even if the engine has been left to warm up. A so-called fully automatic choke device, which automatically reduces the valve opening, is now being adopted.

This fully automatic choke device uses a temperature-sensitive driver containing a reversible thermal expansion material that expands greatly as the temperature rises to rotate the throttle valve once in the direction of decrease, and rotate the choke box in the direction of increase in opening. The temperature-sensitive drive device is configured to be operated in conjunction with the operation, and the temperature-sensitive drive device is heated by engine exhaust gas, lubricating oil, or cooling water.
93]] Publication No. 46-7843, Publication No. 54-1
No. 7893 (publication)) and 'Things that are heated by air resistance heat (for example, Yoshi 1) Takashi [The theory and practice of vaporizers] published by Meishiki Kaisha Railway Japan Co., Ltd., first edition with revised title on May 10, 1980. .

(see pages 134 to 136).

The former heating method is reasonable because it senses the temperature of the fluid, which is closely related to the warm-up state of the engine, and avoids the complexity of piping. It is most advantageous to use cooling water because it can detect the actual engine temperature at startup, but
Due to heat loss, the cooling water around the temperature-sensitive drive unit may not always be at the same temperature as the engine. There is also the problem that water may not flow through the bypass and the engine temperature cannot always be accurately sensed.

The latter heating method has the advantage that it can be used in all types of engines, does not require a phloem, is easy to install, and can quickly release the choke effect, but it Since the choke box is opened, there is a problem in that it cannot be expected to always perform an appropriate choke action depending on the state of the engine.

The purpose of the present invention is to solve the above-mentioned problems and provide an automatic choke device that has a simple configuration that does not use piping such as cooling water bypass, and can perform an appropriate choke action depending on the engine condition. It was invented.

The present invention achieves this objective.

+ I'm Mf feeling in an automatic choke device equipped with a link mechanism that rotates the choke box and throttle valve in conjunction with each other in opposite opening directions, and a temperature-sensitive driver that drives this link mechanism according to temperature. an electric resistance heating element that heats the temperature driver; a temperature sensor that detects the temperature of cooling water around the engine manifold or cylinder; and a predetermined current that is applied to the electric resistance heating element in accordance with an input signal generated by the temperature sensor. It is characterized by being equipped with an electric controller for supplying the electric power.

Next, a specific example of the configuration of the present invention will be explained with reference to the drawings.

In the figure] is the body of the chiffon device, 2 is the choke box, and 3 is the throttle valve.A choke arm 6 and a throttle arm 7 are respectively fixed to the choke valve shaft 4 and the throttle valve shaft 5, and 1 is the choke arm. A protrusion 8a that engages with the protrusion 6a of No. 6
A choke lever 8 having a rotation angle θh is freely supported on the choke valve shaft 4. A cam Oa and a cam lever 11 are rotatably supported on the cam shaft 9, and the choke lever 8 and cam lever 11 are connected by a connecting rod 12. ]3
are in contact engagement with each other. The choke arm 6 and the choke lever 8 are engaged with both ends of a coiled spring 4 surrounding the choke valve shaft 4, and the cam 0 and the cam lever 1 are engaged with a coiled spring 4 surrounding the cam shaft 9. Both ends of a coiled connection spring 15 are engaged, and both ends of a coiled return spring 6 surrounding the cam shaft 9 are engaged with the body 1 and the cam 10.

The aforementioned choke arm 6, aperture arm 7° choke lever 8. Cam10. The cam lever 11° connecting rod 12 is a link mechanism 1 that rotates the choke valve 2 and throttle valve 3 in conjunction with each other.
It forms 7.

The three springs 14, 15, 16 interlock each part of the link mechanism 17 and control its movement.

Before warming up, the link (shock mechanism) 7 is in the state shown in Figure 1, and when the temperature is lower than this, the cam]0
is the return spring] due to the action of 6 r! 71 Rotate clockwise,
A cam lever 11 that rotates together with this rotates the choke lever 8 counterclockwise via a connecting rod 12. At this time, the choke valve 2 is fully opened, and when the spring 14 is twisted, it generates resistance to the opening of the choke valve, and the aperture arm 7 that follows the cam 10 rotates counterclockwise, causing the aperture 9' The opening of f3 increases.

As the engine starts and warms up, the cam lO is rotated counterclockwise, decreasing the opening of the throttle 9P3 and increasing the opening of the choke valve 2. After the choke valve 2 is fully opened, the connecting spring 5 is tightened to prevent the cam lever 11 from rotating.

The cam 0 has an adjustable catch 8.

The temperature-sensitive driver 20 pushes the receiving screw 18 as the temperature rises, thereby rotating the cam 0 counterclockwise in FIG.

The temperature-sensitive actuator 20 includes a reversible thermal expansion material 21 that is solid or viscous at a temperature below a set temperature, gradually becomes liquid at a temperature higher than the set temperature, and expands considerably at that time, and a cylindrical container 22 with a bottom. filled with a highly elastic membrane 23 at its open end.
At the same time, the guide tube 2 is inserted into the container 22 by sandwiching the membrane 23.
4 is fixed to the base thereof, and an elastic auxiliary piston 25 and an operating rod 26 that are in contact with the membrane 23 are attached to this guide cylinder 24.
6 is pressed against the auxiliary histone 25 and a return spring 27 is inserted, and a flange-shaped contact portion 26a formed at the tip of the operating rod 26 protruding from the guide tube 24 is attached to the tip of the receiving screw shaft. It resembles a surface.

When the thermal expansion material 2 expands as the temperature rises, it rotates the cam 10 while advancing the operating rod 26 against the elasticity of the two return springs 16 and 27.

Link mechanism that links choke valve 2 and throttle 9P3]
7 can have a more flexible configuration than the illustrated embodiment, and the temperature-sensitive drive device 20 can be actuated at an appropriate position of the link mechanism 7.

Historically, the temperature-sensitive actuator 20 has sometimes been constructed using a bimetal instead of the thermal expansion material 21.

As shown in FIG. 2, the present invention provides a temperature sensor 32 for detecting the temperature of cooling water 31 in a jacket 30 surrounding an engine manifold and cylinders, and a container filled with a thermal expansion material 21. An electric resistance heating element 33 is provided in almost contact with the electric resistance heating element 3: HC, and an input signal generated by the temperature sensor 32 is sent to the electric controller 34, and a predetermined current according to the temperature is sent to the electric resistance heating element 3: HC to drive the temperature-sensitive drive. 20 is heated.

The temperature sensor 32 is preferably located as close as possible to the manifold or cylinder, and the electrical resistance heating element 33 is made of electrical resistance wire such as nichrome wire or a resistive heating conductive material such as PTC cedar ceramics. The electric controller 34 can use an electronic control device for air-fuel ratio control installed in the automobile, and in addition to the input signal from the temperature sensor 35 that detects the atmospheric temperature, it also receives input signals from the throttle valve once,
Suction pipe negative pressure, engine intake air amount, engine speed,
11) Correction factors such as air composition may be sent as input signals to the heart-air controller 34 to control the electric current supplied to the electrical resistance heating element 33.

As described above, according to the present invention, the conductivity of the cooling water around the engine manifold or cylinder is extracted as an electrical signal, and the electrical controller converts it into a predetermined current to heat the temperature-sensitive drive device. Not only is it easy to install, it eliminates the need for a single pipe such as a bypass to guide the cooling water.
It always accurately detects the engine temperature, heats the temperature-sensitive drive device appropriately, and performs an appropriate choke action depending on the engine condition.

[Brief explanation of drawings]

FIG. 1 is a partially omitted front view showing a practical example of the present invention, and FIG. 2 is a partially cut away side view. 2...Choke valve, 3...throttle valve, 1
7... Link mechanism, 20... Temperature-sensitive driver, 32... Temperature sensor, 33... Electric resistance heating element, 34...・Electrical controller. f-, Fig. 1 Fig. λ

Claims (1)

[Claims] In an automatic choke device comprising a link mechanism for interlockingly rotating a choke square and a throttle square in opposite open IO' directions, and a temperature-sensitive driver for driving this link mechanism according to temperature, the temperature-sensing drive an electric resistance heating element that heats the engine, a temperature sensor that detects the temperature of cooling water around the engine manifold or cylinder, and supplying a predetermined current to the electric resistance heating element in accordance with an input signal generated by the temperature sensor. An automatic choke device in a carburetor, characterized by comprising an electric controller.