JPS5840816Y2 - mobile agricultural machinery - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mobile agricultural machine configured to at least hydraulically drive the working equipment section located near the ground, such as a combine harvester equipped with a reaping pretreatment section that can be raised and lowered hydraulically. It is.

In the above-mentioned mobile agricultural machine, if there is a raised object such as a ridge in front of the machine while working, the working device is forcibly raised, but if the traveling speed is high, the working device must be raised quickly or rapidly. There was a risk of collision with a raised object.

However, if the raising speed is adjusted to match the height when traveling at high speed, the height will be raised more than necessary when traveling at low speed, making it difficult to adjust the working height to the desired height.

In particular, when automatically controlling the elevation by detecting the height of the work equipment above the ground, if the elevation speed is set high for high-speed driving, bunching is likely to occur in the elevation control during low-speed driving. was there.

For this purpose, the hydraulic pump that supplies pressure oil to the hydraulic drive device for lifting and lowering the work equipment is a variable displacement pump, and the discharge amount is automatically and reversibly increased as the traveling speed increases. A means to increase the speed has been proposed, and if a traveling device using a hydraulic continuously variable transmission (H8T) is installed, part of the output from this transmission is used to drive a pump to drive the vehicle. Although it has been considered to synchronize the speed and rising speed, variable displacement pumps are generally precision instruments and are expensive, require high-quality hydraulic oil, and require careful maintenance. This is a requirement, and there were problems in implementing it at a low cost.

Particularly when using the H8T, there was a drawback that when the aircraft stopped traveling, the pump was also stopped, making it impossible to perform an ascent operation with the aircraft stopped.

The present invention has been made in view of the above circumstances, and includes a variable throttle valve and an IJ-F valve in a pressure oil supply path from a fixed displacement hydraulic pump to a lifting hydraulic drive device, and a relief valve. are installed in series to improve the supply of pressure oil, and the opening automatically and reversibly increases as the traveling speed is increased within a traveling speed range exceeding a certain speed, and when the traveling speed is zero. It is characterized in that the variable throttle valve and the traveling speed change lever are linked so that they are open in the state.

In other words, even if you do not use a dedicated high-quality hydraulic oil, you can use an inexpensive gear pump that can easily use gear oil as a hydraulic fluid as a constant displacement hydraulic pump, so even if you add a variable throttle valve, you can use a variable displacement pump. It is cheaper and easier to maintain and manage compared to the case where the system is used.

Furthermore, according to the present invention, the traveling speed and the climbing speed are synchronized only within the working traveling speed range of -f, and the hydraulic drive system can operate even when the traveling speed reaches zero, so when the aircraft is stopped for inspection. etc., the working device section can be raised and lowered arbitrarily.

Embodiments of the present invention will be described below based on illustrative drawings.

Figure 1 is a schematic side view showing the front part of a combine harvester, which is an example of the mobile agricultural machine of the present invention. The processing section 3 is mounted so as to be able to swing up and down.

The reaping pretreatment section 3 is raised and lowered by a single-acting hydraulic cylinder (hydraulic drive device) 4, and its hydraulic circuit is shown in FIG.

The hydraulic cylinder 4 is controlled by an electromagnetic three-position switching valve 5, and the valve 5 is operated based on the detection result of a ground sensor 6 attached to the lower part of the pre-reaping treatment section 3. The height above the ground is automatically controlled to be maintained within the set range.

Note that the valve 5 can also be operated by a manual switch 7.

Although the above configuration is the same as the conventional one, the present invention further adds the following structure to automatically change the operating speed of the hydraulic cylinder 4.

In other words, a variable throttle valve 10 and a relief valve 11 are installed in the middle of a pressure oil supply oil passage a connecting a constant displacement gear pump 9 that is directly rated and driven by the power from the installed engine 8 and the switching valve 5.
are provided in series, and a variable throttle valve 12 is provided in the middle of the oil drainage path from the valve 5, and both of these variable throttle valves 10, 12 are linked to a traveling speed change lever 13.

The speed change lever 13 is interlocked and connected to an operating lever 15 of a hydraulic continuously variable transmission (H8T) 14 driven by an engine 8 via a link mechanism 18, and a rotation lever provided at an intermediate fulcrum of the link mechanism 18. A cam follower 17 for the cam 16 and the two throttle valves 10.12 are connected by wire.

The speed change lever 13 has a forward speed change range F and a reverse speed change range R on both sides of the neutral position N, and is configured such that the farther from the neutral position N the higher the speed becomes.

In the reaping work speed range A that is higher than the predetermined forward low speed position f, both throttle valves TO, 1 become faster.
2 becomes sharp, and the opening at the low speed position f is set as the minimum, and the opening becomes larger again as the speed becomes lower than this, reaching the maximum opening at the neutral position N, and further in the reverse range R. The cam 16 is set so that the maximum opening degree is maintained.

According to the above configuration, in the reaping work speed range A,
As the forward traveling speed increases, the opening degree of the throttle valve 10°120 increases, so the amount of pressure oil supplied to the hydraulic cylinder 4 per unit time increases, and the upward drive speed of the reaping pretreatment section 3 increases, The oil draining resistance from the hydraulic cylinder 4 decreases and the dead weight descending speed increases.

Conversely, as the traveling speed decreases, the upward driving speed and the dead weight downward speed decrease.

In the neutral position N and the reverse range R, the upward driving speed and the dead weight downward speed become maximum.

FIG. 4 shows the above-mentioned relationship between the travel shift position and the throttle valve opening.

Incidentally, in the embodiment, a case where the traveling speed can be changed steplessly has been exemplified, but it goes without saying that the present invention can also be applied to a case where the traveling speed can be changed steplessly.

In the embodiment, the rising and descending speeds are automatically changed, but it is easier to maintain the opening of the oil drain side throttle valve 12 at a constant value and keep the self-weight descending speed at a relatively low constant speed. In this case, it is undeniable that downward tracking is delayed during high-speed running, resulting in high mowing, but collision of the pre-reaping processing section 3 with the ground and control hunting can be sufficiently prevented. .

Furthermore, the present invention can be applied not only to combines but also to other harvesters, mowers, etc.

[Brief Description of the Drawings] The drawings show an embodiment of the mobile agricultural machine according to the present invention, in which Fig. 1 is a front side view of the combine harvester, Fig. 2 is a hydraulic circuit configuration diagram, and Fig. 3 is a speed change lever and variable throttle. FIG. 4 is a side view showing the linkage structure with the valve, and is a diagram showing the relationship between the gear shift position and the opening degree of the throttle valve. 3... Working device section, 4... Hydraulic drive device, 10... Variable throttle valve, 11... Relief valve.

Claims (1)

[Scope of Claim for Utility Model Registration] ■ In a mobile agricultural machine configured to drive at least upwardly the working device section 3 that operates near the ground using hydraulic pressure, pressurized oil is supplied from the fixed displacement hydraulic pump 9 to the hydraulic drive device 4 for lifting/lowering. A variable throttle valve 10 and a relief valve 11 are interposed in series in the supply path so that the relief valve 11 is effective in supplying pressure oil, and the traveling speed is increased within a traveling speed range exceeding a certain speed. A mobile agricultural machine in which the variable throttle valve 10 and the traveling speed change lever 13 are linked so that the opening degree automatically and reversibly increases as the operation is performed, and the variable throttle valve 10 and the traveling speed change lever 13 are opened when the traveling speed is zero. (2) The mobile agricultural machine according to claim 0, wherein the throttle valve 10 is set to the maximum opening degree when the traveling speed is zero.