JPH0243787Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is a sub-transmission, 4-wheel drive system with a 2WD/4WD switching mechanism.
In wheel-drive vehicles, by disabling the 4-wheel drive switching operation when the auxiliary transmission is running at high speeds, this reduces wear on the front wheels when moving, and prevents the front wheels from shifting due to the front load shifting when sudden braking is applied from high speeds. This is intended to enable stable braking by reducing the load on the differential and preventing the rear wheels from lifting.

[Conventional technology]

In a conventional four-wheel drive vehicle of this type, as shown in FIG. It is input to the auxiliary transmission c with drive switching mechanism, and the transmission means (propeller shaft d,
e), the power was transmitted to the rear differential f and the front differential g, respectively. Further, it is common to switch between four-wheel rear two-wheel drive and four-wheel drive, and the main braking brake is usually attached only to the rear wheels.

[Problem that the invention attempts to solve]

However, the high-speed low-speed switching operation and the 2WD/4WD switching operation in the sub-transmission can be performed independently, so it is possible to switch between high-speed and 4WD, and in that case, the front wheels become the driving wheels, so the long When steering during time movement accelerates the wear of the front wheels, or when sudden braking is applied during high-speed 4WD driving, the four wheels become essentially locked, and the load is rapidly transferred to the front wheels, causing the rear wheels to lift up. Braking becomes unstable, which is dangerous, and a load is placed on the front differential, requiring high-strength differential gears, axles, etc., which not only increases capacity but also increases cost.

[Means for solving problems]

Here, this invention has separate high/low speed switching levers and 2WD/4WD switching levers, and connects these high/low speed switching levers and 2WD/4WD switching levers to convert the power from the input shaft into high speed and high speed switching levers. In an agricultural chemical spraying vehicle in which a shifter for switching between low speed and a shifter for switching between 2WD and 4WD is installed in the sub-transmission, the shifter for switching between 2WD and 4WD is switched between the high speed and low speed. A limiting piece is integrally provided on the side edge of the shifter, and when the shifter for switching between high speed and low speed is in the high speed position, the limiting piece comes into contact with the side edge of the shifter to switch between 2WD and 4WD. This invention proposes a speed selection device for an agricultural chemical spraying vehicle, characterized in that the lever is prevented from switching from 2-wheel drive to 4-wheel drive.

[Effect]

In other words, in this invention, a restriction mechanism is installed between the high/low speed switching operation section in the sub-transmission and the 2WD/4WD switching operation section, so that switching to 4WD is not possible when switching to high speed. The vehicle is always in 2-wheel drive mode when traveling, reducing wear on the front wheels, and by leaving the front two wheels free during sudden braking, it reduces load transfer and enables stable braking. This reduces the burden on the front differential, eliminates the need to maintain excessive strength, and reduces costs.

〔Example〕

Next, this invention will be explained with reference to FIGS. 1 to 3.

In FIG. 1, power is transmitted from a main transmission (not shown) to an input shaft 1, which is connected to a gear 4 with a clutch 3 through a bearing 2.
Similarly, a gear 7 with a clutch 6 is rotatably supported on the input shaft 1 via a bearing 5, and between the gear 4 and the gear 7, a high/low speed switching lever 8 is connected as a base point. A shifter 9 is provided which can transmit the power of the input shaft 1 to the clutch 6 and the clutch 3 by moving the shifter 9 in directions A and B, respectively. This shifter 9 is restrained by splines or serrations in the rotational direction of the input shaft 1 and the shaft, but is capable of sliding in the E and F directions.

A gear 11 that meshes with the gear 4 and a gear 13 that meshes with the gears 7 and 12 are fixed to the intermediate shaft 10. Therefore, to describe an example of power transmission, when the lever 8 is operated in the B direction, the shifter 9 moves in the F direction and is connected to the clutch 3, and the power is transmitted from the input shaft 1 → shifter 9 → clutch 3 → It is transmitted to the rear transmission shaft 15 via shafts and gears in the order of gear 4 → gear 11 → intermediate shaft 10 → gear 13 → gear 12.
The rear transmission shaft 15 and the front transmission shaft 16 have a single central axis through a bearing 17 in the center, and a gear 12 is fixed to the rear transmission shaft 15.

A shifter 20 is provided which can turn power on and off to the shaft 16 via a clutch 19 by operating the 2WD/4WD switching lever 18 from the base point in directions C and D. This shifter 20 is restrained by splines or serrations to the rear transmission shaft 15 in its rotational direction, but is capable of sliding in the G and H directions.

A clutch 19 is fixed to the front transmission shaft 16, and at the tip of the 2WD/4WD switching lever 18,
Shifter 20 is fixed. This shifter 20 is integrally formed with a restriction piece 21 that limits the movement of the shifter 9 fixed to the high/low speed switching lever 8.

When power is transmitted to the input shaft 1 in the state shown in FIG. 1, the power is transmitted from the clutch 6, gear 7, gear 13, and gear 12 to the rear transmission shaft 15 via the shifter 9. In other words, it is in a high-speed 2WD state. If you try to switch to 4WD in this state and move the 2WD/4WD switching lever 18 in the D direction, the restriction piece 21 moves the high/low speed switching lever 8 in the B direction via the shifter 9, and at the same time moves the shifter 9 to F. direction, connect with clutch 3, gear 4, gear 11, intermediate shaft 1
0, gear 13, gear 12, shifter 20, and clutch 19, and transmits power to rear transmission shaft 15 and front transmission shaft 16. In other words, the vehicle is in a low-speed 4WD state. That is, when the high/low speed switching lever 8 is set to high speed, the 2WD/4WD switching lever 18 is always in the 2WD state. In addition, the names of the parts corresponding to the components schematically shown in FIG. 1 are clarified in FIG. 2, and
Details of the shifter section are shown in FIG. In this figure, parts corresponding to the same parts in FIG. 1 are given the same reference numerals, and detailed explanations are omitted.

[Effect of idea]

Since the device of this invention has the above-mentioned configuration, it is always in two-wheel drive mode when moving at high speed, reducing wear on the front wheels, and also leaves the two front wheels free when braking suddenly. This reduces load movement, enables stable braking, reduces the burden on the front differential, eliminates the need to maintain excessive strength, and reduces costs.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an auxiliary transmission equipped with the device of this invention, Fig. 2 is an explanatory diagram of its component parts, Fig. 3 is an enlarged perspective view of a part, and Fig. 4 is a conventional It is an explanatory view showing an example of the device. In addition, in the figure, 1 input shaft, 8 high/low speed switching lever, 9 shifter, 10 intermediate shaft, 15
16 front transmission shaft, 18 2WD/4WD switching lever, 20 shifter.

Claims (1)

[Scope of utility model registration request] High/low speed switching lever 8 and 2WD/4WD switching lever 1
8, and these high/low speed switching levers 8
and a shifter 9 that is connected to the 2WD and 4WD switching lever 18 to switch the power from the input shaft 1 between high speed and low speed, and a shifter 20 that switches between 2WD and 4WD. In the agricultural chemical spraying vehicle, the shifter 2 switches between 2-wheel drive and 4-wheel drive.
A limiting piece 21 is integrally provided on the side edge of the shifter 9 side that switches between the high speed and low speed of 0, and when the shifter 9 that switches between the high speed and low speed is in the high speed position, a limiting piece 21 is provided on the side edge of the shifter 9. A speed selection device for an agricultural chemical spraying vehicle, characterized in that the limiting piece 21 abuts to prevent the 2WD/4WD switching lever 18 from switching from 2WD to 4WD.