JP2861288B2 - Auxiliary air amount control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary air amount control device for an internal combustion engine, and more particularly to an orientation structure of an engine temperature-responsive auxiliary air amount control valve.

<Conventional technology> Conventionally, an auxiliary air amount control valve (AAC valve) interposed in an auxiliary air passage that connects the upstream and downstream of an intake throttle valve by bypass.
An electric signal control type which is controlled based on a valve opening control signal from a control unit according to an operation state of an engine, a Japanese Utility Model Laid-Open No. 57-71753 and
As disclosed in JP-A-104340 and the like, a temperature-sensitive part that senses a cooling water temperature as an engine temperature, and a temperature-sensitive type that is controlled based on the cooling water temperature sensed by the temperature-sensitive part. Some are provided separately.

These auxiliary air amount control valves are respectively interposed in mutually parallel passage portions formed in the middle of the auxiliary ventilation passage.

By the way, the electric signal control type auxiliary air amount control valve 1 and the temperature responsive type auxiliary air amount control valve 2 form the above-mentioned parallel passage portions 3 and 4 as shown in FIG. It is provided integrally with the valve assembly 5,
The valve assembly 5 is supported and attached to the air duct 6 or the like by hanging it.

For this reason, the temperature sensing part of the temperature-responsive auxiliary air amount control valve 2
It is necessary to guide the passage of the engine cooling water for rushing into the valve assembly 5 to the valve assembly 5. Conventionally, the cooling water feed pipe 9 through which the cooling water is guided from the water jacket 8 on the cylinder head 7 side, and the pipe 9 and a return pipe 13 for communicating cooling water to a cooling water passage returning the cooling water to the water jacket 12 on the cylinder block 11 side via a water pump 10, and the temperature sensing part 2 a is connected to the cooling water feed pipe 9 and the cooling water It is provided so as to protrude into a connection portion with the return pipe 13.

<Problems to be Solved by the Invention> However, the conventional arrangement structure of the temperature-responsive auxiliary air amount control valve has the following various problems.

That is, a cooling water pipe such as the cooling water feed pipe 9 and the cooling water return pipe 13 as described above is required, and since this pipe is long and has a smaller pipe diameter than a pipe of a normal cooling system, the passage resistance is large. Therefore, a large amount of cooling water cannot be flowed.

In addition, since the piping is long, the heat mass is large, and the temperature rise characteristic with respect to the rise of the engine cooling water temperature is poor.

As a result, there is a problem that the responsiveness of the temperature-responsive auxiliary air amount control valve 2 is poor and the controllability is poor.

Therefore, if the pipe diameter of the pipe is increased to increase the amount of cooling water to the pipe to improve the responsiveness,
The cooling water circulation amount of the normal engine decreases (W _P = W ₁ + in the figure)
When W ₃ is increased by W ₂ + W ₃ [constant], W ₁ becomes small), the amount of cooling water reaching the water jacket 12 via the radiator 14 and the water pump 10 and the water pump 10 is directly passed without passing through the radiator 14. The responsiveness of the thermostat 15 that controls the amount of cooling water that reaches the water jacket 12 via the heat pump 15 deteriorates, and the heat mass increases.

Further, since the valve assembly 5 is supported and attached to the air duct 6 or the like by hanging it, there is an inconvenience that the valve assembly 5 receives vibrations of the intake system directly and adversely affects durability.

Therefore, the present invention has been made in view of the above conventional problems,
A temperature-sensitive auxiliary air amount control valve disposed in an auxiliary air passage that bypasses the upstream and downstream of the intake throttle valve and controlled based on the engine temperature sensed by a temperature sensing unit that senses the engine temperature. It is an object of the present invention to improve the installation structure, improve the response of the auxiliary air amount control valve, and improve the controllability.

<Means for Solving the Problems> Therefore, in the present invention, an intake air passage is provided with an auxiliary air passage provided so as to bypass an intake throttle valve interposed in the passage, and a temperature sensitive sensor for sensing an engine temperature. A supplementary air amount control device for an internal combustion engine, comprising an auxiliary air amount control valve that is controlled based on the engine temperature sensed by the temperature sensing unit in the auxiliary air passage. A valve is disposed near a cylinder head end in the cylinder row direction, and the auxiliary air amount control valve is directly attached to an outer wall surface of a cylinder head corresponding to a water jacket forming portion on the cylinder head end side; Was inserted into the water jacket.

<Operation> In such a configuration, since the temperature sensing portion of the auxiliary air amount control valve is directly exposed to the water jacket of the cylinder head, it is possible to directly sense the water temperature near the combustion chamber, and it is possible to detect the water temperature as in the conventional case. There is no need for a cooling water pipe such as a cooling water feed pipe and a cooling water return pipe, and there is no passage resistance and no heat mass.

As a result, the temperature rising characteristics of the temperature sensing portion with respect to the rise of the engine cooling water temperature are improved, and the responsiveness of the auxiliary air amount control valve is improved, so that the controllability can be improved.

Further, since there is no need to guide the cooling water from the normal cooling system to the water temperature sensing part, there is no effect on the normal engine cooling water circulation amount, and deterioration of the responsiveness of a thermostat or the like can be prevented.

Further, the vibration resistance of the auxiliary air amount control valve is improved, and the durability can be improved. .

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

In the drawings described below, the same elements as those in FIG. 4 are denoted by the same reference numerals, and the description will be simplified.

In FIG. 1, as a cooling water passage of the engine E, a water jacket continuous around the cylinder 16 and the combustion chamber 17 is provided.
8 and 12 are provided on the cylinder head 7 side and the cylinder block 11 side. An outlet pipe 18 and an inlet pipe 19 as main cooling water passages connecting the water jackets 8, 12 and the water pump 10 via a radiator 14 are provided so as to be connected to the water jackets 8, 12. Further, a bottom bypass pipe 20 as a bypass cooling water passage extending from the water jackets 8 and 12 to the water pump 10 by bypassing the radiator 14 is provided so as to be connected to the water jacket 8.

At the junction of the inlet pipe 19 and the bottom bypass pipe 20, a bottom bypass type thermostat 15 for adjusting the mixing ratio of the cooling water flowing through the pipes 19 and 20 is provided.

The water jacket 8 on the cylinder head 7 side, the thermostat 15 of the bottom bypass pipe 20, and the water pump 10 are connected via a heater return pipe 21. The heater return pipe 21 is connected to a heater housing 22. A heater cock 23 located upstream of the housing 22 is interposed.

On the other hand, the cylinder 16 in which the piston 24 is slidably disposed
The combustion chamber 17 has an intake manifold 25 and a collector
An air duct 6 having an intake throttle valve 27 therein is connected via 26.

In such a configuration, the intake throttle valve 27 is disposed near the rear end of the cylinder head 7 in the cylinder row direction.

An auxiliary air passage 28 is connected to the air duct 6, bypassing the intake throttle valve 27.

In the middle of the auxiliary air passage 28, two parallel passage portions
29 and 30 are formed.

One of the passages 29 is provided with an electric signal control type auxiliary air amount control valve 31 controlled based on a valve opening control signal from a control unit according to the operating state of the engine E.
Is interposed.

The other passage section 30 has a water temperature sensing section 32a for sensing a cooling water temperature as an engine temperature.
A temperature-responsive auxiliary air amount control valve 32 controlled based on the cooling water temperature sensed by the controller is interposed.

Here, the temperature-responsive auxiliary air amount control valve 32 is connected to the water jacket 8 at the rear end of the cylinder head 7.
The water temperature sensing part 32a is directly mounted on the outer wall surface of the cylinder head 7 corresponding to the portion where the water jacket 8 is formed.

The arrangement of the temperature-responsive auxiliary air amount control valve 32 will be specifically described with reference to FIGS. 2 and 3. FIG.

In these figures, a rocker cover 33 is provided on the cylinder head 7 above the cylinder block 11,
On the rocker cover 33, the collector 26 is disposed. The air duct 6 described above is connected to the collector 26.

The air duct 6 is provided with a throttle chamber 34 in which an intake throttle valve 27 is mounted.

One end of a hose 36 constituting an auxiliary air passage is connected to a continuous pipe 35 communicating with the air duct 6 at an upstream side of the interposition position of the throttle chamber 34. The other end of the hose 36 is connected to an air inlet 38 of a valve assembly 37 described later.
Connected to.

One end of a hose 40 forming an auxiliary air passage is connected to a connection pipe 39 communicating with the air duct 6 at a position downstream of the interposition position of the throttle chamber 34. This hose 40
Is connected to the air outlet 41 of the valve assembly 37.

These hoses 36 and 40 constitute the auxiliary air passage 28.

The valve assembly 37 includes the auxiliary air passage 28
Two parallel passages 29, 30 are provided integrally,
An electric signal control type auxiliary air amount control valve 31 interposed in one passage 29 and a temperature sensitive auxiliary air amount control valve 32 interposed in the other passage 30 are integrally provided.

Further, insertion holes 43 for mounting bolts 42 of the assembly 37 are formed at four corners of the valve assembly 37.

Note that a water temperature sensing part 32a of the temperature-sensitive auxiliary air flow control valve 32 protrudes outside from a mounting surface on the back surface of the valve assembly 37.

A substantially square valve mounting portion 44 is formed at the rear end of the cylinder head 7 (the end on the side of the air duct 6), and a central portion of the valve mounting portion 44 communicates with the water jacket 8. A communication hole 45 is formed. The four corners of the valve mounting part 44 are respectively provided with mounting bolts 42.
Screw holes 46 are formed.

The valve assembly 37 has a rear mounting surface abutting against a valve mounting portion 44 of the cylinder head 7 via a seal gasket 47, and connects the water temperature sensing portion 32a to the communication hole 45.
Through the water jacket 8 and set it,
The mounting bolts 42 inserted into the respective insertion holes 43 are screwed into the screw holes 46 and fixedly mounted on the outer wall surface of the cylinder head 7.

In this case, the valve assembly 37 is located above the transmission (not shown).

In FIG. 2, reference numeral 48 denotes an oil hole for engine lubrication, 49 denotes a heater outlet, 50 denotes a core hole,
51 is an exhaust manifold.

As described above, the two parallel passage portions 29 and 30 of the auxiliary air passage 28 are provided integrally, and the electric signal control type auxiliary air amount control valve 31 and the temperature sensitive type auxiliary air amount control valve 32
The valve assembly 37 is integrally mounted on the cylinder head 7 and the water temperature sensing part 32a of the temperature-sensitive auxiliary air flow control valve 32 is inserted into the water jacket 8 to provide the following. It has the following functions and effects.

That is, the water temperature sensing portion of the temperature-responsive auxiliary air amount control valve 32
Since 32a faces directly into the water jacket 8 of the cylinder head 7, the water temperature near the combustion chamber 17 can be sensed directly, and the cooling water feed pipe and the cooling water return pipe as in the prior art can be used. No piping is required, there is no passage resistance and there is no heat mass.

As a result, the temperature rising characteristic of the water temperature sensing part 32a with respect to the increase of the engine water temperature becomes good, and the responsiveness of the temperature-responsive auxiliary air amount control valve 32 becomes good, whereby the controllability can be improved.

In addition, since there is no need to guide the cooling water from the normal cooling system to the water temperature sensing part 32a, there is no effect on the cooling water circulation amount of the normal engine (W _P = W ₁ + W ₂ + W ₃ in the figure). The cooling water flow W ₃ ) to the section and the deterioration of the responsiveness of the thermostat 15 can be prevented.

Further, since the valve assembly 37 is directly attached to the cylinder head 7, the valve assembly 37 is not directly subjected to the vibration of the intake system, so that the vibration proof performance is improved and the durability can be improved.

In the present embodiment, the valve assembly 37 is fixedly attached to the rear end of the cylinder head 7.
The valve assembly 37 can be located in an empty space above the transmission, which is advantageous in layout.

Note that the configuration of the above embodiment does not indicate a structural restriction of the present invention, and the present invention basically has a temperature sensing portion for sensing the engine temperature, and based on the engine temperature sensed by the temperature sensing portion. In a configuration in which a controlled auxiliary air amount control valve is provided in an auxiliary air passage that bypasses an intake throttle valve of an intake passage, the intake throttle valve is disposed near an end of a cylinder head in a cylinder row direction. If the auxiliary air amount control valve is directly attached to the outer wall surface of the cylinder head corresponding to the water jacket forming part on the end side of the cylinder head, and the temperature sensing part is inserted into the water jacket so as to be mounted. good.

For example, in this embodiment, a valve assembly 37 in which an electric signal control type auxiliary air amount control valve 31 and a temperature sensitive type auxiliary air amount control valve 32 are integrally mounted is fixedly mounted on the cylinder head 7. Although the configuration has been shown, any configuration may be used as long as the temperature-responsive auxiliary air amount control valve 32 is directly attached to the cylinder head 7, and this configuration can solve the conventional problems.

<Effects of the Invention> As described above, according to the present invention, an auxiliary air amount control valve having a temperature sensing portion for sensing an engine temperature and controlled based on the engine temperature sensed by the temperature sensing portion Is disposed in an auxiliary air passage that bypasses an intake throttle valve of an intake passage, wherein the intake throttle valve is disposed near an end of a cylinder head in a cylinder row direction, and the auxiliary air amount control valve is connected to the cylinder. Directly attached to the cylinder head outer wall surface corresponding to the water jacket forming part on the head end side,
Since the temperature sensing portion is inserted into the water jacket so as to be attached thereto, the temperature rising characteristics of the temperature sensing portion with respect to an increase in engine temperature are improved, and the responsiveness of the auxiliary air amount control valve is improved. Performance can be improved.

In addition, since there is no need to guide the cooling water from the normal cooling system to the temperature sensing part, it is possible to prevent deterioration of the responsiveness of a thermostat or the like for controlling the cooling water amount.

Further, the vibration resistance of the auxiliary air amount control valve can be improved, and the durability can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an auxiliary air amount control device for an internal combustion engine according to the present invention, and FIGS. 2 and 3 are specific examples of the arrangement structure of a temperature-responsive auxiliary air amount control valve in the above embodiment. FIG. 4 is a front view and a perspective view showing the configuration, and FIG. 4 is a schematic configuration diagram of a conventional auxiliary air amount control device. 6 ... air duct, 7 ... cylinder head, 8 ... water jacket, 27 ... intake throttle valve, 28 ... auxiliary air passage, 30 ... passage section, 32 ... temperature-responsive auxiliary air amount control valve , 32a… water temperature sensing part, 36, 40… hose, 37… valve assembly, 42… mounting bolt, 43… insertion hole, 44… valve mounting part, 45… communication hole, 46… ... Screw hole, E ... Engine

Claims (1)

(57) [Claims] An intake passage includes an auxiliary air passage provided in the intake passage so as to bypass an intake throttle valve interposed in the intake passage, and has a temperature sensing portion for sensing engine temperature, which is sensed by the temperature sensing portion. In the auxiliary air amount control device for an internal combustion engine, wherein an auxiliary air amount control valve controlled based on the engine temperature is provided in the auxiliary air passage, the intake throttle valve is provided near a cylinder head end in a cylinder row direction. While arranging, the auxiliary air amount control valve is directly attached to the outer wall surface of the cylinder head corresponding to the water jacket forming portion on the end side of the cylinder head, and the temperature sensing portion is inserted into the water jacket so as to be attached. An auxiliary air amount control device for an internal combustion engine, comprising: