JPH0628248U - Mixture concentration controller for multiple vaporizers - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To obtain a multiple vaporizer that can suppress the concentration tendency of the air-fuel mixture in highlands and control the concentration of the air-fuel mixture over the entire opening of the throttle valve. [Structure] A correction air passage 1 isolated from the intake passage 3 of the carburetor C
1 is provided and the second air valve seat hole 12 is provided on the upstream side in the passage.
B is provided, and the first air valve seat hole 12A is provided on the downstream side. The second upstream flow passage 11D between the first air valve seat hole and the second air valve seat hole and the downstream flow passage 11B downstream of the first air valve seat hole are idling in the correction air passage. A second air opening / closing valve 15 for controlling opening / closing of the valve seat hole is arranged in the second air valve seat hole while communicating with the compensating air passage 13. When the idling opening of the throttle valve 6 is arranged in the first air valve seat hole. The first opening / closing valve 16 that closes the valve seat hole and can increase the effective opening area of the valve seat hole in accordance with the increase in the opening degree of the throttle valve is arranged. Then, it is connected to the inside of the intake passage 3B on the downstream side of the throttle valve of each carburetor C via the downstream flow passage of the correction air passage and the correction air distribution passage 17 to be opened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multiple vaporizer that controls the amount and concentration of air-fuel mixture supplied to an engine.

[0002]

[Prior art]

 The concentration of air-fuel mixture is determined on the assumption that the multiple vaporizers installed in vehicles (two-wheeled vehicles, four-wheeled vehicles, etc.), outboard motors, etc. are generally used on level ground (less than 1500 m above sea level). The main fuel system, low-speed fuel system fuel jet, and air jet that should comply with this are selected. On the other hand, due to the expansion of the leisure industry, these vehicles and outboard motors may be used at high altitudes. When such an engine used on a flat land is used in a highland, the air-fuel mixture concentration tends to be thickened due to a decrease in air density, which is not preferable in terms of engine operating performance. From the above, in the past, an air adjusting screw for increasing the amount of air flowing through the main fuel system of each carburetor constituting the multiple carburetor and the air passage communicating with the low speed fuel system was arranged in each carburetor. There is one that adjusts the air adjusting screw to make the correction air variable so that the mixture concentration of each carburetor is appropriately controlled. (For example, Japanese Utility Model Publication No. 41-3529 discloses air correction in a single vaporizer.)

[0003]

[Problems to be solved by the device]

 According to such a conventional multiple vaporizer, the amount of air flowing in the main fuel system (even low-speed fuel system) of each vaporizer is screwed by the air adjusting screw in order to suppress the tendency of the mixture to thicken. However, it is difficult to correct the concentration. That is, since the air adjusting screw is arranged in each carburetor, and the adjustment of the screw is performed individually, it is difficult to easily make the corrected air amount of each carburetor the same. In addition, the downstream side of the air passage of each carburetor is not opened to the intake passage to which the intake negative pressure is directly applied, but is opened to the fuel passage of the main fuel system. It is not possible to supply a sufficient amount of air by directly acting on the large intake negative pressure that occurs in the road. Therefore, it is difficult to sufficiently dilute the air-fuel mixture concentration, and it becomes difficult to set the air-fuel mixture in high altitudes. (In the conventional example, it is effective because the air-fuel mixture concentration is controlled within a relatively small range.) Further, the air is sufficiently supplied to the fuel passage of the main fuel system. In order to do so, it is considered to enlarge the opening of the air adjusting screw to increase the amount of air, but this causes the negative pressure in the fuel passage of the main fuel system to drop greatly (approaches atmospheric pressure). As a result, the fuel suction action is significantly reduced, making it difficult to achieve accurate and uniform fuel control.

The present invention has been made in view of the above-mentioned problems, and in particular, can suppress the tendency of the air-fuel mixture to thicken at high altitudes and can control the air-fuel mixture concentration in good and proper manners over the entire opening of the throttle valve. To provide a multiple vaporizer.

[0005]

[Means for solving the problem]

 According to the present invention, in order to achieve the above-mentioned object, a carburetor body having an intake passage having a venturi portion inside and a throttle valve shaft rotatably supported by the carburetor body in the intake passage are mounted. A plurality of carburetors consisting of a plate-shaped throttle valve that is attached to control the opening and closing of the intake passage, and a float chamber body that is located below the carburetor body and forms a constant fuel liquid level inside are arranged. In the multiple vaporizer, there are a first air valve seat hole that divides the correction air passage separated from the intake passage into an upstream side flow passage and a downstream side flow passage, and an upstream side flow passage of the correction air passage. , A second air valve seat hole that is divided into a first upstream flow path toward the atmosphere and a second upstream flow path toward the first air valve seat hole, and a downstream flow path across the first air valve seat hole And an idling compensation air passage that constantly connects the second air passage and the second upstream flow passage, and a second air valve seat hole that opens and closes The air opening / closing valve and the first air that can close the first air valve seat hole at the time of idling opening of the throttle valve and increase the effective opening area of the first air valve seat hole according to the increase of the opening degree of the throttle valve. A single air-fuel mixture concentration control device is constituted by the on-off valve, and the throttle valve of each carburetor that constitutes a multiple vaporizer via the correction air distribution passage in the downstream flow passage of the air-fuel mixture concentration control device. It is connected to the intake passage on the more downstream side and opened, and the first upstream side is opened to connect to the intake passage or the atmosphere on the upstream side of the venturi part of one carburetor that constitutes the multiple vaporizer. is there.

[0006]

[Action]

 At high altitude, the second air opening / closing valve opens the second air valve seat hole. During idling operation of the throttle valve, the correction air is supplied from the idling compensation air passage to each intake air passage downstream of the throttle valve of each carburetor through each correction air distribution passage. When the throttle valve is opened, the first air opening / closing valve increases the effective opening area of the first air valve seat in synchronization with the throttle valve, and the correction air according to the opening degree of the throttle valve is supplied through each correction air distribution passage. Can be supplied into the intake passage of each carburetor.

[0007]

【Example】

 An embodiment of the air-fuel mixture concentration control device for a multiple vaporizer according to the present invention will be described below with reference to FIG. This example shows a triple vaporizer, but the number and arrangement of vaporizers are not limited by this example. The vaporizer C forming the multiple vaporizer is formed by the following. Reference numeral 1 denotes a carburetor main body through which an intake passage 3 having a venturi portion 2 penetrates, and air flows from an intake passage 3A on the upstream side of the venturi portion 2 toward the downstream (left side in the figure). A float chamber main body 4 is disposed below the vaporizer main body 1, and a float chamber is formed by the vaporizer main body 1 and the float chamber main body 4, and a constant fuel liquid level is formed and held in the float chamber. Reference numeral 5 denotes a throttle valve shaft that is rotatably supported by the carburetor main body 1 in the intake passage downstream of the venturi portion 2. The throttle valve shaft 5 has a plate-shaped throttle valve 6 (hereinafter simply referred to as a throttle valve). (4) is attached, and the throttle valve 6 controls the intake passage 3 to open and close. The main fuel system communicates with the main fuel jet in the fuel level of the float chamber through the main fuel jet, and also communicates with the main air jet that communicates with the atmosphere, with the main fuel restricted by the main fuel jet and the main air jet. The limited main air is mixed with the main nozzle, and the main air-fuel mixture is sucked toward the venturi section 2 from the tip opening of the main nozzle. On the other hand, the low-speed fuel system is connected to the low-speed fuel jet in the float chamber through the low-speed fuel jet, and is also connected to the low-speed air jet connected to the atmosphere. The low speed air restricted by the jet is mixed, and the low speed air-fuel mixture is sucked into the intake passage 3 through the opening of the bypass hole. Neither the main fuel system nor the low speed fuel system is shown. The above is a conventionally known vaporizer. In this example, three such vaporizers C are arranged vertically.

The air-fuel mixture concentration control device P is configured as follows. Reference numeral 10 denotes a control device body having a correction air passage 11 penetrating the inside thereof, and the correction air passage 11 is formed separately from the intake passage 3. A first air valve seat hole 12A is formed in the correction air passage so as to be divided into an upstream flow passage 11A and a downstream flow passage 11B, and the upstream air passage 11A upstream of the first air valve seat hole 12A is formed. Divides the upstream flow passage 11A into a first upstream flow passage 11C directed to the intake passage 3A upstream of the atmosphere or the venturi portion 2 and a second upstream flow passage 11D directed to the first air valve seat hole 12A. The second air valve seat hole 12B is formed. That is, in the correction air passage 11, the second air valve seat hole 12B and the first air valve seat hole 12A are formed with a space from the upstream side toward the downstream side. The second upstream flow passage 11D is formed in the upstream flow passage 11A between the second air valve seat hole 12B and the first air valve seat hole 12A. Numeral 13 is an idling compensation air passage in which the downstream is opened to the downstream side flow passage 11B and the upstream is opened to the second upstream side flow passage 11D across the first air valve seat hole 12A, and the air amount is accurately controlled. In order to do so, an idle air jet 14 may be provided. Reference numeral 15 is a second air opening / closing valve that is arranged so as to face the second air valve seat hole 12B and controls the opening / closing of the second air valve seat hole 12B. Reference numeral 16 is a first air opening / closing valve that operates in synchronization with the throttle valve 6 to control the first air valve seat hole 12A. When the idling opening of the throttle valve 6 occurs, the first air opening / closing valve 16 is When the first air valve seat hole 12A is closed and the throttle valve 6 is opened from the idling opening degree, the effective opening area of the first air valve seat hole 12A is increased according to the opening of the throttle valve 6. This is achieved by inserting the taper needle valve 16A arranged below the first air opening / closing valve 16 into the first air valve seat hole 12A and moving the taper needle valve 16A together with the first air opening / closing valve 16. To be done. The downstream flow passage 11B of the mixture concentration control device P is connected to the intake passage 3B on the downstream side of the throttle valve 6 of each carburetor C via the correction air distribution passage 17 and opens. On the other hand, the first upstream flow passage 11C of the upstream flow passage 11A is open to the atmosphere. (This may be opened to the intake passage 3A on the upstream side of the venturi portion 2.) The first opening / closing valve 16 is mechanically connected to the throttle valve lever 19 of the intermediate carburetor C via the link 18. .

Next, the operation will be described. First, the operation of the engine on a level ground will be described. In such a situation, the second air opening / closing valve 15 holds the second air valve seat hole 12B in the closed state, and the first upstream side flow passage 11C and the second upstream side flow passage 11D of the correction air passage 11 and the downstream side. The side channel 11B is held in a closed state. Therefore, the correction air is not supplied from the correction air passage 11 into the intake passage 3 of each carburetor C, and the air-fuel mixture previously set to be suitable for running on a level ground is supplied from the main fuel system and the low-speed fuel system. To satisfy the operation of the engine. (Note that the first air opening / closing valve 16 opens the first air valve seat hole 12A in response to opening of the throttle valve 6, but the second air opening / closing valve 15 closes the second air valve seat hole 12B. No air is supplied.) Next, the operation at high altitude of the engine under the condition of increasing altitude will be described. When the driver senses that the engine has reached the highland, the driver pulls the second air opening / closing valve 15 upward and holds the second air valve seat hole 12B open. Then, during idling operation of the engine in which the throttle valve 6 closes the intake passage 3 most, the first air opening / closing valve 16 closes and holds the first air valve seat hole 12A. This is done by adjusting the mechanical connection of the first air on-off valve 16 and the throttle valve lever 19 of the intermediate carburetor C by means of a link 18. Therefore, at the time of idling operation of the engine, the correction air flowing into the first upstream side flow passage 11C, the second air valve seat hole 12B, the second upstream side flow passage 11D, the idling compensation air passage 13, It is sucked into the intake passage 3B on the downstream side of the throttle valve 6 of each carburetor C through the downstream side flow passage 11B and the correction air distribution passage 17, so that the concentration of the air-fuel mixture during such operation can be appropriately diluted. Then, when the throttle valve 6 is opened from the idling operation to the middle opening and the high opening, and when the engine enters the middle and high opening operation, the throttle valve 6 is opened depending on the opening. The 1-air on-off valve 16 moves, whereby the effective opening area of the first air valve seat hole 12A is increased by the tapered needle valve 16A that moves in synchronization with the first air-opening valve 16. Therefore, the correction air corresponding to the increase in the opening degree of the throttle valve 6 can be supplied from the correction air passage 11 and the correction air distribution passage 17 into the intake passage 3B through the correction air distribution passage 17, and thus the engine It is possible to reduce the air-fuel mixture concentration suitable for operation and maintain the operating condition of the engine in good condition. The rate of increase of the correction air with respect to the increase of the opening of the throttle valve 6 is appropriately determined by the shape of the taper needle valve 16A, or by connecting the throttle valve and the first air opening / closing valve 16 with a cam, or the like. It is selected by the institution conformity test.

[0010]

[Effect of device]

 As described above, according to the air-fuel mixture concentration control device for a multiple vaporizer according to the present invention, the correction air distribution passage for controlling the air-fuel mixture concentration is directly opened in the intake passage of each vaporizer. The negative pressure in the intake passage can be directly applied to the correction air passage, and the air-fuel mixture concentration control that is completely unrelated to the main fuel system and the low-speed fuel system can be effectively performed. In addition, at the time of idling opening of the throttle valve that needs to control a very small amount of air, the air amount is controlled not by the first air valve seat hole and the taper needle valve but by the idling compensation air passage. According to this, it is possible to control the correction air amount for each carburetor with extremely high accuracy, and it is possible to obtain a good idling operation of the engine. Furthermore, by controlling the correction air amount of all the vaporizers that make up the multiple vaporizer with a single air-fuel mixture concentration control device, it is possible to reduce the number of parts and make the vaporizer without an air on-off valve. In that case, it suffices to simply provide a correction air distribution passage, which increases the design flexibility of the multiple vaporizer.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a mixture concentration control device for a multiple vaporizer according to the present invention.

[Explanation of symbols]

 1 Vaporizer main body 2 Venturi part 3 Intake passage 3A Intake passage upstream of the venturi portion 3B Intake passage downstream of the throttle valve 6 Throttle valve 11 Correction air passage 11A Upstream passage 11B Downstream passage 11C First upstream side Flow path 11D Second upstream flow path 12A First air valve seat hole 12B Second air valve seat hole 13 Idling compensation air passage 15 Second air opening / closing valve 16 First air opening / closing valve 17 Correcting air distribution path C Vaporizer P Mixing Air concentration controller

Claims (1)

[Scope of utility model registration request] 1. A carburetor main body 1 in which an intake passage 3 having a venturi portion 2 penetrates, and a throttle valve shaft 5 rotatably supported by the carburetor main body 1 in the intake passage 3 are attached. A plurality of carburetors, each of which has a plate-shaped throttle valve 6 for controlling the opening and closing of the intake passage 3 and a float chamber body 4 which is disposed below the carburetor body 1 and which forms a constant fuel liquid level inside In the arranged multiple carburetor, a first air valve seat hole 12A that divides the correction air passage 11 provided so as to be separated from the intake passage 3 into an upstream flow passage 11A and a downstream flow passage 11B, and a correction air passage 11 In the upstream side flow passage 11A, a second air valve seat hole 12B which is divided into a first upstream side flow passage 11C toward the atmosphere and a second upstream side flow passage 11D toward the first air valve seat hole 12A, The downstream side flow passage 11B and the second upstream side flow passage 11D are crossed over the first air valve seat hole 12A. Idling compensating air passage 13 which communicates at a second air-off valve for opening and closing the second air valve seat hole 12B 15
And the first air valve seat hole 12A can be closed when the throttle valve 6 is idling, and the effective opening area of the first air valve seat hole 12A can be increased according to the increase in the opening degree of the throttle valve 6. The air opening / closing valve 16 constitutes a single air-fuel mixture concentration control device P, and the downstream side flow passage 11B of the air-fuel mixture concentration control device constitutes a multiple vaporizer via the correction air distribution passage 17. An intake passage upstream of the venturi section 2 of one carburetor C that constitutes a multiple carburetor and has a first upstream flow passage 11C that is opened by communicating with the intake passage 3B downstream of the throttle valve 6 of the carburetor. 3A or an air-fuel mixture concentration control device for a multiple vaporizer which is opened in communication with the atmosphere.