JPS62101531A - Travel transmission structure for agricultural tractor - Google Patents

Abstract

PURPOSE:To reduce the cost of a front wheel change gear and simplify the structure without degrading the operability by constituting a mechanism for speed change of the front wheel change gear to the reference and acceleration drive condition from a gear system change gear mechanism and a hydraulic friction clutch for power transmission to carry out sequence operation. CONSTITUTION:A front wheel change gear 10 is constituted from a gear system change gear 14 operated to change speed to the reference drive condition or acceleration drive condition for transmitting power to the front wheels and a hydraulic friction clutch 13 for transmitting power from an engine 4 to the gear system change gear 14. Further, a sequence mechanism of a control circuit is constituted such that according to signals from reference and acceleration speed change detecting switches 30, 31 in an operating system is disengaged the friction clutch 13 and then the speed of said change gear 14 is changed by an actuator 20 and thereafter the friction clutch 13 is operatively turned in. By the above constitution, the cost of the front wheel change gear 10 can be reduced and the structure can be simplified without degrading the operatability.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a drive system for 111 steerable wheels with a standard drive state in which the drive system is driven at a drive speed substantially equal to the drive speed of the rear wheels, and a drive system for the rear wheels. Increased speed 111g1 to get pregnant at a drive speed greater than the speed
The present invention relates to a traveling drive structure for an agricultural tractor equipped with a clutch-type front #lI transmission that switches between the J state and the J state.

[Conventional technology]

As mentioned above, the clutch-type structure for switching the front wheels of the agricultural Totsuku between the standard drive state and the accelerated drive state is as follows:
For example, it is disclosed in Japanese Utility Model Application Publication No. 60-102133-
However, this consists of a full-bit gear mechanism and one hydraulic friction clutch, and the critical operation of this friction clutch changes the path of the engine power transmitted through the full-bit gear mechanism to change speeds. However, this mechanism had the following problems.

[Problems to be solved by the invention] In the conventional structure described above, is it possible to change gears? (Hydraulic friction clutches were used for both the standard and increased speed drive states in order to quickly perform the same operation in one turn and from the viewpoint of structure 1.) However, in agricultural tractors, the front wheels are Shifting to the speed-up drive state is performed when changing direction with a small turning radius at the edge of a ridge, or when making a sharp turn to avoid an immediate danger, so this shift position is generally not used often.On the other hand, It is normal work to perform a VC gear shift operation with the front wheels in the standard drive state, and in such cases there are generally few opportunities to perform a gear shift operation quickly, but for the reasons mentioned above, it is generally expensive and Since a hydraulic friction clutch was used, which tends to complicate the overall structure of the device due to its hydraulic path, etc., this resulted in problems such as high cost and complicated structure of the front N+ transmission.

Here, the purpose of the present invention is the above! & To reduce the cost and simplify the structure of a front wheel transmission without reducing its operability.

[Means for solving problems]

The features of the present invention include, in the above-mentioned running class drive structure of an agricultural tractor, a gear-type or transmission mechanism that determines power to the front wheels by shifting the front wheel transmission between a standard drive state and an increased speed drive state; a hydraulic friction clutch that strictly applies power from the engine to the transmission mechanism, and according to a signal from an operating system, the friction clutch is disengaged and then the gear transmission mechanism is operated to change the speed by an actuator, Thereafter, a sequence mechanism configured to engage and operate the friction clutch is provided, and its functions and effects are as follows.

[For production]

As mentioned above, the mechanism for changing speed between standard and increased speed drive states in the front @Ill transmission was replaced from a hydraulic friction clutch type to a gear type transmission mechanism and a hydraulic friction clutch operated by the power method. , it is possible to omit seven hydraulic friction clutches and their hydraulic paths, which were conventionally two, and it is possible to reduce the cost and simplify the structure of the front wheel transmission.

Furthermore, although the operational advantage of the hydraulic friction clutch was lost, the provision of a sequence mechanism that controlled the operation of the front wheel transmission sufficiently compensated for this decrease in operability.

〔Effect of the invention〕

As explained above, in an agricultural tractor equipped with a front wheel transmission, 1Ii can be achieved without reducing its operability.
It was possible to reduce the cost and simplify the structure of the seven-wheel transmission.

In addition, in the conventional structure using two hydraulic friction clutches, there was a risk that both clutches would be accidentally engaged at the same time, resulting in damage to the device, but the gear type speed mechanism and sequence mechanism of the present invention This has eliminated the risk of such accidents occurring.

〔Example〕

Embodiment 2 An agricultural tractor according to a second embodiment of the present invention will be described below with reference to the drawings.

As shown in Figure 3, for a pair of left and right steering type front wheels, +
The engine (4), king clutch (6), transmission case (6), and control section (7) are mounted on the fuselage claim (3), which independently supports the drive wheels 11 and rear wheels (2+, +21), and is mounted on the rear of the fuselage. A lift arm (8) that can be driven up and down to swing up and down to connect various working devices such as a rotary tiller in a vertically movable manner, and a FrO shaft (9) that provides power to the working devices are installed to create a four-wheel-type system. It constitutes an agricultural tractor.

Next, we will discuss the power transmission system and front wheel transmission (1) of agricultural tractors.
0), as shown in Figures 1 and 3, the power from the engine (4) is transferred to the transmission case (6) via the ball clutch (a, m) and the shaft (11). The power is transmitted to the main transmission (not shown) and the auxiliary transmission Q to drive the rear wheels (2+, +21), and the power branched from the auxiliary transmission 1 is transferred to the front wheel transmission (10). The power is sent to the gear type transmission mechanism (14) through the hydraulic friction clutch (13) inside, and is operated to change the speed, and then sent to the front wheel differential mechanism (LA) K through the front export force shaft (15), where the front wheel peaks and peaks are shifted. The FR is designed to drive.

Front wheel transmission (the gear type transmission mechanism 04 at 101K)
), as shown in FIG.
, (16b), f, i passive gear 07) and the second passive gear (18) are loosely fitted to the front export force shaft (+5), and the first and first passive gears θη, (181) In between, a shift member (1i1) is provided which is rotatable integrally with the front export force shaft (1i1) and movable in the axial direction with a spline structure. Shifting is performed by moving the gear in the axial direction using a pair of hydraulic cylinders and engaging the first and second passive gears θη with engaging portions (17a) and (18a) that protrude like claws from the outer side. When the member (+91) is engaged with the first passive gear (+7), it is in a standard drive state.When the member (+91) is engaged with the box receiving gear (+81), it is in an increased speed drive state.

Next, 1. The sequence mechanism that controls the operation of this front wheel transmission (10) will be explained in detail. 2. As shown in Fig. A limit switch-type right brake detection switch that detects the depression of the rotation angle detection sensor (Figure, left and right rear wheels +21, +21 can be braked independently on one side, left and right side brakes (not shown)). A signal from the rake detection switch OFF (1) and the fact that the shift member θ (to) is being operated to standard or increased speed is input to the control circuit Q4.

On the other hand, the Chikuwa transmission (I [ll's friction clutch θ4 and Hydraulic Schilling Co., Ltd.) is more like a pump than an operating pulp.

(c) The control circuit 12 is operated by pressure oil supplied through the control circuit 12, and the control panel 12 and 12s are automatically operated by the υ control circuit.

Normally, the hydraulic cylinder cylinder is operated to the standard drive side by the control circuit C, and when turning with a small turning radius, the steering rotation angle detection sensor wire detects an operation that exceeds the set angle of the steering mechanism. When the right or left brake detection switch [23), 4) detects that only one of the right or left side brake pedals has been pressed down, the control circuit closes the 5) ri operation pulp to prevent friction. Disengage the clutch and operate the hydraulic cylinder 4 to the speed-increasing drive side using the operation switch 4. after that,
When the speed increase detection switch (131) is in the detection state and a signal confirming that it has been operated to the speed increase drive side is input, the operation pulse leg (B) is opened and the friction clutch (131) is engaged and operated.

After that, when the turning force S ends and any of the steering rotation angle detection sensor fixed, left/right brake detection switch (to), and brake control become non-detected, the control circuit steel turns the hydraulic pressure in the same order as above. GTI is standard! ! Then operate it to the #I side.

In addition, the control circuit □□□ is a DT equipped with a control section (not shown) K.
By means of switch (c) K, the automatic operation f\f# to the speed-increasing drive side as described above can be switched between an operating state and a non-operating state.

[Brief explanation of drawings]

The drawings show an embodiment of the traveling structure of an agricultural tractor according to the present invention, and FIG. 1 is a partially cutaway plan view of the vicinity of the 771-wheel transmission and the auxiliary transmission, and FIG. 8 is a control system diagram of the front wheel transmission. , FIG. 3 is an overall side view of the agricultural tractor. Mountain...Front wheel, (4)...Engine, (
101...Front wheel transmission, (11...
Friction clutch, a4)...Gear type transmission, -
...actuator.

Claims (1)

[Claims] A standard drive state in which power is transmitted to the steerable front wheels (1), (1) at a drive speed approximately equal to the rear wheel drive speed, and an increased speed drive state in which power is transmitted at a drive speed greater than the rear wheel drive speed. This is a traveling transmission structure for an agricultural tractor equipped with a clutch-type front wheel transmission (10) that switches between a standard drive state and an increased speed drive state to change the speed of the front wheels (1). , (1), and a hydraulic friction clutch (14) that transmits power from the engine (4) to the gear transmission mechanism (14).
13) and according to the signals from the operation system,
A sequence mechanism configured to disengage the friction clutch (13), then shift the gear type transmission mechanism (14) by an actuator (20), and then engage the friction clutch (13). A running transmission structure for agricultural tractors.