JPH0144042Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is designed to prevent dust clogging in the handling room.
The purpose of this system is to automatically operate the dust feed valve by the operator in a threshing machine.

The present invention uses a handling cylinder shaft rotational speed sensor to detect a decrease in the rotational speed of the handling cylinder due to an overload on the handling cylinder shaft due to dust clogging, etc., and continuously rotates the motor for operating the dust feeding valve in the valve opening direction. At the fully open position, the motor is stopped by the operation of the first limit switch, and the dust clogging in the handling chamber is reduced by fully opening the dust feeding valve, and the handling drum rotation speed recovers to the set value or higher, thereby deactivating the handling drum rotation speed sensor. A negative intermittent pulse is supplied to the motor to intermittently rotate the motor in the valve closing direction, and when the valve position reaches the set open position, the first limit switch is activated to stop the motor, and the dust supply valve is automatically controlled. It is operated to open and close.

The following will explain the embodiments shown in the drawings.

Reference numeral 1 designates a sensor for detecting the rotational speed of the handling cylinder relative to the handling cylinder shaft (for example, a pulse generator that generates one pulse per revolution), and 2 represents a motor for driving the dust feeding valve. The motor 2 is connected to a dust feeding valve 4 via a speed reduction mechanism 3. A lever 5 that rotates integrally with the dust feeding valve 4 is provided, and the dust feeding valve 4 can be opened and closed by manual operation, and a third limit switch S 2 that detects the fully open position of the dust feeding valve 4 and a third limit switch S ₂ are provided. A first limit switch _S1 is provided to detect the closed position of No.4.

FIG. 3 shows an example of a control circuit for controlling the rotation of the motor 2 using the detection sensor 1, the first limit switch _S1 , and the second limit switch _S2 , and converts the AC output of the detection sensor 1 to the F/V converter 6. The first relay is connected between the detection unit A, which converts the DC voltage into a DC voltage proportional to the rotational speed, and then supplies it to the first relay 8 via a voltage comparator 7 having hysteresis, and the DC power supply 9 and the motor 2. Insert contacts 8a and 8b of 8, and when the first relay 8 is activated (relay ON) or deactivated (relay OFF), motor 2
The motor 2 is configured to be switched between forward and reverse by switching the connection between the DC power source 9 and the DC power source 9, and an oscillation circuit 10, a second relay 11 and a first relay are connected in parallel with the DC power source 9.
Connect the series circuit of the third contact 8c of the relay 8 and
Contact 11a of relay 11 is connected to power supply 9 and first relay 8
Switching part B is connected between the second contact of the relay 8 and the switching part B, which is controlled by turning ON and OFF the relay 8, and continuously supplies DC voltage to the motor 2 in the forward direction and pulse voltage in the reverse direction. It is more formed.

In switching unit B, the solid line positions of the contacts 8a, 8b, 8c, and 11a indicate when the relays 8 and 11 are not operating, and the motor 2 is connected for normal rotation, and the dotted line positions indicate when the relays 8 and 11 are operating, and the motor 2 is connected in the reverse direction. connection.

FIG. 4 shows an example of the hysteresis of the voltage comparator 7, the comparator 12,
It consists of a transistor 13, resistors R ₁ , R ₂ , R ₃ , R _f , etc. As shown in Figure 5, when the input voltage Vin rises, the relay turns on at Vp, but when the input voltage Vin falls, the relay turns on at Vq. It becomes OFF (Vp<Vq).
In the example, Vp is the rotation speed of the handling cylinder, 610r・p・
Vq corresponds to the handling cylinder rotation speed of 550r・p・m.

Next, the automatic opening/closing control function of the dust feeding valve according to the present invention will be explained.

During threshing work, if the handling drum is overloaded due to an increase in dust in the handling chamber (just before the culm becomes clogged) or an increase in the number of harvested grain culms being fed, etc., and the handling drum rotation speed decreases (for example,
500 r.p.m), voltage comparator 7 of detection part A is activated, V _L is decreased by the relay input voltage, first relay 8 is deactivated, and contacts 8a, 8 are activated.
b is the solid line position, and switching part B is connected to the motor for continuous forward rotation.

Continuous forward rotation of the motor rotates the dust feed valve 4 to the fully open position. When the dust feed valve 4 moves to the fully open position, the second
Limit switch _S2 opens, opening the motor circuit and stopping motor 2. By fully opening the dust feeding valve 4, the amount of accumulated dust in the handling chamber is reduced, and the overload on the handling cylinder is eliminated.

When the rotation speed of the handling cylinder reaches a set rotation speed (for example, 610 r.p.m.) that is slightly larger than the rated rotation speed (for example, 590 r.p.m.) due to the elimination of the overload, the input voltage Vin to the voltage comparator 7 changes. Vp is reached, the relay input voltage V _L rises, the first relay 8 is activated (relay ON), the contacts 8a, 8b, 8c are set to the dotted line position, the oscillation circuit 10 is connected to the motor 2, and the second relay 11 is activated. to open the contact 11a and supply a pulse current in the opposite direction to the motor 2 to close the dust supply valve 4.
is intermittently closed in the closing direction. When the dust feeding valve 4 reaches a predetermined opening angle, it contacts the first limit switch _S1 to open the first limit switch _S1 , thereby stopping the motor 2 from rotating in reverse.

As described above, the present invention includes a control circuit that controls the electric motor to continuously rotate in the direction of opening the dust feeding valve and also controls the electric motor to supply intermittent pulses to intermittently close the dust feeding valve. Since the control circuit is controlled by the output signal of the sensor that detects the rotation speed of the handling drum, the dust feeding valve can be automatically controlled to maintain the optimum threshing condition, eliminating the need for the operator to automatically operate the dust feeding valve. When opening, the motor continuously rotates, so there is no delay in valve operation, and when closing, the motor rotates intermittently, so the dust valve gradually closes and does not close abruptly. The reverse rotation of the motor can be stopped at the opening angle, which has the effect of preventing repeated opening and closing operations. In other words, since the motor is rotated continuously when opening and intermittently when closing, the control method is different from the conventional technology, which always operates in the closing direction when the rotation speed of the handling cylinder falls below a set value. When the dust exhaust port becomes clogged with dust, the dust supply valve is opened as soon as it detects a drop in the rotation speed of the handling cylinder below the set value to clear the blockage, and the dust supply valve is closed intermittently. It has the feature of being able to prevent the chattering phenomenon (continuously repeated opening and closing operations) by operating the

Furthermore, since the first and second limit switches are provided, which operate at the fully open position and the predetermined open position of the dust feeding valve, respectively, no overload is applied to the motor.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side view of the dust sending valve drive mechanism, Fig. 2 is a plan view showing the position of the limit switch, Fig. 3 is an electric circuit diagram of the control device, and Fig. 4 is a side view of the dust sending valve drive mechanism. The electrical circuit diagram of the voltage comparator, FIG. 5, is also an operational diagram. 1... Handling cylinder rotation speed detection sensor, 2... Motor,
4...Dust feed valve, S ₁ ...1st limit switch, S ₂
...Second limit switch, A...Detection section, B...
...Switching section.

Claims (1)

[Scope of utility model registration request] A motor for opening and closing the dust supply valve, a first limit switch for detecting the closed position of the dust supply valve, a second limit switch for detecting the open position of the dust supply valve, and a detection of the rotation speed of the handling cylinder. A handling drum rotation speed sensor is used to operate the handling drum, and when the handling drum rotation speed drops below a set value, the output of the handling drum rotation speed sensor is activated to continuously supply current to the electric motor in the direction in which the dust feeding valve is opened. When the second limit switch is activated, the current supply to the motor is stopped and the motor is stopped, and when the rotational speed of the handling cylinder has recovered to a rotational speed higher than the set value, the motor is activated in order to intermittently rotate the motor in the direction of closing the dust supply valve. An automatic opening/closing control device for a dust feeding valve, including a control circuit that controls the supply of intermittent pulses in the opposite direction.