JPS62245113A - Quantitative pump - Google Patents

Abstract

PURPOSE:To facilitate the alteration of a mixing ratio without altering apparatus constitution, by a method wherein a pulse counter, a setting switch and a comparator are provided and a pump member is driven by one operation when a count number becomes equal to the set number of pulses. CONSTITUTION:The desired number of pulses are set to a setting switch 1 and a pulse counter 3 counts the number of the pulses of the input pulse signal S0 from a pulse oscillation type flowmeter. The set number N1 of pulses of a switch 1 and the count number N0 of the counter 3 are inputted to a comparator 4 and, when the count number N0 becomes equal to the set number N1 of pulses, the comparator 4 outputs a trigger signal S1. An electromagnetic pump 8 is driven by one operation on the basis of said signal S1 and, herein, if the set number N1 of pulses of the switch 1 are altered, the relation between the number N0 of pulses of the signal S0 and the number of operation times of the member 8 changes. Therefore, the ratio of the emitting amount of a quantitative pump to the flow amount relating to the pulse oscillation type flowmeter can be altered arbitrarily.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a constant m pump, in particular to a pulse oscillation type flow ff
This relates to a metering pump that can be connected to 1fff.

BACKGROUND OF THE INVENTION FIG. 2 is a general control block diagram of a flow rate proportional chemical injection system using a metering pump that can be connected to a pulse oscillation type flow meter. This system is for mixing into the main stream 10 an amount of chemical liquid 12 proportional to the amount of 8i in the main stream 10. The pulse oscillation type flow meter 14 generates a pulse signal SO having a frequency proportional to the flow rate of the main stream 10. Then, the metering pump 16 is operated with this pulse signal So.

That is, when one pulse is input to the regular pump 16, the metering pump 16 operates only once, and a fixed amount of the chemical solution 1 is delivered.
2 is injected into the main stream 10. As a result, when the flow rate of the main stream 10 doubles, the frequency of the pulse signal So doubles,
The maximum injection time of the chemical solution 12 is doubled. Therefore, the mixing ratio of the main stream 10 and the chemical liquid 12 is always constant.

Problems to be Solved by the Invention In the conventional system described above, there is a one-to-one correspondence between the pulse oscillation flowmeter and the metering pump, and in order to obtain a predetermined mixing ratio, it is necessary to It is necessary to prepare a pulse oscillation type flowmeter with characteristics or a metering pump with a specific capacity. Roughly speaking, if one attempts to change the above-mentioned mixing ratio, it is necessary to prepare a new pulse oscillation type flow (In2) with different flow rate/frequency characteristics or a metering pump with a different capacity.

Therefore, an object of the present invention is to provide a metering pump that allows the above-mentioned mixing ratio to be easily changed without changing the device configuration.

Means for Solving the Problems In this invention, a metering pump that can be connected to a pulse oscillation flowmeter is equipped with a pulse counter that counts pulse signals from the pulse oscillation flowmeter, and a digital switch that can set the desired number of pulses. , a comparator for comparing the count number of the pulse counter and the set number of pulses of the digital switch is provided, and the pump member is configured to drive only one operation when the count number becomes equal to the set number of pulses. , which solves the above problems.

The desired number of pulses is set on the action digital switch. The pulse counter counts the number of pulses of the input pulse signal from the pulse oscillation type flowmeter. The set pulse number of the digital switch and the count number of the pulse counter are input to the comparator. When the count number becomes equal to the set number of pulses, the comparator outputs a trigger signal. This bird drives the pump member by one operation based on the signal. When the set number of pulses of the digital switch is changed, the relationship between the number of pulses of the input pulse signal and the number of actuations of the pump member changes. Therefore, the ratio of the discharge amount of the metering pump to the flow rate of the pulse oscillation type flowmeter can be arbitrarily changed.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a metering pump of the present invention, which is a type of metering pump in which a diaphragm is reciprocated by electromagnetic force (rl
ilt! 1 is a block circuit diagram of an embodiment in which a flow m proportional drug injection system is applied to a metering pump (referred to as a "metering pump"). Here, 211! A proportional chemical injection system is a system that injects a chemical into the mainstream in an amount proportional to the flow rate of the mainstream. In other words, it is a system in which the mixing ratio of the mainstream and the chemical liquid is always constant even if the flow rate of the mainstream changes.

FIG. 2 is a general control block diagram of a flow rate proportional chemical injection system, and there is no change in this configuration itself even in the embodiments of the present invention. However, the difference from conventional systems lies in the internal configuration of the electromagnetic stationary pump 16.

In FIG. 1, the portion surrounded by broken lines is contained within the electromagnetic metering pump. First, the basic signal flow in the normal control state of an electromagnetic metering pump will be explained. In the normal control state, the automatic/manual changeover switch 20 is on the contact 22 side.

Pulse signal from the pulse oscillation flowmeter 14 in Fig. 2 @So
is input to the gate in FIG. Under normal control conditions,
The pulse signal So passes through the gate as it is and is input to the pulse counter. Note that the function of the gate will be described later. The pulse counter counts the number of pulses of the pulse signal So and sends the counted number No. to the comparator. On the other hand, the set pulse number N1 set by the setting switch (digital switch) is also input to the comparator (digital comparator). In the comparator, the count number on the pulse counter
and the set pulse number N1, and when the count number No becomes equal to the set pulse number N1, a trigger signal S1 is output. The signal S1 is a monostable multivibrator (
1) and is converted into a square wave pulse signal S2 having the same frequency as the trigger signal S1. This square wave pulse signal S2 is input to the power photocoupler to operate the electromagnetic pump member.

A power photocoupler consists of a light emitting diode and a phototriac. When the square wave pulse signal S2 is input to the light emitting diode, the light emitting diode lights up, and this lighting turns on the phototriac. At this time, N
100V is input to the Wi pump member, and the electromagnetic pump member operates for only one stroke. As a result, a certain amount of chemical liquid is discharged from the electromagnetic Ti pump.

The trigger signal S1 output from the comparator is also fed back to the reset terminal of the pulse counter. Therefore, Coun! - When the number No becomes equal to the set number of pulses N1, the count number of the pulse counter returns to zero, and the number of pulses of the pulse signal So is counted again from the beginning.

In this way, each time the number of pulses of the trigger signal S1 becomes equal to the set number of pulses N1, the electromagnetic pump member operates by one stroke. As a result, a certain amount of the chemical liquid is injected into the mainstream a number of times proportional to the flow rate of the mainstream, and the mixing ratio of the mainstream and the chemical liquid is kept constant.

Next, the upper limit stop function of this electromagnetic metering pump will be explained. The upper limit automatic stop function is a function that automatically stops the electromagnetic metering pump when the frequency of the square wave pulse signal S2 exceeds a predetermined upper limit. The upper limit automatic stop function is for preventing mechanical damage to the electromagnetic pump member when high frequency is input. This upper limit automatic stop function is coupled with a combination of a monostable multivibrator (2), a D flip-flop 23, and a gate.

The square wave pulse signal S2, which is the output of the monostable multivibrator (1), is input to the monostable multivibrator (2) and also to the clock terminal C of the D flip 70 tube 23. The shape of the square wave pulse signal S2 is the third
This is shown in the time chart in the figure. In the monostable multivibrator (2), an upper limit setting signal S3 (also a square wave pulse) is output in response to the square wave pulse signal S2. That is, as shown in FIG. 3, when the pulse 24 of the square wave pulse signal Sz is input to the monostable multivibrator (2), the pulse 26 appears in the upper limit setting signal @S3 with a slight delay Δt, and the pulse 26 is maintained at the -1high level for a predetermined pulse width to, and then returns to the LOW level. The predetermined pulse width to is 50 in this example.
The value of to determines the upper limit frequency of the square wave pulse signal S2. This point will be explained in detail later.

Next, the function of the D flip-flop 23 will be explained. When a pulse is input to the clock terminal C of the D flip-flop 23, the value of the data terminal at that time is output from the output terminal Q, and that value is held. Now, assume that pulse 24 of the square wave pulse signal S2 is input to the clock terminal C.

At this time, the pulse 26 has not yet risen, and the value at the data terminal is at the 1-OW level. Then, the value of the output terminal Q also becomes LOW level. D flip flop 2
The upper limit determination signal $4 output from the output terminal Q of No. 3 is input to the gate. The gate is configured to be OFF when the upper limit judgment signal S4 is Hi (7fi level), but as mentioned above, under normal conditions, the upper limit judgment signal S4 maintains the LOW level and the gate remains ON. be.

Next, the function of the upper limit automatic stop function when the pulse frequency of the square wave pulse signal S2 exceeds the upper limit will be explained. As the pulse frequency of the square wave pulse signal S2 increases, the pulse interval t1 becomes shorter, and finally, as shown in the time chart of FIG. 4, it becomes shorter than the predetermined pulse width to of the upper limit setting signal S3. Become. Then, pulse 2
The output pulses 34, 36, and 38 of the monostable multivibrator (2) corresponding to 8.30.32 overlap with each other, and eventually the upper limit setting signal @S3 maintains the HtOh level without returning to the low level. It turns out. In this state, when the pulse 30.32 is input to the clock terminal C of the D flip-flop 23, the output terminals QG, t
It becomes Hioh level. As a result, the gate is turned off and the pulse signal So is iI! at the gate. Cut off. That is, when the pulse frequency of the square wave pulse signal S2 exceeds the upper limit value, the electromagnetic pump member automatically stops.

Furthermore, when the upper limit determination signal S4 is at the H;gh level, the upper limit indicator (light emitting diode) lights up to notify that the frequency of the square wave pulse signal S2 has reached the upper limit value, that is, that the electromagnetic pump member has stopped. It looks like this.

The predetermined pulse width to is determined based on the mechanical capacity limit of the electromagnetic pump member, so that the electromagnetic pump member is always operated at a safe frequency.

When G1~ is turned off, no pulse is input to the clock terminal C and data terminal of the D flip-flop 23, but as long as no pulse is input to the clock terminal C, the output terminal Q remains at the high level.

It is also conceivable to continue operating the electromagnetic pump member at the upper limit when the pulse frequency of the square wave pulse signal S2 exceeds the upper limit.

However, if this is done, the mixing ratio of the mainstream and the chemical solution will change, which is not preferable. Therefore, it is safer to automatically stop the electromagnetic pump member when the upper limit is exceeded, as in this embodiment.

To restart the electromagnetic fixed price pump, press the reset switch 40. When the reset switch 40 is pressed, a Hioh level signal is input to the reset terminals 1 to R of the D flip-flop 23, and the output terminal Q of the D flip-flop 23 is
The upper limit determination signal S4 from 1 returns to the 1-ow level. As a result, the gate is turned on and the pulse counter starts counting the number of pulses of the input pulse signal So again. Note that when the reset switch 40 is pressed, the pulse counter is also reset at the same time.

Next, a procedure for changing the mixing ratio of the mainstream and the chemical solution will be described. Use the settings switch to change the mixing ratio. The setting switch determines how many times the input pulse signal So is counted to generate one trigger signal S1. If the set number of pulses N1 is increased, the mixing ratio of the chemical liquid to the mainstream will decrease, and if the set number of pulses N1 is decreased, the mixing ratio will increase. Therefore,
If the Mw1 constant pump of this embodiment is used, it becomes possible to control the ratio@chemical injection at any mixing ratio without replacing the pulse oscillation type flow m.

This embodiment is also configured so that the electromagnetic pump member can be driven without using the input pulse signal SO. That is, when the automatic/manual changeover switch 20 is switched to the contact 42, the output of the pulse oscillation circuit is input to the power photocoupler. The pulse frequency of the pulse oscillation circuit can be changed manually, and the electromagnetic pump member can be operated at a desired frequency.

Either the operation of the electromagnetic metering pump by the input pulse signal So or the operation of the electromagnetic fixed price pump by the pulse oscillation circuit can be stopped by an external signal.
By inputting 5 to the gate or oscillation circuit, the operation of the electromagnetic constant pump can be stopped.

Although the embodiments described above relate to electromagnetic metering pumps,
The present invention is not limited to this embodiment, but can be applied to any metering pump that is driven by a pulse signal.

Effects of the Invention This invention provides a metering pump device that can be connected to a pulse oscillation flowmeter, a pulse counter that counts pulse signals from the pulse oscillation flow meter, a digital switch that can set the desired number of pulses, and a pulse counter. A comparator is provided to compare the count number and the set pulse number of the digital reflex switch, and the pump member is driven by one operation when the count number becomes equal to the set pulse number. By changing the set pulse number of the switch, there is an effect that the correspondence relationship between the pulse frequency of the pulse oscillation type flowmeter and the operating number of the pump member can be changed.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of an embodiment in which the present invention is applied to an electromagnetic metering pump to construct a flow proportional drug injection system. FIG. 2 is a general control block diagram of a flow rate proportional chemical injection system. FIG. 3 is a time chart of each signal appearing in the block circuit diagram of FIG. 1. FIG. 4 is a time chart similar to FIG. 3 when the pulse frequency of the square wave pulse signal S2 exceeds the upper limit value.

Claims (1)

[Claims] (1) In a metering pump device that can be connected to a pulse oscillation flowmeter, the metering pump is equipped with a pulse counter that counts pulse signals from the pulse oscillation flowmeter, a digital switch that can set the desired number of pulses, and a pulse counter. A comparator is provided to compare the count number of the digital switch with the set pulse number of the digital switch, and the pump member is configured to drive only one operation when the count number becomes equal to the set pulse number. metering pump.