JP2001303981A - Throttle valve device of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve output of an engine by shortening a part on which a throttle valve having a small internal diameter is positioned, enlarging the diameter toward the downstream of the throttle valve, and reducing intake resistance in a throttle bore without making a device large-sized. SOLUTION: In the throttle bore 15a having the throttle valve 14 downstream whose diameter is enlarged, compared with the inside diameter center A wherein the throttle valve 14 is arranged, the inside diameter center B at the downstream part having the enlarged diameter (the throttle valve 14 downstream end part) is formed to be offset on the other side of an idle control valve 21. Although the diameter of the throttle bore 15a is enlarged toward the throttle valve 14 downstream, a surface on the idle control valve 21 side at the throttle valve 14 downstream of the throttle bore 15a can be formed roughly flat, and mounting of a bypass passage 20 and the idle control valve 21 can be compactly realized with no change.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle valve device for an engine having a throttle bore whose diameter is increased toward the downstream of a throttle valve, and which is particularly excellent in mounting layout.

[0002]

2. Description of the Related Art Conventionally, the shape of a throttle bore provided with a throttle valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-217.
As disclosed in Japanese Unexamined Patent Publication No. 457, there is an apparatus in which the intake resistance is reduced by increasing the diameter downstream of the throttle valve.

[0003]

However, in a throttle body integrally provided with an idle control valve and the like interposed in a bypass passage bypassing the throttle valve,
If the throttle bore is shortened at the small inner diameter where the throttle valve is located and the intake resistance is reduced by increasing the diameter downstream of the throttle valve, a bypass passage is required to avoid the enlarged downstream throttle bore. Etc. must be located outside. As a result, the idle control valve and the like must also be located and mounted on the outside,
There is a problem that the size of the throttle body becomes large, which is not preferable in terms of the device layout.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and without increasing the size of a device, a throttle bore is formed by expanding a portion of a small inner diameter where a throttle valve is located toward a downstream side of the throttle valve in a short time, so that intake air is reduced. It is an object of the present invention to provide an engine throttle valve device capable of reducing resistance and improving engine output.

[0005]

According to a first aspect of the present invention, there is provided a throttle valve device for an engine having a throttle bore whose diameter increases toward a downstream side of a throttle valve. The center of the inside diameter of the downstream portion to be enlarged is offset to one side with respect to the center of the inside diameter of the portion where the throttle valve is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, an idle control valve interposed in a bypass passage bypassing the throttle valve is provided in the throttle body having the throttle bore, The throttle bore is formed on the opposite side of the control valve from the center of the inner diameter of the downstream portion where the diameter is increased.

That is, according to the first aspect of the present invention, in the throttle bore, the intake air from upstream of the throttle valve passes through the throttle valve and flows downstream of the throttle valve. Here, the throttle bore has a shape whose diameter is increased toward the downstream of the throttle valve, and has a small intake resistance, which is preferable for improving the engine output. In addition, the throttle bore is formed such that the center of the inner diameter of the downstream portion that expands is offset to one side with respect to the center of the inner diameter of the portion where the throttle valve is disposed, and the side opposite to this one side is formed. The swelling can be formed less than one side. By arranging the parts by utilizing this, it is possible to reduce the size.

More specifically, an idle control valve interposed in a bypass passage that bypasses the throttle valve is disposed in a throttle body having a throttle bore. If the throttle bore is formed by offsetting the center of the inner diameter of the downstream portion that expands to the opposite side, the idle control valve can be disposed without being located outside as compared with the conventional case.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to an embodiment of the present invention, FIG. 1 is an overall configuration diagram of an engine system, FIG. 2 is a sectional explanatory view of a bypass passage portion of a throttle body, and FIG. It is a front view.

In FIG. 1, reference numeral 1 denotes an engine,
In this embodiment, a horizontally opposed 6-cylinder engine is shown. A cylinder block 2 of the engine 1 is divided into two banks on both sides of a crankshaft. An intake port 4 and an exhaust port 5 are formed in a cylinder head 3 of each bank.

An intake manifold 6 is communicated with the intake port 4 of each cylinder, and the intake manifolds 6 of each cylinder for each bank are assembled and communicated with the intake chambers 7a and 7b. Furthermore, the intake chambers 7a, 7
A variable intake valve 8 driven to be opened and closed by an actuator 9 is interposed in a passage communicating with b.

The actuator 9 is connected to a negative pressure tank 11 which is connected to one intake chamber 7a via a one-way valve 10. A switching solenoid valve provided in a passage connecting the actuator 9 and the negative pressure tank 11 is provided. 1
2, the operating pressure introduced into the actuator 9 is switched between negative pressure and atmospheric pressure in accordance with the engine operating range.

The intake chambers 7 corresponding to the respective banks
a, 7b, passages 13a, 13b extend upstream from respective positions on both sides of the variable intake valve 8, and these passages 13a, 13b
The passages 13a and 13b gather in a passage 13d, and the passage 13d communicates with a throttle body 15 in which a throttle valve 14 interlocked with an accelerator pedal is interposed, so that the intake air is evenly distributed to each bank. An intake pipe 17 is connected to an upstream side of the throttle body 15 via an air chamber 16, and an air cleaner 18 is attached to an upstream side of the intake pipe 17. A chamber is provided in the middle of an air intake passage connected to the air cleaner 18. 19 is communicated.

A bypass passage 20 bypassing the throttle valve 14 is connected to the throttle body 15, and an idle control valve 21 for controlling an idle speed is interposed in the bypass passage 20. The air flow rate in the bypass passage 20 is adjusted by the valve 21.

A spark plug 22 for exposing a discharge electrode portion to the combustion chamber is attached to each cylinder of the cylinder head 3, and an air assist is provided immediately upstream of the intake port 4 of each cylinder of the intake manifold 6. An injector 25 is provided. In the air assist injector 25,
Fuel is supplied via a fuel supply passage 27 extending from a fuel tank 26, and atomization of the injected fuel in a low rotation / low load region is performed via an air assist passage 28 extending from an idle control valve 21. Assist air for promotion is introduced.

An in-tank fuel pump 30 is provided in the fuel tank 26, and fuel from the fuel pump 30 is supplied to the air-assist injector 25 through a fuel supply passage 27.
The pressure is fed to the pressure regulator 31, the excess fuel is returned from the pressure regulator 31 to the fuel tank 26, and the fuel pressure of the fuel supply system to the air assist injector 25 is adjusted to a predetermined pressure.

Further, in order to purge the fuel vapor generated in the fuel tank 26 to the intake system, a first purge passage 32 extends from an upper portion of the fuel tank 26, and a two-way valve 3 is provided.
3, and is communicated with an upper portion of a canister 34 having an adsorbing portion made of activated carbon or the like. The canister 34 is provided at its lower part with a fresh air inlet communicating with the atmosphere, and a second purge for introducing a mixture (evaporative gas) of fresh air from the fresh air inlet and the evaporated fuel gas stored in the adsorption section. A passage 35 extends from the top.

The second purge passage 35 is provided with the throttle valve 1
4, passages 13 a, 13 b communicating from the throttle body 15 to the intake chambers 7 a, 7 b of each bank.
An opening is provided in the intake system at approximately the center and upstream of the branch portion 13c that branches to the intake system. In the middle of the second purge passage 35, a canister purge control (CPC) duty solenoid valve whose valve opening is controlled in accordance with the duty ratio of the drive signal in order to control the purge ratio of evaporated fuel to intake air. 36, and this CP
On the upstream side of the C-duty solenoid valve 36, a chamber 37 for silencing airflow noise and pulsation noise generated when the CPC duty solenoid valve 36 operates is provided.

On the other hand, the exhaust ports 5 of the cylinder head 3 of the engine 1 are collected in the cylinder head 3 for each bank and communicated with the exhaust pipe 38, and the exhaust pipe 38 of each bank is provided.
In addition, a catalytic converter 39 containing a three-way catalyst is interposed, and a catalytic converter 40 also containing a three-way catalyst is interposed at a collecting portion of the exhaust pipe 38 of each bank, and a muffler 42 is provided via a silencer 41. Is communicated to.

Further, EG is supplied from the exhaust pipe 38 of one bank.
An R (exhaust gas recirculation) passage 43 extends, and passages 13a, 13 extending from intake chambers 7a, 7b of each bank.
3b. In the middle of the EGR passage 43, E
An EGR valve 44 for adjusting the GR amount is interposed, and a part of the exhaust gas is recirculated to the intake system according to the degree of opening of the EGR valve 44.

The engine 1 is provided with sensors for detecting an engine operating state. That is, the throttle valve 1 interposed in the throttle body 15
4, the throttle opening sensor 50a and the throttle valve 14
A throttle sensor 50 having a built-in idle switch 50b that is turned on when fully closed is connected in series, and an intake pipe pressure sensor 51 that detects the intake pipe pressure downstream of the throttle valve 14 is provided downstream of the throttle valve 14. . The air chamber 16 has an intake air temperature sensor 52 for detecting the intake air temperature.
Is coming.

Further, a knock sensor 53 is attached to each bank of the cylinder block 2 of the engine 1, and a cooling water temperature sensor 55 faces a cooling water passage 54 formed in the cylinder block 2. A linear air-fuel ratio sensor 56 is disposed upstream of the catalytic converter 39 of the exhaust pipe 38 of each bank.
On the downstream side of the catalytic converter 40 interposed in the collecting portion of
An O2 sensor 57 is provided.

A crank angle sensor 5 is mounted on the outer periphery of a crank rotor 58 which is mounted on the crankshaft of the engine 1.
9 and a half with respect to the crankshaft.
A cylinder discriminating sensor 61 is provided opposite to a cam rotor 60 connected to a rotating camshaft.

The engine 1 is electronically controlled by an electronic control unit (not shown). That is, the electronic control unit processes a detection signal from each sensor / switch, a battery voltage, and the like, and based on various data stored in a memory, various learning value data, fixed data, and the like, a fuel injection amount,
Calculate the ignition timing, the target idle speed, the target purge rate of the evaporative fuel, the target EGR rate, etc., and perform fuel injection control, ignition timing control, idle speed control, evaporative fuel purge control, EG
Engine control such as R control is performed.

Here, the configuration of the passage of the throttle body 15 will be described with reference to FIG. Throttle body 15
Is connected via a gasket 45 to the intake manifold 6 forming the above-described passage 13d.

In the throttle body 15, a throttle valve 14 is rotatably disposed in a throttle bore 15a through which intake air flows, and opens and closes the throttle bore 15a in conjunction with an accelerator pedal. The diameter of the throttle bore 15a is increased toward the upstream and downstream of the throttle valve 14, respectively.

As shown in FIG. 3, the throttle bore 15a has an inner diameter center of a downstream portion (downstream end of the throttle valve 14) with respect to an inner diameter center A of a portion where the throttle valve 14 is disposed. B is formed so as to be offset on one side, that is, on the side opposite to the idle control valve 21. As a result, the surface of the throttle bore 15a on the side of the idle control valve 21 downstream of the throttle valve 14 shortens the small-diameter portion where the throttle valve 14 is located, so that the throttle bore 15a expands toward the throttle valve 14 downstream. Despite that, it is formed almost flat.

The throttle body 15 is connected to the intake manifold 6 by a gradual taper having no step on the downstream side of the throttle valve 14 of the throttle bore 15a so that the intake air flows smoothly from the throttle bore 15a into the passage 13d. Surfaces 46 are formed and connected.

An idle control valve 21 is provided outside the throttle body 15, and an inlet side passage 20a and an outlet side passage 20b of a bypass passage 20 which bypasses the throttle valve 14 are connected. An inlet-side passage 20a of the bypass passage 20 is opened on the upstream side of the throttle body 15, and an outlet-side passage 20b of the bypass passage 20 extends substantially parallel to the throttle bore 15a and communicates with the intake manifold 6. It is open to the passage 13d of the intake manifold 6 from the side.

For this reason, as shown by the dashed line in FIG. 2, when the throttle valve 14 is opened, the intake air flows from the upstream of the throttle valve 14 into the throttle bore 15a.
It flows downstream of the throttle valve 14 via the throttle valve 14 and flows into the passage 13d of the intake manifold 6.

Here, a portion of the throttle bore 15a downstream of the throttle valve 14 is formed by shortening and expanding the portion having a small inner diameter where the throttle valve 14 is located. The intake manifold 6 is formed by a gently tapered surface 46 having no step. 13d, the intake resistance is small, and the output of the engine is improved.

Further, the throttle bore 15a is provided with an inner diameter center B at the downstream end of the throttle valve 14 with respect to an inner diameter center A of the throttle valve 14 at an idle control valve 21.
Therefore, the surface of the throttle bore 15a on the side of the idle control valve 21 downstream of the throttle valve 14 is formed substantially flat. As a result, the outlet side passage 20b of the bypass passage 20 can be formed substantially parallel to the throttle bore 15a and close to the throttle bore 15a, and the throttle valve 1 of the throttle bore 15a can be formed.
(4) It can be realized without changing its position and shape with the increase in diameter on the downstream side. In addition, there is no need to change the position of the idle control valve 21, which is excellent in layout. In other words, even if the diameter of the throttle valve 15 downstream of the throttle bore 15a is increased, it is not necessary to position the idle control valve 21 outside the throttle body 15 by avoiding the increased diameter portion, and it is possible to realize a compact size. .

[0033]

As described above, according to the present invention, when the diameter of the throttle bore is increased toward the downstream of the throttle valve and the engine output is improved by reducing the intake resistance, the throttle bore is provided with the throttle valve. Since the center of the inner diameter of the downstream part to be enlarged is offset to one side with respect to the center of the inner diameter of the part to be expanded, the side opposite to one side can be formed with less swelling than the one side, and this is utilized. In this way, the components can be arranged and a compact configuration can be achieved.

An idle control valve interposed in a bypass passage bypassing the throttle valve is disposed in a throttle body having a throttle bore formed therein, and an inner diameter of a downstream portion expanding in diameter on a side opposite to the idle control valve side. By forming the throttle bore by offsetting the center, the idle control valve can be disposed without being located on the outside as compared with the conventional case, which can be advantageously realized in layout.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an engine system.

FIG. 2 is an explanatory sectional view of a bypass passage portion of a throttle body.

FIG. 3 is a front view of the throttle body downstream of the slot valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 14 Throttle valve 15 Throttle body 15a Throttle bore 20 Bypass passage 20a Inlet passage 20b Outlet passage 21 Idle control valve

Claims (2)

[Claims] 1. A throttle valve device for an engine having a throttle bore whose diameter is increased toward a downstream side of a throttle valve, wherein the throttle bore has a downstream diameter which is increased with respect to a center of an inner diameter of a portion where the throttle valve is disposed. A throttle valve device for an engine, wherein the center of the inner diameter of the side portion is offset to one side. 2. A throttle body having a throttle bore formed therein, wherein an idle control valve disposed in a bypass passage bypassing the throttle valve is disposed, and the diameter of the downstream side is increased to a side opposite to the idle control valve. 2. The throttle valve device for an engine according to claim 1, wherein the throttle bore is formed by offsetting the center of the inner diameter of the portion.