JPH0442754Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressure detection device for detecting intake pipe negative pressure of an internal combustion engine.

[Conventional technology]

BACKGROUND ART In fuel injection control of an internal combustion engine equipped with a fuel injection valve, there is a D-jetronic system that determines the amount of air taken in per cycle from intake pipe negative pressure and controls the injection amount based on this negative pressure. It is also being considered to use the above-mentioned D-jetronic system in an independent intake type in which each intake pipe has a throttle valve. In this way, by adopting the independent intake configuration, interference of pressure waves between the cylinders is reduced on the downstream side of the throttle valve. For this reason, filling efficiency is increased and output is increased. Here, the fuel injection valve is installed in each intake pipe leading to each cylinder, so when determining the amount of fuel injection to each cylinder, the negative pressure in the intake pipe is detected at the same time as the intake stroke, and the amount of intake air is measured. Ideally, this should be done. Therefore, it was necessary to provide a pressure detection device for each cylinder. However, since an increase in the number of pressure detection devices leads to an increase in costs, a configuration in which one pressure detection device is used instead has been adopted. For example, intake pipe negative pressure is detected in some cylinders to measure the intake air amount, and this measured value is used as a parameter to determine the fuel injection amount to other cylinders. In addition, a pipe is provided to communicate between each cylinder, so that the negative pressure in the intake pipe generated from each cylinder can be taken out at one point.

[Problem that the invention attempts to solve]

By the way, if the intake pipe negative pressure is detected only in some cylinders, this detected value is stored in the computer's memory during one cycle and is used instead of the intake pipe negative pressure of other cylinders that are not measured. It is regarded as a thing. However, when the throttle valve opening changes rapidly during one cycle during sudden acceleration/deceleration, the intake pipe negative pressure detected in only one cylinder is not accurate enough to be substituted for the intake pipe negative pressure of other cylinders. It will no longer be. That is, when performing fuel injection control, a problem arises in that there is a timing delay in accurately measuring the amount of intake air during a transient period.

Additionally, when a pipe is provided that communicates between each cylinder, pressure waves from the intake pipe that communicates with cylinders that are not in the intake stroke interfere in the pipe, and the detected intake pipe negative pressure tends to show a low value. However, there is a problem that the amount of intake air cannot be measured accurately.

Therefore, the technical problem of the present invention is to introduce only the negative pressure of the cylinder in the intake stroke into one pressure detection device for each intake stroke of each cylinder. The goal is to accurately detect pressure.

[Means for solving problems]

The measures taken to solve the above technical problem are that throttle valves 6, 7,
8 and 9 and detects the intake pipe negative pressure generated downstream of the throttle valve of each cylinder, the converter 17 outputs air pressure as an electric signal.
and a rotor 1 that rotates in synchronization with the rotation of a camshaft 21 that drives the intake valve to open and close, and has a through hole 18a that induces negative pressure in the intake pipe to the conversion section.
8 are provided at equal intervals along the rotational direction of the rotor, and are individually and independently connected to the intake pipe downstream of the throttle valve of each cylinder, and when the intake valve of each cylinder is opened by the rotation of the rotor, the through holes are It consists of a hole and a cover 24 provided with intake pipe negative pressure outlets 25, 26, 27, and 28 which overlap in sequence.

[Effect]

According to this means, each time the through hole and the intake pipe negative pressure outlet overlap with each other due to the rotation of the rotor, only the intake pipe negative pressure of the cylinder in the intake stroke is guided to the conversion section. This intake pipe negative pressure gives the amount of intake air for each cylinder, and an electrical signal is output from the converter.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 3, the internal combustion engine according to this embodiment has intake pipes 2, 3,
4 and 5 are equipped with throttle valves 6, 7, 8, and 9. The throttle valves 6, 7, 8, and 9 are connected by a shaft 10 and are interlocked with an accelerator pedal (not shown). In this way, an independent intake configuration is adopted. In addition, intake pipes 2, 3, 4,
On the downstream side of the throttle valves 6, 7, 8, 9 of 5,
Fuel injection valves 11, 12, 13, and 14 are installed. The fuel injection amounts of the fuel injection valves 11, 12, 13, and 14 are controlled based on electrical signal commands from a control device 15.

Here, a pressure detection device 16 is mounted on the main body 1 between the intake pipes 3 and 4. As shown in FIG. 1, a disk-shaped rotor 18 is provided with a converter 17 that outputs air pressure as an electric signal, and a through hole 18a that induces negative pressure in the intake pipe to the converter 17. A rotating shaft 19 extends from the rotor and projects into the cam housing 1a of the main body 1, and a gear 20 is provided at the tip of the rotating shaft 19. A drive gear 22 is attached to a camshaft 21 installed in the cam housing 1a, and is in mesh with the gear 20. Here, the gear 20 and drive gear 22 are designed so that the rotation speed of the camshaft 21 and the rotation speed of the rotor 18 match.
3 means that the period in which the rotor 18 opens matches the period in which the rotor 18 rotates.

Incidentally, a cover 24 is provided on which the end surface and the outer circumferential surface of the rotor slide, and as shown in FIG. 2, the cover 24 has intake pipe negative pressure outlets 25, 26, 27,
28 is provided, and the firing order is #1 → #3.
→#4→#2, the outlet 25 is connected to the intake pipe 2, the outlet 26 is connected to the intake pipe 4, the outlet 27 is connected to the intake pipe 5, and the outlet 27 is connected to the intake pipe 3 through piping. ing. Returning to FIG. 1, the cover 24 is provided with a bearing 29 that supports the rotating shaft 19, and the portion of the cover 24 provided with the bearing 29 is inserted and fixed into the cam housing 1a. If the first-mentioned converting portion 17 is set at the flat end of the cover 24, the through hole 18a is formed to connect the end surface of the rotor 18 and the outer circumferential surface. and,
The converting section 17 passes through the hole 30 provided in the cover 18.
Negative pressure in the intake pipe is induced. Here, through hole 18
The opening 18b formed on the outer circumferential surface of the opening 18a is widened in the circumferential direction so as to overlap with the intake pipe negative pressure outlet ports 25, 26, 27, and 28 for an appropriate time. This also prevents high pressure from remaining within the through hole 18a.

Hereinafter, the functions and effects of this embodiment will be explained based on the drawings.

As shown in FIG. 2, when the #1 cylinder is in the intake stroke, the through hole 18a is overlapped with the intake pipe negative pressure outlet 25, and the pressure detection device 16 is installed. Here, the rotation period of the rotor 18 is made to match the opening period of the intake valve 23, so during the intake stroke of the #3, #4, and #2 cylinders, the rotor 18 rotates clockwise and the intake pipe becomes negative. The pressure extraction ports 26, 27, 28 and the through hole 18a overlap at the same timing. Therefore, when a certain cylinder enters the intake stroke, its intake pipe negative pressure is detected by the pressure detection device 16, and the amount of intake air is measured. An amount of fuel determined based on this measured value is supplied to this cylinder.

[Effect of idea]

This invention reduces the influence of pressure waves from cylinders that are not in the intake stroke, detects the individual intake pipe negative pressure that occurs during the intake stroke of each cylinder, and calculates the amount of intake air in the cylinder during the intake stroke. Measures accurately.

Also, for this measurement, there is no need to install a pressure detection device in each intake pipe leading to each cylinder.
The cost required for the pressure detection device can be kept low.

[Brief explanation of the drawing]

Figure 1 clarifies the mounting structure of the pressure detection device of the present invention, and shows a-a and b- in Figure 3.
FIG. 2 is a plan view of the pressure detection device shown in FIG. 1, and FIG. 3 is a plan view of an internal combustion engine equipped with the pressure detection device of the present invention. 2, 3, 4, 5... Intake pipe, 6, 7, 8, 9...
Throttle valve, 16... Pressure detection device, 17...
Conversion part, 18...Rotor, 18a...Through hole, 2
3...Intake valve, 24...Cover, 25, 26, 2
7, 28...Intake pipe negative pressure outlet.

Claims (1)

[Scope of utility model registration request] Throttle valves 6, 7,
8 and 9 and detects the intake pipe negative pressure generated downstream of the throttle valve of each cylinder, the converter 17 outputs air pressure as an electric signal.
and a rotor 1 that rotates in synchronization with the rotation of a camshaft 21 that drives the intake valve to open and close, and has a through hole 18a that induces negative pressure in the intake pipe to the conversion section.
8 are provided at equal intervals along the rotational direction of the rotor, and are individually and independently connected to the intake pipe downstream of the throttle valve of each cylinder, and when the intake valve of each cylinder is opened by the rotation of the rotor, the A pressure detection device comprising a cover 24 having intake pipe negative pressure outlets 25, 26, 27, and 28 that overlap with the through hole in sequence.