JPS628178Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-adjusting power transmission device in an agricultural tractor.

In other words, in agricultural tractors that are configured to transmit power from the engine through the main shaft to the transmission case that drives the rotary work machine, etc., when the load on the rotary work machine increases during work and the engine speed decreases, the automatic When the gearbox is turned into a deceleration transmission and normal rotation is restored, it is automatically activated to the normal transmission state, allowing stable and trouble-free operation without requiring the driver to perform operations each time. In particular, it is possible to transmit power directly from the main shaft to the input shaft on the transmission case side via a group of reduction gears reliably and without causing damage to various parts, and to provide a structure that is simple and suitable for implementation. It is something.

The embodiments shown in the drawings will be described below.

Fig. 1 shows a side view of an agricultural tractor equipped with a rotary work machine R at the rear, and has a structure in which the engine E side mounted in the front part and the transmission case M in the rear part are connected by an intermediate case 3; Inside the case 3, the rear flywheel 4 of the engine E and the clutch 5 are connected, and the transmission main shaft 1 is extended rearward from the clutch 5.
The input shaft 2 is located on the same straight line as the main shaft 1 and is arranged to transmit power into the transmission case M, and the power is transmitted from the inside of the transmission case M to the rear wheels 6 and the rotary working machine R.

Further, an electromagnetic clutch C1 is interposed between the rear end of the main shaft 1 and the front end of the input shaft 2 to enable intermittent shaft transmission. A transmission gear group G is interposed between the two shafts 7, which are parallel to the two shafts 1, 2 and are on a straight line.
An electromagnetic clutch C2 is interposed between the rear gear 8 of the main shaft 1 and the gear 9 of the shaft 7, and the front gear 10 of the input shaft 2.
The shaft 7 and the gear 9 of the shaft 7 are meshed with each other, and the construction is such that transmission is performed at a reduced speed compared to a direct transmission connection between the main shaft 1 and the input shaft 2.

A changeover switch 11 is connected to the battery 12 and to the electromagnetic clutches C1 and C2, so that the changeover switch 11 can operate the electromagnetic clutches C1 and C2.

A indicates a detection actuation device, which is a mechanical type, and has teeth 1 formed around the flywheel 4.
A small gear 14 is meshed with the small gear 14, and a governor a is installed on a rotating shaft 15 extending from the small gear 14, and an operating ring 16 connected to the governor a moves on the shaft while switching the changeover switch 11. The device is configured so that it can be operated by contacting the device.

In agricultural work in which the rotary work machine R is being towed and driven, when a load is normally applied, centrifugal force is applied to the cover a as shown in FIG. As shown in Figure 4, selector switch 11
When the electromagnetic clutch C2 is released, the electromagnetic clutch C1
As a result, the main shaft 1 is rotated directly to the input shaft 2 via the electromagnetic clutch C1, so that the plowing operation can be performed normally.

By the way, as the load from the rotary work machine R increases, the rotational speed of the engine E decreases;
In that case, as shown in FIG. 3, the centrifugal force of the governor a becomes small, and the actuating ring 16 moves and contacts the changeover switch 11, and as shown in FIG. 5, the electromagnetic clutch C2 is turned on. The electromagnetic clutch C1 is switched to disengage, and the main shaft 1
A deceleration transmission is carried out from the input shaft 2 to the input shaft 2 through a gear group, so that the input shaft 2 can be smoothly adapted.

Also, when the rotation of engine E returns to normal,
It automatically operates to the state shown in FIGS. 2 and 4 and returns to the normal rotation state.

As described above, the present invention provides an agricultural tractor configured to transmit power from the engine E to the transmission case M side that drives a rotary working machine R etc. via the main shaft 1. and a reduction gear group G in which an electromagnetic clutch C2 or the like is interposed between the main shaft 1 and the input shaft 2.
The engine rotation speed change detection actuation device A on the transmission upper side of the main shaft 1 automatically switches and operates both electromagnetic clutches C1, C2, etc. to automatically adjust the power transmission. Therefore, when the load of the rotary work machine R etc. increases during work and the rotational speed of the engine E decreases, the detection actuator A can automatically switch to deceleration transmission, and when the rotation returns to normal, it automatically returns to the normal speed. It can be operated in a transmission state, and stable operation can be performed without trouble without requiring the driver to operate it each time as in the conventional case.
In particular, the reduction gear transmission can be switched directly from the main shaft 1 to the input shaft 2 and via the reduction gear group G, so that power can be transmitted reliably and without damage to various parts, and the structure is simple and suitable for implementation. It has the characteristics of being able to Moreover, the present invention has the following unique effects.

In other words, if the load on the work equipment or rear wheels increases, the engine speed will be directly reduced via the transmission case, so the reduced speed will be detected and the changeover switch will be activated immediately. , since it switches to a reduction transmission system, it is possible to obtain accurate detection and quick response, unlike the conventional torque detector proposed in, for example, Japanese Patent Application Laid-Open No. 16333/1983. . To explain this in detail, when a load is applied to the engine, since the engines currently used in agricultural tractors of this type are equipped with a torque spring device, the engine speed is persistently reduced without stalling. Since this state draws a parabola (torque rise curve), the rotation speed in this state is picked up and the changeover switch is activated, so accurate detection is quickly performed. Generally, the torque detection device is configured to detect the torsional distortion of the shaft, and therefore the torque detection appears in a wave-like state and has a lot of so-called noise. Picking up torque fluctuations under such conditions is not only undesirable as it would result in unnecessary control, but also torque detectors are generally unsuitable for agricultural tractors, as they are prone to erroneous operation in high temperature and high humidity conditions.

Since the detection actuation device and the changeover switch are provided in the typical dead space between the engine and the transmission case of an agricultural tractor, there is no need to change the design of the transmission case. In addition, the center of gravity of the agricultural tractor is positioned forward, making it possible to stabilize the agricultural tractor.

It can be fully automated when applied to the reduction transmission system.

Since the engine serves as a load coupling, damage to the gear train in the transmission case can be avoided.

In particular, since the detection actuation device is linked to the flywheel ring gear, since the flywheel ring gear is originally provided for starting the engine, this can be used, and the engine can be started without having to be specially installed or changed. , it is very convenient that they can be linked together. Moreover, since the governor is actuated via the small gear rather than the ring gear of the large-diameter flywheel, high rotation can be obtained and the mechanical detection and actuation device can be made more compact.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a side view of an agricultural tractor, FIG. 2 is a schematic side view of the main parts,
3 is an explanatory diagram of a part of the operation of FIG. 2, FIG. 4 is a circuit diagram, and FIG. 5 is an explanatory diagram of the operation of FIG. 4. R... Rotary work machine, M... Mission case, E... Engine, 1... Main shaft, 2... Input shaft, C1, C2... Electromagnetic clutch, G... Gear group, A... Detection actuation device .

Claims (1)

[Scope of utility model registration request] It is a power transmission structure in which an engine E and a transmission case M located behind it are interlocked and connected via a transmission shaft, and the main shaft 1 is connected to the input shaft 2 of the transmission case M.
A connection transmission system is provided that is directly connected to the main shaft 1, and a reduction transmission system that is connected to the input shaft 8 via the reduction gear group G from the main shaft 1, and a detection system that detects changes in the rotational speed of the engine E due to load fluctuations. An actuating device A is provided near the main shaft 1, and the switching switch 11 is actuated by the actuating part of the detection actuating device A,
When the rotational speed of engine E falls below a certain rotational speed, the direct coupling transmission system is automatically cut off, and when the rotation of engine E returns to normal rotational speed, the reduction transmission system is automatically cut off, and at the same time, the direct coupling transmission system is switched off. In the power transmission structure of an agricultural tractor that is turned on, the detection actuating device is configured such that a small gear 14 is meshed with a ring gear formed around the flywheel 4 of the engine E, and a rotating shaft extending from the small gear 14. Governor a on 15
An operating ring 16 connected to the governor a
A self-adjustable power transmission device for an agricultural tractor, characterized in that the switch can be operated by contacting the changeover switch 11 while moving the rotary shaft 15 in the axial direction.