JPH0326302B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum pressure regulator, and more particularly, it has a built-in nozzle flapper including a piezoelectric element and a pressure sensor for detecting negative pressure, and has a built-in nozzle flapper including a piezoelectric element and a pressure sensor for detecting negative pressure. The present invention relates to a vacuum pressure regulator configured to proportionally change nozzle back pressure to open and close a pilot valve, thereby adjusting negative pressure to always obtain a desired negative pressure with high accuracy.

Generally, when a predetermined negative pressure is required, such as in a suction cup or semiconductor manufacturing equipment, fluid regulators are widely used to control the negative pressure.

The applicant also developed this type of regulator and filed an application for utility model registration as Utility Model Application No. 50-27210. This regulator, filed as a "vacuum pressure regulating valve", has the following configuration. That is, as shown in FIG.
The valve body 1 includes a valve body 1, a bonnet 2 having an atmosphere communication hole, and a diaphragm 3 stretched over a joint portion between the valve body 1 and the bonnet 2. In this case, a diaphragm receiver 3a is provided at approximately the center of the diaphragm 3.
The diaphragm receiver 3a is provided with an air inflow hole 3b for introducing air from the bonnet 2 side to the valve body 1 side.

On the other hand, the valve body 1 is formed with a first port 4 connected to a vacuum pump and a second port 5 connected to a negative pressure device such as a suction cup. A passage is defined that communicates the two. A valve body 6 that opens and closes the passage faces the passage, and a rod extending from the valve body 6 is located approximately in the center of the diaphragm 3 and serves as a valve body 3c that opens and closes the air inflow hole 3b. comes into contact with.

A spring 7 is disposed inside the bonnet 2. One end side of the spring 7 is connected to the diaphragm receiver 3
a, and the other end engages with the spring receiving plate 8.
The spring receiving plate 8 is threadedly engaged with the screw 9. That is, the spring 7 is configured to adjust its elastic force by the spiral movement of the screw 9.

The screw 9 of the regulator A configured as described above is turned to generate a predetermined elastic force in the spring 7,
When the diaphragm 3 is pressed by the elastic force, the pressure or gap between the valve body 6 and the passage is adjusted. When the vacuum pump connected to the first port 4 is driven in this state, the pressure on the second port 5 side decreases and a pressing force acts on the diaphragm 3. When the elastic force of the spring 7 and the pressing force are balanced, the first
The passage communicating port 4 and second port 5 is closed, and a predetermined negative pressure is generated in the negative pressure device connected to the second port 5 side.

By the way, in the case of the above-mentioned regulator A, the negative pressure is generally set manually using a knob attached to the tip of the screw 9, which not only makes it difficult to set the negative pressure. However, it has been pointed out that the drawback is that it is extremely difficult to set the pressure with high precision.

Therefore, it is conceivable to set the pressure using an electric signal and use an electrically controlled actuator to maintain the negative pressure with high precision. However, in this case, since the actuator and the like are relatively expensive, it is impossible to avoid the disadvantages that not only the manufacturing cost of the device increases, but also the space occupied by the device as a whole increases.

The present invention has been made in order to overcome the above-mentioned disadvantages, and includes a nozzle flapper mechanism using a piezoelectric element, a diaphragm that is displaced by nozzle back pressure of the nozzle flapper mechanism, and a suction according to the displacement of the diaphragm. A valve body that controls the opening and closing of the passage and a pressure detection sensor that detects negative pressure in the suction passage are integrated, and the nozzle flapper mechanism is driven by an input electric signal to change the nozzle back pressure. Therefore, it is possible to directly control opening and closing of the valve body to accurately control negative pressure.
Moreover, it is an object of the present invention to provide a vacuum pressure regulator that has a simple configuration and can be manufactured at low cost.

In order to achieve the above object, the present invention is a vacuum pressure regulator that regulates negative pressure in response to an electric signal, and includes a nozzle flapper mechanism driven by the electric signal, and a change in nozzle back pressure caused by the nozzle flapper mechanism. a pilot valve portion for opening and closing a passage communicating between the suction side port and the negative pressure side port in accordance with the above conditions, and for opening and closing an air supply hole for introducing atmospheric air into the respective ports in order to increase the pressure from the negative pressure state; , a sensor that faces a passage communicating with the negative pressure side port, detects the pressure of the negative pressure side port, and converts the pressure signal into an electrical signal, and compares the input electrical signal with the output electrical signal from the sensor. and a control mechanism for applying a signal related to the deviation to the nozzle flapper mechanism, wherein the nozzle flapper mechanism controls the flow rate of fluid discharged from the nozzle back pressure chamber in accordance with the deviation signal.

Next, preferred embodiments of the vacuum pressure regulator according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 2, reference numeral 10 indicates a vacuum pressure regulator according to the present invention, and this vacuum pressure regulator 10 includes a main body 12, a nozzle flapper mechanism 14 provided in the upper part of the interior thereof, and a pilot valve part 16 provided in the lower part of the interior thereof. including. The nozzle flapper mechanism 14 is connected to a nozzle back pressure chamber 18 of the pilot valve section 16.
It is composed of a nozzle 20 of a predetermined diameter communicating with the nozzle 20 and a plate-shaped flapper 22. One end of the flapper 22 is positioned as a free end with a predetermined distance from the nozzle 20, and the other end is fixed to the main body 12 via a screw 24. As shown in the figure, the flapper 22 has two electrodes provided thereon.
Piezoelectric ceramics 26a, 26b and electrode 2 sandwiched between these piezoelectric ceramics 26a, 26b
A predetermined voltage is applied by a controller 32 via conductive wires 30 connected to each of the piezoelectric ceramics 26a and 26b. On the other hand, the pilot valve portion 16 includes two diaphragms 34 and 36 arranged side by side in the vertical direction, a piston 38 that holds these diaphragms 34 and 36 at a predetermined distance from each other approximately in the center thereof, and a piston 38 defined inside the piston 38. It includes a valve body 40 that opens and closes an air supply hole 38a communicating with an atmospheric pressure chamber, which will be described later. Valve body 40
It consists of a bullet-shaped protrusion 42 that substantially opens and closes the air supply hole 38a, a rod 44 extending downward from the protrusion 42, and an inner valve 46 fixed to the tip of the rod 44. Basically, this valve body 40 has a coil spring 4 that presses against an inner valve 46.
8, the protrusion 42 is brought into pressure contact with the air supply hole 38a of the piston 38. Thus, under normal conditions, the side of the inner valve 46 seats against a valve seat 50 defined by the body 12 and is connected to a first port defined in the body 12 and connected to a vacuum pump to be described below. The passage 56, the chamber 58, and the passage 60 that communicate between the passage 52 and the second port 54 connected to the negative pressure device are cut off.

Next, a third port 62 is defined in the main body 12 above the first port 52 for introducing the supplied air, and the third port 62 includes passages 64a, 64b, 64c, 64d. and communicates with the nozzle back pressure chamber 18 via 64e. In this case, an orifice 66 is provided in the passage 64d. Note that a passage 64f branches from the passage 64b and communicates with a supply pressure chamber 68 defined by the diaphragms 34 and 36. Further, an atmospheric pressure chamber 7 defined by the diaphragm 36 and the main body 12
0 is in communication with the atmosphere via a passage 72.
Note that from the second port 54 there are passages 74a, 74.
b, 74c extend and communicate with a recess 76 defined in the main body 12. A pressure sensor 78 is fixed to this recess 76, and this pressure sensor 78 includes, for example, a semiconductor diaphragm (not shown) therein. The amount of displacement of this semiconductor diaphragm is taken out as the amount of change in voltage, and is configured to be introduced to the controller 32 via a conductive wire 80. That is, when negative pressure is introduced into the pressure sensor 78 through the passages 74a to 74c, the value of electrical resistance changes due to the displacement of the semiconductor diaphragm, and this can be used to detect the negative pressure as an electrical signal. is possible.

Next, as shown in FIG. 3, a conduit 9 is connected to the first port 52 of the vacuum pressure regulator 10 according to the present invention.
0 and the other end of the pipe 90 is connected to a vacuum pump 92. On the other hand, the second port 5
4 is connected to a negative pressure device 96 through a conduit 94, and the conduit 94 branches midway and is connected to a vacuum gauge 98. In addition, the third port 62
A pipe line 102 from an air supply source 100 is connected to the pipe line 102 with a relief valve 104 interposed therebetween.

The vacuum pressure regulator according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, as shown in FIG.
Apply a predetermined voltage to. In other words, Fratupa 2
The piezoelectric ceramics 26a and 26b constituting the nozzle 2 are displaced depending on the polarity of the voltage supplied from the controller 32, and as a result, the nozzle back pressure in the nozzle back pressure chamber 18 via the nozzle 20 changes. For example, if the flapper 22 is bent in the direction of closing the nozzle 20 due to the above-described action, the nozzle back pressure in the nozzle back pressure chamber 18 is increased by the air supply source 100.
This will be increased by the air supplied through the third port 62. In this case, the nozzle back pressure acts on the upper surface of the diaphragm 34, causing the piston 38 to move downward as shown by arrow A, thereby pressing the protrusion 42 of the valve body 40. This pressing force pushes down the valve body 40 against the elastic force of the coil spring 48, and as a result, the first port 5
2. The passage 56, the chamber 58, and the passage 60 are in communication with each other, and the pressure on the second port 54 side becomes negative pressure under the suction action of the vacuum pump 92 connected to the first port 52. On the other hand, the negative pressure on the second port 54 side is applied to the recess 76 through passages 74a, 74b, and 74c.
Then, the semiconductor diaphragm of the pressure sensor 78 is displaced. The semiconductor diaphragm changes its resistance value due to the displacement force, generates a voltage corresponding to the resistance value, and sends this voltage to the controller 32 via the conductive wire 80. That is, the output signal of the pressure sensor 78 is fed back to the controller 32. In this case, as shown in FIG. 4, it is possible to monitor the feedback signal of the pressure sensor 78 using a monitor. Then, the controller 32 compares this feedback signal with the input signal, and if there is a difference, applies an electric signal related to the voltage to the flapper 22 made of an electrostrictive element of the nozzle flapper mechanism 14 again to correct the difference. That is, a voltage corresponding to the differential pressure is supplied to the flapper 22, and control is performed via the controller 32 in which the input signal and the feedback signal are always matched in this manner. Eventually, when the input signal and output signal no longer show any difference, equilibrium will be achieved. When such an equilibrium state is reached, a negative pressure proportional to the input signal will be provided to the negative pressure device 96 via the second port 54.

Then, by stopping the vacuum pump 92 and stopping the supply of air from the air supply source 100, the inside of the negative pressure device 96 communicating with the first port 52, the second port 54, and the second port 54 is removed. Negative pressure increases. That is, the air supply source 10
When the air supplied from 0 is stopped, the back pressure in the nozzle back pressure chamber 18 decreases. Along with this, the valve body 40
tries to move upward under the pressing action of the coil spring 48, but the first port 52 to second port 54 side is at negative pressure, while the air supply hole 38a side where the protrusion 42 comes into contact is at atmospheric pressure. , the valve body 40 is pressed downward by the atmospheric pressure on the side of the air supply hole 38a. This pressing force is applied to the coil spring 48.
In order to prevent the valve body 40 from rising against the pressing action of the piston 38, only the piston 38 rises. Therefore, the air supply hole 38a opens, and thereby air flows into the first port 52, the second port 54, and the negative pressure device 96 side, and the pressure increases.

As described above, according to the present invention, negative pressure is fed back by a highly accurate electric-pressure conversion sensor that utilizes a nozzle flapper mechanism. Therefore,
As a result, it becomes possible to easily and accurately control negative pressure using electrical signals. Moreover, as can be easily understood from the above embodiments, the configuration is extremely simple, and therefore the control cost can be reduced.

Additionally, an electrostrictive element is used as a mechanism to control nozzle back pressure. Therefore, it is easy to control electrically, is excellent in miniaturization, and exhibits extremely strong characteristics against repeated fatigue. As a result, the useful life of the vacuum pressure regulator can be significantly increased.

Although the present invention has been described above with reference to a preferred embodiment, the present invention is not limited to this embodiment. Of course, various improvements and changes in design are possible without departing from the gist of the present invention, such as the possibility of achieving the same effect by changing the pressure.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a vacuum pressure regulating valve according to the prior art, FIG. 2 is a vertical cross-sectional view of a vacuum pressure regulator according to the present invention, and FIG. 3 is a longitudinal cross-sectional view showing an embodiment of the vacuum pressure regulator according to the present invention. FIG. 4 is a block diagram showing the operation of the vacuum pressure regulator according to the present invention. 10... Vacuum pressure regulator, 12... Main body, 14
...Nozzle flapper mechanism, 16...Pilot valve part,
18... Nozzle back pressure chamber, 32... Controller, 3
4, 36...Diaphragm, 38...Piston, 40
... Valve body, 52, 54... Port, 68... Supply pressure chamber, 70... Atmospheric pressure chamber, 78... Pressure sensor, 92...
Vacuum pump, 96... Negative pressure equipment, 100... Air supply source.

Claims (1)

[Scope of Claims] 1. A vacuum pressure regulator that regulates negative pressure in response to an electrical signal, comprising: a nozzle flapper mechanism driven by the electrical signal; a pilot valve portion for opening and closing a passage communicating between the port and the negative pressure side port, and for opening and closing an air supply hole for introducing atmospheric air into each of the ports in order to increase the pressure from the negative pressure state; and the negative pressure side port. A sensor facing a passage communicating with the negative pressure side port and detecting the pressure of the negative pressure side port and converting the pressure signal into an electrical signal, and comparing the input electrical signal and the output electrical signal from the sensor and detecting the deviation. a control mechanism that applies such a signal to the nozzle flapper mechanism, and the nozzle flapper mechanism controls a fluid flow rate discharged from the nozzle back pressure chamber in accordance with the deviation signal. 2. The vacuum pressure regulator according to claim 1, wherein the nozzle flapper mechanism includes a flat electrostrictive element. 3. A vacuum pressure regulator according to claim 1 or 2, wherein the pilot valve portion includes a valve body that actually opens and closes, and a piston having an air supply hole.