JPS6144575Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an automatic handling depth adjustment device for a harvesting machine such as a combine harvester.

A conventional automatic handling depth adjustment device will be explained with reference to FIG. 1. Grain culms harvested by a reaping section K are transferred to a threshing section D by a grain culm conveying device 1 such as a vertical conveying chain. The length of the grain culm is detected by two detection switches H and M installed near the entrance of the threshing section D, and if the grain culm is long enough to reach the detection switch H, the grain culm conveying device 1 is moved to the outside of the machine. If the grain culm is too short to reach the detection switch M, the grain culm conveying device 1 is raised toward the inside of the machine body, and the threshing culm such as the feed chain in the threshing section D is The handling depth is automatically adjusted by changing the relative position of the grain culm conveying device 1 with respect to the conveying device 2 and by changing the part where the grain culm is pinched by the threshing culm conveying device 2.

By the way, if we pay attention to the operation immediately after the start of the reaping work, we find that at the start of the reaping work, the grain culm conveying device 1 is generally far from the position that allows for appropriate handling depth, and furthermore, it is difficult to adjust the handling depth. The operation starts when the first harvested grain culm reaches the entrance of the threshing section D where detection switches H and M are installed, so a considerable amount of the grain culm that is harvested immediately after the start of reaping is handled. The grain passes through the threshing section before the depth is properly adjusted, resulting in problems such as being handled too shallowly, resulting in untreated grain, or being handled too deeply, resulting in clogging of the threshing section D.

The present invention has been developed in view of the above circumstances, and is designed to make the response speed of the drive system such as the hydraulic cylinder that drives the grain culm conveyance device faster than the subsequent response speed for a certain period of time from the start of reaping. The purpose of this invention is to provide an automatic handling depth adjustment device for a harvester that eliminates the above-mentioned troubles and does not impair control stability. The details will be explained based on the drawings.

Fig. 1 is an external view of a harvester equipped with an automatic handling depth adjustment device according to the present invention (hereinafter referred to as the proposed device), and the appearance is similar to that of a harvester equipped with a known automatic handling depth adjustment device. are the same, and FIG. 2 is a drawing schematically showing the relationship between the hydraulic circuit of the present device and the grain culm conveying device 1, the threshing culm conveying device 2, etc. whose inclination angle is controlled thereby. Detection switches M and H that open and close by detecting the length of the grain culm are located in the threshing section D.
It is arranged in front of the entrance of the handling cylinder 3, and a detection switch M is attached near the grain culm conveying device 1. L is a detection switch disposed in the middle of the grain culm conveying device 1, and is for detecting that grain culms are being held in the grain culm conveying device 1. The grain culm conveying device 1 is connected to a piston rod 4a of a hydraulic cylinder 4 so that its inclination angle can be changed by the operation of a hydraulic cylinder 4 constituting a hydraulic circuit. 5 is a 4-port 3-position switching type electromagnetic directional control valve, and when the solenoid 5r is energized, it is set to the switching position r, and the piston rod 4a moves back as shown by the arrow, allowing the grain culm conveying device 1 to be deeply handled. When the solenoid 5l is energized, the solenoid 5l is turned to the switching position 1, and the piston rod 4a moves forward to tilt the grain culm conveying device 1 toward the shallow handling side. 10 is a hydraulic pump; the hydraulic pump 10 and the hydraulic pump 1 of the electromagnetic directional control valve 5;
A 2-port, 2-position switching type throttle switching valve 6 is provided between the 0 side port and the solenoid 6s is energized to send the pressure oil from the hydraulic pump 10 as it is to the electromagnetic directional control valve 5. By demagnetizing the solenoid 6s, the pressure oil is throttled and the reduced pressure is supplied to the electromagnetic directional control valve 5. Note that 11 is a relief valve, which constitutes a hydraulic circuit.

FIG. 3 is an electrical circuit diagram of the proposed device. In other words, 7 is a battery, and 8 is a combine key switch that turns on/off power to this electric circuit.

This electric circuit is connected to the detection switch L,
M, H, a limit switch P arranged at an appropriate position so as to be activated when the piston rod 4a of the hydraulic cylinder 4 reaches the most retracted position and the grain culm conveying device 1 is in the most upright state, and the piston rod 4a is in the most advanced position. The limit switch Q and the solenoids 5l and 5 are arranged at appropriate positions so as to be activated when the grain culm conveying device 1 reaches the maximum tilt position.
r, 6s, a magnetic relay 9, and a delay circuit 20 that operates as an off-delay circuit. The normally open contacts La, Ma, and Ha of the detection switches L, M, and H, the normally closed contact Qb of the limit switch Q, and the solenoid 5l are connected in series in this order between the electrodes of the battery 7, which is controlled on and off by the key switch 8. The normally closed contact of the detection switch M is connected between the connection point X between contacts La and Ma and the body ground.
Mb, the normally closed contact Pb of the limit switch P, and the solenoid 5r are connected in series in this order.

Further, a normally open contact 9b of the magnetic relay 9 and a solenoid 6s are connected in series between the connection point X and the body ground.

The delay circuit 20 includes resistors 21 and 2 connected to the connection point
2, a diode 23, a capacitor 24 charged via a resistor 22, and two inverters 25, 2.
6 and a switching transistor 27. One end of the resistor 21 is grounded, and the resistor 22
One end is grounded via a capacitor 24. The diode 23 has its anode connected to the connection point X and its cathode connected to the positive terminal of the capacitor 24, which is connected to both the inverters 25,
It is connected to the base of transistor 27 via 26. The emitter of the transistor 27 is grounded, and the collector is connected to the excitation coil 9 of the magnet relay 9.
It is connected to connection point X via C. Note that the delay time of this delay circuit 20 is determined by the time constant when the capacitor 24 is charged.

Next, the operation of the present device constructed as described above will be explained. When the key switch 8 is closed and the harvester starts harvesting by operating the required operating lever, the harvested grain culm eventually reaches the location where the detection switch L is installed, and the contact La is closed. As a result, charging of the capacitor 24 is started, but until the positive terminal potential reaches a predetermined level, the transistor 27 is in a non-conducting state, so the excitation coil 9C is not energized, and therefore the contact 9b is closed. The circuit is closed, and the solenoid 6s is energized for a while. Therefore, the throttle switching valve 6 supplies the pressure oil from the hydraulic pump 10 to the potential directional control valve 5 without applying a throttle. Therefore, when the solenoid 5l or 5r is energized, the hydraulic cylinder 4 is moved forward and backward at high speed. Therefore, capacitor 2
The potential at the positive terminal of transistor 4 gradually rises and eventually reaches a level sufficient to make transistor 27 conductive. Then, as the transistor 27 becomes conductive, the excitation coil 9C starts to be energized, the contact 9b opens, and the solenoid 6s is demagnetized. Therefore, the throttle switching valve 6 will then throttle the pressure oil from the hydraulic pump 10 and supply the reduced pressure oil to the electromagnetic directional control valve 5.
When r is energized, the hydraulic cylinder 4 is moved slowly forward and backward. That is, the hydraulic cylinder 4 or the grain culm conveying device 1 operates at high speed for a while after the start of reaping, and thereafter operates at low speed.

Therefore, the handling depth can be adjusted by using the normally open contact when the tip of the grain culm being conveyed by the grain culm conveying device 1 is long enough to reach the detection switch H (or when it is so short that it does not reach the detection switch M). Since La is closed and the normally open contacts Ma and Ha (or normally closed contacts Mb) are closed, the solenoid 5l (or 5r) is energized, and the grain culm conveying device 1 is moved toward the outside of the machine. (or inward) until the detection switch H stops operating (or the detection switch M operates), or the limit switch Q
This state is continued until (or P) is activated, but as mentioned above, the oil pressure of the pressure oil is different between a certain period of time after the start of reaping and after that, so the grain culm conveying device 1 is Tilting (or rising) changes between high and low speeds, and this handling depth adjustment is performed at high speed within a certain period of time after the start of reaping, and at low speed thereafter.

Therefore, the handling depth adjustment for the grain culms that have been harvested immediately after the start of reaping is carried out quickly, and these grain culms are left untreated or the threshing section D is made by these grain culms.
This will not cause clogging. After that, the grain culm length will not change suddenly, so there is no need to adjust the handling depth at an unnecessarily high speed, but the handling depth should be adjusted moderately and slowly. This has the advantage of stabilizing the control operation. In other words, if the grain culm conveying device 1 is unnecessarily moved quickly to adjust the handling depth when reaping work is being carried out continuously, if there are partially short or long culms, The grain culm conveying device 1 will faithfully follow this movement and make one round trip.
In such a case, adjusting the handling depth has no practical effect, and the inertia of the grain culm conveying device 1 also causes a chattering phenomenon in the detection switches H and M, making the control operation unstable. It's for a reason.

Note that the throttle amount of the throttle switching valve 6 is determined so that the response speed of the hydraulic cylinder 4 or the grain culm conveying device 1 at normal times, that is, when reaping work is continuously performed, is an appropriate value, and the solenoid 6s
In other words, the delay time of the delay circuit 20 is determined by the conveying speed of the grain culm conveying device 1 and the threshing culm conveying device 2 that inherits the grain culm from the grain culm conveying device 1 and the threshing culm conveying device 2 that inherits the grain culm from the grain culm conveying device 1, and the time from where the detection switches L, M, and H are installed to the handling barrel 3. It goes without saying that the delay time is determined by taking into account the dimensions up to and including the resistance value of the resistor 22 and the capacitance value of the capacitor 24.

In the above embodiment, a hydraulic cylinder, which is a hydraulic actuating device, was used as the drive system of the grain culm conveying device, but the invention is not limited to this, and an electric actuating device such as an electric motor may be used as the drive system. Of course, this is a good thing.

In the case of an actuating device using an electric motor, there is a well-known circuit that switches the rotation speed of the motor between high and low levels. For example, in the case of a DC motor, a circuit that switches the applied voltage between high and low speeds is installed, and the rotation speed is set at high speed for a certain period of time from the start of reaping.
After that, it is sufficient to rotate at a low speed.

As described above, the device of the present invention has the advantage of eliminating problems such as unhandled grains and clogging in the threshing section immediately after the start of the reaping operation, and stable control of threshing depth adjustment thereafter.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is an external view of a harvester equipped with a handling depth adjustment device, Fig. 2 is a hydraulic circuit diagram of the proposed device, and Fig. 3 is its electrical diagram. It is a circuit diagram. DESCRIPTION OF SYMBOLS 1... Grain culm conveyance device, 2... Threshing culm transfer device, 4... Hydraulic cylinder, 5... Electromagnetic directional control valve, 6... Throttle switching valve, 10... Hydraulic pump, 2
0...delay circuit, L, M, H...detection switch,
K... Reaping department, D... Threshing department.

Claims (1)

[Scope of utility model registration request] The length of the grain culm being transported by the grain culm conveying device that transports the grain culm cut by the reaping section to the threshing section is detected, and based on the detection result, the threshing culm is transported in the threshing section. In an automatic handling depth adjustment device for a harvester, the handling depth is automatically adjusted by changing the relative position of the grain culm conveying device with respect to the device, the response speed of the drive system of the grain culm conveying device An automatic handling depth adjustment device characterized in that the response speed is faster than the subsequent response speed for a certain period of time from the start of mowing.