JPH0426417B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to control technology for industrial clean rooms;
This technology relates to multi-point sampling devices for gases related to ventilation control and abnormality detection technology in general buildings, and time-lapse measurement technology for multiple gas sampling.For example, when measuring the concentration of particulates in a cream room at multiple points, The purpose of the present invention is to provide a device that automatically switches between the two.

[Conventional technology]

Conventionally, this type of multi-point sampling device connects a large number of measured points to one sampling suction port of the measuring device via a branch joint, and inserts a solenoid valve in each branch side passage. The measurement point was being switched.

[Problem that the invention seeks to solve]

In the conventional configuration described above, when switching suction at each measurement point, the orifice diameter of the solenoid valve is small and the gas flow path is complicated, so that dust etc. in the suctioned gas can be easily removed from the valve. It was easy to deposit, stagnate, and re-splatter during the process, making it difficult to measure with high precision. However, in order to increase the diameter of the orifice, the valve itself becomes larger, and the entire device becomes larger. Furthermore, it is extremely difficult to change the internal structure of the valve related to the gas flow path.

In view of the above problems, it is an object of the present invention to improve the accuracy of measured values by simplifying the gas flow path in the switching device, making it a linear structure, and making the aperture sufficiently large.

[Means for solving problems]

In order to achieve the above object, the present invention has a plurality of sampling-side suction ports opened at equi-eccentric positions of a main body, and a measuring device that moves forward and backward with respect to the inner surface of the sampling-side suction port on a rotary table that is axially provided with respect to the main body. A selective communication mechanism for connecting or disconnecting the side ports is provided, the rotary table is driven to rotate in steps by a pulse motor, and an inner cavity containing the selective communication mechanism formed by the main body and the rotary table is provided. This is a multi-point gas sampling device that communicates with each other through exhaust ports, and the selective communication mechanism has a structure in which a communication hole is bored in the axis of a pilot member that slides when excited by a solenoid. It is.

[Effect]

The device of the present invention rotates a pulse motor in steps, and sequentially places a selection communication mechanism opposite to a plurality of sampling-side suction ports, and moves the measurement device-side ports that are integrated with the sampling-side suction ports by advancing and retracting the selection communication mechanism. , and is always in exhaust communication with the remaining sampling side suction ports that are not connected to the measuring device side ports via the exhaust port.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view of a multi-point gas sampling device. The main body 1 has a cylindrical peripheral wall 1b on the smooth lower surface of the base portion 1a, and a boss portion 1c at the center of the upper surface.
A shaft hole 2 is formed in the axial center of the boss portion 1c, and a shaft 4 is inserted into the shaft hole 2 through a bearing member 3 from the upper end into the circumferential wall 1b. The shaft is installed so that it can move freely. Reference numeral 5 designates a rotary table which is fastened to the lower end of the shaft 4 by means of a nut, and is located inside the cylindrical peripheral wall 1b via a spacer 6 fitted onto the shaft 4, and whose outer periphery is It is rotatable in close proximity to the cylindrical peripheral wall 1b and forms an inner cavity 7 surrounded by the main body 1 and the rotary table 5, and the support plate 1a has an upper surface and an inner wall located concentrically with the shaft 4. A plurality of small holes 8, 8, . Further, one selection communication mechanism 11 is constructed on one side of the rotary table 5 at the same position as the eccentric position of the sampling side suction port 10, and 12 is connected to a mounting 5a bored in the rotary table 5. This is a pilot member in which the cylindrical part 12a is slidably supported in the sleeve 27 which is airtightly fitted from the lower surface side in the same direction as the shaft 4. The shaft portion 12b is provided with a U-shaped packing 1 having an annular lip 13a that closely abuts the inner surface of the support plate portion 1a.
A communicating hole 14 is formed along the entire length of the pilot member 12, and a tube connecting step cylindrical portion 12c is formed at the lower end to connect the measuring instrument side port 1.
form 5. Reference numeral 16 denotes a solenoid which is fitted and fixed to the side surface of the inner cavity 7 of the rotary table 5 by being inserted into the pilot member 1. When the solenoid 16 is energized and energized, the pilot member 12 slides upward and the U. Annular lip 13 of mold packing 13
a comes into close contact with the lower surface of the support plate 1a, and its own weight falls when demagnetized without electricity. Further, a pulse motor 18 is fixed to the upper end of the boss portion 1c of the main body 1 via a spacer 17, and an output shaft 18a of the pulse motor 18 is rotatably connected to the upper end of the shaft 4. Adapting the step of the motor 18 to the sampling side suction port 10,
Further, a proximity sensor 19 is fixedly installed at one point on each circumference of the rotary table 5, and the axes of the measuring device side port 15 and the sampling side suction port 10 are aligned with the cylindrical peripheral wall 1b corresponding to the proximity sensor 19. A positioning hole 20 is bored at the position shown in FIG. An exhaust port 21 communicating with the inner cavity 7 is bored in a part of the cylindrical peripheral wall 1b, and 22 is a flexible tube for connecting to a measuring device.

As shown in the block diagram of FIG. 2, the gas multi-point sampling device A having the above configuration connects the other end of the flexible tube 22 to the suction port of a measuring device 23 such as a particle counter, and connects the other end of the flexible tube 22 to the exhaust port 21
After connecting to _the exhaust pump 24, for example, if multiple points _{R 1} , _{R 2 .} A sampling side suction port 1
₀ through the sampling _{tube 26} .

That is, the selection communication mechanism 11 is connected to the sampling side suction port 1 by the step of the pulse motor 18.
After rotating so that it is located concentrically with one of the 0s,
Correspondence between the proximity sensor 19 and the positioning hole 20 allows more accurate correction, and the solenoid 16 is energized and energized to move the pilot member 12.
is raised to connect the communication hole 14 with one of the sampling-side suction ports 10. At this time, the inner cavity 7
is constantly sucked by the exhaust pump 24, and the gas to be measured from the clean room 25 is sucked into each sampling side suction port 10 up to its inner end, and is immediately sucked into the measuring device 23 via the measuring device side port 15.

After flowing the gas inside the device for a certain period of time under the above conditions,
After the measurement is completed, the system is connected to the next system and scanned repeatedly, and as shown in FIG. 3, the solenoid 16 is demagnetized and the pilot member 12
falls under its own weight, and the annular lip 1 of the U-shaped packing 13
Since the pulse motor 18 is driven when the support plate 3a is completely separated from the lower surface of the support plate 1a, there is no sliding friction between the two.

Therefore, wear and dust generation of the U-shaped packing 13 are suppressed, and accurate measurement becomes possible.

〔Effect of the invention〕

As described above, the gas multi-point sampling device of the present invention has a simple and linear flow path system for the suction gas, so there is no accumulation, sedimentation, or re-scattering of substances in the gas, and high-precision measurement can be achieved. In addition, since there are no sliding parts in the flow path system of the device, there is no dust generation from the device itself, which improves the reliability of measurement. In addition, since the inside of the tube in the entire system is constantly suctioned by an exhaust pump, not only is there little delay in measurement, but the device of the present invention can use a commonly used part-take counter as a measuring device, and furthermore, it is equipped with a microcomputer. Since it is driven, it is highly reliable and has features such as being able to perform unmanned measurements.

[Brief explanation of drawings]

Fig. 1 is a front sectional view showing an embodiment of the gas multi-point sampling device according to the present invention, Fig. 2 is a block diagram showing an example of the use of the same device, and Fig. 3 is a schematic view of the device with the selective communication mechanism disengaged. FIG. A...Multi-point sampling device, 1...Main body, 4
... Shaft, 5 ... Rotating table, 10 ... Sampling side suction port, 11 ... Selection communication mechanism, 12 ... Pilot member, 13 ... U-shaped packing, 15 ... Measuring device side port, 16 ... Solenoid , 18... Pulse motor, 19... Proximity sensor, 20... Positioning hole, 21... Exhaust port.

Claims (1)

[Claims] 1. For a body formed by opening a plurality of sampling-side suction ports at equidistant positions from the axis of a plate-shaped body with a cylindrical peripheral wall formed on the lower surface, a plurality of sampling-side suction ports are arranged and opened at equal eccentric positions from the axis of the plate-shaped body. A rotary table pivotally attached to a pulse motor is rotatably installed inside the rotary table, forming an inner cavity in which the sampling side suction port is opened, and one of the sampling side suction ports is connected to the rotary table. A gas multi-point sampling device comprising a selective communication mechanism for driving a measuring instrument side port forward and backward to communicate or disconnect both ports, and having an exhaust port communicating with the inner cavity in the main body.