JPH073013Y2 - Auxiliary air control valve for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an auxiliary air control valve for an internal combustion engine, and in particular,
The present invention relates to a rotary valve type auxiliary air control valve that introduces auxiliary air according to the temperature of engine cooling water.

2. Description of the Related Art As an auxiliary air control valve that controls the amount of auxiliary air according to the temperature of cooling water, for example, the auxiliary air control valve having the configuration shown in FIG. 2 is known. In the figure, 31 is a casing in which an air passage portion 32 which is a part of the auxiliary air passage is formed, and 33 is a rotating shaft arranged so as to cross the air passage portion 32. The valve body 3 for opening and closing the opening 32a of the air passage portion 32 in the 33
4 is fixed, and a spiral bimetal 35 is attached to one end thereof.

The spiral bimetal 35 is accommodated in a bimetal accommodating chamber 36 that is recessed at one end of the casing 31.
The base end is fixed to a bimetal bracket 37 that closes the bimetal storage chamber 36. A cooling water passage 38 is formed in the casing 31 in the vicinity of the bimetal storage chamber 36, and a part of the engine cooling water is guided from the engine intake manifold or the like. Incidentally, this cooling water passage 38
Since it is formed at the same time as the casing 31 is cast, it is difficult to secure a large volume, and it is provided in a part of the casing 31.

That is, the auxiliary air control valve controls the amount of auxiliary air according to the temperature of the cooling water that represents the engine temperature,
When the cooling water temperature is low, such as when the engine is cold started,
Due to the contraction of the spiral bimetal 35, the opening degree of the valve element 34 becomes large, and a large amount of auxiliary air bypasses the engine slot valve and is introduced into the engine. When the temperature of the cooling water rises due to the progress of warming up of the internal combustion engine, the spiral bimetal 35 thermally expands, the opening degree of the valve element 34 gradually decreases, and the amount of auxiliary air decreases.

In the above example, the permanent magnet 39 and the electromagnetic coil 40, which are a kind of motor for driving the rotating shaft 33, are integrally provided in the casing 31, and this assists the feedback control of the idle speed. It is configured to control the air amount at the same time.

However, in the above-mentioned conventional configuration, the cooling water passage
Since 38 is formed in the casing 31, the heat of the cooling water is first transferred to the casing 31 and then transferred to the spiral bimetal 35 via the bimetal bracket 37 and the like. Therefore, when the outside temperature is low, the casing 31
A large amount of heat is taken away through the spiral spiral bimetal.
The temperature of 35 is much lower than the actual cooling water temperature. That is, the opening degree of the valve element 34 is easily affected by the outside air temperature, and it is not possible to achieve highly accurate control of the auxiliary air amount corresponding to the actual engine warm-up state. If the cooling water passage 38 is formed so as to surround the entire spiral bimetal 35, the heat transfer is naturally improved, but the casing 31 and thus the entire auxiliary air control valve will be greatly enlarged.

Means for Solving the Problems An auxiliary air control valve for an internal combustion engine according to the present invention includes a casing which is interposed in an auxiliary air passage and has a cylindrical recess formed at one end, and a valve body which opens and closes the auxiliary air passage. And an auxiliary air control valve for an internal combustion engine, which comprises a rotating shaft having a spiral bimetal attached to one end thereof, and a bearing holder inserted into the cylindrical recess of the casing to support the rotating shaft. In the above bearing holder, the outer peripheral portion is fitted to the inner peripheral portion of the cylindrical concave portion, and the outer peripheral portion is formed on the inner peripheral portion of the cylindrical concave portion like the disc-shaped first flange portion which separates the bimetal storage chamber on the outer side of the casing. Fitting, and forming a cooling water passage over the entire circumference with the first flange portion,
A disk-shaped second flange portion for partitioning the cooling water passage and the auxiliary air passage side, and a cylinder integrally formed in the central portion of the first and second flange portions and through which the rotating shaft passes. And a part.

Action According to the above configuration, the cooling water passage is formed to be large over the entire circumference between the first and second flange portions so as to surround the cylindrical portion of the bearing holder, and the engine cooling water flows therethrough.
Moreover, the cooling water passage and the bimetal storage chamber are adjacent to each other with the disc-shaped first flange portion interposed therebetween. Therefore,
The heat of the cooling water is transferred to the spiral bimetal via the bearing holder. That is, heat is exchanged inside the casing. Therefore, the influence of the outside temperature is reduced.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an idle speed control valve 1 for an internal combustion engine to which the present invention is applied. The idle speed control valve 1 is interposed in an auxiliary air passage 2 formed by bypassing a stottle valve of an internal combustion engine, and is designed to mechanically control the amount of auxiliary air according to the engine cooling water temperature. The first auxiliary air control valve 3 according to the above and the second auxiliary air control valve 4 which controls the feedback control of the idle speed are integrally configured.

That is, the auxiliary air passage 2 is provided at the center of the casing 5.
And a rectangular opening 6a and 6b communicating with the auxiliary air passage 2 are formed on the upstream side and the downstream side of the space 6, respectively. The upstream opening 6a is opened and closed by the valve body 7 of the first auxiliary air control valve 3, and the downstream opening 6b is opened and closed by the valve body 8 of the second auxiliary air control valve 4.

The second auxiliary air control valve 4 includes the valve body 8, a rotary shaft 9 fixed to one end of the valve body 8 and arranged concentrically with the cylindrical space 6, and the rotary shaft 9 The permanent magnet 10 attached to the other end of the
An electromagnetic coil 11 disposed together with 12 is mainly configured. The core 12 includes a pair of semi-cylindrical magnetic pole portions 12
A and 12b are formed to face each other so as to surround the permanent magnet 10. The second auxiliary air control valve 4 is adapted to generate a driving torque in the opening direction or the closing direction according to the energization direction of the electromagnetic coil 11, and the duty ratio of the drive pulse signal, that is, the time ratio in the energization direction. Is configured to control the opening of the valve body 8.

Next, the first auxiliary air control valve 3 has a rotation shaft 13 coaxial with the rotation shaft 9 of the second auxiliary air control valve 4, and the valve body 7 is fixed to one end of the rotation shaft 13. A spiral bimetal 15 is attached to the other end. The rotating shaft 13 is rotatably supported by a bearing holder 14 formed of a member different from the casing 5. The bearing holder 14 is inserted and arranged in a cylindrical recess 16 formed in one end of the casing 5, and has a cylindrical portion 17 through which the rotary shaft 13 penetrates.
And an aluminum alloy or the like having a disk-shaped first flange portion 18 and a second flange portion 19 formed along the direction orthogonal to the rotating shaft 13 and having excellent heat conductivity. The whole is integrally formed by using. The first flange portion 18 and the second flange portion 19 are formed in parallel with each other with an appropriate interval, and are fitted relatively tightly to the inner peripheral surface of the cylindrical recess 16 of the casing 5. Above cylindrical part 17
Are connected to the central portions of the first flange portion 18 and the second flange portion 19.

A cover 20 is attached to the outside of the cylindrical recess 16 so as to cover the first flange portion 18 of the bearing holder 14, whereby a bimetal storage chamber 21 is separated. A cooling water passage 22 is formed between the first flange portion 18 and the second flange portion 19. That is, the first flange portion 18 separates the bimetal storage chamber 21 and the cooling water passage 22 from each other, and the second flange portion 19 separates the cooling water passage 22 and the cylindrical space 6 from each other.

Reference numerals 23 and 24 are O-rings that are mounted on the outer peripheral portions of the first and second flange portions 18 and 19 to seal the space with the casing 5, 25
Indicates a bearing sleeve.

Now, in the first auxiliary air control valve 3 having the above-mentioned configuration, the cooling water passage 22 formed between the first and second flange portions 18 and 19 of the bearing holder 14 has a cooling water inlet and a cooling water not shown in the drawing. A part of the engine cooling water is guided through the outlet, and the opening degree of the valve body 7 is determined by the contraction and expansion of the spiral bimetal 15 according to the temperature thereof. Here, the heat of the cooling water is mainly transmitted to the spiral bimetal 15 through the cylindrical portion 17 of the bearing holder 14 and the rotating shaft 13, and a part of the heat is transmitted from the outer peripheral portion of the first flange portion 18 to the spiral bimetal 15. To be done. In addition, some heat is
The ambient temperature in the bimetal storage chamber 21 is raised through the flange portion 18, and is transmitted to the spiral bimetal 15 via this. That is, it is possible to transfer heat from the cooling water passage 22 to the spiral bimetal 15 without passing through the casing 5 exposed to the outside, and therefore it is less affected even when the outside air temperature is low. Further, according to the structure in which the bearing holder 14 is formed as a separate member from the casing 5 as described above, the cooling water passage 22 can be formed in an annular shape that covers the entire circumference of the cylindrical portion 17, and the cylindrical portion 17 and First flange part
Since the wall thickness of 18 can be made as thin as possible, also in this respect, it becomes possible to efficiently transfer heat from the cooling water to the spiral bimetal 15.

In the above embodiment, the valve body 7 exposed to the flow of the auxiliary air is made of synthetic resin, and the valve body 7 is rotated from the rotary shaft 13 to the valve body 7.
The heat is prevented from escaping through. Further, if the cover 20 and the casing 5 that cover the bimetal storage chamber 21 are made of a material having excellent heat insulating properties, the influence of the outside temperature can be further reduced.

In the above embodiment, the first auxiliary air control valve 3 according to the present invention is integrated with the second auxiliary air control valve 4 for the feedback control of the idle speed. However, the present invention is described above. The present invention is not limited to the example,
It goes without saying that it can be configured as a single auxiliary air control valve that introduces auxiliary air according to the engine cooling water temperature.

Effect of the Invention As is clear from the above description, in the auxiliary air control valve of the internal combustion engine according to the present invention, heat is efficiently transferred from the engine cooling water to the spiral bimetal through the bearing holder inside the casing. be able to. Therefore, compared to the conventional configuration that heats the entire casing, the influence of the outside temperature is significantly reduced, and even when the outside temperature is extremely low or extremely high, the actual warm-up state of the internal combustion engine The amount of auxiliary air corresponding to can be accurately given. Further, since the cooling water passage and the bimetal storage chamber are arranged adjacent to each other, the casing does not increase in size and the auxiliary air control valve can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view of the entire idle speed control valve showing an embodiment of the present invention, and FIG. 2 is a sectional view showing an example of a conventional auxiliary air control valve. 3 ... 1st auxiliary air control valve, 13 ... Rotating shaft, 14 ... Bearing holder, 15 ... Spiral bimetal, 16 ... Cylindrical recessed part, 17 ... Cylindrical part, 18 ... 1st flange part, 19 ... 2nd flange part, 21 ... Bimetal storage room, 22 ... Cooling water passage.

Claims (1)

[Scope of utility model registration request] 1. A casing interposed in an auxiliary air passage and having a cylindrical recess formed at one end, a valve body for opening and closing the auxiliary air intake passage is fixed, and a spiral bimetal is attached at one end. An auxiliary air control valve for an internal combustion engine, comprising: a rotating shaft; and a bearing holder that is inserted into a cylindrical recess of the casing to support the rotating shaft. Between a disk-shaped first flange portion that fits on the inner periphery and separates the bimetal storage chamber on the outer side of the casing, and an outer periphery portion that also fits on the inner periphery of the cylindrical recess, and between the first flange portion. A cooling water passage over the entire circumference, and a disc-shaped second flange portion for partitioning the cooling water passage and the auxiliary air passage side, and a center portion of these first and second flange portions. It is integrally formed and the rotation shaft penetrates it. Auxiliary air control valve for an internal combustion engine and having a cylindrical portion, a.