METHOD FOR DETERMINING THE POSITION OF THE DIAPHRAGM OF AN ELECTRIC-MOTOR-DRIVEN DIAPHRAGM PUMP

Abstract

The disclosure relates to a position detection device for determining the position of the diaphragm or the drive piston of an electric-motor-driven diaphragm pump, in particular detecting the upper and lower reversal point (Po, Pu) in the movement curve of the diaphragm of a diaphragm pump operated in an electric-motor-driven manner via eccentric means, wherein a diaphragm actuated by a drive connecting rod closes a conveying chamber with valve means provided on an inlet and outlet side such that the volume can be changed between a minimum and maximum volume, whereby a reciprocating movement of an electric motor having a rotor attached to a shaft is converted into an actuation movement of the drive connecting rod via the effect of the eccentric means, wherein the position detection device has detecting means for detecting the average value position of the rotor shaft, as well as an evaluation device in order to determine at least the position of the upper reversal point of the diaphragm from the average value position.

Claims

1. A position detection device for determining a position of a diaphragm or a drive piston of an electric-motor-driven diaphragm pump, including for detecting an upper and lower reversal point in a movement sequence of the diaphragm of the diaphragm pump that is operated in an electric-motor-driven manner via eccentric elements, in which the diaphragm, which is actuated by a drive connecting rod, closes a feed chamber, which is provided with valve elements on the inlet and outlet side such that a volume can be changed between a minimum and maximum volume in that through action of the eccentric elements, a reciprocating motion of an electric motor with a rotor mounted on a shaft being converted into an actuating motion of the drive connecting rod, wherein the position detection device has detection means for detecting an average position of the rotor shaft and has an evaluation device for determining at least the position of the upper reversal point of the diaphragm from the average position.

2. The position detection device according to claim 1, wherein the detection means are configured to detect the average position of the motor shaft during a complete up and down motion of the diaphragm once the motor shaft has been switched from a rotary motion into a reciprocating motion.

3. The position detection device according to claim 2, wherein an angle gage is provided for detecting the rotor position.

4. A diaphragm pump embodied with a position detection device according to claim 1.

5. The diaphragm pump according to claim 4, wherein the diaphragm pump has a motor control device, configured to set the rotor shaft into a reciprocating motion in an angular range between 150° and 200° and has a valve control device for triggering valves as a function of the diaphragm position determined by the position detection device.

6. A method for determining a position of a diaphragm or a drive piston of an electric-motor-driven diaphragm pump, including for detecting an upper and lower reversal point in a movement sequence of the diaphragm of the diaphragm pump that is operated in an electric-motor-driven manner via eccentric elements in which the diaphragm, which is actuated by a drive connecting rod, closes a feed chamber, which is provided with valve elements on the inlet and outlet side such that a volume can be changed between a minimum and maximum volume in that through the action of the eccentric elements, a reciprocating motion of an electric motor with a rotor mounted on a shaft is converted into an actuating motion of the drive connecting rod, wherein the position of the diaphragm is determined based on at least the detection of the average position of the motor shaft through the use of an angle gage.

7. The method according to claim 7 configured with a position detection device according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other advantageous modifications of the disclosure are disclosed in the dependent claims and will be described in greater detail below together with the description of the preferred embodiment of the disclosure based on the figures.

[0023] In the drawings:

[0024] FIG. 1 shows a diagram, which depicts by way of example the position of the shaft plotted over time and

[0025] FIG. 2 is a flowchart, which shows the steps for determining the turning points according to the disclosure.

DETAILED DESCRIPTION

[0026] The disclosure will be described in greater detail below based on an exemplary embodiment with reference to FIGS. 1 and 2.

[0027] FIG. 1 shows a sample diagram, which represents the angular position of the shaft, beginning with the motor start in speed mode, transitioning into the reciprocating operation; first, an adjustment is made, followed by an adjusted, stable reciprocating operation. The figure also shows the average based on which it is possible to derive the upper reversal point of the diaphragm. The lower reversal point then occurs cyclically in the middle between two successive upper reversal points.

[0028] FIG. 2 shows a flowchart with two processes running in parallel. One process relates to the rotor position determination with an angle gage. In parallel with this, the motor is triggered in such a way that it first rotates clockwise (CW), then rotates counterclockwise (CCW), and the process is repeated until a difference for the position in the clockwise direction (pos_cw) and for the position in the counterclockwise direction (pos_ccw) is less than a predetermined set point (X), in order to thus determine that a stable position has been reached. Based on this, the position for the upper turning point (UT) of the diaphragm is then determined.

[0029] The turning point is determined by calculating the average between the two reversal points. In other words, the maximum value and minimum value are effectively taken from the rotor position and the average is calculated from them.

[0030] The embodiment of the disclosure is not limited to the preferred exemplary embodiments disclosed above. On the contrary, there are a number of conceivable variants that make use of the presented embodiment, even in fundamentally different embodiments.