JPH0524331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a supercharging pressure control valve for a supercharger that utilizes engine power, exhaust heat, and the like.

[Prior art] This type of supercharger is used when idling, when intake air supercharging is not required, and when the intake pressure is at a set value (for example, -200 mm).
A first boost pressure control valve that relieves boost pressure in a partial load range up to Hg) and a second boost pressure control valve that controls maximum boost pressure in a high load range are connected to Many of them are installed downstream of the pump to control the boost pressure within a certain range. In addition, among such things, as prior art of the present invention, for example, as shown in Japanese Utility Model Application Publication No. 63-87233,
Some systems have attempted to make the supercharging pressure control valve more compact by arranging the first supercharging pressure control valve in series and integrating the second supercharging pressure control valve outside the second supercharging pressure control valve.

When the first supercharging pressure control valve is connected to the outside of the second supercharging pressure control valve, the second supercharging pressure control valve is connected to a second rod having a valve body at its tip, and a second rod having a valve body at the tip thereof. a second diaphragm that holds the base end of the second rod and forms a boost pressure chamber inside; and a second spring that brings the valve body into contact with the relief port; The first supercharging pressure control valve includes a first rod that engages with the second rod, and a first diaphragm that holds the proximal end of the first rod and forms a negative pressure chamber on the outside. It is conceivable that the device be configured with the following. According to such a boost pressure control valve, in a partial load region, when the first rod is pulled by negative pressure downstream of the throttle valve, the first rod The second rod is towed,
The valve body at the tip opens the relief port against the elastic force of the second spring, and the supercharging pressure is relieved from the relief port. Also, when the boost pressure in the high load area reaches the maximum boost pressure, the second
The rod is pulled by the expansion of the second diaphragm, and the valve element at its tip is pulled to open the valve, and supercharging pressure is relieved from the relief port.

[Problem to be solved by the invention] However, the supercharging pressure control valve with such a configuration,
Since it has both the function of relieving the boost pressure in the partial load range and the function of controlling the boost pressure in the high load range, there is a large difference in the control pressure. Moreover, if the first boost pressure control valve is connected to the outside of the second boost pressure control valve, the first boost pressure control valve becomes the second boost pressure control valve in the partial load region. will open a relief port through. That is, in order to open the relief port in a partial load range, it is necessary to pull the valve body against the elastic force of the second spring that limits the maximum boost pressure. Therefore, the diameter of the first diaphragm, which controls the boost pressure in the partial load range, must be approximately three times larger than that of the second diaphragm, which controls the boost pressure in the high load range. It is not possible to achieve a compact size.

Further, in such a configuration, the relief port is closed by pressing the valve body against the relief port using the second spring.
Therefore, when the boost pressure increases to near the maximum boost pressure, the valve body tends to be gradually pushed open by the boost pressure. As schematically shown in Figure 3, since the boost pressure is relieved before reaching the maximum boost pressure, a kind of droop (see the solid line) occurs and the desired boost pressure (see the broken line) occurs. ) can no longer be obtained quickly.

The present invention aims to eliminate such problems all at once.

[Means for Solving the Problems] In order to achieve the above object, the present invention employs the following configuration.

That is, the supercharging pressure control valve for a supercharger according to the present invention includes a first supercharging pressure control valve that relieves supercharging pressure in a partial load region, and a second supercharging pressure control valve that controls maximum supercharging pressure in a high load region. A supercharging pressure control valve for a supercharger comprising a supercharging pressure control valve and a supercharging pressure control valve arranged in series, wherein the first supercharging pressure control valve is connected to a first rod having a valve body at its tip. and,
A first diaphragm that holds the base end of the first rod and forms a negative pressure chamber on the side where the valve body is provided from the base end, and a relief port that is disposed in the negative pressure chamber. and a first spring that pulls the valve body toward the closing side, and the second supercharging pressure control valve has its tip abutted against the base end of the first rod. a second diaphragm that holds the base end of the second rod and forms a boost pressure chamber on the side opposite to the side where the valve body is located; and a second spring disposed in an atmospheric pressure chamber formed on the side where the valve body is located and biasing the second rod toward the boost pressure chamber side. Features.

[Function] According to such a configuration, the first diaphragm can be downsized because the first supercharging pressure control valve is not affected by the second supercharging pressure control valve in the partial load range. In the partial load range, the intake pressure introduced into the negative pressure chamber of the first boost pressure control valve causes the first
The first rod is pushed against the elastic force of the spring. As a result, the relief port is opened and the supercharging pressure in the partial load region is relieved from the relief port.

On the other hand, when the boost pressure in the high load region reaches the maximum boost pressure, the boost pressure introduced into the boost pressure chamber of the second boost pressure control valve resists the elastic force of the second spring. As a result, the second rod is biased, and the second rod biases the first rod against the elastic force of the first spring. Then, the valve body provided at the tip of the first rod is pushed to open the relief port, and the supercharging pressure is relieved from this relief port.

[Example] An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 schematically shows an engine installed in an automobile. This engine has a mechanical supercharger 3 interposed between an air cleaner 1 and a carburetor 2, and the supercharger 3 controls the supercharging pressure of intake air supplied to the engine body 4. , the supercharging pressure control valve 5 is used to control the pressure within a certain range.

The supercharging pressure control valve 5 includes a first supercharging pressure control valve 6 that relieves supercharging pressure during idling or in a partial load range where the intake pressure is up to a set value (for example, -200 mmHg);
It consists of a second boost pressure control valve 7 connected in series outside the first boost pressure control valve 6, and is interposed between the carburetor 2 and the supercharger 3. It is provided in a surge tank (not shown).

The first supercharging pressure control valve 6 includes a first rod 9 having a valve body 8 at its tip, and a second rod 9 that holds the base end of the first rod 9 and forms a negative pressure chamber 10 inside. 1 diaphragm 11 and a first spring 13 that is disposed in the negative pressure chamber 10 and pulls the valve body 8 toward the side that closes the relief port 12.
It is equipped with. The valve body 8 has a trapezoidal cross section, and its end face faces into the surge tank.
The relief port 12 is closed off from the surge tank side by the circumferential surface. The proximal end surface of the first rod 9 is connected to the first diaphragm 1.
It faces a first atmospheric pressure chamber 14 provided on the outside of the chamber 1. On the other hand, a sealing material 16 is provided between the intermediate portion of the first rod 9 and the base 15 on which the relief port 12 is provided. Negative pressure chamber 10
is communicated with the intake passage on the downstream side of the carburetor 2. The first spring 13 is made of a coil spring, and its elastic force is set so that it is compressed when the intake pressure of the negative pressure chamber 10 is on the vacuum side compared to the set pressure (for example, -200 mmHg). Further, the supercharging pressure derived from the relief port 12 is recirculated into the intake passage between the air cleaner 1 and the supercharger 3.

The second supercharging pressure control valve 7 is for controlling the maximum supercharging pressure in a high load range, and is a second rod 17 whose tip is close to the base end surface of the first rod 9.
a second diaphragm 19 that holds the base end of the second rod 17 and forms a supercharging pressure chamber 18 on the outside; and a second diaphragm 19 that is an atmospheric pressure chamber formed inside the second diaphragm 19. atmospheric pressure chamber 20
a second spring 2 disposed in
1. The supercharging pressure inside the surge tank is introduced into the supercharging pressure chamber 18 .
The second spring 21 is made of a coil spring, and its elastic force is set in consideration of the elastic force of the first spring 13. and,
The second atmospheric pressure chamber 20 in which the second spring 21 is disposed and the first atmospheric pressure chamber 14 are in communication via a through hole through which the second rod 17 is passed.

According to such a configuration, in a partial load region such as during idling, the intake pressure introduced into the negative pressure chamber 10 of the first boost pressure control valve 6 acts against the elastic force of the first spring 13. The first rod 9 is pressed. Then, the valve body 8 provided at the tip of the first rod 9 is pushed toward the surge tank, opening the relief port 12, and the supercharging pressure is transmitted from the relief port 12 between the air cleaner 1 and the supercharger 3. is relieved in the intake passage.

On the other hand, when the boost pressure in the high load region increases to a set value near the maximum boost pressure, the boost pressure introduced into the boost pressure chamber 18 of the second boost pressure control valve 7 causes the second boost pressure to increase. The second rod 1 resists the elastic force of the spring 21.
7 is energized. When the supercharging pressure further increases and reaches a predetermined maximum supercharging pressure, the second rod 17 urges the first rod 9 against the elastic force of the first spring 13, and the tip of the second rod 17 urges the first rod 9. The valve body 8 is pushed and the relief port 12 is opened. and,
The supercharging pressure is relieved from this relief port 12 into the intake passage between the air cleaner 1 and the supercharger 3, and the supercharging pressure is maintained at the maximum supercharging pressure.

Therefore, according to the above configuration, it is possible to operate the first supercharging pressure control valve 6 without being affected by the second supercharging pressure control valve 7 in the partial load region, so that Not only can the elastic force of the first spring 13 be reduced, but also the diameter of the first diaphragm 11 can be reduced, and the first supercharging pressure control valve 6 and the supercharging pressure control valve 5 as a whole can be made compact.

Moreover, since the relief port 12 is closed by pulling the valve body 8, as the supercharging pressure increases, the supercharging pressure is applied to the valve body 8, and the valve body 8 tends to close. Therefore, even if the boost pressure increases to the maximum boost pressure, the valve body 8 will not be biased by the boost pressure and gradually open. That is,
As schematically shown in Figure 2, it is possible to eliminate the problem of the boost pressure being relieved before it reaches the maximum boost pressure, making it easier to quickly obtain the desired boost pressure. Improves controllability.

Moreover, with the supercharging pressure control valve 5 having such a configuration, the elastic force can be changed by replacing the first spring 13 and the second spring 21, so that the partial load for relieving the supercharging pressure can be changed. The range, maximum boost pressure, etc. can be easily set and changed in accordance with the engine characteristics.

Moreover, according to such a boost pressure control valve 5, the first diaphragm 11 and the second diaphragm 19
The first atmospheric pressure chamber 14 and the second atmospheric pressure chamber 20 are located between the two, and there is no need for a seal between the two.
The only area to be sealed so that the rod can slide is between the first rod 9 and the base 15. Therefore, the number of areas that need to be sealed can be reduced.
Cost reduction can be achieved.

Note that the relief port may be opened directly into the atmosphere, but when a supercharger is disposed downstream of the carburetor, the relief port is communicated with the intake passage.

Further, the supercharger is not limited to a mechanical type that uses engine power, but may also be one that uses exhaust heat.

[Effects of the Invention] Since the present invention has the above-described configuration, it is possible to easily miniaturize a boost pressure control valve that has control functions in control areas where boost pressures are completely different, and it is also possible to easily reduce the size of a boost pressure control valve that has control functions in control areas where boost pressures are completely different. Since it is possible to reduce costs, it is possible to reduce costs.

Further, according to the present invention, the controllability of the supercharging pressure by the supercharging pressure control valve can be reliably improved, and the control range of the supercharging pressure can be easily adjusted, so that the reliability of the control can be improved. Also, it is possible to provide a supercharging pressure control valve for a supercharger that is highly compatible with an engine and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, and FIG. 2 is a diagram showing boost pressure characteristics in the same embodiment. FIG. 3 is a diagram corresponding to FIG. 2 showing a conventional example. 3...supercharger, 5...supercharging pressure control valve, 6...first supercharging pressure control valve, 7...second supercharging pressure control valve, 8...valve body, 9...first rod, 10... Negative pressure chamber, 11...first diaphragm, 12...relief port, 13
...First spring, 17...Second rod, 18
...Supercharging pressure chamber, 19...Second diaphragm, 20...
Atmospheric pressure chamber (second atmospheric pressure chamber), 21...second spring.

Claims (1)

[Claims] 1 A supercharging pressure control valve in which a first boost pressure control valve that relieves boost pressure in a partial load region and a second boost pressure control valve that controls maximum boost pressure in a high load region are connected in series. The first supercharging pressure control valve is a supercharging pressure control valve for a feeder, and the first supercharging pressure control valve includes a first rod having a valve body at its tip, a base end of the first rod being held, and a first rod having a valve body at its tip. A first diaphragm that forms a negative pressure chamber on the side where the valve body is provided from the base end, and a first spring that is disposed in the negative pressure chamber and pulls the valve body toward the side that closes the relief port. The second supercharging pressure control valve includes a second rod whose tip can come into contact with the base end of the first rod, and a base of the second rod. a second diaphragm that holds the end portion and forms a boost pressure chamber on the side opposite to the side where the valve body is located, and an atmospheric pressure chamber formed on the side of the second diaphragm where the valve body is located; 1. A supercharging pressure control valve for a supercharger, comprising: a second spring for biasing the second rod toward the supercharging pressure chamber.