JPS60205317A - Piston prover - Google Patents

Abstract

PURPOSE:To simplify a device and to reduce its size by performing on-off control over a control valve with the output signal of a sensor used for measurement, and only arranging one sensor at both ends of the piston prover and performing the measurement and control over the valve. CONSTITUTION:Single sensors 5 and 5' which detect detected plates 4a and 4a' on driven levers 4 and 4' which slide in contact with a piston 3 are provided to sensor fitting pipes 1 and 1' fixed at both ends of a cylinder 2. Then when a switch SW is turned on, control valves 10 and 11 are opened and the fluid from the measurement part 8 of a flow meter to be inspected flows in the cylinder 2 to move the piston 3 to right. The sensor 5 detects the detected plate 4a to take a measurement. Further, the sensor 5' detects the detected plate 4a' to stop the counter of a display part 6 and also closes the valves 10 and 11 to stop the piston 3 near the left dead point of the cylinder 2. When the switch SW is turned on for calibration, the control valves 10 and 11 are changed over and opened to form the flow passage extending from the right end of the cylinder 2 to the left end, thus calibrating the flow rate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a piston prover used for calibration of flowmeters, etc.

(Conventional technique t#) A piston prover used for calibration of a flowmeter, etc. controls the pulse counting operation from the flowmeter under test using a measurement sensor that detects the start and end of the piston stroke.
The piston is configured to stably reciprocate within a set stroke while controlling the opening/closing of a control valve disposed between the flowmeter to be tested and the piston prover using a valve sensor.

For this reason, in this type of device, two sensors, one for metering and one for valve, must be installed at both ends of the cylinder, and the valve sensor must be placed outside of the metering sensor. There is a problem that the device becomes long.

(Objective) The present invention has been made in view of the above problem, and its object is to provide a new piston prover that enables the device to be significantly simplified and downsized. There is a particular thing.

(Structure) The details of the present invention will be described below based on illustrated embodiments.

FIG. 1 shows an embodiment of the present invention, and reference numerals 1 and 1 in FIG. The display section 6 and valve control circuit 7 of the flowmeter to be tested are detected by detecting the detection plates 4a and 4a' of the driven rod 4.4° 1- which slides inside the pipe l.
A single sensor 5.5' is attached to each of the sensors for outputting a detection signal to the sensor.

The display section 6 shown in Fig. 1.2 shows the output signal from the pulse transmitter 9 provided in the measuring section 8 of the flowmeter to be tested, based on the output signal of the -1-signal sensor 5.5'' installed on the sensor mounting v1.1'. It is configured to measure and display the flow rate measured by the metering section 8 for each stroke of the piston 3 based on the output pulse,
Further, the control circuit 7 controls the measuring unit 8 by using the output pulse from the measuring unit 8 based on the output signal of the −F reporter sensor 5.5°.
The control valves 10 and 11 disposed between the cylinder 2 and the cylinder 2 and between the cylinder 2 and the discharge flow path are configured to open, close, and switch. In the figure, Sw indicates a start switch, P indicates a pump, and ▪ indicates a manual valve that bypasses the fluid from the measuring section 8 of the flowmeter to be tested to the discharge side without passing through the piston prover.

] - In the embodiment described, the start switch SW is now
When turned ON, the control circuit 7 opens the control valves 10.11. As a result, the fluid in the flow meter A] flowing into the cylinder 2 causes the piston 3, which had been stopped near the left dead center of the cylinder 2, to move to the right, and along with this, the fluid flows to the right. The sensor 5 detects the detection target plate 4a on the driven rod 4 that has moved in the direction, and the output signal thereof activates a counter (not shown) on the display section 6 of the flowmeter to be tested to perform measurement.

When the piston 3 moves to the right of the cylinder 2 in this way, the sensor 5' detects the detected plate 4a' of the driven rod 4-1- which is pressed by the piston 3 and starts moving, and sends the detection signal. The counter on the display section 6 is stopped. On the other hand, at the same time, the control circuit 7 receives the detection signal from the sensor 5°, closes the valve 1O111, and stops the piston 3 near the dead center on the right side of the cylinder 2.

When you turn on the start switch SW for calibration again,
Next, the control circuit 7 switches the control valve 1O111 to form a flow path from the right end to the left end of the cylinder 2, and the flow meter is calibrated.

Note that if one sensor is used and the detection signal is used to stop measurement and close the control valve at the same time, the detected plate 4a will be detected immediately after the sensor 5.
is positioned, the piston 3 stops, and the next measurement starts before the flow rate stabilizes, causing the inconvenience of worsening measurement accuracy. Therefore, as shown in Figure 2, the control is The valves 10 and 11 are opened relatively rapidly so that the flow rate is stabilized at the time when the detection plate 4a crosses the sensor 5 and a detection signal is output, and when the measurement is finished, the control valves to and it are adjusted to either the flow rate or the time. It is preferable that the control valve 1O11 closes slowly in proportion to the control valve 1O11.
Water hammer effect can also be prevented at the same time by the slow closing of step 1.

Further, as shown in FIG. 3, the control valve may be closed after a certain period of time (ts) after the detection signal is input from the sensor 5.

(Effects) As described above, according to the present invention, since the opening and closing of the control valve is controlled by the output signal of the sensor used for measurement, one sensor is disposed at each end of the piston prover. Measuring and valve control are possible with just one sensor, the number of detection members can be reduced and the circuit configuration can be simplified, and at the same time, the length of the sensor attachment part can be shortened and the entire device can be downsized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an apparatus showing an embodiment of the present invention;
FIG. 2.3 is a diagram showing quadrant changes during one measurement cycle. ■... Sensor mounting pipe 2... Cylinder 3...
... Piston 4 ... Driven rod 5 ... Display section 8 of the sensor flowmeter to be tested ... Measuring section 1O111 of the flowmeter to be tested ... Control valve applicant Tokyo Tatsuno Co., Ltd. Agent Patent Attorney Keiji Nishikawa □ Time (t) -rl-t11''-1ノ, 1. I 91-11~□-1 珂Threshold (tl

Claims (1)

[Claims] A piston prover in which a flow meter and a control valve are disposed in a wave path communicating with the cylinder, and a single sensor is provided at the end of the cylinder to output a control signal to the flow meter and control valve.