JPH02209669A - Speed change operating mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a synchromesh-type main transmission device that shifts power from an engine into multiple stages, and a synchromesh-type main transmission device that transmits the shifting power to a traveling device. A hydraulic clutch is interposed in the transmission system between the sub-transmission device, and the hydraulic clutch is disengaged at the start of a shift operation by a hydraulic actuator, and the hydraulic clutch is engaged and operated at the completion of the shift operation by a hydraulic actuator. The present invention relates to a speed change operation mechanism, and specifically relates to a technique for arranging the main transmission, the sub-transmission, and the hydraulic actuator in a transmission case.

[Conventional technology]

Conventionally, there is a side shift operating device configured as described above, as shown in Japanese Patent Application Laid-open No. 62-52251. A hydraulic actuator having a shifter that engages with the shift sleeve of each of the main transmission and the auxiliary transmission, and a hydraulic operating mechanism that controls the hydraulic clutch are formed in the side of the transmission case to open the transmission case. It is provided on a lid body that closes the opening.

[Problem to be solved by the invention]

Considering the structure of the above-mentioned reference, in the above-mentioned reference, an opening extending from the main transmission to the auxiliary transmission is formed in the transmission case, so compared to a transmission case without an opening, the thickness of the transmission case itself is reduced. In addition, efforts are being made to improve strength.

However, increasing the thickness of the transmission case to improve its strength not only increases the weight of the transmission case, but also requires work such as forming a drill hole in the transmission case or finishing the end face of the transmission case. This also requires additional time, so there is room for improvement.

The object of the present invention is to maintain sufficient strength of the transmission case in which the opening for operating the transmission and the hydraulic clutch is formed without increasing the thickness of the transmission case, as described above, by rational modification. The point is that it can be obtained as a configuration that can be used.

[Means to solve the problem]

A feature of the present invention is that, in the shift operation mechanism having a main transmission, a sub-transmission, a hydraulic clutch, etc., as described above, the hydraulic clutch is sandwiched inside a transmission case, and the main transmission and the sub-transmission are connected to each other. is arranged along the longitudinal direction of the vehicle body, and has a shift rod extending to the side of the hydraulic clutch that is linked to the transmission parts of the main transmission device and the auxiliary transmission device, and an end of the extending side. An opening is formed in the mission case to enable exposure of the hydraulic clutch, and a lid body that closes the opening is provided with the hydraulic operating mechanism.
The present invention also includes a hydraulic actuator for operating the shift rod, and its functions and effects are as follows.

[Function] When the above characteristics are configured as shown in FIGS. 1 to 4, for example, the end positions of the shift rods (17) and (19) and the hydraulic actuator (T) are linked, and this linked position is Since it is located near the hydraulic clutch (B), even if the opening (14a) is set to a size that opens the hydraulic clutch (B) and the vicinity of this hydraulic clutch (B), the hydraulic actuator (T) Since a speed change operation can be performed and piping to the hydraulic clutch (B) can also be performed through this opening (14a), the hydraulic clutch (B) can also be operated in conjunction with the operation of the hydraulic actuator (T).

In other words, without forming an opening in the transmission case that extends from the main transmission (A) to the sub-transmission (D), the transmission
Also, the hydraulic clutch can be operated.

〔Effect of the invention〕

Therefore, by rationally modifying the speed change operation system, the opening of the transmission case can be made smaller than that of the conventional one, and a structure that can maintain sufficient strength even if the thickness of the transmission case is made smaller than that of the conventional one was created. .

In particular, in the present invention, since the opening is formed at a position where the hydraulic clutch is exposed, the hydraulic clutch and the hydraulic operating mechanism are connected by the shortest distance, and the hydraulic clutch can be operated quickly.

〔Example〕

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

As shown in Fig. 6, 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 auxiliary transmission (D), and the super reduction gear (E), and transmits the shifting power to the front and rear wheels (3).

(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 work 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 (A) has two
The auxiliary transmission (
D) is configured to change speeds using a single hydraulic cylinder (T3), and the forward/reverse switching device (C) is configured to change speeds manually. When the operation is performed, the hydraulic clutch (B) is disengaged at the start of the shift operation, and the hydraulic clutch (B) is engaged and operated at the completion of the shift operation, thereby disengaging the main clutch (2). It is equipped with a hydraulic control system that allows for smooth gear changes.

That is, the hydraulic control system is configured as shown in FIG. 7, and in this system, a pressure control Mechanism (F) and pilot pressure operated switching valve (9)
and the three hydraulic cylinders (T +)
, (Tz), (T3), and a pilot oil passage (11) for obtaining pilot pressure for operating the switching valve (9). be.

In addition, the hydraulic cylinders (TI), (TZ), (
T3) and the operating system of the forward/reverse switching device (C) are each linked with an open/close operation type check valve (12). During a gear shift operation, the switching valve ( 9) to operate 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 Figures 1 to 4, the transmission system of this agricultural tractor is housed in a transmission case that connects a main clutch housing (13), a mid case (14), and a rear case (15). The clutch housing (13) houses the main clutch (2) and the main transmission (A), the mid case (14) houses the hydraulic clutch (B) and the forward/reverse switching device (C), and the rear case (15) houses the hydraulic clutch (B) and the forward/reverse switching device (C). ) is equipped with an auxiliary transmission (D) and a super reduction gear (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 sub-transmission shifter (18) extend to this opening. ), (17), (19)
The three hydraulic cylinders (T I
).

(rz) and (TI), and these hydraulic cylinders (r+).

(TZ), (Tel) Piston Rhodo (21)
, (21) , (21) end bracket (21)
a) , (21a) , (21a) and brackets (17a) , (17a) , (19a) at the ends of shift rods (17) , (17) , (19)
are connected via bins (p), (p), and (P).

Incidentally, a shift rod (25) connected to a shifter (24) for forward/reverse switching is linked to an operating lever (L).

Note that the pressure control mechanism (
F), a switching valve (9), and a speed change control valve (10) are provided respectively, and when configuring a so-called manual speed transmission type transmission system in which the speed change operation is not performed by hydraulic pressure, the lid body (20)
It is now possible to use a mid-case that does not have a

As shown in FIG. 5, the hydraulic clutch (B) has a hydraulic piston (23) and a plurality of friction plates (27a) connected to the input shaft (22) of the forward/reverse switching device (C). Clutch case (23A) with needle bearing (2
6) A holder (28) which is rotatably supported by (26) and supports a plurality of friction plates (27b) arranged between the friction Fi (27a) on this input shaft (22). is externally fitted via a spline structure, and a transmission member (30) that is spline-fitted to the output shaft (29) of the main transmission (A) is fitted to the clutch case (23A), Switching valve (9) provided on the lid (20)
A conduit (32) for operating the hydraulic clutch is formed substantially linearly between the hydraulic clutch and the jigoint part (31) that fits externally into the small diameter part of the clutch case (23A).

[Another example]

In addition to the embodiments described above, the present invention can be implemented in various ways, such as by configuring the hydraulic clutch operating system by forming an operating boat and an operating switching position on the speed change control valve.

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 speed change operation mechanism according to the present invention.
Figure 2 is a side view of the transmission case, Figure 2 is a perspective view showing the lid, hydraulic cylinder, etc., Figure 3 is a side view of the lid, Figure 4 is a sectional view showing the mounting position of the lid, and Figure 5 is a sectional view showing the mounting position of the lid. The figure is a cross-sectional view of the hydraulic clutch, FIG. 6 is a line diagram showing the transmission system, and FIG. 7 is a hydraulic circuit diagram for shifting. (1) Engine, (3), (4) Traveling device, (14a) Opening, (17), (19) Shift rod, (20) Lid, (A)・Main transmission, (B)...Hydraulic clutch, (D)...Sub-transmission, (
T)...Hydraulic actuator.

Claims (1)

[Claims] A synchromesh type main transmission (A) that shifts the power from the engine (1) to multiple stages, and a synchromesh type auxiliary transmission (D) that transmits the shifting power to the traveling devices (3) and (4). A hydraulic clutch (B) is interposed in the transmission system between the two, the hydraulic clutch (B) is disengaged at the start of a gear shift operation by the hydraulic actuator (T), and the hydraulic clutch (B) is operated at the completion of the gear shift operation. A transmission operation mechanism comprising a hydraulic operation mechanism for engaging and operating the main transmission (A) and the sub-transmission (D), with the hydraulic clutch (B) sandwiched inside a transmission case. a shift rod (17) disposed along the front-rear direction of the vehicle body and linked to the transmission portions of the main transmission (A) and the auxiliary transmission (D);
(19) is extended to the side of the hydraulic clutch (B), and the end position of the extended side and the hydraulic clutch (B) are
) is formed in the mission case to allow exposure of the opening (14a), and a lid body (
20), the hydraulic operation mechanism and the shift rod (17).
), (19) hydraulic actuator (Y)...
A speed change operation mechanism comprising: