JP2002295282A - Air intake device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air intake device for an internal combustion engine, capable of preventing the impossibility of detecting an intake pressure caused by the deposition or the like of sediments from the engine, while improving facilitating of the mounting an intake pressure detecting means into an intake pipe. SOLUTION: This air intake device is provided with an intake pipe 10 forming an intake passage 10a, a valve element 30 which is rotatably supported in the intake pipe 10 and makes the opening area of the intake passage 10a variable, and a control box 50 which has a detecting means P for detecting the intake pressure, on the downstream side of the valve element 30, and also a substrate 51 electrically connecting to the detection means P. The detection means P comprises a negative pressure sensor 50, which is disposed on the lower face of the substrate 51 and has a sensing pipe 60a on its tip end, and a pressure inlet pipe 15 opening within the intake pipe 10 is disposed at the position facing the negative pressure sensor 60, so that the lower face of the negative pressure sensor 60 and the pressure inlet pipe 15 sandwich an elastic member 70 therebetween, to be pressingly fixed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an intake device for an internal combustion engine.

[0002]

2. Description of the Related Art As an intake device for an internal combustion engine, a fuel injection valve for injecting fuel into an intake pipe, a valve body for varying the intake flow rate of the intake pipe, and a control box integrated with the intake pipe wall are provided. (Japanese Patent Application Laid-Open No. 11-294216).

According to Japanese Patent Application Laid-Open No. H11-294216, the control box is provided with a board and an intake pressure detecting means arranged on the board and for detecting an intake pressure downstream of the valve element.

[0004] The intake pressure detecting means is an intake pipe negative pressure sensor disposed on the lower surface of the substrate, and one of the intake pipe negative pressure sensors is arranged to face an introduction hole opened in the intake pipe. It is fixed to a cylindrical wall forming an introduction hole via a cylindrical elastic member such as a rubber tube.

[0005]

In the above-mentioned conventional configuration,
Insufficient consideration has been given to improving the assemblability of the intake pipe negative pressure sensor, which is the intake pressure detection means, and the intake pipe. That is, in order to connect the intake pipe negative pressure sensor to the outer periphery of the cylindrical wall forming the introduction hole via a hose-shaped elastic member, when the intake pipe negative pressure sensor is attached to the cylindrical wall, blindness is caused. Since it is a work, the efficiency of the assembly work is low.

When the sensing pipe, which is the tip of the intake pipe negative pressure sensor, is thin, there is a limit in increasing the size of the introduction hole. Therefore, the inner circumference of the elastic member connected to the tip or this elastic member is not limited. Pressure may not be detected due to adhesion of dew on the inner circumference of the introduction hole connected to the member, or accumulation of sludge or the like generated by combustion of the internal combustion engine.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and accordingly, it is an object of the present invention to improve the assemblability of an intake pressure detecting means and an intake pipe while adhering dew condensation and an internal combustion engine. It is an object of the present invention to provide an intake device for an internal combustion engine that can prevent detection of intake pressure due to accumulation of products or the like.

[0008]

According to the first aspect of the present invention, there is provided an intake pipe forming an intake passage, a valve body rotatably supported in the intake pipe, and having a variable opening area of the intake passage.
In an intake device for an internal combustion engine including an intake pressure detection unit that detects an intake pressure on the downstream side of a valve element and a control box having a board that is electrically connected to the intake pressure detection unit, the intake pressure detection unit includes: The suction pipe includes a negative pressure sensor disposed on the lower surface of the substrate and having a sensing pipe at the tip, and a pressure introduction pipe that opens into the intake pipe is provided at a position facing the negative pressure sensor in the intake pipe. The negative pressure sensor is pressed and fixed to the pressure introducing tube such that the elastic member is sandwiched between the lower surface of the negative pressure sensor on the side and the pressure introducing tube.

Thus, when the negative pressure sensor as the intake pressure detecting means is assembled with the intake pipe, particularly the pressure introducing pipe, the elastic member is sandwiched between the lower surface of the negative pressure sensor and the pressure introducing pipe. By doing so, the negative pressure sensor can be pressed and fixed to the pressure introducing pipe. This eliminates the need for blind work as compared with the assembling work in which the inner periphery of the hose-shaped elastic member is fitted to the outer periphery of each of the negative pressure sensor and the pressure introducing pipe by using the elasticity of the elastic member. Adhesion can be improved.

According to the second aspect of the present invention, the elastic member includes:
An axial load of the pressure introducing pipe is applied to an end face formed in a flat plate shape and abutting on the pressure introducing pipe.

Thus, the elastic member is formed in a simple flat plate shape, so that the influence of deformation in the manufacturing process due to the characteristics of the elastic member such as a rubber material can be reduced. For this reason, when assembling the negative pressure sensor and the pressure introducing pipe, the pressure is applied to the end face portion that is in contact with the pressure introducing pipe, that is, the elastic member, without considering whether the shape accuracy of the elastic member in manufacturing is good or bad. A load in the tube axis direction can be easily applied.

According to the third aspect of the present invention, the control box is formed integrally with the outer wall of the intake pipe, and when the substrate is fixed to the outer wall, the substrate is connected via the negative pressure sensor. Then, the elastic member is pressed against the pressure introducing tube.

For this reason, the negative pressure sensor is pressed against the pressure introducing pipe by the substrate via the elastic member sandwiched between the negative pressure sensor and the pressure introducing pipe, so that the lower surface of the negative pressure sensor and the pressure introducing pipe are connected to each other. The elastic member sandwiched between them is securely pressed and fixed.

According to the fourth aspect of the present invention, the sensing pipe projects through the elastic member.

When the intake pressure in the intake pipe, that is, the pressure of the intake air which is a fluid flowing in the intake pipe, is measured by the pressure in the pressure introduction pipe provided in the intake pipe, the air flowing in the intake pipe generally has a pressure of When flowing into the introduction pipe, the inflow velocity is higher at the center of the pressure introduction pipe, and conversely, the wall that forms the inside of the pressure introduction pipe away from the center, that is, the inner periphery of the pressure introduction pipe, and the surface inside the pressure introduction pipe The closer to the surface of the elastic member, the lower the inflow speed. For this reason, sludge or the like, which is a part of the product of the internal combustion engine, easily accumulates on the inner periphery of the pressure introducing pipe or the surface of the elastic member. Also,
Similarly, condensation easily adheres to the inner periphery of the pressure introducing tube or the surface of the elastic member.

On the other hand, since the sensing pipe for sensing the pressure is projected from the elastic member, the sensing pipe, particularly its tip, can be arranged at the center of the pressure introducing pipe. Therefore, the negative pressure sensor, particularly the sensing pipe, is arranged at a position where accumulation of products of the internal combustion engine, adhesion of dew condensation, and the like are unlikely to occur.

According to claim 5 of the present invention, the intake device for an internal combustion engine to which the present invention is applied is suitable for an intake device provided with a negative pressure sensor having a sensing pipe at the tip as an intake pressure detecting means.

In other words, the negative pressure sensor only needs to insert the sensing pipe into the center of the elastic member, sandwich the elastic member together with the pressure introducing pipe, and press and fix the elastic member. It is possible to enlarge the inside of the inside, especially in the radial direction.

For this reason, it is easy to prevent the pressure from being undetectable due to, for example, accumulation of internal combustion engine products and adhesion of dew.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying an intake device for an internal combustion engine according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a schematic configuration of an intake device for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a view II around the intake pressure detecting means which is a main part of the present invention in FIG.
It is sectional drawing which expanded the inside of the circle.

As shown in FIG. 1, the intake device includes an intake throttle device 1, an air filter 200, and an internal combustion engine 300, in particular, an intake manifold 300a. The intake device may be any device that can vary the intake flow rate according to the operating state of the internal combustion engine 300.
Only the intake throttle device 1 that can change the intake flow rate described later may be used. The air filter 200 and the intake manifold 300a of the internal combustion engine 300 have a known structure.

In the intake throttle device 1, when mounted on a vehicle, the upstream side of the air intake is airtightly joined to an intake duct (not shown) having an air filter 200, and the internal combustion engine 300 has an intake manifold 300a at the downstream side of the intake air.
And airtight communication.

As shown in FIG. 1, the intake throttle device 1 has an intake pipe (hereinafter referred to as a valve housing) 10 forming an intake passage 10a, and a valve shaft 20 rotatably supported in the valve housing 10. A valve body 30 fixed to the valve shaft 20 and varying the opening area of the intake passage 10a;
The control box 50 is provided with a detecting means for detecting a state of intake air (hereinafter, referred to as intake air) which is a fluid flowing through the airflow path 0a.

First, the valve housing 10 forms a substantially cylindrical intake pipe, and an intake passage 10a is formed inside the intake pipe.

In the valve housing 10, as shown in FIG. 1, an outer peripheral wall 11 forming an intake passage 10a and a control box 50 are integrally formed of a resin material or the like.
It is configured to include a housing wall portion 12 for fixing a substrate, which will be described later, and a pressure introduction pipe 15 for holding intake pressure detecting means P for detecting a state of intake air.

The outer peripheral wall 11 is formed with a predetermined thickness so as to form a circular intake passage cross section as shown in FIG.

The housing wall 12 and the outer peripheral wall 11
A bottom cover 50a of the control box 50 is formed, and a casing of the control box 50 including the bottom cover 50a and an upper cover 59 described later is formed.

The housing wall 12 has a boss 12a for fixing the board 51 housed in the control box 50 with a screwing member 58 or the like. Especially the housing wall 1
2 are formed integrally.

As shown in FIG. 1, the pressure introducing pipe 15 is provided on the outer peripheral wall portion 11, particularly on the bottom cover portion 50a, and is arranged at a position on the downstream side of the valve body 30 where the intake pressure can be detected. One of the pressure introducing pipes 15 has an introducing hole 15a opened to the intake passage 10a, and the other has an elastic member 7 made of rubber or the like.
0, the intake pressure detecting means P is kept airtight.

The structure for keeping the intake pressure means P airtight will be described later in detail.

Next, the valve shaft 20 has a substantially cylindrical shape, and is rotatably supported in the valve housing 10 (specifically, the outer peripheral wall portion 11). The valve shaft 20 is externally connected to the valve shaft 20.
Is applied.

As a structure to which the external force is applied, a lever (not shown) for transmitting a rotational force from the outside is fixed to one of both ends of the valve shaft 20. A drive motor that rotatably drives the valve shaft 20 without being limited to a configuration in which an accelerator wire that is linked to the movement of the pedal is engaged or an external force applied to the valve shaft 20 is not limited to a mechanical external force that is linked to the accelerator pedal via a lever. (Not shown) or any other configuration using an external electric force.

Next, the valve body 30 is fixed to the valve shaft 20 so that the opening area of the intake passage 10a can be changed, and is disposed in the intake passage 10a so as to be rotatable together with the valve shaft 20. Thus, the flow rate of intake air flowing through the intake passage 10a can be adjusted by the valve body 30.

The control box 50 includes a board 51
, An intake pressure detecting means P, an upper lid 59, and a bottom lid 50a.

As shown in FIG. 1, an electronic component 55 such as a semiconductor is mounted on both sides of the substrate 51, and is electrically connected to the intake pressure detecting means P.

The substrate 51 includes a read only memory (ROM) and a random access memory (R) (not shown).
AM), microprocessor (CPU), input port 3
5 and the output port 36 may be configured as a microcomputer having a known configuration in which they are connected to each other by a bidirectional bus.

The intake pressure detecting means P is disposed on the lower surface of the substrate 51 and comprises a negative pressure sensor 60 having a sensing pipe 60a at the tip shown in FIG. The sensing pipe 60a
Is a sensing unit for sensing pressure.

The intake pressure detecting means P is provided with a negative pressure sensor 6
The negative pressure detection signal transmitted from the control box 50 is transmitted to the substrate 51 in the control box 50, and the microcomputer in the substrate 1 determines the negative pressure detection signal to measure the intake pressure. (Specifically, the negative pressure sensor 6
Measurement of the intake air pressure from the analog signal output from 0). In the present embodiment, the intake pressure detecting means P will be described below using the negative pressure sensor 60.

The upper lid 59 is formed in a flat plate shape as shown in FIG. 1, and is a casing wall as the bottom lid 50a so as to seal the filler 57 such as a resin mold filled in the bottom lid 50a. It is fixed to the part 12.

The filler 57 is filled to improve waterproofness and vibration resistance.

Here, an intake pressure detecting means P for detecting the intake pressure on the downstream side of the valve body 30, which is a main part of the present invention, that is, an intake pressure for detecting the intake pressure after adjusting the intake flow rate of the intake throttle device 1. Means P (specifically, a negative pressure sensor and intake pipe 10 (specifically, pressure introduction pipe 15)) while improving the assemblability, and detecting the intake pressure by adhesion of dew condensation, accumulation of products of the internal combustion engine, and the like. Regarding the structural features that prevent P from being unable to detect pressure,
This will be described below.

First, a configuration for keeping the intake pressure means P, that is, the negative pressure sensor 60 airtight, with respect to the intake air introduced into the pressure introducing pipe 15 will be described.

As shown in FIG. 2, the negative pressure sensor 60 sandwiches the elastic member 70 between the negative pressure sensor 60 and the pressure introducing pipe 15, and applies a pressing load F in the direction of the arrow. At this time, the pressing load F
The negative pressure sensor 60 and the pressure introducing pipe 15 can be kept airtight by the deformation of the elastic member 70 according to the above.

The elastic member 70 has a pressure sensor 60
Is provided with an insertion hole 70c into which the sensing pipe 60a can be inserted.

With respect to the pressing load F, since the pressure of the intake air introduced into the pressure introducing pipe 15 is equal to or lower than the atmospheric pressure, the negative pressure sensor 60 and the elastic member 70 which comes into contact with the pressure introducing pipe 15 respectively. The load may be such that the contact portions 70a and 70b are deformed and can be sealed.

Therefore, the pressure sensor 60 and the pressure introducing pipe 1
5, the pressing load F may be a relatively small load because the flat elastic member 70 is interposed therebetween.
And the pressure introducing pipe 15 can be easily assembled in an airtight manner.

Next, a configuration for generating the pressing load F will be described.

As shown in FIG. 1, the negative pressure sensor 60 is arranged on the lower surface of the substrate 51, and the height of the upper surface of the boss 12 a for fixing the substrate 51 to the housing wall 12. 1, the height of the upper surface of the negative pressure sensor 60 shown in FIG. 1 when the pressing load F has not yet been applied is higher by a predetermined amount.

Thus, when the substrate 51 is fixed to the housing wall 12, the substrate 51 is applied to the negative pressure sensor 60, the elastic member 70, and the pressure introducing pipe 15 as the pressing load F.
The load required to deform the substrate 51 can be applied corresponding to the predetermined amount.

The elastic member 70 is formed in a flat plate shape as shown in FIG.
5 and the pressure introducing pipe 15 are arranged so as to be freely fitted in the radial direction.

For this reason, the negative pressure sensor 60, the elastic member 7
0. The assembling work of the pressure introducing pipe 15 becomes easy.

That is, the negative pressure sensor 60 and the elastic member 70
When the elastic member 70 is provided in advance, or when the negative pressure sensor 60 is provided with the elastic member 70, the elastic member 70
Since the step portion 15b that fits loosely with the outer periphery 70d of the member is visually checked and assembled, the workability of the assembly is improved. Further, even when the negative pressure sensor 60 is fixed to the substrate 51 in advance,
If the amount of radial gap between the outer periphery 70d to be loosely fitted and the step portion 15b is set to be larger than the amount of radial displacement when the substrate 51 and the housing wall portion 12 are fixed, the blind work state is considered. And can be easily assembled.

Further, since the elastic member 70 is formed in a simple flat plate shape, for example, the elastic member 70 such as a rubber material is used.
The effect of deformation in the manufacturing process due to the characteristics of the above can be reduced. Therefore, when assembling the negative pressure sensor 60 and the pressure introducing pipe 15, it is a contact part that comes into contact with the pressure introducing pipe 15 without considering the quality of the shape of the elastic member 70 during manufacturing. The load F in the axial direction of the pressure introducing pipe 15 can be easily applied to the end face portion 70b.

As shown in FIGS. 1 and 2, since the sensing pipe 60 a protrudes from the elastic member 70,
It is possible to prevent the pressure detection of the intake pressure detecting means P from being impossible due to adhesion of dew condensation, accumulation of products of the internal combustion engine, and the like.

That is, when the pressure of the intake air, which is the fluid flowing in the intake pipe 10, is generally measured by the pressure in the pressure introducing pipe 15 provided in the intake pipe 10, the flow in the intake pipe 10 is generally increased. When the flowing air flows into the pressure introducing pipe 15, the inflow velocity is higher at the center of the pressure introducing pipe 15, and conversely, the wall 15 c forming the inside of the pressure introducing pipe 15 away from the center, that is, the pressure introducing pipe Inner circumference 15 within 15
h, and the closer to the vicinity of the surface 70h of the elastic member 70 facing the inside of the pressure introducing pipe 15, the lower the inflow velocity. Therefore, sludge or the like, which is a part of the product of the internal combustion engine 300, easily accumulates on the inner circumference 15h or the surface 70h. Similarly, condensation easily adheres to the inner circumference 15h or the surface 70h.

On the other hand, since the sensing pipe 60a for sensing the pressure is projected from the elastic member 70, the sensing pipe 60a can be arranged at the center of the pressure introducing pipe 15. Therefore, the sensing pipe 60a
Is disposed at a position where deposition of internal combustion engine products, adhesion of dew condensation, and the like are unlikely to occur, so that it is possible to prevent undetectable pressure.

Further, the elastic member 70 adjusts the position of the insertion hole 70c into which the sensing pipe 60a is inserted, as shown in FIGS.
As shown in the figure, it is provided at the center.

For this reason, the negative pressure sensor 60 only needs to insert the sensing pipe 60a into the center of the elastic member 70 and sandwich the elastic member 70 together with the pressure introducing pipe 15 and press and fix it. Regardless, the pressure introduction pipe 15, that is, the introduction hole 15a can be enlarged in the radial direction.

Therefore, it is easy to prevent the pressure from being undetectable due to the accumulation of internal combustion engine products and the adhesion of dew.

(Modification) The same effect can be obtained with the configuration for generating the pressing load F described in the above-described embodiment, even if the configuration according to the following modification is used.

As a first modified example, a cap nut-shaped screwing member made of a resin material or the like which is a non-conductive material is provided between the negative pressure sensor 60 and the substrate 51, and this screwing is performed. The member is configured to be screwed to the outer periphery of the pressure introducing pipe 15.

Thus, the axial force generated by the screwing can be applied to the respective contact portions of the negative pressure sensor 60, the elastic member 70, and the pressure introducing pipe 15 as the pressing load F.

As a second modified example, a flange may be provided on the negative pressure sensor 60 and fixed to the wall 15c of the pressure introducing pipe 15 by fitting or the like. In the case of fitting, for example, the elastic member may be inserted and fitted in the axial direction in consideration of the deformation required for sealing.

As a third modification, the negative pressure sensor 60 itself may be formed in a cylindrical shape and screwed to the outer periphery of the pressure introducing pipe 15.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an intake device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the inside of a circle II showing the periphery of an intake pressure detecting means which is a main part of the present invention in FIG.

[Explanation of symbols]

Reference Signs List 1 intake throttle device 10 valve housing (intake pipe) 10a intake passage 11 outer peripheral wall 12 (12a) housing wall
(Boss part for fixing the substrate 51) 13 Seat part 15 Pressure introducing pipe 15a Introducing hole 15b Step part (step part for loosely fitting the elastic member 70 in the radial direction) 15c Wall part 15h Inner circumference 20 Valve shaft 30 Valve body 50 Control box 51 Substrate 60 Negative pressure sensor (intake pressure detection means P) 60a Sensing pipe 70 Elastic member 70a, 70b Contact portion 70c Insert hole 70d Outer circumference 70h Surface (facing introduction hole) F Pressing load P Intake pressure detection means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiko Kuroda 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Kenichi Yagi 1-1-1, Showa-cho, Kariya-shi, Aichi Co., Ltd. F term in DENSO (reference) 3G065 CA39 DA04 HA21 HA22 3G301 JA20 PA07Z

Claims (5)

[Claims] An intake pipe forming an intake passage, a valve body rotatably supported in the intake pipe and varying an opening area of the intake passage, and detecting an intake pressure downstream of the valve body. Intake pressure detecting means,
A control box having a board electrically connected to the intake pressure detection means, wherein the intake pressure detection means is disposed on a lower surface of the board and has a sensing pipe at a tip thereof. A pressure introduction pipe which is formed of a negative pressure sensor, and which is open to the intake passage, is provided in the intake pipe at a position facing the negative pressure sensor; An intake device for an internal combustion engine, wherein the negative pressure sensor is pressed and fixed to the pressure introducing tube such that an elastic member is sandwiched between the pressure introducing tube and the pressure introducing tube. 2. The pressure member according to claim 1, wherein the elastic member is formed in a flat plate shape, and an axial load of the pressure introducing tube is applied to an end surface portion abutting on the pressure introducing tube. Of the internal combustion engine. 3. The control box is formed integrally with an outer wall of the intake pipe, and when the substrate is fixed to the outer wall, the substrate is connected via the negative pressure sensor. The intake device for an internal combustion engine according to claim 1 or 2, wherein the elastic member is pressed against the pressure introducing pipe. 4. The intake device for an internal combustion engine according to claim 1, wherein the sensing pipe projects through the elastic member. 5. The intake device for an internal combustion engine according to claim 1, wherein the elastic member has an insertion hole for inserting the sensing pipe at a central portion.