JPH0468886B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a clutch in a transmission system for transmitting power from an agricultural vehicle to a working machine in an agricultural vehicle equipped with a working machine such as a harvester.

[Prior Art] Conventionally, a structure in which a working machine is attached to an agricultural vehicle equipped with an engine and power is transmitted from the agricultural vehicle to the working machine is disclosed, for example, in Japanese Patent Laid-Open No. 56-39713. This was known prior to the filing of this application, and many of these types include an electromagnetic clutch in the transmission system that transmits power from the agricultural vehicle to the working machine.

[Problems to be Solved by the Invention] By the way, in the conventional device as described above, when driving the work machine, the electromagnetic clutch is operated to "on", but the clutch is turned on while the engine speed remains high. When the ``on'' operation is performed, not only the electromagnetic clutch but also the transmission system receives a large impact, and not only is there a risk of damage to these parts, but the impact impairs safety and is dangerous for work.

Therefore, in view of the drawbacks of the conventional ones, the present invention has been devised to prevent the electromagnetic clutch interposed in the transmission system between the power take-off shaft of the agricultural vehicle and the input shaft of the working machine from being engaged except when the engine speed is low. In addition, once the clutch is engaged when the engine speed is low, the clutch remains in the engaged state even if the engine throttle lever is moved to the high speed side. By reducing the impact caused by the clutch, it is possible to prevent damage to the transmission system including the electromagnetic clutch, and to maintain work safety, as well as to shift the engine speed to the high speed side after the clutch is engaged. It is an object of the present invention to provide a clutch for a working machine in an agricultural vehicle that can be brought into a state suitable for driving the working machine.

[Means for Solving the Problems] In order to achieve the above object, a clutch for a working machine in an agricultural vehicle according to the present invention is provided by attaching the working machine to the agricultural vehicle equipped with an engine, and transmitting power from the agricultural vehicle to the working machine. An electromagnetic clutch is interposed in the transmission system between the power take-off shaft of the agricultural vehicle and the input shaft of the working vehicle, and the throttle lever of the engine is connected to the excitation circuit of the electromagnetic clutch when the engine is closed at a low speed position. It is equipped with a throttle switch and its self-holding circuit, and constitutes a safety circuit that disables the clutch's "on" operation unless the engine speed is low, and maintains that state after the clutch is "on". be.

[Operation] When driving a working machine attached to an agricultural vehicle, the clutch is turned on to excite the electromagnetic clutch and transmit power from the power output shaft of the agricultural vehicle to the input shaft of the working machine. However, the excitation circuit of the electromagnetic clutch is equipped with a throttle switch that closes the engine throttle lever when it is in a low speed position, and a self-holding circuit for the throttle switch, so if the engine speed remains high, the clutch will not engage. It does not cause excessive shock to the transmission system. The electromagnetic clutch is always engaged when the engine speed is low, but once the clutch is engaged, it remains engaged even if the throttle lever is moved to the high speed side. After the clutch is engaged, the engine speed can be brought to a state suitable for driving the work implement.

[Example] An embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an agricultural vehicle, which is equipped with an engine 2 and a cargo box 3. 4 is gearbox, 5 is
It is the power take-off shaft. 6 is a working machine, and this working machine 6 is attached to the agricultural vehicle 1 by a three-point hitch 7. 8 is an input shaft of the working machine 6. Note that the illustrated working machine 6 is an example of a corn harvester.

The power take-off shaft 5 of the agricultural vehicle 1 and the input shaft 8 of the working machine 6 are connected by a universal joint 9, and an electromagnetic clutch 10 is interposed between the power take-off shaft 5 and the universal joint 9. has been done. 11 is a clutch lever of the electromagnetic clutch 10, and 12 is a throttle lever of the engine 2. As shown in FIGS. 2 and 3, the clutch lever 11 is interlocked with a clutch switch 13 via a spring 14, which closes when the clutch is in the "on" position and opens when the clutch is in the "off" position. Further, as shown in the figure, a throttle switch 15 is connected to the throttle lever 12 via a spring 16, and the throttle switch 15 closes when the engine 2 rotates at a low speed and opens when the engine 2 rotates at a high speed. . 17 is a lever guide plate.

An example of an excitation circuit for the electromagnetic clutch 10 is shown in FIG. That is, the electromagnetic clutch 10
is connected to a power source (a battery mounted on the agricultural vehicle 1) via a clutch switch 13 and a throttle switch 15 in series. Further, a relay 18 is connected in parallel with the electromagnetic clutch 10, and a contact R of the relay 18 is connected to the throttle switch 15, and the throttle switch 15 is self-held by the relay 18 and its contact R. The circuit is configured. This safety circuit disables the "on" operation of the clutch unless the engine 2 is at a low rotational speed, and maintains this state after the clutch is "on".

In the device configured as described above, in order to drive the work implement 6, the clutch lever 11 is turned on.
When the clutch switch 13 is operated to the position shown in FIG. In this case, if the throttle lever 12 is in the low speed position, the throttle switch 15 is closed, so the electromagnetic clutch 10 is energized and the clutch is in the "on" state. and,
Once the electromagnetic clutch 10 is engaged, the relay 18 is energized, its contact R is closed, and the throttle switch 15 is self-held, so the throttle lever 1
Even if the throttle switch 15 is opened by operating the throttle switch 2 to the high speed side, the electromagnetic clutch 10 is kept in the "on" state. Therefore, after the clutch is engaged, the rotational speed of the engine 2 can be appropriately shifted to the high speed side to bring it into a state suitable for driving the work implement 6.

If the throttle lever 12 is in the high speed position when the clutch lever 11 is operated to the "on" position, the throttle switch 15 is open, so even if the clutch switch 13 is closed, the electromagnetic clutch 10 is closed. The excitation circuit remains open and the clutch does not engage. Therefore, clutch lever 1
2 to the "on" position, the electromagnetic clutch 10
Moreover, the clutch can be operated smoothly and safely without exerting an excessive impact on the transmission system such as the universal joint 9.

Note that the electromagnetic clutch 10 may be operated by a clutch pedal (not shown).

[Effects of the Invention] According to the present invention, the electromagnetic clutch interposed in the transmission system between the power take-off shaft of the agricultural vehicle and the input shaft of the working machine is prevented from being engaged except when the engine speed is low. , once the clutch is engaged when the engine speed is low, the clutch remains in the "engaged" state even if the engine throttle lever is operated to the high speed side. This reduces the impact, prevents damage to the transmission system including the electromagnetic clutch, and maintains work safety, as well as shifting the engine speed to a high speed side after the clutch is engaged. This has the effect of creating a state suitable for driving the work machine.

[Brief explanation of the drawing]

The drawings show one embodiment of the device according to the present invention, in which Fig. 1 is an overall side view of an agricultural vehicle and a working machine, Fig. 2 is an enlarged longitudinal sectional side view of the main parts, and Fig. 3 is a front view of the same. 4 are excitation circuit diagrams of the electromagnetic clutch. 1... Agricultural vehicle, 1... Engine, 5... Power take-off shaft, 6... Working machine, 8... Input shaft, 9... Universal joint, 10... Electromagnetic clutch,
11...clutch lever, 12...throttle lever, 13...clutch switch, 15...throttle switch, 18...relay, R...relay contact.

Claims (1)

[Claims] 1. In a structure in which a working machine is attached to an agricultural vehicle equipped with an engine and power is transmitted from the agricultural vehicle to the working machine, an electromagnetic clutch is installed in the transmission system between the power take-off shaft of the agricultural vehicle and the input shaft of the working vehicle. The excitation circuit of this electromagnetic clutch is equipped with a throttle switch that closes when the engine's throttle lever is in a low speed position, and a self-holding circuit for the throttle switch, which disables the clutch's "on" operation unless the engine speed is low. A clutch for a working machine in an agricultural vehicle, characterized in that the clutch is configured with a safety circuit that maintains the state after the clutch is engaged.