JPS63120843A - Carburetor - Google Patents

Abstract

PURPOSE:To prevent the generation of icing, by providing a flow regulator, controlled in accordance with an environmental condition, in a cooling water supply pipe, connected to a fuel increase device responsively acting to a cooling water temperature, so that action of the device delays its release in a condition easily generating the icing. CONSTITUTION:A carburetor control device 30, additionally provided in a carburetor of variable Venturi type, comprises a fast idle device (not shown in the drawing) and a fuel increasing device, and in its housing 31 a push rod 35, actuated by a wax valve 34, is inserted. An internal chamber 38, formed between swollen parts 36, 37 of the push rod 35, communicates with an inlet part of an intake passage 2 from an air bleed hole 39, and an air bleed hole 41, opened and closed by a cone-shaped internal end part 37a of the swollen part 37, communicates with an air bleed passage 26. Here a flow regulator 51, controlled by a controller 54 in accordance with air temperature, humidity and cooling water temperature, is provided interposing in a cooling water supply pipe 50 connected to a cooling water introducing chamber 46 housing the wax valve 34.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is applicable to internal combustion nfjl! The present invention relates to a carburetor for a carburetor (hereinafter also referred to as an engine), and particularly to a means for preventing icing of the carburetor.

(Prior Art) Conventionally, since the warming up of the engine corresponds to the increase in engine coolant temperature, engine warm-up control is often performed based on changes in the engine coolant temperature. There is a carburetor controlling the 77 stroke idle and starting fuel booster by a wax valve that is responsive to coolant temperature.

In this way, engine cooling water is often used for engine warm-up control by electrical means or engine TX control.
This is because it is easier to handle than when I lubricating oil is used, and the structure of the warm-up control device can be simplified.

(Problem to be solved by the invention) However, in an environment of low temperature and high humidity, the throttle valve, fuel nozzle, metering
If icing occurs on the needle or the like, conventional warm-up control controls only the engine cooling water temperature, so fast idle and starting fuel increase may be canceled with icing remaining. As a result, there is a problem in that the air-fuel ratio becomes unstable, resulting in unstable idling, engine stalling, or engine stoppage.

As a prior art for delaying wax valve operation due to rise in engine cooling water temperature, for example, Japanese Patent Application Laid-Open No. 58-126455
In this case, the transmission of the engine cooling water temperature to the temperature-sensing part of the wax valve is delayed, so even when icing is not occurring because the temperature is low but the humidity is low, fast idle and starting fuel increase are canceled. There is a problem in that the speed becomes slower and there is a disadvantage in terms of fuel efficiency.

An object of the present invention is to provide a carburetor that can prevent the occurrence of icing by delaying the deactivation of the fast idle and fuel R increase device only when the environmental conditions are such that icing is likely to occur.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a carburetor equipped with a fast idle and starting fuel increasing device that responds to engine cooling water temperature, in which an engine cooling water supply pipe to the device is provided. The engine cooling water flow rate regulator is provided with a control I3 for detecting air temperature, humidity, and engine cooling water temperature.

(Example) The present invention will be described below based on drawings showing examples. FIG. 1 shows a longitudinal sectional view of a variable venturi carburetor according to the invention. 1 is a carburetor main body, 2 is an intake passage, 3 is a suction piston that moves laterally within the intake passage 2, 4
5 shows a metering needle attached to the tip surface of the suction piston 3, 5 the inner wall surface of the intake passage 2 facing the tip surface of the suction piston 3, 6 a throttle valve, and 7 a float. A venturi portion 8 is formed between the distal end surface of the suction piston 3 and the inner wall surface 5 of the intake passage 2. A cylindrical casing 9 is fixed to the carburetor body 1, and a suction piston 3 is slidably inserted therein. 10 is a negative pressure chamber, 11 is an atmospheric pressure chamber, 12 is a compression spring, 13 is a negative pressure hole, and 14 is an atmospheric hole.

Reference numeral 20 denotes a fuel passage formed within the carburetor main body 1, which extends in the axial direction of the metering needle 4, and has a fuel jet 21 provided therein. The fuel passage 20 on the upstream side of the fuel jet 21 is communicated with the float seedling 7 via a fuel pipe 22 extending downward. A nozzle 23 is fixed to the inner wall surface 5 and is coaxially arranged at the end of the fuel passage 20 . The metering needle 4 extends through the nozzle 23 and the fuel jet 21, and the fuel is metered by an annular passage 24 formed between the metering needle 4 and the fuel jet 210 before passing from the nozzle 23 to the intake passage. Supplied within 2 days.

A plurality of air bleed holes 25 are formed on the inner peripheral surface of the fuel jet 21, and the annular passage 24 is connected to an air bleed passage 26 formed in the carburetor body 1 through the air bleed holes 25. is communicated with. Further, on the upper wall surface of the fuel passage 20 on the downstream side of the fuel jet 21, an auxiliary air
A bleed hole 27 is formed, and the auxiliary air bleed hole 27 is connected to the air bleed passage 26.

30 is a carburetor control device, which consists of a fast idle device and a fuel increase device (however, in Fig. 1)? (excluding standstill and idle equipment). Inside the housing 31 of the carburetor control device 30, there are a large diameter hole 32 and a small diameter hole 3 that communicate with each other.
3 is formed, a wax valve 34 is inserted into the large diameter hole 32, and a bushing rod 35 operated by the wax valve 34 is inserted into the small diameter hole 33. The bushing rod 35 has a pair of enlarged portions 3 spaced apart from each other.
6.37 and formed between the enlarged portions 36.37, the internal chamber 38 is formed between the enlarged portions 36.37 through an air bleed hole 39 formed in the housing 31 and an air bleed hole 40 formed in the carburetor body 1. and communicates with the inlet portion of the intake passage 2. The inner end 37a of the enlarged portion 37 is formed into a conical shape, and the housing 31 is formed with an air bleed hole 41 whose frontage area is controlled by the conical inner end 37a. An air bleed jet 42 is inserted into the air bleed hole 41 and communicates with the air bleed passage 26 of the carburetor body 1.

The outer end of the enlarged portion 37 projects outward from the housing 31, and a disc-shaped head 43 is integrally formed at the tip.

The wax valve 34 includes a flange portion 34a and a temperature sensing portion 34b. An O-ring 4/I is fitted into an annular groove provided on the outer periphery of the flange portion 34a. A plug 45 is fitted into the end of the large diameter hole 32, and the wax valve 3
4 is fixed within the housing 31 by a plug 45. An engine cooling water introduction chamber 46 is formed between the temperature sensing portion 34b and the plug 45, and a cooling water supply pipe 50 is connected thereto. 46a is a cooling water discharge hole.

A flow rate regulator 51 is attached to the cooling water supply pipe 50. The flow regulator 51 has an intercalary valve 53 operated by a renoid 52, and controls the area of the cooling water supply pipe 50. 54 is a controller for the flow rate regulator 51, and a temperature sensor 55
, humidity sensor 56 and engine coolant temperature sensor 5
7, converts each signal into predetermined coefficients, and inputs the synthesized signal to the rumor adjuster 51. Figure 3(a)
An example is shown in ~(d).

FIG. 2 shows the fast idle system of the carburetor control Il system 30. A cam 61 and a lever 62 are rotatably attached to the housing 31 by a bolt 60 that functions as a pivot. The cam 61 and the lever 62 are connected by a screw 63, and the lever 62 is provided with a receiving part (not shown) in the middle part thereof which comes into contact with the bushing rod head 43.

The pin 6 fixed to the tip of the lever 62 and the housing 31
4, a tension spring 65 is attached.

Due to the spring force of the tension spring 65, the lever 62 is constantly pressed against the bushing rod head 43. The rotational force received by the lever 62 is transmitted to the cam 61 via the screw 63. A lever 67 is fixed to t*6G of the throttle valve 6, and a pin 68 fixed to the tip thereof engages with a cam surface 69 of the cam 61.

The operation of the vaporizer configured as above will be explained. Second
The figure shows a case where the engine temperature is low, and the throttle valve 6 is held open to the fast idle position by the cam 61 and lever 67.

When the engine is started and the air temperature, humidity, and engine cooling water temperature detected by the controller 54 do not meet the icing generation conditions, the flow regulator 51 supplies the engine cooling water to the vaporizer controller 30 at a normal flow rate. Cooling water introduction chamber 46
send to. When the engine cooling water temperature rises, the wax valve 34 moves the bushing rod 35 to the left in the figure. As a result, the lever 62 is rotated counterclockwise, and the throttle valve 6 is gradually closed until it reaches the idle link opening when warming is completed.

On the other hand, when the engine is started and the engine cooling water temperature rises, and the bushing rod 35 moves to the left in the figure, the inner chamber 3 passes through the air bleed hole 40°39.
The air ■ supplied to the chamber 8 increases, and the air
The amount of air supplied to the air bleed passage 26 via the bleed hole 41 increases. Therefore, the fuel jet 21
Since the amount of air supplied to the fuel passage 20 increases through the air bleed holes 25 and 27 of the fuel passage 20, the fuel supplied from the nozzle 23 gradually decreases and is supplied to the engine cylinder (not shown). The air-fuel mixture gradually becomes leaner.

Next, under the icing generation conditions where the air temperature and engine cooling water temperature are low and humidity is high, the flow rate of the engine cooling water is throttled by the regulator 51 after receiving the signal from the controller 54 (see Fig. 3). (e)) The flow rate of engine cooling water entering the engine cooling water introduction chamber 46 decreases. For this reason, the deactivation of the fast idle-like function and the starting fuel increase function of the carburetor control device 30 is delayed and is delayed.
)), the engine is sufficiently warmed up and icing is prevented.

<Effects of the Invention> As explained above, the present invention provides a carburetor equipped with a fast idle and starting fuel increasing device that responds to engine cooling water temperature, in which air temperature and humidity are connected to the engine cooling water supply pipe to the device. By providing an engine cooling 141 water flow regulator with a controller that detects the temperature of the engine cooling water and the temperature of the engine cooling water, the deactivation of the fast idle and fuel lift system can be delayed only when environmental conditions are likely to cause icing. , the occurrence of icing can be prevented. In the case of environmental conditions where humidity is low and icing does not occur even at low temperatures, there is no delay in deactivating the fast idle and fuel intensifier as in the past, which also has the effect of improving fuel efficiency.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is a longitudinal sectional view of a variable venturi carburetor equipped with a fast idle and starting fuel increase device responsive to engine cooling water temperature, and Figure 2 is a front view of the fast idle device. Figure 3 (a) to (f)
) are explanatory diagrams of the output coefficients of the engine cooling water flow rate regulators, respectively. 1... Carburetor body 6... Throttle valve 26.40... Air bleed passage 3o... Carburetor controller 34... Wax valve 35... Bush rod 50... Engine cooling Water supply pipe 51... Engine cooling water flow adjustment device 54... Controller 55... Air temperature sensor 56... Humidity sensor 57... Engine cooling water temperature sensor 61... Cam 62, 67... lever

Claims (1)

[Claims] A carburetor equipped with a fast idle and starting fuel increase device that responds to engine coolant temperature, the engine coolant having a controller in the engine coolant supply pipe to the device that detects air temperature, humidity, and engine coolant temperature. A vaporizer characterized by being equipped with a flow rate regulator.