JPS63192940A - Engine lpg mixer - Google Patents

Abstract

PURPOSE:To eliminate a temporary delay in the supply of LPG during increase in the rotational speed of an engine by providing an auxiliary LPG passage opened to both upstream side of a throttle valve adapted to open and close an intake-passage and downstream side of the valve closing position. CONSTITUTION:An LPG mixer includes a venturi 1 having an annular chamber and a nozzle port 7, and primary and secondary intake-air passages 2, 3 laid downstream of the venturi 1 and adapted to be opened and closed by primary and secondary throttle valves 4, 5, respectively. Further, the annular chamber 6 is connected to a secondary chamber in a vaporizer through an inlet passage 10 whose opening area is regulated by a regulator valve 9 integrally incorporated with a main adjusting screw 8. With this arrangement, an auxiliary passage 11 branches off from the inlet passage 10 upstream of the regulator valve 9. Further, the auxiliary passage 11 is communicated with the primary intake passage 2 through openings 12, 13, and is provided in its intermediary section with a jet 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The LPG mixer of the present invention is utilized for mixing with LPGtt air supplied to an automatic tunnel/engine.

The LPG mixer that mixes LPG gasified under reduced pressure with the vaporizer with air and supplies it to the factory/engine is 0, for example, No. C.
As shown in the figure, a pet/churi 22 is provided in the intake passage 21 forming a part of the intake passage of the engine.
A slit-shaped nozzle opening 23 extending in the circumferential direction formed in 2
Normally, LPG is supplied in all operating ranges. L gasified under reduced pressure with a vaporizer
PG is a regulating valve 2 integrated with the main regulating screw 25 of the inlet passage 24.
6, the air enters the annular chamber 27 of the venturi 22, and is sucked out from the nozzle port 23 into the intake passage 21.The diameter of the venturi 22 is determined by taking into account the maximum output of the engine, so it In the low speed range of 4Iil- with no load or low melon load, the venturi negative pressure is extremely low and LPG of the evening wave is being supplied. From this state, the rotation speed is 4
If you separate 1N, the venturi negative pressure will increase and the LPG Hongf@
The amount increases and becomes the appropriate amount, but during this time there is a temporary delay in the supply of LPG and the mixture becomes lean, and when the car is started, the engine may suffocate or stop. there were.

Furthermore, in systems that perform air-fuel ratio feedback control as a measure against exhaust emissions, a region where the air-fuel mixture falls outside the control air-fuel ratio range and becomes uncontrollable may occur.

Therefore, the present invention provides an LPG mixer that supplies an appropriate amount of LPG during idle or when the rotational speed increases from a low rotational speed range, thereby preventing engine/engine breathing or stoppage.

The present invention provides an L L having openings on the upstream side of the throttle valve that opens and closes the intake passage and slightly below the valve closing position [1111].
The provision of an auxiliary passage for the PG is a means for solving the above-mentioned problems.

During idling or in a low-speed rotation range with no load or low load, the throttle valve is in the closed position or in the slightly open position. Therefore, as air flows in the auxiliary passage from the upstream opening to the downstream opening, iC and LPG are sucked in and sent out from the downstream opening to the intake passage. When the throttle valve is in a slightly wide open position, the two openings are both on the upstream side of the throttle valve, so LPG is no longer sucked. At this time, the required amount of LPG is supplied by the negative and positive venturis.

According to the present invention, when the throttle valve is in the closed position or in the slightly open position, air flows bypassing the throttle valve through the auxiliary passage, and LPG is sucked and supplied.
For this reason, even if the diameter of the barrel is set large, it will not only be possible to properly supply the LPG required during idling.

By supplying LPG auxiliaryly until the LPG supply by venturi negative pressure reaches the required amount, there is no temporary supply delay when the rotation speed increases from a low rotation range. This eliminates the inconvenience of not being able to control feedback and allows stable operation.

Example FIG. 1 shows an embodiment of the invention.

The LPG mixer in this embodiment consists of a primary intake path 2. It has a secondary intake passage 3, and these two intake passages 2.3 are opened and closed by a primary throttle valve 4 and a secondary throttle valve 9, and when the secondary throttle valve 4 reaches a predetermined opening or more, the secondary throttle valve 5 begins to open. The pipe has an annular chamber 6 and a slit-shaped nozzle lower extending in the circumferential direction.The secondary chamber of the vaporizer (not shown) and the annular chamber 6 have an effective passage area that can be adjusted by a main adjustment screw 8 and an integrated adjustment valve 9. They are connected by a regulating inlet passage 10.

An auxiliary passage 11 is provided which is branched from the upstream side of the regulating valve 9 of the inlet passage IO, and this auxiliary passage 11 has openings 12 and 13 at the upstream side of the primary throttle box 4 and slightly downstream from its valve closing position. It communicates with the primary air intake passage 2, and has a metering jet 14 in the middle.

FIG. 2 shows the state in which the primary throttle valve 4 is in the closed position or in the slightly open position, and the downstream opening 13 is
The suction negative pressure generated by the engine rotation acts, and air flows in the auxiliary passage 11 from the upstream opening 12 to the lower tAt side opening 13, and the downstream opening 13KLPG passes from the inlet passage 10 through the auxiliary passage 11 and is sucked. primary intake path 2
sent to. The flow of this air and LPG is indicated by arrows. Figure 3 shows a state where the opening degree of the primary throttle valve 4 is increased, and the two openings 12 and 13 are both on the upstream side of the K-order throttle valve 4. Therefore, the suction negative pressure no longer acts, and the auxiliary passage 11
Air and LPG do not flow inside, and since the venturi negative pressure is starting to rise at this time, the required amount of LPG is supplied from the nozzle lower.

FIG. 5 shows a location 1 near the opening 12 on the upstream side of the auxiliary passage 11.
It shows the relationship between the negative pressure generated at 1a and the opening degree of the throttle valve. If there is no opening 12 on the upstream side, the suction negative pressure acts on the 11^ 11a part as it is in the state shown in Fig. 2, and no longer acts on the inlet part in the state shown in Fig. 3, so the negative pressure characteristic of the lla part is as shown in Fig. 5. As shown in Figure C, an unnecessarily large amount of LPG is also supplied to the downstream opening 13 during idle, etc., and there is a concern that the air-fuel mixture may become over-rich. By providing the upstream opening [2], the suction negative pressure acting on the portion 111 is weakened, resulting in a negative pressure characteristic similar to that shown in Figure 5, and an appropriate amount of LPG can be supplied during idling. If the downstream opening 13 is provided further downstream than shown in 1, -
Since the opening degree of the throttle valve becomes larger when it is on the upstream side of the next throttle valve 4, a negative pressure characteristic as shown in FIG. 5B is obtained, and the auxiliary passage 1
1, the LPG supply period becomes longer.

That is, the supply amount and supply period of LPG by the auxiliary passage 11 can be arbitrarily set depending on the diameters of the openings 12 and 13 and the jet 14 and the position of the downstream opening 13. This is an embodiment in which the effective area of the auxiliary passage 110 is adjusted by the v4MI valve 16 integrated with the v4MI valve 15, and the supply amount of LPG can be adjusted steplessly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention. FIGS. 2 and 3 are partial vertical cross-sectional views illustrating its operation, FIG. 4 is a partial vertical cross-sectional view showing different embodiments of the present invention, and FIG.
The figure is a negative/positive characteristic diagram of the auxiliary passage, and FIG. 6 is a vertical cross-sectional view showing a conventional example.
-Next intake path, 4... -Next throttle valve, IQ...
...Public passageway, 11...Auxiliary passageway, 12.1
3...Opening. Agent Mutsumi Nozawa, ゛Figure 1

Claims (1)

[Claims] An LPG having openings upstream of a throttle valve that opens and closes the intake passage and slightly downstream of the valve closing position.
An LPG for an engine characterized by having an auxiliary passage of
mixer.