JPH10317995A - Warming-up accelerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fuel economy of an internal combustion engine by easily accelerating its warming-up with no excessive rise in its load. SOLUTION: A warming-up accelerator, which involves an exhaust throttle valve 13 arranged in an exhaust port 9 on an engine 1 to throttle exhaust gas, accelerates a warming-up of the engine 1 by the operation of the valve 13 while the engine 1 is cool. The port 9 is provided with a cooling water passage 14A defined according to at least the portion of the port 9 where the valve 13 is arranged, and is shaped up at least part of its inside wall along the direction of exhaust gas flowing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a warm-up promoting device,
More specifically, the present invention relates to a warm-up promoting device for warming up an internal combustion engine from an overcooled state to an appropriate temperature after starting the internal combustion engine, that is, for promoting so-called warm-up.

[0002]

BACKGROUND OF THE INVENTION Since internal combustion engines are designed to operate well over a certain temperature range, overheating is poor but overcooling is undesirable.

[0003] In the overcooled state, the temperature of the entire internal combustion engine is low, so that the fuel is difficult to vaporize or ignite, or the combustion speed is reduced. Further, since the clearance of each component constituting the internal combustion engine is designed to be just right in an assumed temperature range, a gap between the components is too large in a low temperature state out of the temperature range. For example, in terms of the relationship between the cylinder and the piston, if the gap between the two is large, the air-fuel mixture or the combustion gas easily blows through the gap. In addition, even if there is a clearance between other components, if the clearance is large, a phenomenon such as being hit by a rotating portion or a sliding portion is likely to occur.

Further, in the overcooled state, the temperature of the engine oil is low, so that the viscosity thereof is high, and therefore the friction increases. For the above reasons, in an overcooled state such as when the internal combustion engine is started, the inherent power and throttle response of the internal combustion engine cannot be expected, and if a large load is applied in the overcooled state, the internal combustion engine may be damaged.

[0005] Therefore, it is necessary to warm up the internal combustion engine immediately after starting, and it is necessary to quickly warm up the internal combustion engine. Therefore, a technology that promotes warm-up by narrowing the exhaust pipe passage when the engine temperature is low is disclosed in, for example,
No. 1373409.

[0006]

However, the prior art as described in the above-mentioned publications merely increases the pumping loss by narrowing the exhaust pipe, thereby increasing the load on the engine and receiving the cooling water from the engine. Since the warm-up is promoted by increasing the amount of heat, the load on the internal combustion engine must be excessively increased in order to promote the warm-up, and as a result, fuel economy is deteriorated.

[0007] The present invention has been made in view of the above points, and the present invention facilitates warm-up easily without excessively increasing the load on an internal combustion engine, and as a result, can improve fuel economy. It is to provide a promotion device.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, a warm-up promoting device of the present invention has the following configuration. That is, the warm-up promoting device of the present invention includes exhaust throttle means for narrowing the flow of exhaust gas in the exhaust passage of the internal combustion engine, and warms up the warm-up by operating the exhaust throttle means when the internal combustion engine is cold. In the machine promotion device, the exhaust passage includes:
A cooling water passage is provided so as to correspond to at least a portion where the exhaust throttle means is provided. In addition, it is preferable that at least a part of the inner wall surface of the exhaust passage is formed so as to be in a form along the direction of the flow of the exhaust gas when the exhaust gas is throttled by the exhaust throttle means.

Further, the exhaust passage inner wall surface or / and / or the exhaust passage at the place where the exhaust throttle means is provided.
Further, it is more preferable that the inner wall surface of the cooling water passage has a fin shape.

In the warming-up promoting device of the present invention, when the exhaust throttle means is operated to reduce the flow of the exhaust gas, the pressure loss at that time generates heat in the portion of the exhaust passage where the exhaust throttle means is provided. However, since the cooling water passage is provided at a position corresponding to the exhaust throttle means, most of the heat is recovered by the cooling water flowing in the cooling water passage.
That is, since the heat is efficiently recovered by the cooling water, the load on the internal combustion engine does not need to be excessively increased in order to promote warm-up. Therefore, fuel efficiency is improved.

Further, at least a part of the inner wall surfaces of the exhaust passage is formed so as to be in a form along the flow direction of the exhaust gas when the flow of the exhaust gas is reduced by the exhaust throttle means. Exhaust gas flow is smooth,
Since the flow rate of the exhaust gas increases, the amount of heat generated by the cooling water increases without increasing the load on the internal combustion engine excessively.

Further, the heat receiving area at the place where the exhaust throttle means is provided is increased by making the inner wall face of the exhaust passage or the inner wall face of the cooling water passage at the place where the exhaust throttle means is provided. Therefore, the efficiency of collecting heat generated due to the pressure loss when the flow of the exhaust gas is reduced by the exhaust throttle means is improved. Therefore, in this case, fuel efficiency is further improved.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. <Description of Apparatus Configuration> This will be described with reference to FIGS.

A piston 3 is provided in a cylinder bore 2a formed in a cylinder block 2 of a diesel engine 1 as an internal combustion engine so as to be vertically movable. Also,
The piston 3 is connected to a crankshaft (not shown) via a connecting rod 4.

A recess (hereinafter referred to as "combustion chamber") 6 for the combustion chamber is formed in the piston head 3a. A cylinder head 7 is mounted and fixed on an upper portion of the cylinder block 2, and an intake port 8 and an exhaust port 9 facing the combustion chamber 6 are provided inside the cylinder head 7. Further, the intake port 8 and the exhaust port 9 incorporate an intake valve 8a and an exhaust valve 9a, respectively. An injection 11 is disposed between the intake valve 8a and the exhaust valve 9a so as to face the combustion chamber 6, and fuel is injected from the injection 11 into the combustion chamber 6. The injection 11 pumps an appropriate amount of fuel to the combustion chamber 6 at an appropriate time and at a high pressure by an injection pump (not shown). The injection pump has a rotation speed sensor 11 for detecting an engine rotation speed.
a is attached.

The intake port 8 is connected to an intake pipe 8b, and the exhaust port (exhaust passage) 9 is connected to an exhaust pipe (exhaust passage) 9b. A throttle valve 12 is incorporated in the intake port 8, and its opening is detected by an idle switch (throttle sensor) 12a provided on the rotation shaft of the throttle valve 12.

Outside air is introduced from an air cleaner (not shown) into the intake port 8 via the intake pipe 8a, and fuel is injected from the injector 11 toward the combustion chamber 6, and a mixture of the injected fuel and the outside air is formed. Due to the high pressure during combustion in the combustion process, the piston 3 moves down the cylinder bore 2 a and rotates the crankshaft via the connecting rod 4.

In the exhaust step, the combustion gas is
When the exhaust valve 9a is opened, the gas is exhausted from the exhaust port 9 to the outside through the exhaust pipe 9b. The exhaust port 9 is provided with an exhaust throttle valve (exhaust throttle means) 13. The exhaust throttle valve 13 is driven together with the throttle valve 12 by drive means such as a drive motor (not shown).
The exhaust throttle valve 13 is also provided with a sensor for detecting the opening thereof, like the throttle valve 12, but is omitted here.

The exhaust port 9 corresponds to the portion of the cylinder head 7 where the exhaust throttle valve 13 is provided.
Around the cooling water passage 14 is formed. The cooling water passage 14 is provided not only around the exhaust port 9 but also around the intake port 8.
Around and the cylinder bore 2 of the cylinder block 2
It is also formed around a. Of these cooling water passages 14, at least the cooling water passage 14 around the exhaust port 9 is provided with a water temperature sensor 14a. The cooling water passage 14 around the exhaust port 9 is referred to as another cooling water passage 1.
For convenience, it is indicated by reference numeral 14A.

The rotation speed sensor 11a, idle switch 12a and water temperature sensor 14a are electrically connected to an engine electronic control unit (hereinafter referred to as "ECU") 16. The ECU 16 calculates the parameters output by the sensors 11a, 12a, and 14a to drive the driving means of the exhaust throttle valve 13. As a result, the exhaust throttle valve 13 The valve is opened as appropriate.

<Flow> Next, an open / close control routine of the exhaust throttle valve will be described with reference to flowcharts shown in FIGS.

After the engine 1 is started, when the processing shifts to this routine, first in step 101,
The ECU determines whether the engine speed is equal to or less than 2000 revolutions per minute based on the parameters of the revolution speed sensor 11a.
16 (hereinafter, the determination by the ECU 16 is simply referred to as “determination”). This numerical value is one standard for making the warm-up function work, and is not a fixed numerical value, but naturally varies depending on running conditions and vehicle type. Note that the same applies to other numerical values shown below in this flowchart, and is merely one exemplary numerical value.

If the engine speed is less than 2000 revolutions per minute, an affirmative decision is made and the routine proceeds to step 102. If the engine speed is greater than 2000 revolutions per minute, a negative determination is made and the routine proceeds to step 103, where the exhaust throttle valve 13 is opened, and the routine returns to step 101.

In step 102, it is determined whether the coolant temperature of the cooling water passage 14A, which is the engine coolant temperature, is, for example, 60 ° C. or less. If the engine water temperature is 60 ° C. or lower, the determination is affirmative and the routine proceeds to step 104. If the engine water temperature is higher than 60 ° C., a negative determination is made and the routine proceeds to step 103, where the exhaust throttle valve 13 is opened, and the routine returns to step 101.

In step 104, whether the engine 1 is in an idle state, that is, the idle switch 12a is
It is determined whether N or OFF. Idle switch 12a is O
If the answer is N, the determination is affirmative and the routine proceeds to step 105 in FIG. If the idle switch 12a is OFF, a negative determination is made and the routine proceeds to step 106, where the opening of the throttle valve 12 is detected. Idle switch 12
Based on the parameter a, for example, it is determined whether the opening degree is 40 ° or less, and if so, an affirmative determination is made and step 1
07, the exhaust throttle valve 13 is closed and the original
Return to 1.

In step 105, the idling speed is increased in order to increase the engine load and increase the amount of heat received by the engine cooling water to improve the warm-up function.
Set to 00 rotation. It is preferable that this numerical value is set in advance to a value higher than a value necessary for maintaining the warm-up function during idling (hereinafter, this value is referred to as a “target value”). By setting such a high value, setting to the target value can be quickly performed.

In step 105, a predetermined rotation speed (1200
rpm), in the next step 108, the exhaust throttle valve 13 is closed, and the next step 10 is performed toward the target value.
At 9, control is performed to reduce the idle speed. For example, the idle speed is controlled by setting the target value to 1100 revolutions per minute.

When the idling speed reaches the target value, in the next step 110, the engine water temperature becomes, for example, 6
It is determined whether it is 0 ° C or less based on the parameters of the water temperature sensor 14a. If the engine water temperature is 60 ° C. or lower, an affirmative determination is made and the routine proceeds to the next step 111, where it is determined whether or not the engine is idle, that is, whether or not the idle switch 12a is ON or OFF. If it is ON, an affirmative determination is made and the process returns to step 109. If it is OFF, a negative determination is made and the process returns to step 101 in FIG. 3, and this routine is repeated.

Return to step 110. If the engine water temperature is higher than 60 ° C., a negative determination is made and the process returns to step 103 in FIG. 3, and the exhaust throttle valve 13 is opened. Thereafter, the process returns to the original step 101, and this routine is repeated. <Operation and Effect of Embodiment> Next, the operation and effect of the engine 1 configured as described above will be described.

The exhaust throttle valve 13 is operated according to the routine described above.
Operates, due to the pressure loss at that time, heat is generated in a portion of the exhaust port 9 where the exhaust throttle valve 13 is provided, but the cooling water passage 1 is located at a position corresponding to the exhaust throttle valve 13.
Since 4A is provided, most of the heat is collected by the cooling water flowing in the cooling water passage 14A. That is, since the heat is efficiently collected by the cooling water, the load on the engine 1 does not need to be excessively increased in order to promote warm-up. Therefore, fuel efficiency is improved.

<Modifications> The present invention is not limited to the above-described embodiment, and may be modified as follows by appropriately changing a part of the configuration without departing from the spirit of the invention. . (First Modification) A first modification will be described with reference to FIGS.

The first modification is different from the above embodiment only in that the inner surface 9c of the exhaust port 9 is formed in a fin shape, and the other parts are the same. Details will be described.

A fin-shaped portion is indicated by reference numeral 18. A plurality of fin-shaped portions 18 are provided on the inner surface 9 c of the exhaust port 9. Specifically, the exhaust port 9 is straight in a comb shape from the inner surface 9 c of the exhaust port 9 toward the inside of the exhaust port 9, and a certain distance is provided between adjacent fin-shaped portions 18. Are extended along the longitudinal direction.

By providing the fin-shaped portion 18 on the inner surface 9c of the exhaust port 9, the heat receiving area at the location where the exhaust throttle valve 13 is provided increases accordingly. Recovery efficiency of the heat generated due to the loss is improved. Therefore, in this case, fuel efficiency is further improved. (Second Modification) A second modification will be described with reference to FIGS.

The second modified example is different from the first modified example in that a fin-shaped portion 18 is formed along the flow direction of the exhaust gas when the exhaust gas is throttled by the exhaust throttle valve 13. Are the same, so only the different parts will be described in detail.

FIGS. 7 and 8 show the flow directions of the exhaust gas when the exhaust throttle valve 13 is closed and when the exhaust throttle valve 13 is opened, respectively. FIG.
Is an enlarged view of a fin-shaped portion.

In the fin-shaped portion according to the second modified example, the upper fin 18U located at the upper portion and the lower fin 18D located at the lower portion are each formed of the following nodes. That is, as shown in FIG. 9, the upper fin 18U is formed by connecting the nodes 19-20-21-22-23-24-25 sequentially from the exhaust valve 9a side toward the longitudinal direction thereof. The node is continuous with the adjacent node and has a gentle ridgeline shape as a whole. As can be seen from FIG. 7, the inclination of each of the joints 19 to 25 depends on the exhaust throttle valve 1.
3 is set so as to follow the flow direction of the exhaust gas (see the dotted arrow) at the time of throttling by 3.

The lower fin 18D has the same idea as that of the upper fin 18U, and its constituent parts, ie, the nodes 26-27.
−28−29 is set so as to be along the flow direction of the exhaust gas at the time of restricting by the exhaust restrictor valve 13.

The dotted arrows shown in FIG. 8 indicate the flow direction of the exhaust gas when the exhaust throttle valve 13 is opened.
As can be seen from FIG. 8, when the exhaust throttle valve 13 is completely opened, the inclination direction of the exhaust throttle valve 13 is set so as to match the flow direction of the exhaust gas.

As described above, the lower fin 18D and the upper fin 18U are formed on the inner surface 9c of the exhaust port 9 so as to follow the flow direction of the exhaust gas when the flow of the exhaust gas is restricted by the exhaust throttle valve 13. Exhaust gas flow is smooth. As a result, the flow rate of the exhaust gas increases, so that the amount of heat generated by the cooling water can be increased without excessively increasing the load on the engine 1. Therefore,
Fuel efficiency is further improved.

(Third Modification) A third modification will be described with reference to FIGS. This third modification is different from the above-described embodiments in that a cooling water passage 14 provided corresponding to the exhaust valve 13 and the exhaust throttle valve 13 is provided.
Since only the position of A is different and the part related thereto is different, the other same parts are denoted by the same reference numerals and description thereof is omitted.

The exhaust throttle valve 13 and the cooling water passage 14A in the third modified example are provided on a joint 31 constituting a horizontal portion 30 of the exhaust pipe 9b. More specifically, the exhaust throttle valve 13 is set in the passage 31 a of the joint 31, and the cooling water passage 14 A is formed in the thickness of the wall 33 of the joint 31 and is disposed so as to surround the exhaust valve 13. Have been. This cooling water passage 14A is also EC
A water temperature sensor 14a electrically connected to U16 is provided. The cooling water in the cooling water passage 14A is sent into the cooling water passage 14 in the engine 1 by the water pump 34, contributes to warm-up by the heater mechanism 35, and is returned to the cooling water passage 14A again. Thus, the cooling water according to the third modification circulates between the engine 1 and the horizontal portion 30 of the exhaust pipe 9b.

Even in the third modification, the exhaust throttle valve 1
3 operates, the pressure loss at that time causes heat generation at the portion where the exhaust throttle valve 13 is provided. However, since the cooling water passage 14A is provided at a position corresponding to the exhaust throttle valve 13, the heat is generated. Most of them are collected by the cooling water flowing in the cooling water passage 14A. That is, since the heat is efficiently collected by the cooling water, the load on the engine 1 does not need to be excessively increased in order to promote warm-up.
Therefore, fuel efficiency is improved.

(Fourth Modification) A fourth modification will be described with reference to FIGS. The fourth modification is different from the third modification only in that a fin-shaped portion 38 is provided on the inner wall surface 31b of the joint portion 31 of the exhaust pipe 9b according to the third modification. The same reference numerals are given to the other same parts, and the description is omitted.

The fin-shaped portion 38 extends straight from the inner wall surface 30a toward the inside of the exhaust pipe 9b in a comb-like shape, and extends at a certain interval along the longitudinal direction of the horizontal joint portion 31. Have been.

Also in the fourth modification, the fin-shaped portion 38 is provided corresponding to the location where the exhaust throttle valve 13 is provided, so that the heat reception at the location where the exhaust throttle valve 13 is provided is provided. The area is increased, and as a result, the efficiency of heat recovery is improved. Therefore, also in this case, fuel efficiency is improved.

In each of the above embodiments, the inner wall surface of the exhaust passage is shown as having a fin shape.
The same effect can be obtained even if the inner wall surface of the cooling water passage 14A is formed into a fin shape.

Further, by performing the exhaust throttling, the engine load is increased and the exhaust gas temperature is increased. Therefore, the temperature of the exhaust purification catalyst at the time of warm-up is increased, and the emission is greatly reduced.

Further, by operating the exhaust throttle at the time of deceleration, a function as an auxiliary brake is exhibited. Furthermore, operating the exhaust throttle at the time of engine overrun or the like is effective in preventing overrun or the like.

By performing the exhaust throttling, the engine load is increased and the exhaust gas is increased, so that the soot and the like in the exhaust system are burned and the generation of soot can be suppressed.

[0051]

As described above, according to the present invention, since the cooling water passage is provided corresponding to the location where the exhaust throttle means is provided, when the flow of the exhaust gas is reduced by the exhaust throttle means. The efficiency of heat recovery due to the pressure loss of the above is improved. Therefore, the warm-up is easily promoted without excessively increasing the load of the internal combustion engine, and as a result, the fuel efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram of a diesel engine employing a warm-up promoting device according to the present invention.

FIG. 2 is an enlarged view of a region II in FIG. 2;

FIG. 3 is a part of a flowchart illustrating an opening / closing control routine of an exhaust throttle valve.

FIG. 4 is a part of a flowchart illustrating an opening / closing control routine of an exhaust throttle valve.

FIG. 5 is a diagram corresponding to FIG. 2 showing a first modified example.

FIG. 6 is a view corresponding to FIG. 2 showing a second modified example, showing a state in which an exhaust throttle valve is closed.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a view showing a state where an exhaust throttle valve is opened in FIG. 6;

9 is an enlarged view of a main part of FIG. 6 or FIG.
FIG. 4 is a diagram showing the exhaust valve and a broken arrow indicating a flow direction of exhaust gas removed.

FIG. 10 is a view corresponding to FIG. 1 showing a third modification.

11 is an enlarged view of an area XI in FIG.

FIG. 12 is a diagram showing a fourth modification.

13 is a sectional view taken along line XII-XII in FIG.

[Explanation of symbols]

 Reference Signs List 1 diesel engine 2 cylinder block 2a cylinder bore 3 piston 3a piston head 4 connecting rod 6 combustion chamber 8 intake port 8a intake valve 8b intake pipe 9 exhaust port 9a exhaust valve 9b exhaust pipe 9c ... inner surface of exhaust port 9 11 ... injection 11a ... rotation speed sensor 12 ... throttle valve 12a ... idle switch (throttle sensor) 13 ... exhaust throttle valve (exhaust throttle means) 14 ... cooling water passage 14A ... cooling water passage 14a ... water temperature Sensor 16: ECU 18: Fin-shaped part 18U: Upper fin 18D: Lower fin 19-29: Node part 30: Horizontal part of the exhaust pipe 9b 30a: Inner wall surface of the horizontal part 30 ... Joint 33: Wall part of the joint 31 34 … Water pump 35… heater mechanism 38… fin shape

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02F 1/42 F02F 1/42 B F02N 17/08 F02N 17/08 C

Claims (3)

[Claims] 1. A warming-up promoting device comprising: an exhaust throttling means for restricting a flow of exhaust gas in an exhaust passage of an internal combustion engine; A warm-up promoting device, wherein a cooling water passage is provided in the exhaust passage at least corresponding to a portion where the exhaust throttle means is provided. 2. The method according to claim 1, wherein an inner wall surface of at least a part of the exhaust passage is formed so as to be in a form along a flow direction of the exhaust gas when the exhaust throttle unit restricts the exhaust gas. The warm-up promoting device according to claim 1. 3. An inner wall surface of the exhaust passage and / or an inner wall surface of the cooling water passage at a location where the exhaust throttle means is provided in the exhaust passage is formed in a fin shape. 2. The warm-up promoting device according to 1.