JPH074849U - Engine intake pressure detector - Google Patents

Abstract

(57) [Summary] [Purpose] In an intake pressure detection device that takes in intake pressure from the intake passage of the engine, pollutants trapped by the filter are purged by the flow of intake air to prevent contamination of the filter and to detect intake pressure. Prevent delay in response of the device and decrease in pressure-sensitive value. [Structure] An intake pressure sensor 8 of an engine, an intake pressure sensor 8 for detecting intake pressure, and a pressure intake port 1 of an intake passage 10.
3 and a filter portion 14 that is attached in communication with the intake air pressure sensor 8 and the pressure guiding portion 9 that communicates between the intake air pressure sensor 8 and the filter portion 14 in an airtight manner. It was installed in space 11

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for preventing contamination of an intake pressure sensor that detects intake pressure from an intake passage of an engine.

[0002]

[Prior art]

 Usually, in a conventional engine, the intake valve and the exhaust valve are provided with an overlap period, so that contaminants such as oil mist, soot, and sludge that flow back to the intake pipe exist in the intake pipe. Therefore, conventionally, in the intake pressure detecting device for detecting the intake pressure from the intake passage, for example, as described in Japanese Utility Model Laid-Open No. 62-162360, the contaminant is prevented from adhering to the intake pressure sensor. Filter is installed. However, in such a conventional technique, the filter is installed at a deep position of the pressure guiding passage that guides the pressure from the intake pressure taking-out opening provided in the intake passage wall to the intake pressure sensor, and the filter is installed on the surface of the filter. If there is no flow of intake air into the filter and the above-mentioned pollutant adheres to the filter, the pollutant cannot be removed. There is a problem such as a decrease in the pressure-sensitive value.

[0003]

[Problems to be solved by the device]

 The purpose of the present invention, which was devised to solve the above-mentioned problems, is to purify the contaminants trapped by the filter in the intake pressure detection device that takes in the intake pressure from the intake passage downstream of the throttle valve to prevent the contamination of the filter. It is intended to prevent the delay of the response of the intake pressure detection device and the reduction of the pressure sensitive value.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is provided with a pressure sensing unit for sensing intake pressure in a device for detecting intake pressure used as a control signal for controlling the intake system and fuel supply system of an engine. The intake pressure sensor and a filter section installed at the pressure intake port of the intake passage and a pressure guiding section that communicates airtightly between the intake pressure sensor and the filter section constitute the filter section of the intake passage. It is characterized by being installed in a space with flow.

[0005]

[Action]

 The intake pressure is transmitted as a control signal by passing through a filter portion installed in the pressure intake port of the intake passage of the engine and being guided to the intake pressure sensor via the pressure passage to activate the pressure sensitive portion. In that case, since the filter part is installed in the space where the intake air flows, contaminants such as oil mist, soot, and sludge in the intake air are temporarily captured by the filter part and then purged by the intake air flow. Since the accumulation of contaminants on the parts is prevented, the response of the intake pressure sensor is not delayed and the pressure-sensitive value is not reduced. Further, since the contaminants do not enter the pressure guiding passage, the intake pressure sensor is not polluted.

[0006]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. 1 is a first embodiment of the present invention, in which 1 is an air cleaner, 2 is a throttle body, 3 is a surge tank, 4 is an intake manifold (not shown), and an intake pipe 5 is a throttle body 2 A throttle valve, which is provided inside the engine, for controlling the intake air amount of the engine, and 6 is an intake air pressure detection device for the engine. The air cleaner 1, the throttle body 2, the surge tank 3, and the intake pipe 4 are coupled to form an intake cylinder 7 of the engine, and the intake air flows through the intake passage 10 inside the intake cylinder during operation. . The intake pressure detecting device 6 includes an intake pressure sensor 8 having a pressure sensitive portion 12 for detecting intake pressure, a filter portion 14 installed in communication with a pressure intake port 13, the intake pressure sensor 8 and a filter portion 14. And an inlet pressure sensor 9 for introducing intake pressure into the intake pressure sensor 8.

The filter portion 14 is composed of a filter case 16 communicating with the pressure intake port 13 of the pressure guiding portion 9, and a coarse filter 17 and a fine fiber filter attached to the side surface and the ceiling portion of the filter case 16. 18 and is arranged in the space 11 of the intake passage 10 of the surge tank 3. A window 19 through which intake air can flow in and out is provided on a side surface of the filter case 16, and a filter 17 is attached to the entire surface of the window 19. Further, a pressure inlet 13 of the pressure guiding portion 9 is opened vertically in the ceiling portion of the filter case 16, and a fine fiber filter 18 is attached so as to cover the pressure inlet 13 from below. There is. The pressure guiding portion 9 forms a sealed pressure guiding passage 15 from the pressure intake port 13 to the intake pressure sensor 8, whereby the intake pressure is guided to the intake pressure sensor 8. A flange portion 20 is formed on the outer wall of the pressure guiding portion 9, and the filter portion 14 is inserted through a mounting hole 21 formed in the wall of the surge tank 3 and fastened to the surge tank 3 with bolts or the like. Reference numeral 22 is a drain hole for discharging residual water, oil mist, etc. accumulated on the bottom of the filter case. In the above structure, the intake pressure is guided to the intake pressure sensor 8 through the filter portion 14, but the contaminants in the intake air are captured by the filter portion 14 and do not pollute the intake pressure sensor 8. In this case, since the filter unit 14 is installed in the space 11 where the intake air flows, the contaminants adhering to the surfaces of the filters 17 and 18 are purged by the subsequent intake air flow, and the contaminants of the filters 17 and 18 are polluted. This has the effect of preventing the accumulation of pollutants and contaminants and eliminating the problems of the response delay of the intake pressure detection device 6 and the reduction of the pressure-sensitive value. Further, in this embodiment, since the filter 17 having the coarse mesh and the filter 18 having the fine mesh are used in the two-layer structure, the inflow of the contaminants can be completely blocked and the clogging hardly occurs.

FIG. 2 shows a second embodiment of the present invention, in which a filter portion 14 is integrally formed below the intake pressure sensor 8 and the intake pressure sensor 8 is directly attached to the surge tank 3 with a bolt. It is a thing. According to this embodiment, the intake pressure detecting device 6 can be made small and inexpensive. The other structure is the same as that of the first embodiment.

[0009]

EFFECTS OF THE INVENTION The present invention provides the following effects. In addition to preventing fouling of the pressure sensing part of the intake air pressure sensor, fouling substances temporarily captured by the filter are purged in a short time by the intake air flowing through the intake passage, preventing fouling of the filter and accumulation of fouling substances. It is effective in preventing the delay of the response of the intake pressure detection device to the change of the intake pressure and the problem of the decrease of the pressure sensitive value.

[Brief description of drawings]

FIG. 1 is a view showing a mounting state of an intake pressure detecting device according to the present invention, and is a partially longitudinal view.

FIG. 2 is a vertical sectional view of a second embodiment of the present invention.

[Explanation of symbols]

 6 Engine Intake Pressure Detection Device 8 Intake Pressure Sensor 9 Pressure Guide 10 Intake Passage 11 Space 12 Pressure Sensing 13 Pressure Intake 14 Filter

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An intake pressure sensor for detecting an intake pressure, which is used as a control signal for controlling an intake system and a fuel supply system of an engine, and an intake pressure sensor provided with a pressure sensing section for detecting the intake pressure, and a pressure of an intake passage. A filter part installed at the intake port and a pressure guiding part that communicates airtightly between the intake pressure sensor and the filter part, and the filter part is installed in a space where intake air flows in the intake passage. An intake pressure detection device for an engine characterized by.