JPH0330640Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a vacuum pressure detection device in an air ejector pump used to attract and move various objects using vacuum pressure.

[Conventional technology]

Compressed air is ejected from the injection nozzle into the merging chamber, and the ejected air is discharged to the atmosphere from the exhaust port to generate negative pressure in the merging chamber, and air is taken in through the vacuum piping connected to the merging chamber. Air ejector pumps are known and are widely used, for example, in conveyance devices that move various objects using rubber suction cups provided on the vacuum piping.

By the way, in this type of conveyance device, vacuum leakage may occur between the suction cup and the suction part of the object due to the roughness of the surface of the object to be moved or the deterioration or damage of the suction cup material. There were problems such as the suction cup not being able to reach the desired vacuum pressure and moving the suction cup without an object being suctioned, and objects that had been suctioned falling once during the movement. Therefore, a pressure sensor for detecting vacuum pressure is usually provided in the air confluence chamber of the air ejector pump, and a vacuum pressure detection device is provided for controlling the vacuum pressure in accordance with the detection state of the sensor.

Conventional vacuum pressure detection devices use a balanced bridge circuit composed of a strain gauge and other resistance elements as a pressure sensor, and the unbalanced current obtained from this is processed by a differential amplifier etc. to the level required for signal processing. It is amplified to obtain an analog signal proportional to vacuum pressure. Then, this signal is supplied to one input of the comparator circuit, and compared with the reference signal supplied to the other input to obtain a deviation (change amount), and based on this deviation, the vacuum pressure is controlled to a regular value, etc. The necessary control signals were obtained (see Utility Model Application Publication No. 112593/1983).

[Problem that the invention attempts to solve]

However, since conventional vacuum pressure detection devices are used for detecting vacuum pressure and mainly correcting the reduced vacuum pressure to normal vacuum pressure, the circuit is also constructed from an analog signal processing system.

For this reason, in addition to the measured value of vacuum pressure, it is not possible to display and record various things such as the set value that is the normal vacuum pressure, the number of failures, the minimum and maximum vacuum pressure, and other wide-ranging control as necessary. Furthermore, for air ejector pumps that are required to be downsized, there are problems in that the number of circuit components increases, resulting in an increase in overall size, increased costs, and power consumption.

[Means for solving problems]

The present invention aims to provide a vacuum pressure detection device for an air ejector pump that solves the problems existing in the prior art described above, and is achieved by the device 1 shown below.

That is, the present invention detects the vacuum state in the air confluence chamber 2 and controls the vacuum pressure based on the detected vacuum pressure detection device 1 for an air ejector pump. a pressure sensor unit 3 that outputs an analog signal corresponding to the
An analog-to-digital converter (hereinafter referred to as A/D converter) 4 converts the output of the pressure sensor unit 3 into a digital signal, and performs arithmetic processing on the output value of the A/D converter 4, as well as data such as setting values. an arithmetic processing section 5 which has an input section 9 for inputting the information, and a storage section 7 for storing data such as measured values, set values, number of failures, etc., and processes the output of the arithmetic processing section 5 and outputs it to the outside. It is characterized by comprising an output section 6 for. In this case, at least the A/D conversion section 4 and the arithmetic processing section 5 can be constituted by a one-chip microcomputer 23. Further, the vacuum pressure detection device 1 includes a block-shaped body 11, and has a merging chamber 2 and a concave housing part 21 inside, and a pressure sensor part 3 and a one-chip microcomputer 23 are mounted inside this concave housing part 21. It is preferable that a printed wiring board 22 is arranged. Note that the storage section 7 includes a second output section 8.

[Effect]

Next, the operation of the present invention will be explained.

According to the vacuum pressure detection device 1 according to the present invention, first, the analog signal X1 corresponding to (proportional to) the vacuum pressure in the merging chamber 2 is obtained by the pressure sensor section 3. This analog signal X1 is converted into a digital signal X2 by the linear A/D converter 4, and is applied to the arithmetic processing section 5. Further, data such as set values are inputted from the input section 9 and stored in the storage section 7. Then, the arithmetic processing unit 5 compares the set value provided from the storage unit 7 with the measured value (digital signal X2) according to a preset program, and determines whether the vacuum pressure is normal or abnormal. The determination result is applied to the output section 6 and outputted to the outside as necessary signals such as control signals and display signals. Note that the storage unit 7 stores not only set values but also various data such as measured values and the number of failures processed.

〔Example〕

Below, preferred embodiments of the present invention are listed,
This will be explained in detail based on the drawings. FIG. 1 is a functional block diagram of a vacuum pressure detection device according to the present invention, and FIG. 2 is a longitudinal sectional view of an air ejector pump equipped with the same device.

First, the configuration of the air ejector pump M will be explained with reference to FIG. 2. 11 is a block-shaped aircraft, and there is an air confluence chamber 2 formed hollow inside.
has. An injection nozzle 13 for ejecting compressed air faces into the merging chamber 2, and an exhaust port 14 is formed in the fuselage 11, facing the tip of the nozzle 13 and having an axis located on the axis of the nozzle 13. do.
In addition, a nipple 16 for connecting vacuum piping is installed at another position facing the merging chamber 2 and at a position perpendicular to the jetting direction of the compressed air.
6 is connected to the rear end of vacuum piping 15, which is a flexible hose, for example. On the other hand, a suction cup 17 is provided at the tip of the pipe 15, and the suction cup 17 is moved to a predetermined location by a moving arm mechanism 18. Therefore, when compressed air is ejected from the injection nozzle 13, the compressed air passes through the merging chamber 2 and is further discharged to the atmosphere through the exhaust port 14. At this time, negative pressure is generated in the confluence chamber 2,
A suction cup 17 at the tip of the vacuum pipe 15 sucks air.

On the other hand, facing the merging room 2 and the nipple 16
A pressure sensor 20 such as a piezoelectric transducer that outputs an electrical signal proportional to the vacuum pressure in the merging chamber 2 is disposed at a position facing the merging chamber 2 . This pressure sensor 20
is mounted on a printed wiring board 22, and this board 22 is mounted on a concave storage portion 21 formed in a part of the fuselage 11.
to be installed. Moreover, chip elements and the like, which are circuit components, are mounted on this board 22. In addition, aircraft 1
1 is configured in a block shape, so the concave storage section 2
Although the size of the sensor 1 is extremely limited, since the signal processing system except the pressure sensor 20 is constructed as a chip element, it can be easily accommodated in the limited concave storage section 21.

Next, the signal processing system of the apparatus 1 will be explained with reference to FIG.

First, 20 is the pressure sensor described above, and its output side is connected to a 1-chip microcomputer (hereinafter abbreviated as microcomputer chip) 23. This microcomputer chip 23 is the central arithmetic processing section 5.
, an A/D converter 4, and other necessary functional units (not shown). The arithmetic processing section 5 includes a storage section 7 and an input section 9. Also, microcomputer chip 23
The output of is connected to an output section (interface) 6. Note that this output section 6 may be built in the microcomputer chip 23.

Next, the functions of the signal processing system will be described. The analog signal X1, which is the output of the pressure sensor 20, is input to the microcomputer chip 23, and is converted by the A/D converter 4 into a digital signal X2. On the other hand, data such as setting values are inputted from an input unit 9, which includes a keyboard, a volume (for example, semi-fixed), etc., and are stored in the storage unit 7 in advance to input arbitrary setting values from the outside. Note that the set values include both set values programmed in advance as standard values and set values input from the input unit 9 as necessary. Then, the arithmetic processing unit 5 receives the digital signal
For example, the value of the digital signal X2 is subtracted from the set value, and if the calculated value is positive, a reduced pressure state is output, and if it is negative, an overpressure state is output. The output of the arithmetic processing section 5 is given to the output section 6. This output section 6 drives various actuators, lamps, etc., which are external devices, according to the output of the processing section 5, and includes a digital-to-analog conversion section. It controls the vacuum pressure and lights up an alarm lamp to indicate that the vacuum pressure is not normal.

Note that the arithmetic processing section 5 performs arbitrary arithmetic processing along with the data stored in the storage section 7 as necessary. For example, by storing measured values, control can be performed with a time delay, or predetermined data processing can be performed in conjunction with the original processing function of the arithmetic processing unit 5, such as calculation results of average values, maximum values, etc. The data can be stored for the minimum value, counting of the number of failures, monitoring thereof, etc. Furthermore, it can also handle peak (transient) changes (such as noise). Furthermore, the storage unit 7 can output, for example, the overpressure state as a serial signal or a parallel signal.

Note that a second output section 8 is connected to the storage section 7. The second output section 8 can be composed of a display device that displays the measured values and setting values stored in the storage section 7, and various types of data that have been arithmetic-processed, or a printer that records the data on paper or the like.

Although various embodiments have been described above, the present invention is not limited to these embodiments, and the detailed structure, shape, etc. can be arbitrarily changed without departing from the gist of the present invention.

[Effect of idea]

As described above, the vacuum pressure detection device for an air ejector pump according to the present invention has the following advantages because the output of the pressure sensor section that detects vacuum pressure is processed by the digital signal processing system. .

By using arithmetic processing functions including a storage section, etc., the range of data processing can be dramatically expanded, and the diversity of control and the like and the functionality of the device can be greatly improved.

Since a 1-chip microcomputer can be used, circuit components such as amplifiers and comparison circuits are completely unnecessary compared to conventional analog signal processing systems, making it possible to achieve miniaturization, cost reduction, and power consumption reduction.
It is particularly suitable for air ejector pumps equipped with small bodies where installation space is limited.

[Brief explanation of drawings]

FIG. 1: A functional block diagram of a vacuum pressure detection device according to the present invention, and FIG. 2: A vertical sectional view of an air ejector pump equipped with the same device. In the drawing, 1: vacuum pressure detection device, 2: merging chamber, 3: pressure sensor section, 4: A/D conversion section,
5: Arithmetic processing unit, 6: Output unit, 7: Storage unit,
8: second output section, 9: input section.

Claims (1)

[Scope of Claim for Utility Model Registration] [1] In a vacuum pressure detection device for an air ejector pump that detects the vacuum state in the air merging chamber 2 and controls the vacuum pressure based on the detected vacuum state, A pressure sensor section 3 that outputs an analog signal corresponding to the pressure; an analog-to-digital conversion section 4 that converts the output of the pressure sensor section 3 into a digital signal; an arithmetic processing section 5 having an input section 9 for inputting data such as, and a storage section 7 for storing data such as measured values, set values, number of failures, etc.; A vacuum pressure detection device for an air ejector pump, characterized in that it is equipped with an output section 6 for outputting to the outside. [2] At least analog-digital converter 4
The vacuum pressure detection device for an air ejector pump according to claim 1, wherein the arithmetic processing section 5 is constructed of a one-chip microcomputer 23. [3] A block-shaped body 11 is provided, and the above-mentioned merging chamber 2 and a concave storage part 21 are provided inside, and a printed wiring board 22 on which a pressure sensor part 3 and a one-chip microcomputer 23 are mounted is mounted inside the concave housing part 21. A vacuum pressure detection device for an air ejector pump according to claim 1 or 2, characterized in that: [4] The vacuum pressure detection device for an air ejector pump according to claim 1, wherein the memory section 7 includes a second output section 8.