JPS5868506A - Reversion preventive device of diaphragm for hydraulic operation apparatus - Google Patents

Abstract

PURPOSE:To enable to prevent simply the diaphragm reversal to occur due to the negative pressure in the chamber by a method wherein the check valve and the orifice are provided at the working fluid inlet of the diaphragm chamber, thereby the positive pressure in the chamber is maintained. CONSTITUTION:The diaphragm 2 is provided in the casing 1. The working fluid is introduced through the inlet 4, and fed into the diaphragm chamber 3 being formed by the diaphragm 2 and the upper half part case 1a. In this case, the cap body 3a is provided for covering the inlet 4 of the diaphragm chamber 3, then the check valve 10 and the orifice 11 are provided on the cap body 3a. When the valve 10 is closed when the negative pressure is fed into the inlet 4, and the working fluid is gradually fed only through the orifice 11. Thereby, even when the section connected to the inlet 4 becomes the negative pressure, the pressure in the diaphragm chamber 3 is continually maintained at the positive pressure state, thus reversal of the diaphragn 2 caused by the negative pressure in the chamber 3 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing an unexpected reversal phenomenon occurring in a diaphragm in a fluid pressure operating region device using a diaphragm. A diaphragm suitable for application to an operating actuator for a waste gate pulp provided in an exhaust gas bypass passage or a diaphragm operating mechanism provided for an exhaust gas recirculation pulp in order to control boost pressure in a device. This invention relates to a reversal prevention device.

Normally, the actuator for operating the wastegate pulp, which is installed in a supercharger using exhaust gas, introduces positive pressure into the diaphragm chamber to control the opening and closing of the pulp. There is a region where the introduction pressure becomes negative pressure, and in this case, the diaphragm (D) may be inverted as shown by the broken line in FIG. If such a reversal phenomenon is repeated, the diaphragm will crack and fail due to fatigue, leading to autorun failure of the supercharger turbine.

In addition, normally, when using pulp for exhaust gas recirculation, negative pressure is introduced into the diaphragm chamber to control the pulp, but even in this case, positive pressure is applied to the diaphragm chamber during supercharging. , a reversal phenomenon will occur in the diamond slam.

For this reason, in conventional exhaust gas recirculation pulp, consideration has been taken to prevent positive pressure from being applied to the pulp by installing a positive pressure cut pulp in a connecting pipe line between the pulp and the intake manifold. However, as mentioned above, this positive pressure cut pulp is an independent component placed in the pipeline, and it not only takes up space in the engine room, which has many restrictions.
In terms of economy, this method inevitably had the disadvantage of high costs.

In view of the slanting point, the present invention introduces a working fluid into a diaphragm chamber formed by partitioning the inside of a casing with a diaphragm, and provides an actuated member that is interlocked with the diaphragm by positive or negative pressure applied to the diaphragm. In a fluid pressure operating device for operating a diaphragm, even if a working fluid pressure opposite to the expected positive pressure or negative pressure is introduced into the diaphragm chamber, the above-mentioned diaphragm inversion phenomenon can be built into the device itself. The purpose is to do so.

Therefore, in the present invention, as a means to prevent the diaphragm from reversing, a check pulp and an orifice are provided at the intake port for introducing the working fluid into the diaphragm chamber, and the planned introduction pressure of positive or negative pressure is When a reverse fluid pressure is applied to the intake port, the check valve is closed and the working fluid is introduced into the diaphragm chamber only through the orifice to eliminate the reverse pressure that is intermittently applied to the diaphragm chamber. An object of the present invention is to provide an inversion prevention device that prevents a diaphragm from inverting by providing delay buffering.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a wastegate pulp control actuator shown in the drawings will be described in detail below.

In Figure 2, (1) is the hat-shaped upper half case (
1a) and a lower half case (1bJ) are opposed to each other and connected to each other. A diaphragm (2) is disposed inside this casing (1), and its periphery is connected to both cases (1a). ) and (1b), and are airtightly clamped and fixed.The diaphragm (2) and the upper half case (1a) form a diaphragm chamber (3). Compressed air from the compressor discharge side of a supercharger (not shown) is introduced into the diaphragm chamber (8) as a working fluid through a working fluid intake port (4).

As shown in Fig. 2, reinforcing members (5) and (6) are attached to the center of the diaphragm (2) marked Aj from both sides, respectively, and the reinforcing member (5) on the top side A stopper (5a) that comes into contact with the upper half case (1a) to limit the upward movement of the diaphragm (2) is integrally formed on the peripheral edge. Between the reinforcing member (6) on the bottom side of the trench and the bottom of the lower half case (11), there is a spring (7) that constantly biases the diaphragm 12) toward the diaphragm chamber (3) at a constant pressure. is interposed. And, these both sleeve strength members (51, (6) and diaphragm (2),
It is integrally connected and fixed to the upper end of an operating rod (8) passing through the center of the lower half case (1b) via a nut (9). Note that the lower end of the operating rod (8) is connected to a wastegate pulp (not shown) via an interlocking mechanism.

As shown in FIG. 6, the actuator is equipped with a cup body (3a) that covers the working fluid intake port (4) in the diaphragm chamber (3).
5a] check valve (10) and orifice (11)
are provided in parallel. As shown in the figure, the check valve (10) is configured to close when negative pressure is introduced into the intake port (4), and when the intake port (4) is closed, only the orifice (11) is present in the diaphragm chamber (3). The negative working fluid will be gradually introduced through the .

To explain the operation mode of the reversal prevention device according to the above configuration with reference to Fig. 5, the figure shows changes in the pressure at the outlet side of the compressor of the supercharger, that is, the pressure on the Innotake manifold side (solid line graph) and the inside of the diaphragm chamber (3). The graph shows pressure changes over time (dashed line graph), and the intake manifold pressure increases with acceleration and decreases with deceleration.

and check valve αO) and orifice (11)
If the pressure inside the diaphragm chamber (31) does not exist as in the past, the pressure inside the diaphragm chamber (31) will also directly follow this. Therefore, if the intake manifold pressure temporarily enters the negative pressure region during acceleration/deceleration, the pressure inside the diaphragm chamber (31) will directly follow this. The pressure inside (3) also becomes negative pressure, causing the diaphragm (2) to reverse.

However, in the case of the present invention in which the check valve α0) and the orifice (11) are provided as described above, when the intake manifold pressure gradually increases to reach the top dead center and then gradually decreases, the working fluid intake port 14) side When the pressure in the diaphragm chamber (3) becomes low compared to the pressure in the diaphragm chamber (3), the check pulp is closed as shown in Figure 4 and the working fluid enters the diaphragm chamber (3) only through the orifice (01). It will gradually flow in.

As a result, as shown by the broken line graph in FIG. 5, the rate of decrease in pressure in the diaphragm chamber (3) is delayed compared to the rate of decrease in intake manifold pressure.

Since the time for the intake manifold pressure to become negative is usually about 1 to 2 seconds, by appropriately setting the diameter of the orifice (11), even if the intake manifold pressure becomes negative, it is possible to .

Next, when the intake manifold pressure starts to rise, the pressure on the working fluid intake (4) side increases to the diaphragm chamber (3).
) Since the pressure becomes higher than the pressure inside the diaphragm chamber (31), the check pulp signal is opened, and the pressure inside the diaphragm chamber (31) follows the increase in the intake manifold pressure.

As described above, according to the present invention, the diaphragm chamber (3
) will always be maintained at positive pressure.

Inversion of the diaphragm (2) can be effectively prevented. Therefore, there is no risk of cracking or breaking the diaphragm (2) due to the recurring reversal phenomenon, which would damage the engine or supercharger, as in the conventional case. Furthermore, since the check valve (10) and the orifice α1) are integrally incorporated into the actuator, the engine room space can be used effectively without affecting the system configuration. In particular, the provision of the orifice (11) has the effect of buffering the sudden acting force applied to the diaphragm (2) and significantly improving its durability.

Although the above-mentioned embodiment shows a specific example in which the present invention is applied to an actuator, it is of course applicable to a diaphragm pulp for exhaust gas recirculation that is controlled by negative pressure; however, in this case, Since this is negative pressure control, it goes without saying that the check valve must be installed in the opposite direction. Further, in the above embodiments, the orifice is arranged in parallel with the check pulp, but it is also possible to provide it, for example, in the check valve itself, and various pulp structures can also be used.

As explained above, according to the present invention, the inversion of the diaphragm can be prevented with an extremely simple structure, and the inconveniences (Φ, etc.) associated with the damage can be solved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the reversal phenomenon of the diaphragm, Fig. 2 is a sectional view showing an embodiment of the present invention, Fig. 6 is an enlarged sectional view of the main part of Fig. 2, and Fig. 4 is the closing of the check valve. A sectional view showing the state and FIG. 5 are graphs showing the effects of the check pulp and orifice.

Claims (1)

[Claims] In the fluid pressure operation region device for introducing a working fluid into a diaphragm chamber formed by partitioning the inside of a casing by a diaphragm, and controlling the operation of an actuated member interlocked with the diaphragm by positive pressure or negative pressure applied to the diaphragm, the above-mentioned A check pulp and an orifice are provided at the working fluid inlet of the diaphragm chamber, and the check pulp is closed when a pressure opposite to the expected pressure of the working fluid is applied to the diaphragm chamber through the inlet. 1. An inversion prevention device for a diaphragm in a fluid pressure operating device, characterized in that the diaphragm is prevented from inversion by allowing only the orifice to communicate with the diaphragm.