JP2534634B2 - Meat box front stop mechanism of meat cutting machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front position stop control for a meat slicing machine, and more particularly to a control system for accurately stopping a meat box at a predetermined front position.

[Background of the Invention]

In the conventional meat cutting machine, even if the reciprocating speed of the meat box is changed, the front stop position of the meat box is set within a predetermined range.
As shown in FIG. 2 and FIG. 2, the detector 13 detects the protrusion 13 fitted to the output shaft 7a of the speed reducer 7, and from the time when the detector 14 senses the protrusion 13, the meat box 3 After the reciprocating speed is sensed and the time inversely proportional to the reciprocating speed of the meat box 3 has elapsed, the electric motor 6 that drives the meat box 3 is stopped, and inertial feed is performed for a preset time t ₁ and then for a time t ₂ . The meat box 3 was stopped by applying a DC current to the winding of the electric motor 6 for braking.

However, according to the above method, when the temperature of the winding of the electric motor 6 rises, the resistance of the winding increases, the direct current decreases, and the braking torque decreases. Therefore, there is a problem that the stop position of the meat box 3 gradually deviates from a predetermined position until the temperature of the winding stabilizes.

[Object of the Invention]

The present invention has been made in view of the above, and an object thereof is to set the meat box to a predetermined front stop position even when the reciprocating speed of the meat box is adjusted and the temperature of the winding of the electric motor is increased or decreased. It is to stop with high accuracy.

[Outline of Invention]

The present invention automatically adjusts the power cutoff time of an electric motor that reciprocates in a meat box according to the reciprocating speed, and corrects the power cutoff time in consideration of a decrease amount of a braking torque due to a temperature rise of a winding of the electric motor. Focusing on improving the accuracy of the front stop position of the meat box, when stopping the meat box at the front position, make it inversely proportional to the reciprocating speed and according to the temperature rise value of the winding of the electric motor. In order to automatically adjust the time until the electric power of the electric motor is cut off, a front stop position approach detector is provided, the reciprocating speed of the meat box and the winding temperature of the electric motor are measured,
According to this measured value, calculate the electric power interruption time of the motor,
Moreover, after the electric power is cut off, an arithmetic processing unit for restricting the time t ₁ for moving the meat box by inertia and the time t ₂ for operating the braking mechanism is provided, and the meat box is stopped at the front position. .

Embodiments of the Invention The present invention will be described in detail with reference to the embodiments shown in FIGS. 1 to 3.

FIG. 1 is a schematic configuration diagram showing an embodiment of a meat cutting machine equipped with a front position stop control mechanism for a meat box, and FIG. 2 is a side view of the means stop position approach detector of FIG. In FIG. 1, two parallel sliding members 2 are arranged on the upper surface of the supporting member 1, and a meat box 3 is supported and fitted on the sliding member 2 so as to reciprocate (in the front-back direction in the drawing). Have been combined. One end of an arm 4 is rotatably supported on the bottom of the meat box 3, and the other end of the arm 4 is rotatably supported by a crank 5. A continuously variable transmission pulley is attached to a meat box driving electric motor 6 (hereinafter abbreviated as M2) and is connected to a speed reducer 7 by a power transmission means such as a belt. The output shaft of the speed reducer 7 is provided with a crank 5. It is fitted. Therefore, by rotating M2, the crank 5 can be rotated via the speed reducer 7, and the meat box 3 can be reciprocated via the arm 4. A round blade 9 is rotated by a power transmission means such as a belt from a round blade driving electric motor 8 (hereinafter abbreviated as M1).

Operate the operation switch 10 to start M1 and M2, rotate the circular blade 9 and reciprocate the meat box 3 to move the meat box 3
Cut the chunks of meat stored in to cut continuously or intermittently. The speed adjuster 11 adjusts the reciprocating speed of the meat box 3, and generally has a mechanism capable of adjusting a continuously variable pulley and the like. Reference numeral 12 denotes a front stop position approaching detector of the meat box 3, and as shown in FIG. 2, the support member 1 for detecting the presence or absence of the projecting piece 13 and the projecting piece 13 fitted into the output shaft 7a of the speed reducer 7 at a proper position. And a detector 14 fixed in place.

FIG. 3 is a block circuit diagram showing an embodiment of the front position stop control circuit of the meat box 3. In Fig. 3, alternating current
l _1, between the l _2, l ₃ and M1 connects the normally open relay contact 16a in series, whereas between the M2 is connected to the normally open relay contact 17a in series. Therefore, when the normally open relay contact 16a is closed, M1 is activated and the circular blade 9 is rotated, and the normally open relay contact 17a is rotated.
When a is closed, M2 is activated and the meat box 3 can be reciprocated via the speed reducer 7, the crank 5, and the arm 4.

Further connecting from l ₁ of the AC power supply to one terminal of one contact and M2 normally open relay contact 18a in series, it connects the remaining two-terminal of M2 to one of the remaining two contacts of the normally-open relay contacts 18a, both the other The anode side of the thyristor 20 is connected, and the cathode side of the thyristor 20 is connected to l ₃ of the AC power supply. Therefore, the normally open relay contact 17a is opened during the operation of M2, and the normally open relay contact 18a is closed for a certain period of time.
By appropriately firing, the DC current flows through the winding of M2, braking is applied to M2, and the meat box 3 can be stopped via the above-described transmission mechanism.

The relay coils of the above-mentioned normally open relay contacts 16a, 17a, 18a are 16, 17, 18 respectively, and these relay coils 16,
Each of the normally open relay contacts can be closed or opened by exciting 17 or 18 or stopping. Thyristor 20
The ignition control is performed by activating or deactivating the trigger circuit section 19. The output signal from the operation switch 10 is inputted to the PA1 terminal of the microcomputer 21, and receives the input signal of logic "H", the microcomputer 21 judges that it is the operation instruction signal, and receives the input signal of "L" from logic "H". And determines that it is a stop instruction signal. The output signal from the changeover switch 15 is a microcomputer
It is input to the PA2 terminal 21 and receives the logic "L" input signal to determine the polishing mode in which only the circular blade 9 is operated, and receives the logic "H" input signal to drive the round blade 9 and the meat box 3. Judge as continuous mode. When the microcomputer 21 inputs a signal of logic "H" from the operation switch 10, it checks the output signal of the changeover switch 15 and determines the PB of the microcomputer 21 according to each mode.
1, PB2 output is controlled, and relay coils 16 and 17 are excited and controlled.

The detector 14 is a section where the protruding piece 13 fitted to the output shaft 7a of the reduction gear 7 is detected, that is, the meat box 3 is at a distance from the front stop position.
L than ₀ a position spaced further distance L1 (L ₁ is L ₁ <relation L ₀₎ by interval meat box 3 is moved, and outputs a pulse signal of logic "H", the input to the PA3 terminal of the microcomputer 21 To be done. The microcomputer 21 receives the pulse signal from the detector 14, measures its period and pulse width, calculates and senses the reciprocating speed of the meat box 3,
When the meat box 3 is stopped at the front position, it is stored as information for adjusting the delay time t _D until the power of M2 is cut off. The thermistor 22 is mounted near the winding of M2, and its resistance value changes according to the temperature change of the winding.
Connected in series with the resistor 23 to form a circuit that divides the circuit power supply Vc and outputs the voltage V _AD . If the thermistor 22 has a resistance value that is inversely proportional to the temperature rise and its resistance value decreases,
The voltage V _AD increases in proportion to the temperature rise. This voltage V _AD is input to the AD pin of the microcomputer 21, and the voltage is
The analog information of V _AD is digitized and the temperature of the winding of M2 is calculated and sensed. When the winding resistance increases due to the temperature rise of the winding of M2, the direct current decreases and the braking torque decreases, so that the meat box 3 will stop past the predetermined front position and stop. If the microcomputer 21 calculates and the delay time is corrected so as to be in inverse proportion to the sensed value of the temperature rise of the winding, the accuracy of stopping the front position of the meat box 3 can be improved.

Hereinafter, the operation will be described in detail with reference to FIGS.
FIG. 4 is a time chart, and the parts A to F attached in FIG. 3 correspond to (A) to (F), respectively. 5 and 6 are empirical information for calculating the delay time t _D.
FIG. 8 is a flow chart. When the operation switch 10 is operated, a signal of logic “H” is input to the PA1 terminal of the microcomputer 21 as shown in FIG. 4 (A). The microcomputer 21 senses this logic "H", then reads the output of the changeover switch 15, and if this output is logic "L", it is judged that it is the polishing mode of the round blade 9, and the PB1 output is logic "H". , The relay coil 16 is excited, the normally open relay contact 16a is closed, and M1 is activated. In this mode, when the operation switch 10 is turned off, the PB1 output returns to logic "L" and the operation of M1 is stopped.

On the other hand, when the output of the changeover switch 15 is logic "H", it is determined that the continuous mode is selected, and as shown in (C) and (D) of FIG. 4, the PB1 output of the microcomputer 21 is set to logic "H" and M1 Is set to the time t required to start, the PB2 output is set to logic "H", the relay coils 16 and 17 are excited, and the normally open relay contact 16
Close a and 17a. Therefore, after M1 is started and the rotation of the round blade 9 is sufficiently increased, M2 is started so that the starting current is not concentrated, the meat box 3 reciprocates as described above, and the stored meat chunks are sequentially sent out to make the round blade You will be able to cut at 9.

When the meat box 3 is reciprocating, the detector 14 outputs a synchronous pulse signal as shown in FIG. 4 (B). The period ts and the pulse width tp of this pulse signal are measured by the microcomputer 21, and the measured value is updated every time the meat box 3 makes one reciprocation. This time measurement is performed by a method in which sampling is performed and the time is counted up with reference to the cycle of an integral multiple of the clock signal for operating the microcomputer 21.

When the output signal of the detector 14 changes from the logic "L" to "H" after the operation switch 10 is turned from ON to OFF, the measurement of the period ts of the pulse signal is completed, and FIG.
As shown in, the PB1 output of the microcomputer 21 is set to logic "L", the normally open relay contact 16a is opened, and the power supply to M1 is cut off.

Next, start measuring the pulse width tp from the rise time of the pulse signal logic "L" to "H", and measure the pulse width tp when the pulse signal changes from logic "H" to "L". Complete. From the period ts and the pulse width tp of this pulse signal, the reciprocating speed of the meat box 3 is obtained by the following equations.

Vts = 60 / ts (times / minute) Vtp = 60 × 360 / α ・ tp (times / minute) where α is the detector 14 that causes the protrusion 13 to move while the output shaft 7a of the speed reducer 7 makes one revolution. This is the detected angle, which is determined by the width of the protrusion 13 and the detection capability range of the detector 14.

The reciprocating speeds Vts and Vtp thus calculated are compared in magnitude, and the larger one is prioritized, and that is determined as the true reciprocating speed Vs. However, when the meat box 3 is stopped by one reciprocation, the pulse period ts becomes indefinite, so Vtp is calculated from the pulse width tp, and this Vtp is set as the reciprocating speed Vs.

When the reciprocating speed Vs is obtained, the delay time TD can be easily calculated because the relationship of the delay time TD corresponding to the reciprocating speed Vs is empirically determined as shown in FIG.

In the ROM (Read Only Memory) built in the microcomputer 21, the values of the delay times TD ₁ to TD ₄ corresponding to a plurality of points indicated by the reciprocating speeds Vs ₁ to Vs ₄ in FIG.
As shown in the figure, it is stored and held at addresses N to N + 3. Therefore, if the reciprocating speed of the meat box 3 calculated by the measurement calculation from the pulse signal is Vs = Vs ₂ , the delay time can be calculated as TD = TD ₂ , and the reciprocating speed is Vs ₁
Even if it does not match Vs ₄ , it can be obtained by a simple proportional calculation based on the front and back values. However, the delay time TD calculated in this way is not corrected for the decrease in the control torque due to the temperature rise of the winding of M2. The correction method will be described with reference to FIG. FIG. 6 shows the relationship between the time correction value Tk of the delay time TD corresponding to the winding temperature K of M2. The ROM incorporated in the microcomputer 21 has time correction values Tk ₁ to T corresponding to a plurality of points indicated by winding temperatures K ₁ to K ₃ of M2 in FIG.
The value of k ₃ is stored and held at addresses N + 4 to N + 6 as shown in FIG. Therefore by measuring the voltage VAD the microcomputer 21 is input to the AD terminal, the sensed M2 if winding temperature if at K = K _2, can be determined as a time correction value Tk = Tk _2, also of M2 Even if the winding temperature does not match K ₁ to K ₃ , it can be obtained by a simple proportional calculation.

Therefore, when the reciprocating speed of the meat box 3 is Vs = Vs ₂ , M2 at this time is
When the winding temperature K is K = K ₂ , the delay time finally calculated
t _D is calculated by the following equation.

t _D = TD + Tk = TD ₂ −Tk _{2 The} microcomputer 21 controls the delay time t _D from when the output signal of the detector 14 changes from logic “H” to “L” until the power of M2 is cut off, As shown in FIG. 4 (D), a microcomputer
The PB2 output of 21 is set to logic "L", the excitation of the relay coil 17 is stopped, the normally open relay contact 17a is opened, and the power supply of M2 is shut off. After that, as shown in Fig. 4 (E), the PB of the microcomputer 21
3 Set the output to logic "H", excite the relay coil 18,
The normally open relay contact 18a is closed, the meat box 3 is moved inertially for a time t ₁ as shown in FIG. 4 (F), and then the PB4 output of the microcomputer 21 is set to logic “L” for a time t ₂ to trigger. Circuit part 19
Is energized, the thyristor 20 is ignited, and a direct current is passed through M2 for braking to stop the meat box 3 at a predetermined front stop position. After the time t ₂ has elapsed, to complete the braking operation returns the PB4 output and PB3 output of microcomputer 21 to logic "L".

The above description is a method of measuring the temperature change of the winding of M2, performing time correction as shown in FIG. 6, and calculating the delay time t _D. As another method, as shown in FIG. 9, the change in the temperature rise of the M2 winding with respect to the operating time and the change in the temperature drop when the temperature is once raised, then stopped and left, are stored in the internal ROM of the microcomputer 21 as information. The temperature of the winding of M2 can be calculated and estimated by holding it and knowing the operating time and the stopping time of M2.

The operating time of M2 is obtained by sequentially adding this time ts since the cycle ts of the pulse signal output from the detector 14 is measured by the microcomputer 21. Further, the stop time of M2 can be roughly obtained by measuring the time during which the operation switch 10 is in the OFF state by the microcomputer 21. Therefore, the winding temperature is calculated and estimated by the microcomputer from the operating time and the stop time of M2, and the time correction value Tk is calculated based on the information of FIG. 6 as described above, and the delay time t _D is calculated. You can ask. Once the delay time t _D is obtained, the meat box 3
Can be stopped at the front position.

Although the two methods have been described above, in either case, in order to stop the meat box 3, after turning off the operation switch 10,
The pulse signal detected by the detector 14 by the detector 14 is used by the microcomputer.
21 must sense.

However, if the meat box 3 does not move due to mechanical abnormality or cutting of frozen meat or the like, and M2 is in a restrained state, the microcomputer 21 cannot detect the pulse signal.

If this condition is left, M2 may be burnt out. In order to prevent this, if the pulse signal from the detector 14 does not change for a preset time t ₃ after the M2 operation, it is determined to be abnormal, and as shown in the flowchart in FIG. I'm trying to shut it off.

〔The invention's effect〕

According to the present invention, the reciprocating speed of the meat box is detected, and the increase / decrease in the temperature of the winding of the electric motor is sensed, and in accordance with these values, the protrusion cuts off the electric power of the electric motor after passing through the detector. The delay time until is automatically adjusted and corrected by the arithmetic processing unit, the power is shut off, the meat box is moved by inertia during time t ₁ , and the electric motor is braked during a certain time t _2. Therefore, the meat box can be accurately stopped at the front stop position regardless of the reciprocating speed of the meat box and even when the temperature of the winding of the electric motor increases or decreases.

Furthermore, during the time t _3, since to sense whether the output signal of the detector is changed, even meat box drive system falls into constrained state, quickly can cut off the power, the burnout of the motor It can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a meat cutting machine provided with a front position stop mechanism for a meat box, FIG. 2 is a side view of the front stop position approach detector of FIG. 1, and FIG. 3 is one embodiment of the present invention. FIG. 4 is a block circuit diagram showing an example, FIG. 4 is a time chart of signals of respective parts in FIG. 3, FIG. 5 is an explanatory diagram of delay time, FIG. 6 is an explanatory diagram of correction time,
FIG. 7 is memory data, FIG. 8 is a flow chart, and FIG.
The figure is an illustration of changes in the winding temperature of M2 with respect to the operating time. In the figure, 3 is a meat box, 4 is an arm, 5 is a crank, 6
Is an electric motor for driving a meat box, 7 is a speed reducer, 8 is an electric motor for driving a circular blade, 9 is a circular blade, 10 is an operation switch, 11 is a speed controller, 12 is a front stop position approach detection unit, and 13 is a protrusion. Piece, 14
Is a detector, 16 to 18 are relay coils, 16a to 18a are normally open relay contacts, 19 is a trigger circuit section, 20 is a thyristor, 21 is a microcomputer, 22 is a thermistor, and 23 is a resistor.

Claims (4)

(57) [Claims] 1. A crank mechanism is connected to an output shaft of a speed reducer connected to an electric motor through a variable speed means, a meat box is reciprocated through the crank mechanism, and the meat box is stored in the meat box along with the reciprocation. While sequentially sending out the chunks of meat to the round blade side,
In a meat cutting machine equipped with a braking means for stopping the meat box at the front stop position after the cutting operation, the meat box approaches a position separated by a distance L ₀ from the front stop position, and further the distance L ₁ (L ₁ Is
(Relationship of L ₁ <L ₀ ) When the meat box moves toward you, a protruding piece detected by the detector is attached to the output shaft of the reducer, and the reciprocating speed of the meat box is detected by detecting the protruding piece. A front stop position approach detector that outputs a pulse signal having an inversely proportional pulse width, and a pulse period and a pulse width of the pulse signal output from the approach detector are measured, and the motor is inversely proportional to the pulse period and the pulse width. Delay time to shut off the power of
An arithmetic processing unit for calculating t _D is provided, and after the electric power of the electric motor is delayed and cut off by an instruction from the arithmetic processing unit, the meat box is inertially moved for a fixed time t ₁ and then for a fixed time t ₂ . A front stop mechanism for a meat box of a meat slicing machine, characterized in that the braking means is operated to stop the meat box at a predetermined front stop position. 2. When a DC current is applied to the electric motor for braking, a temperature sensitive element is mounted in the vicinity of the winding of the electric motor, and an electric change of the temperature sensitive element is detected by the arithmetic processing unit,
2. The front stopping mechanism for the meat box of the meat slicing machine according to claim 1, further comprising the arithmetic processing unit having an arithmetic function for correcting the delay time t _D according to an increase or decrease in the temperature of the winding of the electric motor. . 3. An arithmetic function for correcting the delay time t _D according to an increase or decrease in the temperature of the winding of the electric motor based on an empirical relationship between the operating time and the stop time of the electric motor and the temperature change of the winding. The front stopping mechanism for the meat box of the meat slicing machine according to claim 1, further comprising the arithmetic processing unit having the same. 4. When the pulse signal of the pulse signal output from the front stop position approach detector is measured, and the pulse signal does not change for a preset time t ₃ , it is determined that an abnormality has occurred. The meat box front stop mechanism of the meat slicing machine according to claim 1, further comprising the arithmetic processing unit that outputs a signal to shut off the power supply to the electric motor.