JPH02199342A - Transmission construction for wheel - Google Patents

Abstract

PURPOSE:To enable prompt synchro-mesh by arranging gears on the free rotation side and a sleeve for speed changing, in gears and sleeves for speed changing which are engaged with each other in a speed change gear, on the upper side of transmission so as to reduce action of moment of inertia. CONSTITUTION:In a main speed change gear A, a forward and backward switching device C and an auxiliary speed change gear B are both constituted in the synchro-mesh manner. The auxiliary speed change gear D switches driving speed in two stage of high and low. A sleeve for speed changing and a pair of free-rotating gears are provided against a transmission axis from a hydraulic clutch B, and a gear engaging with the pair of free-rotating gears are provided at a transmission axis communicating with front and rear wheels. As the sleeve for speed changing was provided on the lower side of transmission before and installed on the transmission axis on the side having the free-rotating gear, moment of inertia leading to a driving device acted on the sleeve for speed changing, which increased time required for synchronization. By this device, inertia is reduced and speed can be changed promptly whereby, reduces non- driven driving state at switching.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a traveling transmission system with a hydraulic clutch, disengages the hydraulic clutch at the start of a gear shift operation, and disconnects the hydraulic clutch at the completion of the gear shift operation. The present invention relates to a transmission structure for a vehicle having a hydraulic operation system for inputting and operating a transmission, and more specifically, it relates to an improvement for smoothly performing a transmission operation.

[Conventional technology]

Conventionally, as a transmission structure in which a hydraulic clutch is disengaged and operated during gear shifting as described above, there is one shown in Japanese Patent Application Laid-open No. 62-52247, and in this reference, each main transmission is operated by a hydraulic actuator. A hydraulic clutch is interposed in the transmission system between the auxiliary transmission and the auxiliary transmission, and the auxiliary transmission is configured to switch the traveling speed between high and low speeds.

[Problem to be solved by the invention]

Now, considering the transmission structure of the above-mentioned reference, since the main transmission and the sub-transmission are each shifted by the shift operation of a hydraulic actuator, they are synchronized with gears that engage with each other and a shift sleeper. It is structured in a shoe shape.

Furthermore, based on the hydraulic clutch, the auxiliary transmission is installed on the side of the transmission system that transmits power to the traveling gear, and the gear shift sleeper of this auxiliary transmission is installed on the transmission shaft on the lower side of the transmission, so this Since the moment of inertia including the traveling device connected to the side transmission shaft acts on the shift sleep, it may increase the time required for synchronization when shifting.

Furthermore, since this sub-transmission device is operated relatively frequently while driving, the longer the time required for synchronization as mentioned above, the longer it takes to complete the gear shift, which prevents the vehicle from driving without being driven. There is room for improvement from this perspective.

Incidentally, the shift sleeper is provided on the transmission shaft on the side having the gear on the idle rotation side.

The purpose of the present invention is to rationalize a synchronized mesh type transmission for changing the traveling speed between high and low speeds as quickly as possible in a transmission structure equipped with a hydraulic clutch for transmission as described above. The point is that it can be obtained by remodeling.

[Means to solve the problem]

A feature of the present invention is that in a transmission structure equipped with a hydraulic clutch that is operated on and off as described above, a transmission system that transmits power from the hydraulic clutch to a traveling device includes gears and a transmission sleeper that mesh with each other, It is equipped with a synchromesh type transmission that switches the traveling speed between two high and low speeds, and the idling side gear of this transmission is installed on the transmission shaft on the upper side of the transmission. , and the effects are as follows.

[For production]

If the above characteristics are configured as shown in FIG. 1, for example, the transmission shaft (21) on the upper side of the transmission is provided with the gear (23) on the idle side and the gear shift sleeper (22), so the shifter (
During the operation 18), a moment of inertia as large as that in the conventional structure does not act on the shift sleeper (22), making it possible to shorten the time required for synchronization.

〔Effect of the invention〕

Therefore, the synchromesh type transmission for switching the traveling speed between high and low speeds can be quickly operated.
This was achieved through a rational modification by changing the layout of the gear shift sleeper.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Fig. 1, power from the engine (1) is transmitted via a multi-disc main clutch (2) to a main transmission (A), a multi-disc hydraulic clutch (B), and a forward/reverse switching device ( C), the sub-transmission device (D), and the super-reduction device (E), respectively, and transmit the shifting power to the front and rear wheels (3) as a traveling device.
(4) A travel transmission system is formed to transmit the power to the respective differentials (3a) and (4a), and the power from the main clutch (2) is transmitted to the external power output shaft (5) via the transmission mechanism (5).
6), a working transmission system is formed to transmit the information to the drive system of the four-wheel drive agricultural tractor.

The main transmission (A) is composed of two synchromesh type gear transmission mechanisms, and is capable of shifting into four stages. The main transmission (8) has two hydraulic cylinders (TI).

(T2), the auxiliary transmission (D) is a single hydraulic cylinder (
) to change gears, and forward/reverse switching device (C).
) is configured to perform a manual speed change operation, and furthermore, in this agricultural tractor, when these three types of speed change operations are performed, the hydraulic clutch (B) is disengaged at the start of the speed change operation, and the speed change operation is performed. A hydraulic control system is provided for shifting the gear without disengaging the main clutch (2) by engaging the hydraulic clutch (B) at the time of completion.

That is, the hydraulic control system is configured as shown in FIG. A mechanism (F) and a pilot pressure operated switching valve (9) are interposed, and the three hydraulic cylinders (TI),
(rz) and (T3), and a pilot oil passage (11) for obtaining pilot pressure for operating the switching valve (9) is arranged in a branched manner. .

In addition, the hydraulic cylinders (TI), (rz), (Tz
) and the operation system of the forward/reverse switching device (C) are each linked with an open/close operating type check valve (12)...
During a gear shift operation, the pilot pressure applied to the switching valve (9) is changed by opening and closing the check valves, thereby operating the hydraulic clutch (B) on and off as described above.

Incidentally, the pressure control mechanism (F) is configured to suppress a sudden increase in clutch pressure and increase the clutch pressure with predetermined characteristics when the switching valve (9) is turned on and operated.

As shown in Figure 2, the transmission system of this agricultural tractor consists of a main clutch housing (13), a mid case (14),
The main clutch housing (13) houses the main clutch (2) and the main transmission (A), and the mid case (15) is housed in a transmission case that connects the rear cases (15).
4) is equipped with a hydraulic clutch (B) and a forward/reverse switching device (C), and the rear case (15) is equipped with an auxiliary transmission (D) and an ultra-reduction device (E).

As shown in the figure, the mid case (14) is formed with an opening (14a) that opens the side of the hydraulic clutch (B), and a shifter that connects with two shifters (16), (16) for main gear shifting. The ends of the rods (17), (17) and the end of the shift rod (19) connected to the shifter (18) for sub-transmission are extended to this opening, and the third
As shown in the figure and Fig. 4, these shift rods (17
), (17), and (19) can be operated from the end. The three hydraulic cylinders (TI), (Tz), and (T
3), and the speed change control valve (10), the switching valve (9), and the pressure control mechanism (F) are provided on the outer surface A'1 of the lid (20), respectively.

The auxiliary transmission (D) is for switching the traveling speed between high and low speeds, and has a transmission sleeper (22) and a pair of idlers connected to the transmission shaft (21) from the hydraulic clutch (B). Rotating gears (23), (23) are provided, and gears (24), (24) that mesh with the pair of free rotating gears (23), (23) are connected to the front and rear wheels (3), (
4) is provided on the transmission shaft (25) that is linked to the transmission shaft (25) to shorten the synchronization time during gear changes.

Incidentally, as shown in FIG. 2, the forward/reverse switching device (C)
The gear shifter (26) and shift rod (27) are also provided, and these are linked to a manual operation system (not shown).

[Another Embodiment] In addition to the embodiments described above, the present invention can also be applied, for example, by changing the running speed to high or low.
The gear changing device may be of a manually operated type.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the transmission structure for a vehicle according to the present invention, in which Fig. 1 is a diagram showing the transmission system, Fig. 2 is a side view of the transmission case, and Fig. 3 is a perspective view showing the hydraulic cylinder and the lid. 4 is a side view showing the speed change control valve and the lid, and FIG. 5 is a hydraulic circuit diagram for speed change. (1), (2)... Traveling device, (21)...
...Transmission shaft, (22)...Sleep for speed change,
(23), (24)...Gear, (B)・
...Hydraulic clutch, (D) ...Transmission device.

Claims (1)

[Claims] A hydraulic clutch (B) is interposed in the travel transmission system, and the hydraulic clutch (B) is disengaged at the start of a gear shift operation, and the hydraulic clutch (B) is engaged and operated at the completion of the gear shift operation. A transmission structure for a vehicle comprising gears (23) and (24) that mesh with each other in a transmission system that transmits power from the hydraulic clutch (B) to the traveling devices (1) and (2).
) and a gear shift sleeper (22), and a synchromesh type transmission (D
) and the gear (23) of this transmission (D).
), (24), the idling side gear (23) is provided on the transmission shaft (21) on the transmission upper side.