JPH0474727B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum pressure regulator, and more particularly, the present invention relates to a vacuum pressure regulator, and more particularly, the invention includes a nozzle flapper including a piezoelectric element and a pressure sensor for detecting negative pressure, and the piezoelectric element This invention relates to a vacuum pressure regulator configured to open and close a pilot valve by changing nozzle back pressure in proportion to an electrical signal applied to the nozzle, thereby adjusting negative pressure to constantly obtain a desired negative pressure with high accuracy. .

[Background of the Invention] Generally, in cases where a predetermined negative pressure is required, such as in suction cups or semiconductor manufacturing equipment, fluid regulators are widely used to control the negative pressure.

The applicant has also developed this type of regulator and disclosed it in, for example, Japanese Utility Model Publication No. 12650/1983.
This regulator, filed as a "vacuum pressure regulating valve", has the following configuration.

That is, as shown in FIG. 1, this regulator A includes a valve body 1, a bonnet 2 having an atmosphere communication hole, and a diaphragm 3 stretched over the joint portion of the valve body 1 and the bonnet 2. In this case, a diaphragm receiver 3a is attached to the approximate center of the diaphragm 3, and the diaphragm receiver 3a
An atmospheric air inlet hole 3b for introducing atmospheric air from the bonnet 2 side to the valve body 1 side is bored in the valve a.

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. 5 is defined. A valve body 6 that opens and closes the passage faces the passage, and a rod extending from the valve body 6 has a rod at the tip located approximately at the center of the diaphragm 3 that opens and closes the air inflow hole 3b. A valve body 3c is fixed thereto.

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 a screw 9 which is rotated by the knob. 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 through the knob to generate a predetermined elastic force in the spring 7, and when the elastic force presses the diaphragm 3, the valve body 6 is pressed against the passage. The force or gap will be 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 passage connecting the first port 4 and the second port 5 is closed by the valve body 6, and the passage connecting the first port 4 and the second port 5 is closed, and the passage connecting the first port 4 and the second port 5 is closed. A predetermined negative pressure is generated in the connected negative pressure equipment.

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 accuracy. 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.

[Object of the Invention] The present invention has been made to overcome the above-mentioned disadvantages, and includes a nozzle flapper mechanism using a piezoelectric element, a nozzle flapper mechanism that is displaced by a negative pressure in a suction passage, and a nozzle back pressure of the nozzle flapper mechanism. A diaphragm, a valve body that controls the opening and closing of the suction passage according to the displacement of the diaphragm, and a pressure detection sensor that detects negative pressure in the suction passage are integrally incorporated, and the nozzle flapper mechanism is driven by an input electric signal. It is possible to control the negative pressure with high accuracy by directly controlling the opening and closing of the valve body, and furthermore, the control of the nozzle back pressure is achieved by using the negative pressure. It is an object of the present invention to provide a vacuum pressure regulator whose structure is further simplified and which can be manufactured at low cost.

[Means for achieving the object] In order to achieve the above object, the present invention provides a main body 1.
2, the vacuum pressure regulator 10 has a negative pressure supply port 52 and a negative pressure output port 54, and adjusts the negative pressure in response to an electrical signal, the vacuum pressure regulator 10 having a negative pressure supply port 52 and a negative pressure output port 54 in the negative pressure supply port 52 and the negative pressure output port 54.
and a nozzle back pressure chamber 18.
2, a sensor 78 that communicates with the negative pressure output port 54 via passages 74a to 74c and converts a pressure signal caused by the negative pressure into an electrical signal, and a nozzle 20 and a flapper 22 that make the nozzle back pressure variable. Nozzle flapper mechanism 14
and derives a control signal to the nozzle flapper mechanism 14, and introduces an output signal from the sensor 78, compares the control signal and the output signal, and further sends a control signal to the nozzle flapper mechanism 14 based on the deviation. a controller 32 that constitutes a feedback system, and a chamber 6 that communicates with the atmospheric chamber 71 and the negative pressure supply port 52 through the first and second diaphragms 34 and 36.
8, and a piston 38 defining a chamber 70 communicating with the nozzle back pressure chamber 18 and displacing in response to the displacement of the first and second diaphragms 34, 36, which is caused by the control of the nozzle flapper mechanism 14. In addition to opening and closing the passages 56 and 60 that communicate the negative pressure supply port 52 and the negative pressure output port 54 in response to changes in nozzle back pressure, the passages 56 and 60 communicating with the negative pressure output port 54 are opened and closed, and in order to increase the pressure from the negative pressure state, Air supply hole 38a defined in the piston to introduce atmospheric air
a pilot valve section 16 for opening and closing the nozzle, and the nozzle back pressure is supplied to the negative pressure supply port 52.
The negative pressure obtained from the nozzle flapper mechanism 14
It is characterized in that it is obtained by controlling with the flapper 22 of.

[Operation] The vacuum pressure regulator 10 according to the present invention derives a control signal from the controller 32 to the nozzle flapper mechanism 14, and by controlling the nozzle flapper mechanism 14, negative pressure is generated on the nozzle back pressure side. Due to the negative pressure action of the nozzle back pressure, the piston 38 and the valve body 40 of the pilot valve section 16 are displaced to open the passages 56 and 60 that communicate the negative pressure supply port 52 and the negative pressure output port 54, and the negative pressure is increased. Negative pressure can be generated on the output port 54 side. The negative pressure state of the negative pressure output port 54 is detected by the sensor 7 through passages 74a to 74c communicating with the negative pressure output port 54.
The sensor 78 is detected by the controller 3
2, a feedback signal is derived. The controller 32 compares the feedback signal and the control signal, and further derives a control signal to the nozzle flapper mechanism 14 based on the deviation.

Further, the nozzle back pressure is
The negative pressure supplied from the negative pressure supply port 52 through d is applied to the flapper 22 of the nozzle flapper mechanism 14.
It can be controlled by

[Embodiments] 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. 16. The nozzle flapper mechanism 14 includes a nozzle 20 of a predetermined diameter communicating with the nozzle back pressure chamber 18 of the pilot valve portion 16, and a plate-shaped flapper 22. The flapper 22
One end 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 is formed of a so-called electrostrictive element consisting of two piezoelectric ceramics 26a and 26b provided with electrodes and an electrode 28 sandwiched between these piezoelectric ceramics 26a and 26b. A predetermined voltage is applied by a controller 32 via conductive wires 30 connected to each of these piezoelectric ceramics 26a and 26b.

On the other hand, the pilot valve section 16 includes two diaphragms 34 and 36 arranged in parallel 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 an inner portion of the piston 38. It includes a valve body 40 that opens and closes an air supply hole 38a that is defined in the air and communicates with an atmospheric pressure chamber that will be described later. The valve body 40 essentially includes a bullet-shaped protrusion 42 that 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. This valve body 40 is basically composed of the protrusion 42 under the action of a coil spring 48 that presses the inner valve 46 upward in the figure.
is in pressure contact with the air supply hole 38a of the piston 38.
Therefore, in the normal state, the hemispherically bulging side portion of the inner valve 46 seats against the valve seat 50 defined by the body 12, and the vacuum pump defined by the body 12 and described later. The passage 56, the chamber 58, and the passage 60 that communicate the first port 52 connected to the negative pressure device and the second port 54 connected to the negative pressure device are cut off. Note that the first port 52 and the second port 54 function as a negative pressure supply port and a negative pressure output port, respectively.

Next, a passage is defined in the main body 12 that extends above the first port 52 and communicates with the nozzle back pressure chamber 18 . The passageway is a substantially continuous passageway 64.
Passage 6 consists of a, 64b, 64c and 64d.
An orifice 66 is arranged at 4d. Note that a passage 64f branches from the passage 64b and communicates with a chamber 68 defined by the diaphragms 34 and 36. In this case, the nozzle backpressure chamber 18 communicates via a curved passageway 62 with a chamber 70 defined by the diaphragm 36 and the body 12, while the chamber 70 is defined by the diaphragm 34 and the body 12. The chamber 71 is in communication with the atmosphere via a passage 72. Note that from the second port 54 there are passages 74a, 7
4b, 74c extend and communicate with a recess 76 defined in the 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. This position change of the semiconductor diaphragm is taken out as a voltage change amount 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 the electrical resistance changes due to the displacement of the semiconductor diaphragm.
Utilizing this, it is possible to detect the negative pressure as an electrical signal.

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 line 90 is connected to a vacuum pump 92 or an ejector. On the other hand, the second port 54 is connected to a negative pressure device 96 via a conduit 94 and a vacuum gauge 96 via a conduit that branches in the middle.
It is connected to 8.

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. 4a, the controller 3
2 to the nozzle flapper mechanism 14, the piezoelectric ceramics 26a and 26b constituting the flapper 22 maintain their straight shape. That is, the flapper 22 remains open, and therefore, even if the vacuum pump 92 is temporarily driven, the back pressure in the nozzle back pressure chamber 18 will be close to atmospheric pressure. This substantially atmospheric back pressure is introduced into chamber 70 via passageway 62, causing piston 38 to rise slightly. That is, since the piston 38 is separated from the valve body 40, atmospheric pressure flows into the second port 54 side through the chamber 71 and the supply hole 38a. As a result, the pressure at the second port 54 increases to approximately atmospheric pressure.

Next, as shown in FIG.
A predetermined voltage is applied to 4. That is, the piezoelectric ceramics 26a and 26b constituting the flapper 22 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 becomes negative pressure through the nozzle 20. . As a result, the chamber 70 communicating with the nozzle back pressure chamber 18 becomes negative pressure, while the piston 38 descends because atmospheric pressure is introduced into the chamber 71.
After the lower end contacts the valve body 40, it is lowered. During this time, the air supply hole 38a is closed by the protrusion 42 of the valve body 40. In the end, valve body 4
The downward movement of 0 moves the inner valve 46, which is integrated with this, to the valve seat 5.
0, so that first port 52, passage 56, chamber 58, passage 60 and second port 54
The second port 54 side is brought into negative pressure.

On the other hand, the negative pressure on the second port 54 side is
a, 74b, and 74c to reach the recess 76 and displace the semiconductor diaphragm of the pressure sensor 78.
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. 5, 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 reached (see Figure 4c). When such an equilibrium state is reached, a negative pressure proportional to the input signal becomes the second
Negative pressure equipment 96 will be available via port 54 .

[Effects of the Invention] As described above, according to the present invention, the negative pressure obtained from the negative pressure output port 54 side is fed back by the highly accurate electric-pressure conversion sensor 78 that utilizes the nozzle flapper mechanism 14. Therefore, as a result, it becomes possible to easily and accurately control negative pressure using electrical signals. Moreover, the negative pressure is obtained from the negative pressure supply port 52 through passages 64a to 64d that communicate directly with the nozzle back pressure chamber 18. Therefore, the configuration is extremely simple because there is no need for a pressure supply source for independently obtaining the nozzle back pressure, nor for a pipe line communicating with this pressure supply source, and therefore, the manufacturing cost can be reduced. Effects can be obtained.

Moreover, electrostrictive elements 26a and 26b are employed as a mechanism for controlling the 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 10 can be significantly increased.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a vacuum pressure regulating valve according to the prior art, FIG. 2 is a longitudinal 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. The piping system diagram and FIGS. 4a to 4c are explanatory views of the operation of the vacuum pressure regulator according to the present invention, and FIG. 5 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, 70... Chamber,
78...Pressure sensor, 92...Vacuum pump, 96...Negative pressure equipment.

Claims (1)

[Claims] 1. A vacuum pressure regulator 10 that has a negative pressure supply port 52 and a negative pressure output port 54 in the main body 12 and adjusts the negative pressure in response to an electrical signal, the negative pressure supply port 52 and negative pressure output port 54
and a nozzle back pressure chamber 18.
2, a sensor 78 that communicates with the negative pressure output port 54 via passages 74a to 74c and converts a pressure signal caused by the negative pressure into an electrical signal, and a nozzle 20 and a flapper 22 that make the nozzle back pressure variable. Nozzle flapper mechanism 14
and derives a control signal to the nozzle flapper mechanism 14, and introduces an output signal from the sensor 78, compares the control signal and the output signal, and further sends a control signal to the nozzle flapper mechanism 14 based on the deviation. a controller 32 that constitutes a feedback system, and a chamber 6 that communicates with the atmospheric chamber 71 and the negative pressure supply port 52 through the first and second diaphragms 34 and 36.
8, and a piston 38 defining a chamber 70 communicating with the nozzle back pressure chamber 18 and displacing in response to the displacement of the first and second diaphragms 34, 36, which is caused by the control of the nozzle flapper mechanism 14. In addition to opening and closing the passages 56 and 60 that communicate the negative pressure supply port 52 and the negative pressure output port 54 in response to changes in nozzle back pressure, the passages 56 and 60 communicating with the negative pressure output port 54 are opened and closed, and in order to increase the pressure from the negative pressure state, Air supply hole 38a defined in the piston to introduce atmospheric air
a pilot valve section 16 for opening and closing the nozzle, and the nozzle back pressure is supplied to the negative pressure supply port 52.
The negative pressure obtained from the nozzle flapper mechanism 14
A vacuum pressure regulator characterized in that the vacuum pressure is obtained by controlling the flapper 22 of. 2. The vacuum pressure regulator according to claim 1, wherein the nozzle flapper mechanism 14 includes flat electrostrictive elements 26a and 26b. 3. In the regulator according to claim 1 or 2, the pilot valve section 16 is a valve body 40 that actually opens and closes the passages 56 and 60 that communicate the negative pressure supply port 52 and the negative pressure output port 54. A vacuum pressure regulator comprising: