JPH0224946Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to an auxiliary air supply device for an engine that supplies air by bypassing a throttle valve during warm-up or the like.

(Prior Art) For example, some engines use an auxiliary air supply device that bypasses the throttle valve to supply air during warm-up, thereby improving warm-up performance. .

As shown in Japanese Unexamined Patent Publication No. 59-5856, this auxiliary air supply device provides auxiliary air that bypasses the throttle valve in the intake passage of the throttle body of the engine, and adjusts the amount of auxiliary air flowing through this auxiliary passage to the temperature of the engine. It is configured with a valve mechanism that adjusts according to changes, and for example, the above-mentioned valve mechanism is configured as follows.

That is, the valve mechanism includes a housing that communicates with the auxiliary passage through an inlet and an outlet;
In addition to forming a valve hole in this housing, a thermally responsive cylinder that can expand and contract in response to engine temperature changes is provided, and a valve body is connected to the output rod of this cylinder via a valve stem. . When the temperature of the engine is low, such as during startup, the valve body is separated from the valve hole via the valve stem due to the contraction of the output rod, which causes the valve hole to become larger. When opened, a large amount of air is supplied to the engine. In addition, when warm-up progresses and the engine temperature reaches the set temperature or higher, the valve hole is closed by the valve body as the output rod expands, and the flow of water to the engine through the auxiliary passage. The air is shut off, which causes the engine to idle normally.

By the way, in the supply device having the above configuration, when the valve body is opened and closed through the valve stem by the expansion and contraction of the cylinder, for example, the movable part such as the valve stem slides back and forth using the inner surface of the housing as a guide surface. This allows the valve body to be accurately seated and unseated from the valve hole.

(Problem to be Solved by the Invention) However, the conventional auxiliary air supply device as described above is manufactured separately from the throttle body in which the throttle valve is installed, and has an auxiliary passage and an auxiliary air supply system that bypasses the throttle valve in the intake pipe. The inlet and outlet of the air supply device are aligned and fastened and fixed with screws, etc. via a sealing member, and such a configuration requires a large number of parts and a large number of assembly steps. However, productivity was poor and there were problems in terms of cost. It also poses a major hindrance in terms of miniaturization.

Therefore, an object of the present invention is to provide an auxiliary air supply device for an engine that can increase productivity, reduce costs, and be downsized by reducing the number of parts and assembly man-hours. There is a particular thing.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a throttle body which forms an intake passage of an engine and has a throttle valve in the intake passage, and a throttle body which forms an intake passage of the engine and has a throttle valve in the intake passage. a housing having an inlet and an outlet that bypass the valve; a valve hole provided in the housing; A thermally responsive cylinder that can expand and contract the output rod according to temperature changes,
A valve stem whose proximal end side accommodates the output rod and is slidably fitted into the outer surface of the cylinder of the cylinder and is reciprocated as the output rod expands and contracts, and the valve hole provided at the tip of the valve stem. In the auxiliary air supply device for an engine, which includes a valve body that opens and closes, the housing is molded integrally with the throttle body when the throttle body is molded, and one end of the housing on the side where the valve body is provided is connected to the intake passage. The auxiliary air supply device for the engine is opened along with a portion where an inlet or an outlet is formed, and an upstream pipe or a downstream pipe communicating with the intake passage is connected to this opening portion.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In the figure, 1 is an engine, and intake air flowing through an intake passage 2 of a throttle body 50 is supplied to this engine 1 via a surge tank 1a.
Note that 3 is a throttle valve.

The throttle body 50 and the housing 5 of the auxiliary air supply device 30 are made of the same material, and the housing 5 is integrally molded when the throttle body 50 is molded. The integral member consisting of the throttle body 50 and the housing 5 has an inflow port that communicates with the intake passage 2 of the throttle body 50 and the inside of the housing 5 at a position upstream of the position where the throttle valve 3 of the intake passage 2 in the throttle body 50 is provided. 6 is formed in the intake passage 2 of the throttle body 50 at a downstream position of the position provided in the throttle valve 3 of the intake passage 2 in the throttle body 50, and when the integral member consisting of the throttle body 50 and the housing 5 is a single unit, the intake passage 2 of the throttle body 50 One end of the housing 5 of the auxiliary air supply device 30 is opened in series with the part where the outlet 7 is formed, and by connecting the surge tank 1a to the core part, the one end of the housing 5 is connected to the surge tank housing 1b. An outflow port 7 is formed between the surge tank housing 1b and the throttle body 50, which communicates the intake passage 2 with the inside of the housing 5 and is isolated from the outside space. an inlet 6 that bypasses the throttle valve 3 as described above;
An outlet 7 is formed. Note that the throttle body 50 and the housing 5 of the auxiliary air supply device 30
and surge tank housing 1 of surge tank 1a
b is connected via a gasket 40 to prevent intake air from leaking from this connection.

A closing plate 9 is disposed within the housing 5, located between the inlet 6 and the outlet 7, and spaced apart from the surge tank housing 1b. It is divided into an inlet 6 side and an outlet 7 side. A valve hole 10 is formed in the center of the closing plate 9, and air flowing into the housing 5 through the inlet 6 is guided through the valve hole 10 and into the intake passage 2 through the outlet 7. It's becoming possible.

A thermally responsive cylinder 12 is accommodated within the housing 5, and this cylinder 12 is positioned away from the flow path connecting the inlet 6, valve hole 10, and outlet 7. This cylinder 12 is composed of a heat sensing section 13 and a cylinder section 14.
The cylinder portion 14 is located on the valve hole 10 side, and the heat sensing portion 13 is located on the left end side of the housing 5 as shown in the figure.
They are arranged with a gap 15 between them. Note that this gap 15 is kept liquid-tight by an O-ring 16 provided between the cylinder section 14 and the heat sensing section 13.

A cooling water inflow pipe 17 and a cooling water outflow pipe 18 are communicated with the gap 15 . Incidentally, the inflow pipe 17 and the outflow pipe 18 are also formed when the throttle body 50 and the housing 5 are molded. The inflow pipe 17 and the outflow pipe 18 are each connected to a cooling water passage (not shown) of the engine 1, and the cooling water flowing in this cooling water passage circulates through the gap 15 through the inflow pipe 17 and the outflow pipe 18. It's becoming like that. Therefore, the heat sensing section 13 senses the temperature of the engine 1 from the temperature of the cooling water, and based on this temperature change, the cylinder section 14
The output rod 14a is expanded and contracted in a direction along the flow direction A of the intake air. In this embodiment, the heat sensing section 13 is connected to the output rod 14 due to thermal expansion and contraction of thermowax or the like.
It has a structure that expands and contracts a. Further, 19 is an engagement pin that prevents the entire cylinder 12 from moving.

A valve rod 20 is connected to the cylinder portion 14 . The valve rod 20 has a proximal end slidably fitted to the outer surface of the cylinder tube 21 of the cylinder portion 14, and has a structure in which the output rod 14a is accommodated therein.

A valve body 22 is provided at the tip of the valve stem 20. The valve body 22 is composed of a cylindrical body with a substantially conical tip, and a plate 23 is fixed to a stepped portion inside the valve body 22. This plate 23 passes through the distal end side of the valve stem 20 and connects the large diameter portion 20a formed at the distal end to its tongue pieces 24, 24.
It has a structure that locks it in place. Note that 20b is a relief portion at the tip of the valve stem 20. Further, a connecting spring 25 is provided between the base end of the valve stem 20 and the plate 23, and this connecting spring 25
The valve rod 20 and the valve body 22 are connected to each other.
Note that 26 is a return spring installed between the valve body 22 and the closing plate 9, and the return spring 26 urges the valve body 22 in a direction away from the valve hole 10.

Next, the operation of one embodiment with the above configuration will be explained.

When starting the engine 1, the cooling water temperature is still low, so the output rod 14a of the thermally responsive cylinder 12 is in a contracted state. Therefore, the valve body 22 is pressed leftward in the drawing by the return spring 26, and the valve stem 20 is also slid leftward along the outer surface of the cylinder tube 21 via the connection spring 25. It is in a state of movement. As a result, the valve hole 10 is opened wide during startup, and even if the throttle valve 3 of the intake passage 2 is in a fully closed state, a large amount of auxiliary air bypasses the throttle valve 3 and flows through the inlet 6 and the valve hole. 10 and is supplied to the engine 1 via the outlet 7. Further, at this time, the amount of fuel is increased by a fuel injection device (not shown), thereby increasing the output of the engine 1 and improving its startability.

And in this way, engine 1 starts,
As the warm-up operation progresses, the temperature of the cooling water gradually increases. As a result, the heat sensing section 13 of the cylinder 12 detects this rise in the temperature of the cooling water, and gradually extends the output rod 14a. Therefore, as the valve stem 20 is slid in the same direction as the flow direction A of the intake air, that is, in the right direction in the figure, due to the extension of the output rod 14a, the valve body 22 is moved through the connection spring 25. And it is made to approach the valve hole 10 against the return spring 26. Therefore, since the opening degree of the valve body 10 is gradually reduced, the amount of auxiliary air supplied through the valve hole 10 is gradually reduced. Furthermore, in this case, since the fuel supply is gradually reduced, the output of the engine 1 is controlled in accordance with the progress of the warm-up operation.

When the warm-up operation is completed and the cooling water temperature reaches the set temperature, the valve body 22 is further closed to completely close the valve hole 10 and cut off the supply of auxiliary air. As a result, after the warm-up operation is completed, air is taken into the engine 1 through the throttle valve 3 of the intake passage 2, resulting in a normal idling state.

Note that if the cooling water temperature rises further than the set temperature, the tip of the valve stem 20
5 and escapes to a relief portion 20b within the valve body 22.

Furthermore, as the engine 1 is stopped and the cooling water temperature decreases, the output rod 14a contracts, and the valve rod 20 is pushed back in the direction opposite to the intake air flow direction A, that is, to the left in the figure. Valve body 22
is pushed back by the return spring 26, and the opening degree of the valve hole 10 returns to the state at the time of startup described above.

According to this embodiment, the throttle body 50 and the housing 5 of the auxiliary air supply device 30 are integrally formed, and one end of the housing 5 and the intake passage 2 of the throttle body 50 are connected to the outlet 7.
A surge tank 1 is opened in series with the forming portion and is provided on the downstream side of the throttle body 50.
a is connected to this opening, its surge tank housing 1b closes one end of the housing 5 at a distance from the closing plate 9 of the auxiliary air supply device 30, and the outlet 7 is connected to the throttle body 50 and the surge tank housing 1b. Since the interior of the housing 5 and the intake passage 2 are communicated with each other while being cut off from the external space, the members connecting the throttle body 50 and the auxiliary air supply device 30 and the housing 5 are connected to each other, as in the conventional structure. There is no need for any member to close one end of the device, and the number of parts is extremely reduced, and the space for arranging the connecting member and closing member can be eliminated, making it possible to reduce the size. Furthermore, the throttle body 50
The surge tank housing 1b is integrated with the housing 5, and one end of the housing 5 of the surge tank housing 1b is also used as a closing member, so that the external space and the airtight part are connected to the surge tank housing 1b, the throttle body 50, and the housing 5.
The airtightness between the throttle body 50 and the auxiliary air supply device 30 with respect to the external space is improved.

Note that this invention is not limited to the above embodiment; for example, the closing member for the opening at one end of the housing 5 was provided in the surge tank housing 1b on the downstream side of the throttle body 50; When the housing 5 and the housing 5 are integrally molded, the opening at one end of the housing 5 faces upstream of the intake passage 2, and the auxiliary air supply device 30 is arranged in the opposite direction to that shown in the figure. The molded portion 6 and one end of the housing 5 may be opened in series, and this opening may be connected to a pipe located upstream of the throttle body 50 in the same manner as in the above embodiment. In this case, as the engine 1 warms up, the valve rod 20 moves in the opposite direction to the flow direction A of the intake air.

Further, as a means for sensing the temperature of the engine 1, it may be possible to detect the temperature of the engine oil or the like in addition to the temperature of the cooling water.

Furthermore, the heat sensing portion 13 in the thermally responsive cylinder 12 is not limited to thermowax, but may also be made of bimetal, or may be an electric heating means such as a heat wire or PCT that is heated according to changes in the temperature of the engine 1. It is also possible to use

Note that the configuration of the present invention can also be applied to a device that controls the supply of auxiliary air using a linear solenoid valve or the like to control the idle rotational speed of the engine to a predetermined value when the engine is idling.

(Effects of the Invention) As described above, according to the present invention, there is provided a throttle body that forms an intake passage of an engine and has a throttle valve in the intake passage, and an inlet and an inflow port that bypasses the throttle valve of the intake passage. a housing having an outlet, a valve hole provided in the housing, and located within the housing away from a flow path connecting the inlet and the outlet;
A heat-responsive cylinder that can expand and contract the output rod according to engine temperature changes, and a base end of the cylinder that accommodates the output rod and is slidably fitted to the outer surface of the cylinder cylinder, and as the output rod expands and contracts. a valve stem that is reciprocated with the valve stem, and a valve stem provided at the tip of the valve stem,
In the auxiliary air supply device for an engine, which includes a valve body that opens and closes the valve hole, the housing is molded integrally with the throttle body during molding of the throttle body, and one end of the housing on the side where the valve body is provided. is an auxiliary air supply device for an engine, which opens together with the intake passage and a portion where the inlet or outlet is formed, and an upstream pipe or downstream pipe communicating with the intake passage is connected to this opening portion; There is no need for any parts to connect the throttle body and the auxiliary air control device or to close one end of the housing, which greatly reduces the number of parts and the number of assembly steps. It has the excellent effect of making it possible to downsize because the space for arranging the closing parts and closing parts can be eliminated. Furthermore, the airtight part with the outside space is only between the upstream pipe or the downstream pipe, making the throttle body Another advantageous effect is that the airtightness between the air supply and the auxiliary air supply device is greatly improved.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of this invention. 1...Engine, 1a...Surge tank, 1b
...Surge tank housing, 2...Intake passage,
3...Throttle valve, 5...Housing, 6...
Inflow port, 7... Outlet port, 10... Valve hole, 12...
Thermal responsive cylinder, 20... Valve stem, 21... Cylinder tube, 22... Valve body, 30... Auxiliary air supply device, 50... Throttle body.

Claims (1)

[Scope of utility model registration request] a throttle body forming an intake passage of an engine and having a throttle valve in the intake passage; a housing having an inlet and an outlet that bypass the throttle valve of the intake passage; and a valve hole provided in the housing; A thermally responsive cylinder is located within the housing away from the flow path connecting the inlet, valve hole, and outlet and is capable of expanding and contracting an output rod in response to changes in engine temperature; A valve rod whose end side accommodates the output rod and is slidably fitted therein and is reciprocated as the output rod expands and contracts; and a valve body provided at the tip of the valve rod to open and close the valve hole. In the auxiliary air supply device for an engine, the housing is molded integrally with the throttle body when the throttle body is molded, and one end of the housing on the side where the valve body is provided is connected to the intake passage and the inlet or air flow. 1. An auxiliary air supply device for an engine, characterized in that it opens together with a portion where an outlet is formed, and an upstream pipe or a downstream pipe that interlocks with the intake passage is connected to this opening portion.