JPH02199364A - Transmission structure for speed change - 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] [Industrial Application Field] The present invention provides a synchromesh type main transmission that is interposed between an output shaft from a main transmission and an input shaft to a forward/reverse switching device, and The present invention relates to a hydraulic clutch for gear shifting that is disengaged at the start of a gear shifting operation and engaged when the gear shifting operation is completed, and more specifically, relates to a technology for shortening the synchronization time of a forward/reverse switching device as much as possible during gear shifting. .

[Conventional technology]

Conventionally, a technique for shortening the synchronization time of a hydraulic clutch configured as described above is disclosed in Japanese Patent Application Laid-Open No. 63-15.
There is a system disclosed in Japanese Patent No. 2751, in which a clutch case is provided on the output shaft of the main transmission to reduce the inertial force from the hydraulic clutch to the transmission system connected to the traveling system. It is configured to shorten the synchronization time when changing the speed of the transmission system.

[Problem to be solved by the invention]

Now, considering the structure of a conventional hydraulic clutch, the structure of a hydraulic clutch consists of a clutch case including a hydraulic piston and a plurality of friction plates, and a holder that supports each of the plurality of friction plates. In the above cited example,
The clutch case is externally fitted via a spline structure to the output shaft of the main transmission side, and the holder is externally fitted via the spline structure to the input shaft of the transmission system that is linked to the traveling system.

In addition, since the clutch case has a hydraulic piston, high precision is required, and high strength is required for the spline part, so conventionally the clutch case has been manufactured by cutting a relatively high strength metal material. It is being produced.

However, when manufacturing a clutch case, it is desirable to use a material with high strength as mentioned above, but if a material with high strength is used, it is difficult to process, so it takes time to manufacture it. This requires time and effort, so there is room for improvement.

Also, considering the synchronization time mentioned above, in a transmission system in which a forward/reverse switching device is provided in the transmission system linked to the driving system, when the forward/reverse switching device is operated, the hydraulic clutch is affected before and after the operation. Since the force in the opposite direction acts, extra time is required to complete dicyclo, and it is desired to shorten this synchronization time.

An object of the present invention is to construct a hydraulic clutch that can shorten the synchronization time even during forward/reverse switching operations by rational modification, and has a structure that can be manufactured as easily as possible.

[Means to solve the problem]

A feature of the present invention is that, in the hydraulic clutch for speed change interposed between the output shaft and the input shaft as described above, a clutch case including a hydraulic piston and a plurality of friction plates is provided for the input shaft. A holder supporting a plurality of friction plates disposed between the friction plates is externally fitted on the input shaft so as to transmit rotational power, and a rotary shaft is provided between the output shaft and the clutch case. The main feature is that a transmission member for power transmission is provided, and its functions and effects are as follows.

[For production]

If the above characteristics are configured as shown in FIG. 1, for example, among the members constituting the hydraulic clutch (B), those that apply inertia force to the input shaft are the holder (28) and the holder (28).
The friction plate (27b) is supported by the clutch case (23A), and the power from the output shaft (29) is transmitted to the clutch case (23A) via the transmission member (30). A transmission member (3) is attached to the outer edge of the clutch case (23A).
If o) is configured to engage and transmit power, it is also possible to use a material with low strength for the clutch case (23A).

In other words, in the present invention, the hydraulic clutch (B
) to prevent inertia from acting on the clutch case (23).
A) can be linked to rotate integrally with the output shaft (29), and the transmission member (3
By setting the power transmission position from 0), it is also possible to manufacture the clutch case (23A) by aluminum die-casting, for example.

〔Effect of the invention〕

Therefore, with reasonable modification, a hydraulic clutch that can shorten synchronization time even when switching between forward and forward travel is possible.
The structure could be constructed relatively easily.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Fig. 3, 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 traveling 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 take-off shaft ( 6
) to form a work transmission system to transmit the information to the four-wheel drive agricultural tractor.

The main transmission (A) is composed of two synchronized mesh gear transmission mechanisms, and is capable of shifting into four stages. It is configured in a mesh type, and the main transmission (A) has two
The auxiliary transmission (D) uses two hydraulic cylinders ('r+) and (TI) to perform gear shifting operations, and the forward/reverse switching device (C) performs gear shifting operations manually. Further, in this agricultural tractor, when performing these three types of speed change operations, the hydraulic clutch (B) is disengaged at the start of the speed change operation, and the hydraulic clutch (B) is operated to disengage the hydraulic clutch (B) at the completion of the speed change operation. A hydraulic control system is provided for shifting gears by engaging the main clutch (2) without disengaging the main clutch (2).

That is, the hydraulic control system is configured as shown in FIG. A mechanism (F) and a pilot pressure-operated switching valve (9) are installed, and the three hydraulic cylinders ('r+)
, ('rz), and (TI), and a pilot oil passage (11) for obtaining pilot pressure for operating the switching valve (9).
This is a branch arrangement.

In addition, the hydraulic cylinders (T, ), ('rz),
(TI) and the forward/reverse switching device (C) are each connected with an open/close type check valve (12). By changing the pilot pressure for (9), the hydraulic clutch (B) is operated 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 Fig. 4, the transmission system of this agricultural tractor consists of a main clutch housing (I3), 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 mechanism (C), and the rear case (15) is equipped with an auxiliary transmission (D) and an ultra-reduction device (E).

As shown in the figure, an opening (14a) is formed in the mid case (14) to open the side of the hydraulic clutch (B), and the shifter is connected to two shifters (16) for main transmission. the rod (17), the end of (17), and
A shift rod (1) connected to a shifter (18) for the sub-transmission
The end of the shift rod (17) extends to this opening, as shown in FIGS. 2 to 6.
Openings (17) and (19) can be operated from the ends.
The three hydraulic cylinders (T+), (T2), (TI) are provided on the inner surface side of the lid (20) that closes the lid (20), and these hydraulic cylinders (T+), (T2),
(TI) piston rod (21), (21), (
21) end bracket (21a), (21a),
(21a) and shift rods (17), (17).

Bracket (17a) at the end of (19), (17a)
, (19a) are connected via pins (p), (p), and (P).

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

Note that the pressure control mechanism (
F), a switching valve (9), and a speed change operation control valve (10) are provided respectively, and when configuring a so-called manual transmission type transmission system in which the speed change operation is not performed by hydraulic pressure, the opening (1) is provided.
4a) is used.

As shown in FIG. 1, 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 (2) that supports a plurality of friction plates (27b) arranged between the friction plates (27a) on this input shaft (22) and that is rotatably supported by (26).
8) is externally fitted through 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). , a switching valve (9) provided on the lid (20);
A conduit (32) for hydraulic clutch operation is formed approximately linearly between the joint part (31) that fits onto the small diameter part of the clutch case (23A).

Incidentally, the end portion of the transmission member (30) is engaged with the engagement portion for supporting the friction plate of the clutch case (23A).

[Another example]

In addition to the embodiments described above, the present invention can be implemented in various transmission structures, such as connecting the transmission member to the clutch case with bolts, or connecting the transmission member to the output shaft with a key.

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 structure according to the present invention, and the first embodiment
The figure is a cross-sectional view of the hydraulic clutch, Figure 2 is a cross-sectional view showing the transmission case, lid, etc., Figure 3 is a diagram showing the transmission system, Figure 4 is a side view of the transmission case, and Figure 5 is the hydraulic cylinder. , a perspective view showing the lid body, etc., FIG. 6 is a side view showing the speed change control valve, the lid body, etc., and FIG. 7 is a hydraulic circuit diagram for speed change. (22) Input shaft, (23) Unmanned hydraulic piston, (23A) Clutch case, (27a
), (27b)...Friction plate, (28)...
...Holder, (29) ...Output shaft, (30)
......Transmission member, (A)...Main transmission,

Claims (1)

[Claims] The output shaft from the synchromesh type main transmission (A) (
29) and the input shaft (22) to the forward/reverse switching device (C), and is a shift hydraulic clutch that is disengaged at the start of the shift operation and engaged when the shift operation is completed. A clutch case (23A) including a hydraulic piston (23) and a plurality of friction plates (27a) is freely rotatably supported on the input shaft (22), and a clutch case (23A) is supported on the input shaft (22). A holder (28) supporting a plurality of friction plates (27b) arranged between the friction plates (27a) is fitted onto the outside so as to be able to transmit rotational power, and the output shaft (
29) and the clutch case (23A), a transmission member (30) for transmitting rotational power is provided.