JP2987752B2 - Milk volume detection device for milking machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting the amount of milk in a milking machine, based on the resistance between a pair of electrodes attached to a milk tube.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Utility Model Publication No. 6-46291, a milk amount detecting device of a milking machine has a pair of electrodes attached to a milk tube provided in a distributor connected to a milk tap of a milk pipe. Along with
The resistance value between the electrodes, which changes due to the flow of milk, was measured by a detection processing circuit, and the measured resistance value was converted to milk mass (in the description, milk mass is the flow rate of milk).

[0003] By the way, various types of electrodes have been proposed, and a ring-type electrode which is a part of a milk tube is also known from Japanese Utility Model Application Laid-Open No. 7-28342. FIG. 4 shows a detection processing circuit 51 for the electrodes disclosed in the publication.
Shows the milk amount detection device 50 connected to the device. In FIG.
A milk pipe 1 is connected to a milk tube 62. In addition, milk pipe 6
When actually connecting the milk tube 1 to the milk tube 62, a distributor provided with the milk tube 62 is attached to the milk tap provided on the milk pipe 61, but the milk tap and the distributor are omitted in FIG.

On the other hand, 52 and 53 are ring-type electrodes. The electrode 52 is assembled as a part of a milk tube 62 near a milk pipe 61, and the electrode 53 is a conductive material which becomes a part of the milk tube 62. The pipe is used as is. The detection processing circuit 51 is a CPU
And the like, and the resistances Ra, R
A detection unit 55 having b, Rc, Rd, Re, Rf and switching transistors Qx, Qy is provided. In addition, 5
Reference numeral 6 denotes a power supply circuit for supplying power to the detection processing circuit 51, and a control signal supplied from the pulsation controller 57 to the pulsator is used as primary power.

Accordingly, as shown in FIG. 5, when the switching transistor Qy is turned on by the processing unit 54, a current Io flows from the DC power supply line through the resistor Rc, the electrodes 52 and 53, and the path of the switching transistor Qy. The resistance Ro generated by milk between the electrodes 52 and 53 is measured by the detection voltage Vy and the current Io applied to the processing unit 54, and the measured resistance Ro is measured by the processing unit 54
Is converted to milk yield. In order to prevent the electrodes 52 and 53 from touching each other, as shown in FIGS.
By turning on the switching transistors Qx and Qy alternately, the direction of current flow is reversed. FIG.
(C) and (d) show switching transistors Qx,
The detection voltages Vx and Vy measured when Qy is turned on are shown.

[0006]

The milk pipe 61 is usually made of a metal pipe and grounded in consideration of safety and the like.
Becomes the ground potential.

For this reason, in the conventional milk amount detecting device 50,
When milk flows into the milk tube 62, as shown in FIG. 5, a resistance rx is generated between the electrode 52 and the ground, and a resistance ry is generated between the electrode 53 and the ground.
, Leakage currents ix and iy, which are part of the current Io, flow. Therefore, the presence of each of the resistors rx and ry increases the measurement error of the resistance Ro. In particular, the magnitude of the resistors rx and ry is
Since it depends on the distance between the electrodes 52, 53 and the milk pipe 61, when the electrodes 52, 53 are assembled close to the milk pipe 61, they cannot be ignored and accurate detection of milk amount cannot be performed. There was a problem.

The present invention has been made to solve the problems existing in the prior art and eliminates a measurement error to provide a milking amount detecting device of a milking machine capable of accurately detecting the amount of milk. For the purpose of providing.

[0009]

According to the present invention, a pair of electrodes 4 and 5 attached to a milk tube 3 connected to a milk pipe 2 and a resistance R between the electrodes 4 and 5 are provided.
When configuring the milk amount detection device 1 of the milking machine including the detection processing circuit 6 for detecting the amount of milk based on o, a transformer 7 is interposed between the pair of electrodes 4 and 5 and the detection processing circuit 6. The two ends of the primary winding 7f are connected to electrode connection portions in the detection processing circuit 6, respectively, and both ends of the secondary winding 7s of the transformer 7 are connected to a pair of electrodes 4 and 5, respectively.

In this case, according to a preferred embodiment, the electrodes 4 and 5 use ring-shaped electrodes which are a part of the milk tube 3, and the detection processing circuit 6 performs the detection obtained from the primary winding 7f of the transformer 7. It has a processing function of comparing the voltages Vm and Vn with a preset reference voltage Vs, and converting the duration Tw in which the detection voltages Vm and Vn exceed the reference voltage Vs into milk amount.

As a result, since the resistance Ro is connected to both ends of the secondary winding 7s of the transformer 7, a loop circuit is formed on the secondary side of the transformer 7 by the secondary winding 7s and the resistance Ro. You. As a result, when the current If flows through the primary winding 7f of the transformer 7, the current Is flowing through the secondary winding 7s
Circulates through the loop circuit, and no current Is flows through the resistances rx and ry generated between the electrodes 4 and 5 and the ground. Therefore, the resistances rx and ry are ignored without causing an error.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of the present invention.

First, the configuration of the milk amount detection device 1 according to the present embodiment will be described with reference to FIG.

In FIG. 1, reference numeral 2 denotes a milk pipe, to which a milk tube 3 is connected. When the milk pipe 2 and the milk tube 3 are actually connected, a distributor provided with the milk tube 3 is attached to the milk tap provided on the milk pipe 2, but the milk tap and the distributor are omitted in FIG. On the other hand, 4 and 5 are a pair of electrodes of a ring type. The electrode 4 is assembled as a part of the milk tube 3 near the milk pipe 2, and the electrode 5 is a conductive pipe 5 p that is a part of the milk tube 3.

The detection processing circuit 6 includes a processing unit 11 including a CPU and the like, and a detection unit 12. The detection unit 12 has switching transistors Qm and Qn,
The base of the switching transistor Qm is connected to the processing unit 11 via a bias circuit including resistors R1 and R2, and the base of the switching transistor Qn is connected to the processing unit 11 via a bias circuit including bias resistors R3 and R4. On the other hand, the emitters of the switching transistors Qm and Qn are grounded, and the collectors of the switching transistors Qm and Qn, which are electrode connections, are connected to both ends of the primary winding 7f of the transformer 7, respectively. Furthermore, both ends of the primary winding 7f of the transformer 7 are connected to the DC power supply line 1 via resistors R5 and R6, respectively.
3, and both ends of the primary winding 7 f of the transformer 7 are connected to the processing unit 11. On the other hand, both ends of the secondary winding 7s of the transformer 7 are connected to the electrodes 4 and 5, respectively.

A power supply circuit 14 supplies power to the detection processing circuit 6, and a control signal supplied from the pulsation controller 15 to the pulsator is used as primary power.

Next, the operation of the milk amount detecting device 1 according to the present embodiment will be described with reference to FIGS.

First, as shown in FIG. 2, when the switching transistor Qn is turned on by the processing unit 11,
A current If flows from the DC power supply line 13 through a path of the resistor R5, the primary winding 7f, and the switching transistor Qn.
Note that rf is an equivalent resistance of the primary winding 7f. In this case, the detection voltage Vn obtained from the primary winding 7f input to the processing unit 11 has a triangular waveform as shown in FIG. on the other hand,
The processing unit 11 compares the preset reference voltage Vs with the detection voltage Vn, measures the duration Tw in which the detection voltage Vn exceeds the reference voltage Vs, and measures the measured duration Tw.
Is converted to a milk amount.

On the other hand, the resistance Ro generated by milk between the electrodes 4 and 5 is connected to both ends of the secondary winding 7s of the transformer 7, so that the secondary winding of the transformer 7 is connected to the secondary winding 7s. 7
A loop circuit Cs is formed by s and the resistance value Ro. The current Is flowing through the secondary winding 7s circulates through the loop circuit Cs and does not flow through the resistances rx and ry generated between the electrodes 4 and 5 and the ground. Note that rs is the equivalent resistance of the secondary winding 7s.
Therefore, the resistances rx and ry generated between the electrodes 4 and 5 and the ground are ignored without causing an error. Further, since the attenuation characteristic of the detection voltage Vn changes according to the magnitude of the resistance value Ro (the magnitude of the time constant in the loop circuit Cs), the duration Tw is obtained as a function of the resistance value Ro.

In order to prevent the electrodes 4 and 5 from touching each other,
As shown in FIGS. 3A and 3B, the direction in which the current flows is reversed by alternately turning on the switching transistors Qm and Qn. FIG. 3D shows the detected voltage Vm obtained from the primary winding 7f when the switching transistor Qm is turned on.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, the shape and position of the electrode can be arbitrarily set. In the embodiment, the measurement time Tw is measured, and the measurement time Tw is measured.
Was converted to the amount of milk, but the magnitudes (instantaneous values) of the detection voltages Vm and Vn after a certain period of time have elapsed since the start of flowing the current If may be measured, and the detected voltage may be converted to the amount of milk. Alternatively, the integrated value or the average value of the detection voltages Vm and Vn may be converted into the milk amount. In addition, the details of the circuit configuration and the like can be arbitrarily changed without departing from the gist of the present invention.

[0022]

As described above, the present invention provides a milking machine including a pair of electrodes attached to a milk tube connected to a milk pipe and a detection processing circuit for detecting the amount of milk based on a resistance value between the electrodes. In a milk amount detection device, a transformer is interposed between a pair of electrodes and a detection processing circuit, and both ends of a primary winding of the transformer are respectively connected to electrode connection portions in the detection processing circuit, and both ends of a secondary winding of the transformer are connected. Are connected to the pair of electrodes, respectively, so that an error factor due to a resistance generated between the electrode and the ground can be eliminated, thereby providing a remarkable effect that accurate detection of milk amount can be performed.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a milk amount detection device according to the present invention,

FIG. 2 is an explanatory diagram of an operation of an electric circuit in the milk amount detection device,

FIG. 3 is a time chart of signals of various parts in the electric circuit of the milk amount detection device;

FIG. 4 is an electric circuit diagram of a milk amount detection device according to the related art;

FIG. 5 is an explanatory diagram of an operation of an electric circuit in the milk amount detection device,

FIG. 6 is a time chart of signals of various parts in the electric circuit of the milk amount detection device;

[Explanation of symbols]

 Reference Signs List 1 milk amount detection device 2 milk pipe 3 milk tube 4 electrode 5 electrode 6 detection processing circuit 7 transformer 7f primary winding 7s secondary winding Ro resistance value Vm detection voltage Vn detection voltage Vs reference voltage Tw duration

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-271306 (JP, A) JP-A-61-153525 (JP, A) JP-A-7-28342 (JP, U) 16851 (JP, B2) Jiko 6-46291 (JP, Y2) Jiko 5-45170 (JP, Y2) (58) Field surveyed (Int. Cl. ⁶ , DB name) A01J 7/00

Claims (3)

(57) [Claims] 1. A milking amount detecting device for a milking machine, comprising: a pair of electrodes attached to a milk tube connected to a milk pipe; and a detection processing circuit for detecting milk amount based on a resistance value between the electrodes. A transformer is interposed between the electrodes and the detection processing circuit, and both ends of a primary winding of the transformer are respectively connected to electrode connection portions in the detection processing circuit, and both ends of a secondary winding of the transformer are connected to the pair of electrodes. A milk amount detection device for a milking machine, which is connected to each of the electrodes. 2. The electrode according to claim 1, wherein said electrode is a ring-type electrode which is a part of said milk tube.
A milk amount detection device for a milking machine according to the above. 3. A process for comparing a detection voltage obtained from a primary winding of the transformer with a preset reference voltage, and converting a duration in which the detection voltage exceeds the reference voltage into a milk amount. The milk amount detection device for a milking machine according to claim 1, further comprising a function.