JPH0264235A - Throttle valve assemblie - Google Patents

Abstract

PURPOSE:To prevent a throttle valve from biting at the inner wall of an inlet cylinder by providing a cavity through which a rotating shaft is exposed among plural numbers of inlet ports of a main body member, and thereby providing seals for sections of the main body member among the cavity and the inlet ports, where the rotating shaft is supported. CONSTITUTION:Inlet ports 2 are bored in the main body member 1 of throttle valve assemblies, and throttle valves 3 are arranged for each inlet port 2. The throttle valves 3 are fixed onto a rotating shaft 4, passing through two of the inlet ports 2 for the throttle valves, with set screws 5. A cavity 15 is provided for a space between two of the inlet ports 2 of the main body member 1 through which the rotating shaft 4 is exposed. Seals 31 are provided for each gap 30 at each section of the main body member 1 between the cavity 15 and 16 and each inlet port 2, where the rotating shaft 4 is supported. This constitution enables a clearance between the inner wall of an inlet cylinder and the throttle valve to be made small, and also makes it possible to prevent the throttle valve from biting at the inlet cylinder.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a throttle valve assembly for an automobile engine, and in particular to a fuel injection device that allows a throttle valve to open and close smoothly even when the thermal conditions of the engine change. This invention relates to a multiple throttle valve type throttle valve assembly.

[Prior Art J] A throttle valve assembly in which a plurality of throttle valves arranged in each intake hole are fixed to a rotation axis passing through the central axis of each of the plurality of intake holes is disclosed in, for example, US Pat. No. 3,897.52. It is known as described in No. 4. In this throttle valve assembly, a cavity is provided between the intake holes of the main body member provided with the intake holes, except for the support portion of the rotating shaft.

On the other hand, in recent years, for the purpose of improving engine output, a throttle valve assembly for a $1 fuel injection system has been proposed, which has one throttle valve per engine cylinder, that is, a so-called multiple throttle valve. This throttle valve assembly is desirably installed near the intake valve of the engine in order to shorten the intake passage and minimize ventilation resistance, thereby improving the output of the engine.

[Problem to be solved by the invention]

Conventional throttle valve assemblies, such as the one described in U.S. Pat. No. 3,897,754, were located further away from the engine's intake valves and thus received less heat from the engine; Multiple throttle valve type throttle valve assemblies that are placed as close as possible to the intake valves are affected by the heat of the engine, and this poses a problem of thermal deformation, which has not been a problem in the past.

That is, the main body member, rotating shaft, and throttle valve thermally expand due to the thermal influence on the throttle valve assembly, and the inner wall of the intake hole, the rotating shaft, and the throttle valve are thermally deformed, and the throttle valve bites into the inner wall of the intake hole. occurs. To accommodate this, conventional throttle valve assemblies of this type have a clearance between the inner wall of the intake hole and the throttle valve of approximately 80 to 150 mm.
It was enlarged compared to μrn.

However, it is being considered that the multiple throttle valve type throttle valve assembly can be applied not only to special sporty cars, but also to forged molds. There is a need to reduce the interval. Therefore, the clearance between the inner wall of the intake hole and the throttle valve is approximately 10 to 30μ.
It is necessary to make it as small as In. However, when the clearance is made small, it becomes impossible to absorb the dimensions changed due to the thermal expansion described above, and there is a problem in that the throttle valve bites into the inner wall of the intake cylinder.

SUMMARY OF THE INVENTION An object of the present invention is to provide a throttle valve assembly that can reduce the clearance between the inner wall of the intake cylinder and the throttle valve and prevent the throttle valve from biting into the intake cylinder.

[Means to solve the problem]

In order to achieve the above object, the throttle valve assembly' of the present invention is characterized in that a cavity is provided between the plurality of intake holes of the main body member, through which the rotating shaft is exposed.

In this case, a seal is preferably provided at a portion of the main body member between the cavity and the intake hole that supports the rotating shaft.

[Effect]

In the throttle valve assembly of the present invention configured in this way,
By providing a cavity in which the rotating shaft is exposed between the plurality of intake holes of the main body member, the amount of material between the intake holes of the main body member is reduced, and thermal stress in the direction of the rotating shaft of the main body member is reduced. Thermal expansion generated in the direction is absorbed by the cavity, and the thermal deformation of the inner wall of the intake cylinder is evenly distributed. This prevents abnormal thermal deformation of the inner wall of the intake cylinder, and prevents the throttle valve from biting into the inner wall of the intake cylinder.

By providing a seal between the cavity and the intake hole in the part where the main body member supports the rotating shaft, the breathing effect of the engine pulsation prevents gases such as crackling and blow-by gas in the engine intake system from passing through the support part and into the cavity. This prevents the air and fuel from accumulating and being supplied to the engine to be rapidly sucked out at idle, when the amount is small, and the air-fuel ratio from changing significantly.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. Six embodiments are examples in which the present invention is applied to a dual throttle valve type throttle valve assembly.

In FIGS. 1 to 3, the main body member l of the throttle valve assembly is generally made of aluminum, and has intake holes 2 formed in two places, and a throttle valve 3 is arranged in each intake hole 2. .

The throttle valve 3 is fixed by a set screw 5 to a rotating shaft 4 for the throttle valve passing through the central axes of the two intake holes 2, and the rotating shaft 4 is supported at both ends by bearings 6 held by the main body member 1. There is.

An accelerator lever of a vehicle (not shown) is attached to one end of the rotating shaft 4.
The operating lever 7, which is driven via the side of the link R by stepping on it, is fixed by a washer 8 and a nut 9, and
l! ! A zero-rotation shaft 4, to which a spring holder 11 with a return spring 10 attached is fixed by a washer 12 and a nut 13, is rotated by an operating lever 7 when the accelerator pedal is depressed, and when the accelerator pedal is released. The return spring 10 returns it to its original position, and at the same time, the throttle valve 3 opens and opens. Reference numeral 14 denotes a hole for attaching the main body member 1.

The main body member 1 is also provided with a cavity 15 in the area between the two air intake holes 2 by hollowing out the area. A portion 16 of the cavity 15 is located around the axis of rotation 4 between the intake holes 2, so that the axis of rotation 4 is exposed in the cavity portion 16.

In this embodiment configured in this way, when the throttle valve assembly is affected by the heat of the engine and the main body member l is heated and the intake holes 2 thermally expand, a cavity 15 is formed between the two intake holes 2. As a result, the amount of material between the intake holes of the main body member 1 is reduced, and the amount of thermal expansion of the main body member in the rotation axis direction is reduced. Therefore, thermal deformation of the intake hole 2 is reduced. Moreover, since the wall materials of the two intake holes 2 are separated from each other by the cavity 15 and the cavity portion 16 between the intake holes 2, thermal expansion in the direction of the rotation axis is absorbed, and the material between the wall surfaces of the two intake holes 2 is The distance changes to become smaller.

Therefore, the thermal deformation of the intake hole 2 is evenly distributed, and the thermal deformation of the intake hole 2 is evenly distributed.
Abnormal thermal deformation of the material is prevented. At this time, if the amount of thermal expansion of the throttle valve 3 is within the range of thermal deformation of the intake hole 2, the throttle valve 3 will not interfere with the intake hole 2 when opened or closed.

For comparison, a conventional throttle valve assembly is shown in FIG.

This throttle valve assembly includes an air intake 1! of body member 1 in accordance with the teachings of U.S. Pat. No. 3,897,524. A cavity 20 is provided between J2 except for the support portion of the rotating shaft 4. In the case of this conventional structure, considering that the main body member 1 thermally expanded in the same way as described above, the amount of thermal expansion decreases due to the formation of the cavity 20, but the part through which the rotating shaft 4 passes is covered with the material of the main body member 1. Therefore, thermal expansion in the direction of the rotation axis is not absorbed, and the distance between the closest wall surfaces of the two intake holes 2 changes to become larger. Therefore, uneven thermal deformation occurs in the intake hole 2, which tends to interfere with the throttle valve whose outer diameter increases due to thermal expansion. Conventionally, in order to avoid this interference, as mentioned above, there was a distance of 80 to 15 mm between the inner wall of the intake hole 2 and the outer periphery of the throttle valve 3.
A relatively large clearance of about 0 μm was provided.

As a result, the amount of air supplied to the engine also increases, making it impossible to lower the idle speed of the engine and reduce fuel consumption and noise.

In this embodiment, as described above, the distance between the wall surfaces closest to the intake hole 2 is small, and the thermal deformation of the intake hole 2 is evenly distributed, so that the inner wall of the intake hole 2 and the throttle valve 3 are Outside JM
It is now possible to create a clearance determined by the coefficient of thermal expansion of the material, and even if the clearance is smaller than before, the throttle valve 3 will not bite into the inner wall of the intake pipe 2. Although there is some variation depending on the material, if the throttle valve 3 is made of brass and the main body member 1 is made of aluminum, the thickness can be about 10 to 20 μm. By reducing the clearance in this way, the amount of air during idle rotation can be reduced, lowering the idle rotation speed and improving fuel efficiency and I! You can do this without reducing the I sound.

Another embodiment of the present invention will be described with reference to FIG. A seal 31 is provided in the gap rm30 between the portion supporting the rotary shaft 4 and the rotary shaft 4.

In the embodiment described above, the rotating shaft 4 is exposed in the cavity 16, so that the intake hole 2 communicates with the cavity 15, 16 via the gap 30. Therefore, due to the breathing action caused by engine pulsation in the cavities 15 and 16 and the gap 30, gasoline, blow-by gas, etc. in the engine intake system are absorbed into the gap 30.
It collects in cavities 15, 16 through the engine and can be rapidly sucked out at idle, when the amount of air and fuel supplied to the engine is minimal, causing a change in the air-fuel ratio.

Also, air other than the air stored in the air cleaner section is sent into the intake hole 2 from the air 5.6 and the gap 30,
There is a possibility that the air-fuel ratio may change. By providing the seal 31 as in this embodiment, the outflow of gasoline, blow-by gas, etc. from the cavity 15.16'\ and the flow of air from the cavity 15.16 into the intake hole 2 are prevented. It is possible to prevent the intrusion and prevent the air-fuel ratio from changing.

〔Effect of the invention〕

According to the present invention, the plurality of intake holes of the main body member! Since a cavity is provided in jl to expose the rotating shaft, abnormal thermal deformation of the inner wall of the intake cylinder can be prevented, and the clearance between the intake cylinder and the throttle valve can be reduced while preventing the throttle valve from biting into the inner wall of the intake cylinder. Therefore, the amount of air during idle rotation can be reduced, the idle rotation speed can be lowered, fuel consumption and noise can be reduced, and the throttle valve can be opened and closed smoothly.

If a seal is provided at the portion of the main body member between the cavity and the intake hole that supports the rotating shaft, changes in the air-fuel ratio can be further prevented and stable operation can be guaranteed.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a throttle valve assembly according to a modified example of the present invention, FIG. 2 is a side view of the throttle valve assembly, and FIG.
The figure is a sectional view taken along the line [g] in Fig. 2, and Fig. 4 is a sectional view taken along the
FIG. 5 is a sectional view showing a conventional throttle valve assembly for comparison;
The figure is a sectional view similar to FIG. 3 showing a throttle valve assembly according to another embodiment of the invention. Description of symbols 1... Body member 2... Intake hole 3... Throttle valve 4... Rotating shaft 15.16... Cavity 31... Seal applicant Hitachi, Ltd. Hitachi Automotive Engineering Co., Ltd.

Claims (2)

[Claims] (1) It has a main body member provided with a plurality of intake holes, and a plurality of throttle valves are fixed to this main body member, passing through the central axis of each of the plurality of intake holes and disposed at each of the plurality of intake holes. A throttle valve assembly equipped with a rotating shaft for a throttle valve, characterized in that a cavity is provided between a plurality of intake holes of a main body member, through which the rotating shaft is exposed. (2) The throttle valve assembly according to claim 1, wherein the main body member between the cavity and the intake hole is provided with a seal at a portion supporting the rotating shaft.