JPS6227269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a thermo-valve device that controls the intake negative pressure in accordance with the engine temperature to operate two negative pressure control devices such as an exhaust gas recirculation (EGR) device and an ignition timing advance device of an internal combustion engine. Regarding.

Exhaust recirculation returns part of the exhaust gas to the intake side,
Although this method effectively reduces NOx, performing exhaust gas recirculation before warming up is not preferable because the engine becomes extremely unstable and drivability and fuel efficiency deteriorate significantly.

Conventionally, NOx is reduced by delaying the ignition timing without exhaust gas recirculation before warm-up, and after warm-up, exhaust gas recirculation is performed to significantly reduce NOx and improve driveability and fuel efficiency. The time was moving forward.

However, if the ignition timing is delayed even when the engine is cold, for example at temperatures below 10° C., the engine tends to become unstable, which has the drawback of worsening exhaust assembly and drivability.

The present invention was made in view of the conventional drawbacks as described above, and when the engine temperature is low, e.g.
Advance the ignition timing without performing exhaust recirculation during the following cold periods to ensure engine stability and improve exhaust composition, and do not perform exhaust recirculation before warm-up, for example when the temperature is between 10℃ and 60℃. During normal operation after warming up, for example, if the temperature is 60°C or higher, exhaust gas recirculation is performed to advance the ignition timing and reduce NOx.
An object of the present invention is to obtain a thermo-valve device which reduces the amount of heat and improves drivability and fuel efficiency at the same time.

In order to achieve this object, the present invention is characterized in that the suction negative pressure that controls two negative pressure control devices such as the exhaust recirculation valve and the ignition timing advance device is controlled by the engine cooling water temperature.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

In FIG. 1, 1 is a thermovalve device, and this thermovalve device 1 has two first and second valves 3 and 4, one end of which communicates with a port 1a formed in the thermovalve device 1, and the other end of which communicates with a port 1a formed in the thermovalve device 1. is connected to an air cleaner 5 or the like and is opened to the atmosphere, and one end thereof communicates with a port 1b formed in the thermovalve device 1, and the other end communicates with a port 1b formed in the thermovalve device 1 through a branch passage.
One end is the outlet 6 of the vaporizer 6.
ignition timing advance device 9 as a first negative pressure control device whose other end is controlled by suction negative pressure;
The passage 1B communicates with the thermovalve device 1, one end communicates with the port 1c formed in the thermovalve device 1, and the other end is branched into two by a branch path, one end of which communicates with the outlet 6A of the vaporizer 6. , and a passage IC whose other end communicates with an exhaust gas recirculation valve 10 as a second negative pressure control device controlled by suction negative pressure.

The ignition timing advance device 9 is attached to the distributor 8 and adjusts the ignition timing.

The thermovalve device 1 is constructed as shown in FIG. That is, 12 is the first of three,
This upper case 12 has a valve chamber 3A in which the ports 1a, 1b, and 1c communicate with each other, and a valve chamber 3A in which the ports 1a, 1b, and 1c communicate with each other. 1
b, 1c, the first port 1a and the second port 1b
The openings of the third port 1c are formed to face each other on the axial center of the upper case 12, and the opening of the third port 1c is formed adjacent to the first port 1a. Further, a rod hole 13 is provided at the center of the lower end of the valve chamber 3A.
The lower case 13 with the O-ring 19,1
It is attached across 9a. Also, valve chamber 3A
A first valve 3 and a second valve 4 are provided at both ends of the rod 20. That is, the first valve 3 has an insertion hole 23 for the rod 20 in the center.
A spring retainer 23, the first and third ports 1a of this spring retainer 23,
A first annular protrusion 22A ₁ that is attached to the end of the port 1c and sealed around the opening of the port 1a and an outer edge of the first annular protrusion 22A ₁ and concentrically close the opening of the port 1c. Second annular projection 22 that includes
A ₂ , and a seal 22B that seals the gap between the insertion hole 23A of the spring retainer 23 and the rod 20. A spring 27 is attached to the spring retainer 23 in the direction of the arrow, that is, the port 1a,
1c is energized in the opening direction. Said rod 2
0 has a head 20A formed at the upper end to prevent it from coming off,
Seals 25A and 25B, which are integral with the spring retainer 24, are fixed to the lower end. A spring 28 is interposed between the spring retainer 24 and the spring retainer 23.

However, the elastic force of the spring 28 is stronger than that of the spring 27.

The second valve 4 includes a spring retainer 24;
The seals 25A and 25B block the port 1b.
It is made up of.

The lower case 13 is formed with the rod hole 13A and a grease chamber 13B, and a case 14 containing a thermally expandable material 2 such as paraffin or wax is fixed to the lower end of the case 13 via a diaphragm 15. The case 14 is brought into contact with the cooling water 11 of the engine. Rod hole 13 of the lower case 13
A rod 18 is inserted into A, the upper end of which is in responsive contact with the lower end of said rod 20. Further, a rubber piston 17 is inserted into the lower end of the rod 18. Furthermore, the grease chamber 13B is shaped so that its cross-sectional area decreases as it goes toward the rod 18, and the grease 16 is inserted therein. Therefore, the grease 16 is in contact with the diaphragm 15 on one side and the rubber piston 17 on the other side.

The thermovalve device 1 having the above configuration is shown in FIG.
It operates as shown in B and C (this operating state is shown in Fig. 3). That is, (1) When the engine temperature is below the first set temperature, for example 10°C, the temperature of the engine cooling water 11 is low, so the volume of the thermal expansion body 2 is small as shown in Figure 2A. . For this reason, the spring retainer 23,
24 is biased to the lowest position by springs 27 and 28. The first valve 3 is therefore open, and its seals 22A are respectively open to the first and third valves.
away from ports 1a, 1c, and communicate these ports 1a, 1c to maintain atmospheric pressure,
The second valve is closed and its seals 25A and 25B isolate the second port 1b from the other ports 1c and 1a, so that atmospheric pressure is not applied to the port 1b.

Therefore, the exhaust gas recirculation valve 10 is closed by the atmosphere to prevent exhaust gas recirculation, and the ignition timing advance device 9 is controlled by the suction negative pressure at the outlet of the carburetor 6 to advance the ignition timing. .

(2) When the engine temperature is between the first set temperature and the second set temperature, for example, between 10°C and 60°C before warming up.

As shown in FIG. 2B, the thermal expansion body 2 is heated by the cooling water 11 and expands. Therefore, the rods 118, 20 are moved via the diaphragm 15, the grease 16, and the rubber piston 17 against the elastic force of the springs 27, 28. At this time, the first valve 3 and the second valve 4 are both opened, and the seals 22A, 22B and the seals 25A, 25B are separated from each port, and the ports 1a, 1b, and 1c are connected to each other. Ports 1a, 1b, and 1c are maintained at atmospheric pressure.

Therefore, the exhaust recirculation valve 10 is closed by atmospheric pressure to prevent exhaust recirculation, and the ignition timing advance device 9 is closed by atmospheric pressure.
Delay ignition timing.

(3) During normal operation after warming up when the engine temperature reaches the second set temperature, for example 60℃ or higher.

Thermal expander 2 expands further, as shown in FIG. 2C, causing rods 18, 20 to move significantly.
That is, when the warm-up temperature is reached, the first valve 3 closes and its seal 22A closes the ports 1a and 1a, respectively.
1c almost simultaneously, the three ports 1a,
1b and 1c are cut off from each other. At this time, the seal 22A has the first and second annular protrusions 22.
Since A ₁ and 22A ₂ are formed, the first and third ports 1a and 1c are reliably isolated,
It is possible to prevent atmospheric pressure from leaking from port 1a toward port 1c.

Therefore, the exhaust recirculation valve 10
The ignition timing advance device 9 is also controlled by the suction negative pressure at the outlet 6B of the carburetor 6 to advance the ignition timing.

Note that during normal operation at temperatures above 60° C., the aforementioned operating state does not change, but the spring 28 is further compressed and only the rod 20 is moved. Therefore, damage to the diaphragm 15 etc. can be prevented.

Further, since the crease chamber 13B is shaped so that the cross-sectional area decreases as it goes toward the rod 18, the stroke of the seal can be changed. Furthermore, since two rods 18 and 20 are used, the rod is eccentric compared to the case where only one rod is used, and the rod hole 13
This can prevent the movement from being carried out smoothly if it gets stuck in A.

Of course, these are not limited to the above-mentioned configurations, and normal methods may be used.

Next, different embodiments of the thermovalve shown in FIG. 4 will be explained.

In the description of the thermovalve device 11 in FIG. 4, parts that are considered to have the same or equivalent configuration as the thermovalve device 1 in FIG.

The embodiment shown in FIG. 4 uses a bimetal 30 for the thermal expansion body 2 such as wax, and the upper case 12 has three first, second, and third ports 1a, 1.
b, 1c and these ports 1a, 1b, 1
A valve chamber 3A with which c communicates is provided. A lower case 13 is attached to the lower end of the upper case 12 with an intermediate member 33 in between. A spring 27 and a spring retainer 23 are provided in the valve chamber 3A, and the spring retainer 23 has a seal 2 at its upper end that blocks the first and third ports 1a and 1c.
2, attach the rod 31 to the lower end, and connect the first valve 3.
It consists of A retainer 24 is provided in the middle of the rod 31, and the port 1b is connected to the retainer 24.
The second valve 4 is constructed by attaching a seal 25 that shuts off.

Bimetal 3 is attached to the inner lower end of the lower case 13.
0 is inserted and held by a pressing member 29. Also, on this bimetal 30 there is a rod 31.
are in contact with each other through the intermediate member 33.

The operation of the thermovalve device using the thermovalve configured as described above is as follows.

(1) When the engine temperature is cold, for example below 10℃,
Since the bimetal 30 is convex downward, the retainer 23 is urged by the spring 27 to the lowest position. At this time, the seal 22
Seal 25 closes the second port 1b and isolates it from the other first and third ports 1a and 1c, while keeping them at atmospheric pressure apart from ports 1a and 1c.

Therefore, the exhaust gas recirculation valve 10 is closed by atmospheric pressure to prevent exhaust gas recirculation, and at the same time, the ignition timing advance device 9 is controlled by the suction negative pressure at the outlet 6B of the carburetor 6 to advance the ignition timing. .

(2) When the engine temperature is, for example, from 10℃ to 60℃ before warming up, the bimetal 30 overcomes the elastic force of the spring 27 and moves the rod 31 in the direction of the arrow.
While seal 25 is moved away from port 1b, seal 22 is also kept separate from ports 1a, 1c, so that these ports 1a, 1b,
1c is all at atmospheric pressure.

Therefore, the exhaust gas recirculation valve 10 is closed by atmospheric pressure to prevent exhaust gas recirculation, and at the same time, atmospheric pressure is also applied to the ignition timing advance device 9, thereby retarding the ignition timing.

(3) During normal operation after warming up when the engine temperature is 60°C or higher, the bimetal 30 is
is further moved in the direction of the arrow, and the seal 25 remains separated from the port 1b, but the seal 2
2 closes the ports 1a and 1c to cut off these ports 1a, 1b, and 1c from each other.

Therefore, the exhaust recirculation valve 10
At the same time, the ignition timing advance device 9 is controlled by the suction negative pressure at the outlet 6B of the carburetor 6 to advance the ignition timing.

Furthermore, even if the engine cooling water temperature reaches 60°C or higher, there is no need to worry about damage to these parts because the bimetal 30 and rod 31 are in metal-to-metal contact and the upper limit of the cooling water temperature is limited. There isn't.

In addition, even in this embodiment, the first valve 3 is provided with the first and second annular projections 22A ₁ and 22A ₂ ,
This allows for reliable sealing between the first and third ports 1a and 1c.

As is clear from the above description, in the present invention, when the temperature is lower than the first set temperature, the first valve is opened to communicate the first port and the third port, and the second valve is closed to communicate with the third port. 2 ports are shut off, and when the temperature is between the first set temperature and the second set temperature, the first valve and the second valve are opened to communicate the first port, second port, and third port, respectively. When the temperature is higher than the second set temperature, the first port, second port, and third port are each shut off by closing the first valve, so that the exhaust gas recirculation controlled by the suction negative pressure is Two negative pressure control devices, such as a valve and an ignition timing adjustment device, detect the engine cooling water temperature and control the intake negative pressure, organically improving the fuel efficiency, drivability, exhaust composition, etc. of the internal combustion engine. You can. That is, (1) when the engine is cooled, the ignition timing is advanced without exhaust gas recirculation, so the stability and drivability of the engine are increased, and the exhaust composition and fuel efficiency can be improved. (2) Before warming up, the ignition timing is delayed without exhaust gas recirculation, which improves the exhaust composition (in this case, the engine temperature is not very low, so stability will not deteriorate). (3) During normal operation after warming up, exhaust gas recirculation is performed and the ignition timing is advanced at the same time to improve the exhaust composition and improve fuel efficiency and drivability (exhaust gas recirculation is more effective than adjusting the ignition timing). The crab is big.).

Furthermore, since the present invention uses a thermovalve with a simple structure, it is easy to manufacture and low cost. Furthermore, since one thermo valve controls the exhaust recirculation valve and the ignition timing advance device, the control timing of the exhaust recirculation and ignition timing does not deviate compared to the case where separate thermo valves are provided to control these. , stable operation can be expected.

By the way, in this embodiment, since the first and second annular projections are formed on the first valve, when the first valve is closed, the first and third ports are reliably isolated. This provides an excellent effect in that the second negative pressure control device can be reliably controlled.

Note that the outlet ports 6A and 6B of the carburetor 6 are provided above the position of the fully closed throttle valve 7,
In addition, the throttle valve 7 is provided at a lower position when it is fully opened, but at this time, the outlet 6A is
If installed slightly above B, the ignition timing advance device will be controlled slightly earlier than the exhaust recirculation valve, even though the thermovalve device opens the valves at the same time, and better results can be obtained. .

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention;
FIGS. 2A, B, and C are diagrams showing the operating states of the thermovalve, FIG. 3 is a graph showing the operating states of the device of the present invention, and FIG. 4 is a sectional view showing different embodiments of the thermovalve. 1...Thermovalve device, 1a...1st port, 1b...2nd port, 1c...3rd port,
1A, 1B, 1C... passage, 3... first valve, 3
A... Valve chamber, 4... Second valve, 5... Air cleaner, 6... Carburetor, 6A, 6B... Outlet, 8...
...Distributor, 9...Ignition timing advance device (first negative pressure control device), 10...Exhaust recirculation valve (second negative pressure control device), 12...Upper case,
13... Lower case, 22A ₁ ... First annular projection, 22A ₂ ... Second annular projection.

Claims (1)

[Scope of Claims] 1. A valve chamber formed by a top case and a lower case; a first port provided in the top case and communicating with an atmospheric communication passage on one side and opening into the valve chamber on the other side;
a second port provided in the lower case, one side communicating with the first negative pressure control device and the other side opening in the valve chamber so as to face the first port; and a second port formed in the upper case adjacent to the first port. a third port that communicates with the second negative pressure control device on one side and opens into the valve chamber on the other side; a first valve that simultaneously opens and closes the first port and the third port; and a third port that opens and closes the second port. and a rod that moves the first valve and the second valve in response to the thermal expansion body, and when the temperature is lower than the first set temperature, the first valve is opened and the first valve is moved. The port and the third port are communicated, and atmospheric pressure is supplied to the second negative pressure control device to stop exhaust gas recirculation, while the second valve is closed to isolate the second port from the valve chamber, and the first negative pressure control device is controlled. The atmospheric pressure supply to the device is cut off to advance the ignition timing, and when the temperature is between the first set temperature and the second set temperature, the first and second valves are opened and the first and second ports are opened. The second port and the third port are connected to each other, and atmospheric pressure is supplied to the first negative pressure control device and the second negative pressure control device, respectively, to delay the ignition timing and stop exhaust gas recirculation. When the first negative pressure control device and the second
A thermovalve device characterized in that it is configured to advance ignition timing and recirculate exhaust gas by cutting off atmospheric pressure supply to each negative pressure control device.