JPS6048610B2 - Actuator for controlling exhaust bypass valve of internal combustion engine with turbocharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm actuator for controlling an exhaust bypass valve of a turbocharged internal combustion engine, and particularly to a water-blocking structure for an atmospheric chamber.

Conventionally, in an internal combustion engine with a turbocharger, for example, the first
As shown in the figure, an exhaust bypass valve 5 is provided in an exhaust bypass passage 4 that bypasses a turbine 3A of a turbocharger 3 provided in an exhaust passage 2 of an engine 1.
The compressor 3 of the turbocharger 3 in the intake passage 6
The boost pressure to the engine 1 is controlled by opening and closing the diaphragm actuator 7 based on the boost pressure downstream of B.

As shown in detail in FIG. 2, the diaphragm actuator 7 has a diaphragm 14 that defines a pressure chamber 11 into which the boost pressure downstream of the compressor 3b is introduced and an atmospheric chamber 13 in which the spring 12 is housed. An operating shaft 15 connected to the diaphragm 14 is passed through an atmosphere opening 16 provided in the wall of the atmospheric chamber 13, and the tip of the operating shaft 15 is connected to the exhaust bypass valve 5 (FIG. 1). It will be done.

The atmosphere opening port 16 is connected to the outer wall surface of the atmospheric chamber 13 and the actuator support bracket 1 attached to this wall surface.
An annular felt stopper seal member 18 sandwiched between 7 and 7.
The air chamber 13 is formed between the air chamber 13 and the actuating shaft 15 passing through the air chamber 13, thereby allowing the atmospheric chamber 13 to breathe while preventing the intrusion of dust and the like as much as possible (see US Pat. No. 25,105). However, such a diaphragm actuator 7 is generally arranged so that its operating axis 15 is approximately horizontal, and the atmosphere opening port 16 of the atmospheric chamber 13 prevents the breathing action of the atmospheric chamber 13. A felt sealing member 1 is installed so as not to interfere with the operation of the operating shaft 15.
8 and the actuating shaft 15, so if the actuator 7 gets wet with water,
Water enters the atmosphere chamber 13 through the atmosphere opening 16 and accumulates therein, which slows down the movement of the diaphragm 14. In addition, it freezes in cold weather and interferes with the normal operation of the diaphragm 14.

In particular, in vehicles with ventilation holes in the body hood for heat dissipation in the engine compartment, rainwater, car wash water, etc. enter through the ventilation holes, and the water droplets collect on the actuator. This caused a problem.

The present invention has been made in view of the above circumstances, and the present invention covers the upper side of the air opening hole on the outside of the atmospheric chamber of the operating shaft of the diaphragm type actuator and opens the lower side, and one end edge is connected to the outside wall of the atmospheric chamber. By providing a water shielding member that is always in close contact with the air chamber, water is prevented from entering the atmospheric chamber, thereby solving the above-mentioned problem. Hereinafter, the present invention will be explained based on the drawings.

3A, B, and C show an embodiment of the present invention.

In this embodiment, the same parts as in the conventional example (FIG. 2) are given the same reference numerals, and only the different parts will be explained.
A boss portion 21a of a water-shielding member 21 made of an elastic material such as rubber is fitted into the vicinity of the penetration portion of the atmosphere opening 16 on the outside of the atmosphere chamber 13 of the operating shaft 15 which is arranged approximately horizontally.
The inner diameter of the shaft 1a is made slightly smaller than the outer diameter of the actuating shaft 15, and the shaft 1a is fixed by its own elastic force, or it is fixed by tightening with a clamp 22 from the outer periphery of the boss portion 21a.

In addition, the water-shielding member 21 is formed with a thin-walled cylindrical lip portion 21b integrally with the boss portion 21a, and has a cutout on the lower side. is the 17th side of the bracket. The material is brought into close contact with the material by its own elastic force.

In this configuration, when there is no supercharging force (including when the engine is stopped), the diaphragm 14 is moved to the third position by the spring 12.
As shown in FIG. The end face completely shields the atmosphere opening 16 to prevent water from entering the atmosphere chamber 13.

For example, when the supercharging pressure increases, the diaphragm 14 is displaced to the right as shown in FIG. The edge of the bracket 17 remains in close contact with the surface of the bracket 17 due to its own elastic force.

This lip portion 21b covers the upper side of the through-hole of the atmospheric opening 16 on the outside of the atmospheric chamber 13 of the operating shaft 15, and partially opens the lower side. It is possible to allow air to circulate through the air chamber 13 through its breathing action. Further, water droplets traveling from the tip side of the operating shaft 15 are also blocked by the boss portion 21a of the water shielding member 21 and fall from there, so that they do not enter the atmospheric chamber 13. In order to set the water shielding member 21 so as to completely shield the atmosphere opening 16 when the engine is stopped, as described above, the water shielding member 21 must be inserted until it hits the bracket 17 and cannot move any further. Bye.

Of course, even when the engine is stopped, the boss part 2 of the water-blocking part/material 21
1a end face and the bracket 17 are separated, and the lip portion 21
It is also possible to make contact only at point b. Figure 4 A, B, C
shows another example.

In this embodiment, a water shielding member 31 made of metal or resin that covers the outside of the atmospheric chamber 13 of the operating shaft 15 and the upper side of the through hole of the atmospheric opening 16 is provided, with one end of the water shielding member 31 tightly fixed to the bracket 17. The other side edge of the water shielding member 31 is bent inward and arranged to surround the operating shaft 15.

Further, a projection 3 is provided on a part of the operating shaft 15 covered by the water shielding member 31.
2 (or a groove may be used), and an annular water-shielding member 33 made of rubber or the like is provided by fitting into this. Therefore, the water shielding member 31 can prevent water from splashing around the portion of the operating shaft 15 through which the air opening 16 passes, and can also block water transmitted from the bracket 17.

Further, the water blocking member 33 can also block water transmitted from the tip end side of the operating shaft 15. Of course, the breathing action of the atmospheric chamber 13 is carried out from the atmospheric opening 16 through the lower portion not covered by the water shielding member 31. As explained above, according to the present invention, it is possible to prevent water from entering the atmospheric chamber without interfering with the breathing action of the atmospheric chamber, and to maintain normal operation of the actuator. The effect is that it can be configured and realized.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional example of an internal combustion engine with a turbo supercharger, Fig. 2 is a sectional view showing a conventional example of an actuator for controlling an exhaust bypass valve, and Figs. 3A and B show an actuator according to the present invention. 3C is a right side view of FIG. 3A, FIGS. 4A and B are sectional views of another embodiment shown in each operating state, and FIG. 4C is the same view. The right side view of A is shown. 3...Turbo supercharger, 3A...Turbine, 3B...
・Compressor, 4...Exhaust bypass passage, 5...
・Exhaust bypass valve, 7...Diaphragm actuator, 11...Pressure chamber, 12...Spring, 13
... Atmospheric chamber, 14... Diaphragm, 15... Operating shaft, 16... Atmospheric opening, 21... Water shielding member, 2
1a...Boss part, 21b...Lip part, 31, 33
...Water shielding material.

Claims (1)

[Claims] 1. An operating shaft that extends substantially horizontally and is connected to a diaphragm that defines a pressure chamber into which the boost pressure downstream of the compressor of the turbocharger is introduced and an atmospheric chamber in which a spring is housed is attached to the wall of the atmospheric chamber. The actuator is connected to an exhaust bypass valve provided in an exhaust bypass passage that bypasses the turbine of the turbocharger by passing through the air release port provided on the outside of the atmospheric chamber of the operating shaft. An actuator for controlling an exhaust bypass valve of an internal combustion engine with a turbocharger, characterized in that a water shielding member is provided, the upper side of which is covered, the lower side is open, and one end of which is always in close contact with an outer wall surface of an atmospheric chamber.