JPS5928141Y2 - Metering pump device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump device, and particularly to a pump device (metering pump) that supplies a set flow rate of fluid by a piston that reciprocates within a cylinder.

Conventional metering pumps have been able to supply from the maximum amount to the minimum amount by either controlling the reciprocating sliding speed of the piston or controlling the stroke position and sound of the piston.

However, when only the stroke position is controlled, the variable flow rate range is narrow, and when only the reciprocating sliding speed is controlled, disturbances tend to occur in the extremely small supply region.

In order to solve such problems, the present invention attempts to provide a pump that skillfully combines both of the above-mentioned methods, and the gist of its configuration is that the set supply amount is If the supply amount is above a certain value, the stroke position of the piston is kept constant and the supply amount is adjusted by sliding speed control, and if the supply amount is below a certain value, the above piston is adjusted upward. The piston sliding speed is kept constant and the supply amount is adjusted by controlling the stroke position.
A metering pump device characterized by being provided with a piston drive section.

Next, the present invention will be explained based on FIG. 1, which is a diagram illustrating the main parts of one embodiment.

In FIG. 1, reference numeral 1 indicates a supply flow rate setting section, and a signal (2) from a supply amount controller 8 that controls the amount of fluid supplied by the piston pump.

In response to the meeting, a setting signal 11 is generated.

Further, the actual supply amount signal B generated by the supply amount calculation section 7 is input to the supply flow rate setting section 1, and negative feedback control is performed.

The setting signal 11 is displayed by the ratio of the maximum supply setting signal,
It shall take a value from O to 1 (from 0φ to 100%), and the same applies to ■o and ■/.

Reference numeral 2 denotes a signal converter, which inputs the supply amount setting signal 11 and generates a stroke position setting signal 11.

The signal converter 2 converts a stroke position setting signal 11 proportional to the setting signal 11 when the setting signal 11 is smaller than a specific value.
When the setting signal 1 is larger than the specific value, the stroke position setting signal 11 has the same magnitude as when the setting signal is equal to the specific value (i.e., a specific signal maintained constant corresponding to the specific value). Full output.

As an example, let this specific value kH be used, and the stroke position signal ks
Then, it is expressed by the following equation. However, S is expressed as a signal ratio to the maximum stroke position, and takes a value from 0 to 1.

When expressed as a relationship graph of equation (1), it becomes as shown in Figure 2 a.

On the other hand, the reciprocating sliding speed (■) of the piston is determined as c5 below.

That is, when the setting signal 1 is smaller than the specific value mentioned above, a constant speed β is always taken, and when the setting signal 1 is greater than the specific value, a value proportional to the setting signal 11 is taken.

If it is expressed as the ratio of speed Vk to maximum speed and takes a value from 0 to 1, the following relationship holds true.

(The specific value was 100.

)(2) When expressed as a graph, it is shown in Figure 2(b).

In FIG. 1, a complete example of the configuration of the 5th fc in the above-mentioned speed control ascending mode is shown, and its operation will be explained.

3a, 3c, 5. The calculation mechanism composed of 3b performs calculations on Io and β as described below.

That is, the constant subtraction unit 3a receives the setting signal Ik and calculates (11
-1), the constant subtraction unit 3c operates the piston, and the motor's reciprocating sliding speed becomes
Output signal β of minimum rotation speed setting section 4 for setting all minimum rotation speeds
A signal of (1-β) is generated by all the parties.

The multiplier 5 receives the above two signals (11-1) and (1-β)
In response, a signal of [2.(1-β).(■1-1)] is generated, and the constant addition section 3b receives the output signal of the multiplication section 5 and generates a signal of [2.(1-.beta.).(■1-1)]. A signal sound of 11-1)+1) is output.

The signal comparison and selection section 6 receives the output signal [2.
(1-β)・(11-1)+1] and the minimum rotation speed setting section 4
After receiving the output signal β of
12, and the speed of the reciprocating sliding of the piston is controlled in accordance with this output.

In this example, O≦■1≦100! constant speed β
The piston slides back and forth at a speed proportional to 11 when □-≦1.

In this embodiment, the sliding speed signal 9 and cylinder position signal 10 from the actual pump are input to the supply amount calculating section 7.

The supply amount calculating section 7 multiplies the above two signals 9 and 11 and outputs the result as an actual supply amount signal I', and this signal (2) is input to the supply flow rate setting section 1 and negative feedback control is performed.

(In other words, the setting signal 11 is the signal ■ of the supply amount controller 8.

and the actual supply amount signal I' (Io-IQ).

) As described in detail above, the present invention combines the stroke position control of the piston and the reciprocating sliding speed to provide a stable flow rate that can be varied over a wide range and that does not cause disturbances even in extremely small supply areas. The present invention provides a metering pump device that can perform the supply.

In addition, the present invention has the feature that even if the set value of the minimum rotational speed β is changed, there is no need to change other constituent food amounts, which is convenient for use and easy to adjust.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the main parts of a metering pump according to an embodiment of the present invention.
FIGS. 2a and 2b are diagrams showing the relationship between the stroke movement and reciprocating sliding speed of the piston of the metering pump of the present invention and the set amount signal. 1... Supply flow rate setting section, 2... Signal conversion section, 3a, 3c... Constant subtraction section, 3b...
...Constant addition section, 4...Minimum rotation speed setting section, 5
...Multiplication section, 6...Signal comparison selection section,
7... Supply amount calculation unit, 8... Supply amount controller, 9... Sliding speed signal, 10...
Cylinder position signal, 11... Stroke position setting signal, 12... Speed setting signal.

Claims (1)

[Scope of utility model registration request] A supply flow rate setting section 1 generates a setting signal sound in response to a signal sound from a supply amount controller 8 that controls the total amount of fluid supplied by the piston pump, and when this setting signal is smaller than a specific value, a signal proportional to the setting signal is set. a signal conversion unit 2 which outputs a specific signal corresponding to the specific value when the set signal is thicker than a specific value, and controls the position of the piston stroke of the piston pump in accordance with this output; A calculation mechanism for the signal from the supply flow rate setting section 1 and a signal from the minimum rotation speed setting section 4 that sets the minimum rotation speed sound of the motor that is the reciprocating sliding speed of the piston, and the output from this calculation mechanism and the minimum rotation speed. The metering pump device has a signal comparing and selecting section 6 which compares the signal from the setting section 4, outputs the full signal of the larger one, and controls the speed and duration of the reciprocating sliding of the piston in response to this output.