JPH0643249U - Vaporizer for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] A carburetor comprising a fuel supply path 4 from the float chamber 3 to the main nozzle 6 and a pressure-operated power mechanism operated by intake negative pressure downstream of the throttle valve 8. To ensure that the amount of fuel can be increased by the power mechanism during acceleration. [Structure] A throttle orifice 15 and a check valve 16 which is opened only in the direction toward the pressure chamber 11 are provided in parallel in a negative pressure transmission passage 14 to the pressure chamber 11 in the power mechanism.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a carburetor in an internal combustion engine, which is equipped with a pressure-operated power mechanism that operates at a negative pressure of intake air.

[0002]

[Prior art]

 Generally, in a carburetor, a pressure-operated power mechanism that operates by intake negative pressure downstream of the throttle valve is provided in the fuel supply path from the float chamber to the main nozzle, so that this power can be maintained during acceleration of the internal combustion engine. The mechanism is designed to increase the amount of fuel.

By the way, there is a pulsation in the intake negative pressure downstream of the throttle valve, and this pulsation is transmitted to the pressure chamber in the power mechanism and the power mechanism is opened and closed. Will occur. Therefore, conventionally, a throttle orifice is provided in the intake negative pressure transmission passage to the power mechanism to prevent the transmission of the intake negative pressure pulsation to the power mechanism.

[0004]

[Problems to be solved by the device]

 However, if a throttle orifice is provided in the intake negative pressure transmission passage to the power mechanism as described above, transmission of pulsation to the pressure chamber in the power mechanism can be reduced, but acceleration by rapidly opening the throttle valve is achieved. At this time, even if the intake negative pressure downstream of the throttle valve is reduced to approach atmospheric pressure, a large negative pressure remains on the vacuum side in the pressure chamber of the power mechanism due to the throttle orifice. As a result, there was a problem that the increase in fuel amount by the power mechanism could be delayed and the acceleration could be reduced.

The present invention has a technical problem to solve this problem.

[0006]

[Means for Solving the Problems]

 In order to achieve this technical problem, the present invention relates to a carburetor which is provided with a pressure-operated power mechanism that is operated by an intake negative pressure downstream of a throttle valve in a fuel supply path from a float chamber to a main nozzle. A throttle orifice and a check valve that opens only in the direction toward the pressure chamber are provided in parallel in the negative pressure transmission passage to the pressure chamber in the power mechanism.

[0007]

[Work]

 As described above, the throttle orifice and the check valve that opens only in the direction toward the pressure chamber are provided in parallel in the negative pressure transmission passage to the pressure chamber in the power mechanism. While pulsation transmission can be reduced by the throttle orifice, during acceleration by rapidly opening the throttle valve, the suction negative pressure downstream of the throttle valve changes so as to decrease to approach atmospheric pressure. Then, this pressure change can be quickly transmitted to the pressure chamber by opening the check valve, so that a large negative pressure on the vacuum side can be reliably prevented from remaining in the pressure chamber.

[0008]

[Effect of device]

 Therefore, according to the present invention, at the time of acceleration, it is possible to reliably achieve the increase of fuel by the power mechanism, and there is an effect that the acceleration response of the internal combustion engine can be improved.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 indicates an intake manifold, and reference numeral 2 indicates a horizontal carburetor attached to the intake manifold 1. The carburetor 2 includes a float chamber 3 and a fuel supply passage with a main orifice 5. A main nozzle 6 communicating with the main nozzle 6 is provided, a choke valve 7 is provided on the upstream side of the main nozzle 6, and a throttle valve 8 is provided on the downstream side.

Further, the fuel supply passage 4 in the carburetor 2 is provided with a power system bypass passage 9 for the main orifice 5, and the power system bypass passage 9 is opened / closed in the power system bypass passage 9. The power valve 10 is provided. The power valve 10 is connected to a diaphragm 12 forming a pressure chamber 11 and is urged in an opening direction by a spring 13 provided in the pressure chamber 11, while the throttle valve is provided in the pressure chamber 11. By introducing the intake negative pressure downstream of 8 via the negative pressure transmission passage 14, when the intake negative pressure is large on the vacuum side, the power valve 10 is closed against its spring 13 and the intake negative pressure is increased. The power valve 10 is configured to open by its spring 13 when the pressure becomes small so as to approach the atmospheric pressure.

A throttle orifice 15 and a check valve 16 that opens only in the direction toward the pressure chamber 11 are provided in parallel in the negative pressure transmission passage 14. In this configuration, in the low load state in which the throttle valve 8 is closed, the intake negative pressure is large on the vacuum side, and this intake negative pressure is transmitted to the pressure chamber 11 via the negative pressure transmission passage 14, whereby the power valve 10 Is closed. In this case, since the check valve 16 in the negative pressure transmission passage 14 is closed, the intake negative pressure is transmitted to the pressure chamber 11 through the restriction orifice 15, so that the pulsation in the intake negative pressure is generated in the pressure chamber 11. Can be reliably reduced by the throttle orifice 15.

When the throttle valve 8 is suddenly opened and accelerated, the intake negative pressure downstream of the throttle valve 8 is changed so as to decrease to approach atmospheric pressure. When the valve is opened, the power can be quickly transmitted to the pressure chamber 11, and a large negative pressure on the vacuum side can be prevented from remaining in the pressure chamber 11, so that the power valve 10 can be opened without delay to increase the amount of fuel. It is done with good response.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a carburetor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 1 Intake Manifold 2 Vaporizer 3 Float Chamber 4 Fuel Supply Passage 6 Main Nozzle 8 Throttle Valve 9 Power Bypass Passage 10 Power Valve 11 Pressure Chamber 12 Diaphragm 13 Spring 14 Negative Pressure Transmission Passage 15 Throttle Orifice 16 Check Valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Hirokazu Konohara 1-1-1-1, Kyowa-cho, Obu City, Aichi Prefecture Inside Aisan Industry Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A carburetor comprising a pressure-actuated power mechanism operated by an intake negative pressure downstream of a throttle valve in a fuel supply path from a float chamber to a main nozzle. A carburetor for an internal combustion engine, characterized in that a throttle orifice and a check valve which opens only in the direction toward the pressure chamber are provided in parallel in the negative pressure transmission passage.