DEVICE FOR DETECTING MASS PARTICLES AND METHOD FOR CONTROL

• US 20150112556A1
• Filed: 10/21/2014
• Published: 04/23/2015
• Est. Priority Date: 10/21/2013
• Status: Active Grant

• Current Assignee: Mueller-Elektronik GmbH
• Original Assignee: Company Mueller-Elektronik GmbH & Co., KG
• Inventors: Meyer zu Hoberge, Sebastian, Liebich, Martin
• Granted Patent: US 9,869,571 B2
• Time in Patent Office: Days
• US Class Current: 701/50
• CPC Class Codes: A01C 21/005 Following a specific plan, e.g. pattern
• CPC Class Codes: A01C 7/105 Seed sensors
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01L 1/16 using properties of piezoelectric devices

Abstract

A device for detecting mass particles in air flows guided in a pipe, in particular of seeds to be distributed in a seed drill. A sensor element is disposed on the pipe. The sensor element is a piezoelectric element. An impact surface is disposed on the side of the piezoelectric element facing the interior of the pipe. A damping body is arranged on the side of the piezoelectric element facing away from the interior of the pipe. A rigid base body is disposed on the side of the piezoelectric element facing away from the interior of the pipe.

Claims

1. A device for detecting mass particles carried in air streams, in particular seeds to be distributed in a seed drill, comprising a pipe through which the air stream containing the mass particles is guided, with a sensor element arranged on the pipe, the sensor element comprising

a piezo-element,

an impact plate arranged on the side of the piezoelectric element facing the inside of the pipe

a damping body arranged on the side of the piezoelectric element facing away from the inside of the pipe, and

a rigid base body or securing element disposed on the side of the piezoelectric element facing away from the inside of the pipe, wherein

between the damping body (10) and the rigid base body or securing element (12) a contact disk (11) is arranged having a first connecting element (17) and a second connecting element (19) at a radial distance to the first connecting element,

the damping body (10) is designed as a damping disc, having electrical connecting elements (14, 16) spaced-apart from one another in the radial direction, wherein, on the one hand, a first connecting element (14) electrically connects only the first connecting surface (17) of the contact disk (11) with a first connecting element (21) of the piezo element (9), and on the other hand, a second connecting element (16) of the damping plate electrically connects only the second connecting element (19) of the contact disk (11) to the second connecting element (22) of the piezo element (9).

2. The device according to claim 1, wherein on the one hand the first connecting element (17, 21) of the contact disk (11) or the piezoelectric element (9) and the first connecting element (14) of the damping body (10) is circular, and on the other hand the second connecting element (19, 22) of the contact disk (11) or the piezoelectric element (9) and the second connecting portion (16) of the damping body (10) is circular.

3. The device according to claim 1, wherein a diameter (d_K1) of the first connecting element (17) is smaller than an inner diameter of the second connecting element (16) of the damping body (10), and wherein a diameter (d_D1) of the first connecting element (14) of the damping body (10) is smaller than an inner diameter of the second connecting element (22) of the piezoelectric element (9).

4. The device according to claim 1, wherein an inner diameter of the second connecting element (19) of the contact disk (11) is greater than a diameter (d_Dl) of the first connecting element (14) of the damping body (10) and the inner diameter of the is the second connecting element (16) of the damping body (10) is greater than the inner diameter of the second connecting element (22) of the piezo element (9).

5. The device according to claim 1, wherein the damping disc (10) is formed completely rubberized.

6. The device according to claim 1, wherein the bore throat (6) and/or the feed section (31) and/or the downstream transfer section (32) and/or of the deflection portion (2) is formed resilient.

7. The device according to claim 1, wherein the sensor element (3) is disposed in a deflection section (2) of the pipe (1), and wherein an upstream arranged feed section (31) of the pipe (1) is tapered in the flow direction (S) such that substantially all the mass particles conveyed in the feed section (31) and to be detected impact once on the impact surface (8) of the sensor element (3).

8. The device according to claim 1, wherein the sensor element (3) is arranged in a deflection section (2) of the pipe (1) and wherein an outer region (5) of the deflection portion (2) has a bore throat (6), which can be brought into engagement with a securing element (12) via a threaded connection, so that in a locking position of the securing element (12) the piezoelectric element (9), the damping body (10) and the impact plate (8) are compressed in the bore throat (6) in the assembled position.

9. A method for regulating mass particles to be distributed in a sowing machine, wherein the mass particles are fed to a distributor in a pipe by means of an air stream and are then branched to multiple distribution lines, wherein an actual distribution rate of the mass particles is detected by a sensor device and fed as sensor signals to a control device, in which a correcting variable is determined in dependence upon a target application rate for application to a metering device, by means of which the actual application rate of the mass particles is adjusted, comprising

continuously forming a correction factor (67) as the ratio of actual flow rate (62) and actual rotational frequency (72),

converting the desired output rate (65) using a calibration factor (K) and the correction factor (67) into a predetermined rotational frequency (70) for the metering device (59),

wherein a controller (69) of the control means (61) determines the correcting variable (63) acting on the metering means (59) depending on the control deviation (73), and wherein the control deviation (73) is determined as the difference between the desired rotational frequency (70) and the actual rotation frequency (72) of the metering device (59).

10. The method according to claim 9, wherein the calibration factor (K) is dependent on the type of metering device and/or of the type of the mass particles and is set as initial value for the desired rotational frequency (70), and that the calibration factor (K), and the therefrom derived desired rotational frequency (70), is continuously corrected during the sowing process by the correction factor (67).

11. The method of claim 9, wherein the actual output rate (65) of the mass particles is detected in the conduit (53) and/or in the distributor (56) and/or in at least one of the distribution lines (57).

12. The method according to claim 9, wherein the actual output rate (65) is measured by counting pulses of the mass particles in the sensor device (58), wherein by measured pulse count spacing between the pulses and/or comparing a number of counted mass particles per unit time a measure of the distribution accuracy in the direction of travel of the seed drill is supplied.

13. The method according to claim 9, wherein by means of the metering device (59) the proportion of the mass particles in the air flow is adjusted.

14. The method according to claim 13, wherein the proportion of the mass particles in the air stream is controlled by changing a rotation speed of a servo motor (60) in the metering device (59) and/or an actuator for varying the cross section of the distribution line (57).

15. A device for control of mass particles to be distributed in a seed drill, with a pipe for conveying the mass particles from a seed storage to a distribution device, from which several distribution lines lead to seed drills or application elements, with a metering device for adjusting an actual application rate of the mass particles, with a control device for determining a correcting variable for the metering device in dependence upon a desired application rate, wherein only the desired flow rate (65) of the mass particles is applied as an input to the control device (61).

16. The device according to claim 15, wherein the control device (61) comprises a converter and/or amplifier unit (68) by means of which the desired flow rate (65) is converted into a command value adapted for the controller (69), and that the conversion and/or amplifying purity (68) can be acted upon by a calibration factor (K) for setting a starting value for a predetermined rotational frequency (70) at the beginning of sowing process, as well as a correction factor (67) for correcting the calibration factor (K) be during the sowing process.