JPH0227178A - Display of pressure with pulsation of reciprocating pump or the like - Google Patents

Abstract

PURPOSE:To minimize an error of pressure display as possible by adopting a display method that is different in a case a detection signal is output from a stroke terminal detector of a booster and in cases other than this. CONSTITUTION:The pressure oil generated at a hydraulic pump 100 is transferred to a booster 102 at a hydraulic line 101 through a directional control valve 107. The direction of supply of the pressure oil to the booster 102 is changed by the directional control valve 107. A pressure detector 111 is arranged at the hydraulic line 101. When a detection signal is output from stroke terminal detectors 109, 110 of the booster 102, a pressure value before signal output is displayed at an indicator 116 for a predetermined period of time from the time of the signal output. In cases other than this, an average detection value obtained at the pressure detector 111 in a predetermined period of time is operated by an operation device 115, and the value based on this average detection value is displayed at the indicator 116.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressure display method, and particularly to a pressure display method in a circuit with pulsation such as a reciprocating pump.

[Prior Art] When displaying oil pressure, pneumatic pressure, or other fluid pressure, there are two methods: connecting a pressure gauge directly to the fluid circuit and displaying it, and connecting a pressure detector to the fluid circuit and extracting the electrical signal as an electrical signal. A method of converting and converting the signal and displaying it as pressure is used.

In fluid circuits with pulsations, such as reciprocating pumps, pressure gauges are damaged early due to fatigue failure due to pulsations, so a throttle valve is provided to prevent pulsations from directly acting on the pressure gauge. On the other hand, in the method of electrically detecting pressure,
Since there are no moving parts due to pulsation, damage due to pulsation can be avoided, but if the pressure that changes frequently is displayed as is, it will be difficult to read the pressure displayed on the display, so the pressure within a predetermined period of time is averaged. A method was used to display it.

One of the fields related to the present invention is a reciprocating ultra-high pressure pump using a hydraulic booster system. An example of a circuit diagram of the pump device is shown in FIG. In the figure, 100 is a hydraulic pump connected to a pressure booster 102 through a hydraulic line 101. 103 is the secondary liquid suction pipe and check valve 1
The secondary liquid is discharged through the discharge pipe 106 via the discharge pipe 106. In such a device, if the pressure gauge is used to directly display the pressure, it is done by connecting the pressure gauge to the discharge pipe 106, and if it is to be detected electrically, it is generally done by attaching a pressure detector to the hydraulic pipe 101. It is true.

However, the pressure of the secondary liquid applied in the device
Since the pressure is extremely high (floO~400 MMa), the pressure gauge is expensive, and a common problem when using a pressure gauge is that it is unsuitable for remote display. Therefore, in this field, a method of displaying pressure by electrically detecting and converting the primary oil pressure is often used.

[Problems to be Solved by the Invention] In the above-mentioned electrical pressure detection and display method, when displaying pressure during a time period where pressure changes are relatively large, such as when switching to reciprocating motion of a reciprocating pump, pressure that changes significantly in a short period of time is displayed. If the pressure is displayed sequentially, the display becomes unstable and difficult to read, and the actual working pressure becomes difficult to judge. Therefore, conventionally, in a region where the pressure decreases significantly, a process is performed to exclude the rapidly decreasing pressure from the display target to reduce the fluctuation in the displayed pressure. On the other hand, changes in the actual pump discharge liquid pressure are detected as changes in the waveform shown in FIG. The pressure PU will be processed and displayed for a certain period of time. In other words, a pressure higher than the actual pressure is displayed. The reason for this is that the pressure is detected by the next oil pressure, and at the end of the stroke of the reciprocating pump, the circuit oil pressure suddenly increases momentarily and immediately before the pump operation direction switches, and then it rapidly decreases and returns to a steady pressure. Occurs to return to. This phenomenon becomes more noticeable as the pump reciprocates faster.

[Means for Solving the Problems] The present invention attempts to reduce such errors in display pressure as much as possible, and specifically employs the following method. In other words, in a reciprocating pump that discharges secondary liquid by reciprocating the pressure booster using hydraulic pressure, a pressure detector installed in the hydraulic line, a stroke end detector of the pressure booster piston, and each detector are used. It has a calculation device that processes the detected value of the calculation device, and a display device that displays the calculation result of the calculation device. The value before the signal output is displayed on the display over a period of time, and for other than that, an arithmetic device calculates the average detected value of the detected value of the pressure detector within a predetermined period of time, and the value is based on the average detected value. The purpose is achieved by displaying on the display.

[Example] Based on examples (will be explained).

In the configuration shown in FIG. 1, pressure oil generated by a hydraulic pump 100 is sent to a pressure booster 102 via a directional control valve 107 and a hydraulic line 101. The directional control valve 107 is the pressure booster 102
Pressure booster 1 by switching the direction of supply of pressure oil to
It acts to switch the direction of operation of 02.

The pressure intensifier 102 has a built-in piston 108 that moves to the right and to the left in accordance with the direction in which pressure oil is supplied, alternately performing suction and discharge operations. The direction control valve 107 is switched and controlled by detection signals from stroke end detectors 109 and 110 provided in the pressure booster 102. A pressure detector 111 is disposed in the hydraulic pipe line 10 and is configured to detect the pressure inside the hydraulic pipe line 101.The nozzle 12 is connected to the discharge pipe line 1.
It is connected to the end of the pressure intensifier 10 as needed.
An accumulator 113 may be disposed in the discharge line 106 between the nozzle 112 and the nozzle 112 .

Now, the hydraulic pump 1.00 is driven and pressure oil is sent from the hydraulic pipe line 101 to the pressure booster 102. Directional switching valve 1
07 is in the illustrated state, the pressure booster 102 has a discharge stroke on the right side and a suction stroke on the left side. In the meantime, the pressure booster 10
When the piston 108 of No. 2 approaches the right stroke end, the detector 11
0 detects piston 108 and issues a signal.

Then, a signal from the detector +10 is sent to the control device 114, and the control device 114 operates to switch the directional control valve 07 based on the signal. When the directional control valve 107 is switched, the pressure oil is sent to the pressure booster 102 along the path shown by the broken line in the figure, and the pressure booster 102 has a suction stroke on the right side and a discharge stroke on the left side, contrary to the previous one, and the piston 108 moves on the left side in the figure. move in the direction. When the piston 108 approaches the left stroke end, the detector 109 detects the piston 108 and issues a signal.The signal is sent to the control device 114, and the direction control valve 107 is switched by the signal from the control device 114, and the solid line shown in the figure changes. Pressure oil is sent to the pressure intensifier 102 through the hydraulic line 101 to operate the pressure intensifier 102. Thereafter, the same procedure is repeated to continuously move the pressure booster 102 back and forth.

Here, the hydraulic pipe line 10 discharged from the hydraulic pump 100
Ideally, the pressure oil of 1 should always be at a constant pressure under any conditions, but due to economic efficiency, equipment dimensions, and other constraints, the capacity of the hydraulic pump 100, the piping resistance of the hydraulic conduit 101, the hydraulic oil It generally varies depending on the load condition of the pressure booster 102 due to the viscosity of the pressure booster 102, etc.

In particular, when the moving direction of the piston 108 of the pressure intensifier D2 is switched, the pressure fluctuation becomes the largest. Therefore,
The signals generated from the detectors 109 and 110 when the piston 108 of the pressure intensifier 102 reaches the stroke end are processed so as to be reflected in the displayed pressure.

Specifically, the pressure in the hydraulic pipe 101 and the detector 10
The timing relationship between the signals 9 and 110 is as shown in FIG. That is, from the time when the detectors 109 and 110 detect the stroke end of the piston 108 until the direction of movement of the piston 108 is actually switched, the hydraulic line 10
The pressure of the piston 108 increases once, rapidly decreases in the direction of movement of the piston 108, and then reaches a desired steady pressure. This is due to a delay in the operation of the mechanical system from when the signal of detection u 109, 110 is received until the direction control valve 107 is activated and the piston 108 determines the direction of movement. Therefore, the pressure in the hydraulic pipe line 101 is converted and the pressure in the discharge pipe line 101 is
6 To display the pressure as 1. Normally, the values detected by the pressure detector 111 at predetermined intervals within a predetermined sampling time are extracted, the extracted values are averaged, and the value obtained by multiplying by the pressure increase ratio is displayed on the display 116. Output and display pressure. Pressure booster 10
When the piston 108 of No. 2 approaches the end of its stroke and the detector 109 or 110 is activated, the immediately previous displayed pressure is displayed as is, and after a predetermined period of time, for example 0.5 seconds or 1 second, sampling is performed again using the above method. The pressure is displayed based on average processing.

The following table shows actual measured values comparing the conventional method shown in FIG. 4 and the method of the present invention under the same conditions.

As can be seen from this result, the accuracy of the displayed pressure improved near the maximum rated output.

1 Effect of invention] As described above in detail based on the embodiments.

In displaying the pressure of a reciprocating pump that drives a pressure booster reciprocatingly using hydraulic pressure to discharge the next liquid, the present invention uses a pressure detector provided in a hydraulic pipe line and a stroke end detection of a piston of the pressure booster. It has an arithmetic device that processes the detected values of each detector, and a display device that displays the calculation results of the arithmetic device, and when a detection signal is output from the stroke end detector of the pressure booster, the signal is displayed. The value before the signal is output is displayed on a display for a predetermined period of time from the time of output, and other than that, the average detection value of the pressure detector detection value within a predetermined period of time is calculated by a calculation device, and the value is based on the average detection value. Since the value is displayed on the display, there is less error between the displayed pressure and the actual pressure in the discharge pipe, making it possible to display a more realistic pressure, improving the reliability of the equipment. This could have been improved.

(*Maximum rated output t4ookgr/cn+~1450kgf/i)

[Brief explanation of the drawing]

Hydraulic pump 101: Hydraulic line pressure intensifier 107: Direction control valve piston 109.110 Stroke end detection various pressure detectors 112 Nozzle calculation device 1161 Display device

Claims (1)

[Claims] (1) In a reciprocating pump that discharges secondary liquid by reciprocating the pressure booster using hydraulic pressure, a pressure detector installed in the hydraulic line, a stroke end detector of the pressure booster piston, and each detection It has an arithmetic device that processes the detected value of the intensifier, and a display device that displays the arithmetic result of the arithmetic device, and when a detection signal is output from the stroke end detector of the pressure booster, it is displayed for a predetermined period of time from the time when the signal is output. The value before the signal output is displayed on the display over the period of time, and for other than that, the calculation device calculates the average detection value of the detection value of the pressure detector within a predetermined time, and the value based on the average detection value is displayed on the display. Pressure display method.