JPS6015282B2 - Combine cutting height adjustment device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement in a cutting height adjusting device for a combine harvester.

The mowing height adjustment device of the combine uses a hydraulic cylinder to control the oil passage through the operation of an electromagnetic directional control valve equipped with a solenoid that is energized and controlled by a manual switch and an automatic switch that opens and closes according to the distance between the reaping part and the ground surface. The mowing height of the grain in the field can be adjusted by operating the mowing section to raise and lower the mowing section. By the way, in conventional cutting height adjustment devices, the mowing section is raised and lowered continuously, and the raising and lowering speed is the same in both cases of manual adjustment by operating a manual switch and automatic adjustment by operating an automatic switch. This speed is adjusted to a speed suitable for manual operation, which requires extremely rapid lifting and lowering, such as raising the reaping section during rounding and lowering the reaping section at the beginning of mowing. However, this speed is too far for automatic adjustment and tends to cause control hunting, which impairs control stability. Furthermore, even when the reaping section is manually adjusted up and down during the reaping operation, the up and down speed is too fast and the cutting height is drastically changed, resulting in disturbances in the conveying posture and clogging. The present invention has been made in view of such circumstances, and in the case of manual adjustment, the reaping section is raised and lowered relatively quickly, and in the case of automatic adjustment, the reaping section is raised and lowered at a slower speed. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments thereof, with the object of providing a cutting height adjusting device which can be made to be more stable and stable. FIG. 1 shows a combine harvester equipped with a cutting height adjustment device according to the present invention, in which the distance between the grass dividing plate 2 and the ground surface is determined in the mounting area of the grass dividing plate 2 constituting the reaping section 1. Sensor arm 3 rotates to lower and raise in response to
is pivoted.

The reaping section 1, threshing section 9, driver's seat 10, etc. are moved up and down as one body around the rear part of the main frame as a center of rotation by the vertical movement of the piston rod 4a of the hydraulic cylinder 4 attached to the front part of the main frame. The reaping section 1 is moved up and down. As shown in FIG.
, a 3-boat 3-position switching type electromagnetic directional control valve 5, a hydraulic pump 6, and the like.
Then, the oil pressure in the hydraulic cylinder 4 rises and raises the reaping part 1, and the solenoid 5d is energized, so the electromagnetic directional control valve 5 moves to the cutting position d, the oil pressure in the hydraulic cylinder 4 decreases, and the reaping part 1 is raised. part 1 is lowered by its own weight, and both solenoids 5
When the power to u and 5d is cut off, the electromagnetic directional control valve 5 is at the neutral position n, and the hydraulic cylinder 4 is maintained at the hydraulic pressure at the time when the electromagnetic directional control valve 6 returns to the neutral position n, and the reaping section 1 stops rising or falling at that point. Second
The electric circuit shown in the figure shows a control circuit for controlling energization to the solenoids 5u and 5d, including a battery 11, a combine harvester key switch 12, a manual movement changeover switch 13, a single-pole dual-purpose manual switch 14, and A switching member 1 that is adjusted to repeat opening and closing at relatively short predetermined time intervals, such as an automatic switch 15, a flicker relay, a timer relay, or a combination of a pulse generation circuit and a switching circuit controlled on and off by the pulse generation circuit.
Consists of 6A,168. The reaping up/down lever 7 is arranged at the rear left of the driver's cab 8. The T-shaped switching operation groove 70 shown together with the head of the reaping upper and lower lever 7 in FIG.
The right side of the figure is shown as the front of the machine, and the left side of the figure is shown as the rear of the machine in plan view, and the operation of the reaping up/down lever 7 in the left and right direction of the machine (the operation in the up and down direction in Figure 2) This allows manual and automatic switching, and manual lowering and lowering can be switched by operating the machine in the longitudinal direction (right and left direction in FIG. 2). That is, by locking the reaping up/down bar 7 to the groove 70a on the right side of the machine body (lower side in the figure), the manual movement changeover switch 13 is turned on, and the left side (upper side in the figure) of the front (right side in the figure) of the machine body is turned on. direction)
The manual switch 14 is inserted into the switching terminal 14d by engaging the groove 70d in the groove 70d on the rear left side of the machine.
By engaging 0u, the manual switch 14 is turned on to the active terminal 14u. On the other hand, the automatic switch 15 is interlocked with the sensor arm 3, and when the sensor arm 3 is lowered by a predetermined amount or more, the automatic switch 15 is turned on to the switching terminal 15d, and the sensor arm is raised by a predetermined amount or more. When this happens, the automatic switch 15 is turned on to the switching side 15u side. And these connections are as follows. The common terminal 14c of the manual switch 14 is the switching member 16
It is connected to the battery 11 via the key switch 12 and the key switch 12, and the active side terminals 14u and 14d of the handheld switch 14 are connected to one end of the solenoids 5u and 5d, respectively. On the other hand, one end of the intermittent switching member 16A is connected to the key switch 1.
The terminal of the intermittent switching member 16 is connected to the common terminal 15c of the automatic switch 15 through the manual automatic changeover switch 13. Switching side terminals 15u and 15d of the automatic switch 15 are connected to one ends of the solenoids 5u and 6d, respectively.
The rest of u and 5d are body grounded. and the third
As shown in Figures A and B, the on-time of the intermittent switching member 16A, that is, the opening time t^, is the same as that of the intermittent switching member 16B.
The opening time, that is, the closing time tB, is adjusted to be shorter than the closing time tB, so that the reaping section lifting speed during automatic adjustment when the intermittent switching member 16A is activated is the same as the reaping section lifting speed during manual adjustment when the intermittent switching member 16B is activated. It will be slower than the speed. The device of the present invention configured as described above operates when the key switch 12 is closed and the reaping up/down lever 7 is locked in the groove 70a on the right side of the switching operation register 70.
The manual eye movement changeover switch 13 is closed. Sensor arm 3
is lowered or raised depending on the size of the distance between the grass dividing board 2 and the ground surface, so when the amount of descent or increase exceeds a predetermined amount, the common terminal 15c of the automatic switch 15 and the switching side terminal 15d or 15u is connected. As a result, energization to the solenoid 5d or 5u is started, but since the intermittent switching unit 16A is operated by the closing of the manual sliding switch 13 and the automatic switch 15, the solenoid 5d or 5u is energized for a predetermined time t^. It is done intermittently in cycles. Therefore, the electromagnetic directional control valve 5 is repeatedly switched between the switching position d or u and the neutral position n in response to interruptions in energization, and the oil pressure in the hydraulic cylinder 4 is gradually lowered or increased. As a result, the lowering or raising of the reaping section 1 is also performed gradually. Therefore, there is no problem with excessive lowering, causing hunting due to the upward movement, and the stability of the control is increased. In addition, the driver's seat 10 moves up and down together with the reaping section 1 as in the above embodiment. In the case where the cutting height is adjusted, the driver's seat 10, which moves up and down integrally with the reaping part 1, is gradually raised and lowered, and as a result, the riding comfort of the combine harvester equipped with the device of the present invention is improved, and You won't receive any unexpected shocks. Note that although the oil passage is operated intermittently by the electromagnetic directional control valve 5, the rise and fall characteristics when the oil pressure rises and falls in the hydraulic circuit are slow, so the reaping section 1 moves up and down smoothly. There is no unnatural pulse-like rise and fall. Next, the reaping upper and lower levers 7 are switched between the front groove 70b on the left side of the machine body or the rear groove 70 of the operation groove 70.
By engaging u, the common terminal 14c of the manual switch 14 and the switching side terminal 14d or 14u are connected, and the solenoid 5d or 5u is energized. As a result, the electromagnetic directional control valve 5 becomes the switching position d or u, so the hydraulic cylinder 4
The oil pressure inside the cutting section 1 is lowered or raised, and the reaping section 1 is lowered or raised. In other words, the cutting height is manually adjusted by such an operation, but since the intermittent switching section 16B operates, the energization to the solenoid 5d or 5u is performed intermittently under the control of the closing time tB of the switching member 16B. . Since this time t8 is longer than the closing time t^ in the case of automatic adjustment, the lifting speed of the reaping section is faster than that during automatic adjustment, and the reaping operation can be carried out while making emergency adjustment of the cutting height, which is the purpose of manual adjustment. It does not cause any drastic lifting or lowering inside, and does not cause abnormalities in the conveyance system. As described in detail above, the present invention allows the mowing section to be raised and lowered intermittently to adjust the cutting height, thereby increasing the stability of control during automatic adjustment. However, since it is designed to be raised and lowered intermittently, there is no sharpening that occurs when the cutting height is drastically changed due to the raising and lowering speed being too fast, which occurs when the grain is raised and lowered intermittently. No clogging occurs.

Furthermore, because lifting and lowering by manual adjustment is performed at a higher speed than lifting and lowering by automatic adjustment, the reaping section can be raised and lowered relatively quickly even when lifting and lowering by manual adjustment is required, such as in an emergency or when turning after one stroke. The present invention has excellent effects, such as eliminating the risk of safety and workability being compromised.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view of a combine harvester equipped with the device of the present invention, FIG. 2 is an electric circuit diagram shown together with a hydraulic circuit diagram of the device of the present invention, and FIG. 3A ，
B is a time chart showing the opening and closing times of the intermittent switching members 16A and 16B. 1. ．． ．． Reaping section, 2... Grass dividing board, 3... Sensor arm, 4... Hydraulic cylinder, 5... Electromagnetic directional control valve,
5u, 5d... Solenoid, 7... Reaping up and down bar,
13...Manual movement changeover switch, 14...Manual switch, 15...Automatic switch, 16A, 16B...
Intermittent switching member. Figure 1 Figure 3 Figure 2

Claims (1)

[Claims] 1. The oil path is switched by the operation of an electromagnetic directional control valve equipped with a solenoid whose energization is controlled on and off by a manual switch and an automatic switch that opens and closes according to the distance between the reaping part and the ground surface, and a hydraulic cylinder is operated. In a cutting height adjusting device for a combine harvester that raises and lowers a reaping part, a control circuit for controlling energization to the solenoid by the manual switch and the automatic switch is configured to energize the solenoid intermittently at predetermined time intervals. A mowing height adjusting device characterized in that an intermittent switching member is provided for each solenoid, and the time for energization of the solenoid by the manual switch is longer than the time for energization by the automatic switch.