JPS5927234A - Apparatus for detecting pressure of suction pipe - Google Patents

Abstract

PURPOSE:To make it possible to accurately measure the pressure of a suction pipe, by a method wherein negative pressure release pipes are provided to the downstream side of each throttle value to be united by a unity pipe and an atmospheric pressure release pipe is provided to the upstream side of the throttle valve. CONSTITUTION:A throttle valve is provided to each air cylinder and an atmospheric release pipe 26 is provided to a surge tank 12. In addition, negative pressure release pipes 28, 30, 32, 34 are united by a unity pipe at every each cylinder. In this case, the pipes are arranged so as to equalize the substantial distance from each air cylinder to a confluence part 52. In this state, a pressure sensor 40 is interposed between the aforementioned atmospheric pressure release pipe 26 and the unity pipe 36 and differential pressure between the pressure in the surge tank 12 and the pressure of a suction pipe is measured. By this method, the pressure of the suction pipe can be accurately measured by simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake pipe pressure detection device for an internal combustion engine, and particularly for a multi-cylinder internal combustion engine.
The present invention relates to an intake pipe pressure detection device VT which can be detected by two pressure sensors.

Internal combustion engines have divine control devices 1 such as ignition timing system #,
Control devices such as EGR control, air-fuel ratio control, and fuel injection amount control are provided.

It is common to use the intake pipe negative pressure as the signal negative pressure.

Conventional 1, for example, an electronically controlled fuel injection system using the D-EFI system has a detection device for intake pipe negative pressure as a first fuel injection amount control parameter, but this device N has a
It has a senna for the surge tank internal pressure, a negative pressure pipe and a senna for the intake ρ pressure, and further has a negative pressure pipe and a hinge for controlling the ignition timing separately from the detection device 6 for the fuel injection device. Met. This makes the structure extremely complex.

Manufacturing costs were high, and maintenance to maintain the reliability of the signals and negative pressure values was extremely difficult.

Further, a negative pressure pipe for deriving negative pressure has an open end at each branch intake pipe of the multi-cylinder internal combustion engine. For this reason, the intake pipe negative pressure, which is caused by the pulsation unique to each cylinder and has extremely large fluctuations, must be used as a signal, resulting in the inconvenience that ideal control cannot be achieved.

Therefore, the purpose of this invention is to be able to accurately measure the intake pipe pressure, and to have a simple configuration, so the manufacturing cost is low.

The object of the present invention is to realize an intake pipe pressure detection device that is easy to maintain in order to maintain reliability.

Embodiments of the present invention will be described in detail below based on the drawings. ). In the figure, numeral 2 is the cylinder, 4 is the injector #6 is the slot/l/c, I+
/ -y-, J, Oti<I)it', Q /< /
l/ 7-, 11 ij: tJP Qiha/l/ 7
', 12 is a siege tank, 20 is an air cleaner,
22 is a piston, 24 is an intake pipe H7, and 24 is an exhaust pipe.

Front i+E throttle palflo is provided for each attack cylinder. An air pressure outlet pipe 26 is provided in the Zagekunk J2. Also.

Negative pressure outlet pipe 2B for each cylinder on the downstream side of the throttle valve
, 30, 32, and 34 are provided, respectively, and the negative pressure outlet pipes 28, 30, and 32, 34 are integrated by 'Pf: (6).

On this occasion.

The pipes are arranged so that the distance from each cylinder to the merging portion 52t is substantially the same. Front ML pressure outlet pipe 26 and the integrated pipe 36
(11i-difference between) 1-sensor capable pressure sensor 4
A differential pressure 'f' between the pressure inside the surge tank 12 and the tracheal pressure 'f;C6' is established.

In addition, before A (2 atm 7.'71J-1'N'f 2+'i
and JE Derivation '772B, 30.

32.34 zo tl) shini kj, air damper 112
, 44, 46°, 48, 50 to prevent the influence of pulsation. Further, the front dCC alloy tube 16vc is provided with a negative pressure 4114 path: 38 and connected to a pressure regulator (not shown).

Since the embodiment of the present invention is constructed as described above, it operates as follows.

The branch intake pipe negative pressure pH of each cylinder produces a pulse N)l due to the forward motion of the piston, but in this invention, each negative pressure outlet pipe 28.
:(Since 0, 32, and 34 are integrated into the integrated pipe 36, the pressure within the integrated pipe 36 becomes the integrated pipe negative pressure Pln in which the pulsations are averaged.

The pressure in the air pressure outlet pipe 26 is equal to the pressure P0 in the surge tank 12, and the pressure difference ΔPn between the surge tank pressure P8 and the integrated pipe pressure P111 is determined by the single pressure sensor 40.
It can be detected by

In this embodiment, the air pressure outlet pipe is installed in the surge tank, but it may be installed as far above the throttle valve as long as it is above the throttle valve.

In addition, in the above embodiment, ti, atmospheric pressure 2,1 outlet pipe 26.

It is provided in the surge tank 12 located 11'7 downstream of the air cleaner 20. However, as the air cleaner zO deteriorates due to clogging or the like, the intake pipe negative pressure becomes higher. However, if the comparison standard value is taken from the downstream side of the air cleaner 2o as in the above embodiment, the air cleaner Fluctuations in the negative pressure value due to deterioration of the 2o can be corrected skillfully, and the negative pressure value can be detected with high reliability.

As is clear from the above description, the present invention provides the following effects.

(1) Since the intake pipe pressure can be detected with a single pressure sensor, costs can be reduced compared to conventional devices that use several pressure sensors. management becomes easier, thereby improving the control device's performance requirements.

C2), connect one negative pressure outlet pipe for each branch intake pipe, integrate each negative pressure outlet pipe into a unified pipe, and reduce the internal pressure of this integrated pipe! Since the configuration is configured to detect
, (rr It becomes possible to accurately detect the high intake pipe pressure of NiM.

(S) Install a pressure outlet pipe downstream from the air cleaner 1
′! (It is possible to prevent the inconvenience of detecting negative pressure in the intake pipe due to the influence of deterioration such as air cleaner dirt or F4F1g clumping).

[Brief explanation of drawings]

The drawing is a schematic diagram showing the structure of an embodiment of the present invention. In the figure, 6 is a throttle valve, 26 is an air pressure outlet pipe, 28. 34 is a negative pressure outlet pipe, 36 is an integrated pipe, and 40 is a pressure sensor. Agent Patent Attorney Yoshimi Saigo

Claims (1)

[Claims] In a multi-cylinder internal combustion engine having a throttle valve for each cylinder, a negative pressure outlet pipe is provided on the downstream side of each throttle valve, the negative pressure outlet pipe is integrated into a unified pipe, and a pressure outlet pipe is provided on the upstream side of the throttle valve. An intake pipe pressure detection device comprising: a pressure sensor for detecting a differential pressure between the air pressure outlet pipe and the integrated pipe.