JPH0658145U - Idle control valve for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] The rotary shutter type idle control valve
Prevents malfunction due to dirt. [Structure] Cylindrical housing 1 having an opening 2 in a peripheral wall
And a cylindrical slider 5 fitted into the inner circumference of the housing 1 and having an opening 6 in the peripheral wall. Then, by the rotation of the slider 5, the opening 6 on the slider 5 side is formed.
And the degree of overlap between the opening 2 on the housing 1 side,
This controls the amount of auxiliary air. Here, as the material of the slider 5, a material having a thermal expansion coefficient larger than that of the material of the housing 1 is used. Therefore, when the engine is stopped and the temperature decreases, the clearance between the slider 5 and the housing 1 increases, and the slider 5 and the housing 1 do not lock even if the adhered dirt hardens due to the temperature decrease.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an idle control valve for an internal combustion engine, and more particularly to a technique capable of avoiding the occurrence of malfunction due to adhesion of dirt.

[0002]

[Prior art]

 In an internal combustion engine, an auxiliary air passage that bypasses the throttle valve is provided for the engine intake passage, and a rotary shutter type idle control valve is installed here to control the auxiliary air amount by the idle control valve. There is one (Japanese Utility Model Laid-Open No. 61-63448).

An example of the rotary shutter type idle control valve is a valve structure as shown in FIG. The idle control valve shown in FIG. 2 has a cylindrical housing 1 having an opening 2 on its peripheral wall and a cylindrical slider 5 fitted on the inner periphery of the housing 1 and having an opening 6 on its peripheral wall. By rotating the slider 5 with an electromagnetic actuator (not shown), the degree of overlap between the opening 6 on the slider 5 side and the opening 2 on the housing 1 side is adjusted, thereby controlling the amount of auxiliary air. To do.

[0004]

[Problems to be solved by the device]

 By the way, in the rotary shutter type idle control valve as described above, carbon and oil components may be deposited and accumulated between the slider 5 and the housing 1 due to blowback from the engine side. Such deposits generally remain liquid when the temperature is relatively high, and do not significantly affect the operation of the idle control valve during normal engine operation. However, when the engine is stopped and the outside air temperature is still low, the adhered and accumulated dirt is solidified, and the solidified dirt on the slider 5 and the housing 1 are fixed or solidified due to the solidified dirt when the engine is started at a low temperature. There is a fear that dirt may get caught in the sliding part and the slider 5 cannot be normally rotated, resulting in a start failure.

The present invention has been made in view of the above problems. In an idle control valve of a rotary shutter type, even if an adhering substance cools and solidifies when the engine is stopped, this causes malfunction of the idle control valve at the time of starting. The purpose is to be able to avoid the occurrence.

[0006]

[Means for Solving the Problems]

 Therefore, in the present invention, an idle control valve for an internal combustion engine installed in an auxiliary air passage that bypasses a throttle valve installed in the intake passage of the engine, and a cylindrical housing having an opening in a peripheral wall, A slider that is inserted into the inner circumference of the housing and changes the passage area of the opening of the housing according to the rotational position, and the amount of auxiliary air is controlled according to the passage area. As the material of the housing, a material having a larger thermal expansion coefficient than that of the housing is used.

[0007]

[Action]

 With this configuration, the coefficient of thermal expansion of the slider material is larger than the coefficient of thermal expansion of the housing material, so the clearance between the slider and the housing has a relatively high temperature that controls the amount of auxiliary air in the operating state of the machine. When the engine is stopped and the temperature drops, it becomes greater than when the engine temperature is high.

Therefore, even if the adhered substances (dirt components) such as carbon and oil solidify as the temperature lowers, the solidification becomes large because the clearance between the slider and the housing becomes large at that time. The slider and housing will not stick to each other due to adhered matter.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a rotary shutter type idle control valve in the present embodiment. The idle control valve shown in this figure is an auxiliary device provided by bypassing a throttle valve provided in an engine intake passage. It is provided in the air passage and controls the amount of auxiliary air sucked into the engine through the auxiliary air passage.

In FIGS. 1 and 2, a cylindrical housing 1 has an opening 2 formed in a peripheral wall at one end thereof. The outer rings of the two ball bearings 3 are fitted and fixed to the inner circumference of the other end of the housing 1, and the rotary shaft 4 is inserted and held in the inner rings of these ball bearings 3. A cylindrical slider 5 (shutter) is integrally formed at one end of the rotary shaft 4, and is slidably fitted into a sliding portion 1a surrounding the opening 2 on the inner circumference of the housing 1. In FIG. 2, reference numeral 1b indicates an escape portion formed on the inner circumference of the housing 1. An opening 6 is formed on the peripheral wall of the slider 5.

Here, a magnet 7 is fixed to the rotating shaft 4, and a coil 8 is provided so as to surround the magnet 7. The coil 8 is divided into a valve opening coil and a valve closing coil, and the energization of these coils is controlled by a duty signal whose phase is reversed to generate a driving force in the valve opening direction or the valve closing direction. , The slider 5 is rotated via the rotation shaft 4.

By such rotation of the slider 5, the degree of overlap (effective passage area) between the opening 6 on the slider 5 side and the opening 2 on the housing 1 side is controlled. A cover 9 is provided to cover the housing 1, and an auxiliary air inlet portion 10 and an auxiliary air outlet portion 11 are formed. The auxiliary air inlet portion 10 communicates from one end portion of the housing 1 to the inner space of the slider 5 therein. The auxiliary air outlet 11 communicates with the space on the outer periphery of the housing 1.

Therefore, the air introduced from the upstream side of the throttle valve of the engine intake passage reaches the space of the inner peripheral portion of the slider 5 from the auxiliary air inlet portion 10 and from there, the opening portion 6 on the slider 5 side and the housing 1 side After passing through the overlapping portion with the opening 2, the space reaches the outer peripheral portion of the housing 1 and flows from the auxiliary air outlet 11 to the downstream side of the throttle valve in the engine intake passage.

In the idle control valve having such a configuration, in the present embodiment, both the housing 1 and the slider 5 are resin molded products, but resin materials of both have different thermal expansion coefficients (for example, PPS resin and phenol resin). ) Is used to form the slider 5 with a resin material having a larger coefficient of thermal expansion. When the housing 1 and the slider 5 are formed by using materials having different coefficients of thermal expansion as described above, the sliding between the housing 1 and the slider 5 in a normal operating condition in which the temperature is relatively high during engine operation. If the clearance of the part 1a is set to a level at which the leakage flow rate can be regulated below the permissible level (state of FIG. 2), the slider 5 side becomes larger when the engine is stopped and the outside air temperature is low. Due to thermal contraction, the clearance of the sliding portion 1a becomes larger than that during the normal engine operation shown in FIG. 2 as shown in FIG.

During normal operation, even if liquid carbon or oil is deposited between the slider 5 and the housing 1, the atmospheric temperature is relatively high, so these do not solidify, and the slider 5 and the housing 1 do not solidify. It is possible to perform a normal operation in a state in which the sliding portion between 1 and 1 is interposed. However, if the temperature drops to the clearance during the normal operation, the carbon and oil components adhering to the sliding portion 1a are hardened, and the slider 5 and the housing 1 are fixed to each other. There is a fear that the rider 5 cannot rotate normally.

However, by using materials having different thermal expansion coefficients as described above, the clearance can be positively expanded at low temperatures, and the clearance will be large under the temperature conditions where the carbon and oil components solidify. Therefore, the slider 5 and the housing 1 are not fixed to each other due to the hardened dirt component, and the hardened dirt is not caught. Therefore, even if dirt such as carbon or oil adheres and the dirt solidifies when the engine is stopped after that, the slider 5 is normally rotated when restarting, and the normal amount of auxiliary air The control can be executed, and thus the low temperature startability can be improved.

Further, at the stage where the clearance is reduced as the temperature rises, it is possible to scrape off the contaminated dirt component with the sliding portion 1a as the slider 5 rotates. Further, although the increase in the clearance causes an increase in the amount of leaked air, generally, the required amount of the auxiliary air amount becomes large at a low temperature, so that the increase in the clearance largely impairs the original control function. There is no such thing.

In the above embodiment, both the housing 1 and the slider 5 are resin molded products, but the material is not limited to resin, and may be metal or a combination of metal and resin. Further, in the above-mentioned embodiment, the slider 5 having a cylindrical shape having the opening 6 on the peripheral wall is used, but any rotary shutter type idle control valve may be used, and for example, the opening 2 on the housing 1 side may be provided inside. An arc-shaped valve body that can be closed from the circumferential side may be used as the slider 5.

[0019]

[Effect of device]

 As described above, according to the present invention, even if dirt such as carbon or oil adhered during engine operation is hardened due to a temperature decrease after the engine is stopped, the slider and the housing are stuck or caught. It is possible to prevent the occurrence of the above, and thereby to operate the idle control valve normally at the time of low temperature restart and ensure good startability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a rotary shutter type idle control valve.

FIG. 2 is a sectional view showing a valve structure of the idle control valve of the above.

FIG. 3 is a cross-sectional view for explaining a clearance change in a low temperature state.

[Explanation of symbols]

 1 Housing 2 Opening 3 Ball Bearing 4 Rotating Shaft 5 Slider 6 Opening 7 Magnet 8 Coil

Claims (1)

[Scope of utility model registration request] 1. An idle control valve for an internal combustion engine installed in an auxiliary air passage that bypasses a throttle valve installed in an intake passage of the engine, the cylindrical housing having an opening in a peripheral wall thereof. A slider that is inserted into the inner circumference of the housing and that changes the passage area of the opening of the housing according to the rotational position, and that controls the amount of auxiliary air according to the passage area. An idle control valve for an internal combustion engine, which is made of a material having a thermal expansion coefficient larger than that of a housing.