JPH0517510Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an inertia rotation reduction device for a power transmission device for a vehicle.

<Prior art> Vehicles such as tractors are equipped with a high/low speed switching device in the power transmission system including the transmission on the downstream side of the main clutch, and when the engine load increases, the high/low speed switching device is switched from high speed to low speed. There are some that reduce the speed and reduce the load.

This type of high-low speed switching device consists of a speed reducer such as a planetary speed reducer and a high-low speed hydraulic clutch built into a single clutch body, and switches between high and low speeds by selectively operating the hydraulic clutch. This uses a hydraulic clutch, so
It has the advantage of being able to switch smoothly in an extremely short time.

<Problems to be Solved by the Invention> However, in this type of case, when the high-speed hydraulic clutch is engaged to achieve high speed, the clutch body, which has a large mass, rotates. Therefore, when the main clutch is disengaged to operate the transmission, the inertial rotation of the clutch body is very large, resulting in a disadvantage that it takes a long time until the gear can be changed. Furthermore, if the inertial rotation is large, there is a drawback that when a synchromesh is used as a transmission, the life of the synchromesh is shortened.

<Means for Solving the Problems> The present invention is intended to solve these conventional problems, and as a specific means for that purpose, a high-low speed switching device and a transmission device are installed after the main clutch. The high-low speed switching device has a high-speed hydraulic clutch and a low-speed hydraulic clutch in the clutch body, which are respectively connected and disconnected by a switching valve, and the clutch body rotates when the high-speed hydraulic clutch is connected and stops when the high-speed hydraulic clutch is disconnected. The power transmission device for a vehicle is provided with interlocking means for switching the switching valve in the direction of disengaging the high-speed hydraulic clutch in conjunction with a shift-related operation of the transmission device.

<Function> When shifting the main transmission 7, the clutch pedal 1
2, the main clutch 4 is disengaged, the high/low speed switching valve 20 is switched from the high speed side to the low speed side, the high speed hydraulic clutch 33 is disconnected, and the low speed hydraulic clutch 34 is connected. Therefore, the clutch body 32, which has a large mass, stops rotating, and after the main clutch 4 is disengaged, the inertial rotation of the rear stage side from the travel propulsion shaft 35 is suppressed, and the speed change operation of the main transmission 7 can be performed smoothly.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 1, 1 is an engine, 2 is a flywheel, and 3 is a clutch housing. clutch 4
is provided. Reference numeral 5 denotes a transmission case, in which a traveling system including a high/low speed switching device 6, a main transmission 7, an auxiliary transmission 8, and a differential device 9, and a PTO system including a PTO transmission 10 are incorporated.
11 is a step, 12 is a clutch pedal, which is pivotally supported by a pedal shaft 13, and includes a clutch rod 14, a clutch lever 15, a lever shaft 16, and a release fork 1.
7. Clutch pedal 1 via release hub 18 etc.
The main clutch 4 is disengaged when the clutch 2 is depressed. 19 is a hydraulic pump, 20 is a high/low speed switching valve that controls the high/low speed switching device 6, and its spool 21 is connected to a bell crank 22.
23 is a high/low speed switching lever, with a rod 24 and a spring 2.
It is connected to the bell crank 25 via 5 or the like. 26 is clutch lever 15 and bell crank 2
It is an interlocking mechanism that interlocks the rod 2 and has a bell crank 27.
The clutch lever 15 is connected to the clutch lever 15 via a rod 29, a spring 30, and the like to a bell crank 22. As shown in FIG. 2, within the entire operating range of the clutch pedal 12,
Switching area B so that the high/low speed switching valve 20 switches from high speed to low speed at the terminal end of main clutch disengagement area A.
is set. Note that C is the play range.

As shown in FIG. 3, the high/low speed switching device 6 is composed of a planetary reduction gear 31 and high/low speed hydraulic clutches 33, 34 incorporated in a clutch body 32. The planetary speed reduction device 31 is a traveling propulsion shaft 3
5, an inner gear 37 formed thereon, and an inner gear 3
The planetary gear 38 meshing with 7 and the planetary gear 38
A sun gear 39 that meshes with the sun gear 39 and a planetary carrier 41 that supports the planetary gear 38 by a pin 40 are provided, and the planetary carrier 41 is connected to a running transmission shaft 42 . The propulsion shaft 35 is connected to the engine 1 via the main clutch 4 and supported by a bearing case 44 via a bearing.

The clutch body 32 is rotatably fitted into a support cylinder 46 fixed to a partition wall 45 of the transmission case 5 via a bearing 47, etc., and hydraulic clutches 33 and 34 are installed in this in parallel in the axial direction. ing. Clutch body 32 is engaged with sun gear 39 via engagement portion 48 . The high-speed hydraulic clutch 33 is for connecting the planetary carrier 41 to the clutch body 32 by clamping the clutch plate 51 between the piston 49 and the receiving plate 50, and the clutch body 32 rotates during this connection. . The low-speed hydraulic clutch 34 clamps the clutch plate 54 between the receiving plate 52 and the piston 53, and
The clutch body 32 is fixed to the support cylinder 46 side via the clutch plate 54 and connector 55, and therefore, the sun gear 39 is fixed when this is connected. The traveling power transmission shaft 42 is supported coaxially with the traveling propulsion shaft 35 via a bearing 56, and a PTO propulsion shaft 57 is fitted therein. Note that the PTO propulsion shaft 57 is directly connected to the engine 1.

The main transmission 8 is a synchronized mesh type including a plurality of gears 58 fixed to the traveling transmission shaft 42 and a plurality of idling gears 60 loosely fitted to the traveling main transmission shaft 59. A main shift lever 62 supported by a stand 61 allows gear shifting operations to be performed via a shift rod 63, a shift fork 64, and the like.

Next, the effect will be explained. During traveling, the high-speed hydraulic clutch 33 is normally connected, and the traveling transmission shaft 42 rotates at high speed in conjunction with the traveling propulsion shaft 35. That is, when the high-speed hydraulic clutch 33 is connected, the planetary carrier 41, the sun gear 39, and the clutch body 32
are integrally connected, the traveling transmission shaft 4 is connected to the traveling propulsion shaft 35 via the driving carrier 36, the inner gear 37, the planetary gear 38, and the planetary carrier 41.
Power is transmitted to 2 at high speed.

When the engine load increases, the switching lever 23 is operated from the high speed position H to the low speed position L, the switching valve 20 is switched to the low speed side, and the low speed hydraulic clutch 34
Connect. Then, since the clutch body 32 and the sun gear 39 are fixed, the planetary gear 38 rotates, and the rotational speed of the planetary carrier 41 decreases, and the speed of the running transmission shaft 42 decreases by about 10 to 20% compared to when it is at high speed. It rotates at a low speed. This reduces the engine load and restores the rotational speed of the engine 1.

When changing the speed of the main transmission 7, first the clutch pedal 12 is depressed to disconnect the main clutch 4 and cut off the transmission of power from the engine 1 to the propulsion shaft 35. On the other hand, when the clutch pedal 12 is depressed to the switching area B on the terminal side, the spool 21 of the switching valve 20 is operated from the clutch lever 15 via the interlocking mechanism 26, and the switching valve 20 is switched to low speed. 33 is disengaged and the low speed hydraulic clutch 34 is connected. Therefore, since the clutch body 32 having a large mass is in a fixed state, the inertial rotation on the propulsion shaft 35 side after the main clutch 4 is disengaged can be suppressed in a very short time, and the main transmission 7 can be controlled in a short time. You can move on to switching operation. Furthermore, since the inertial rotation is small, even if it is a synchronized mesh type, wear and tear on the friction parts of the main transmission 7 can be reduced and its life can be extended.

When the switching valve 20 is a solenoid valve, the fourth
As shown in the figure, a switch 65 which operates at the end of the actuation of the clutch pedal 12 may be provided to operate the switching valve 20.

Further, it is also possible to make it interlock with the operation of the main shift lever 62.

For example, as shown in FIG.
In addition to the forward gears 66, 67, 68 and idling gears 69, 70, 71, a back gear 72, an idling gear 73, and a back gear 74 are incorporated, in conjunction with the back operation. It may be possible to switch from high speed to low speed. That is, if the shift fork 75 that engages with the shifter 74a is supported by the shift rod 76, and the shift rod 76 can be positioned at the neutral position N, forward position F, and reverse position R by the positioning mechanism 77, then Before the shift rod 76 moves from the neutral position N to the reverse position R, the switch 7
8 works, the solenoid part 20 of the switching valve 20
It is sufficient to excite a to the low speed side. In addition,
The switch 78 is attached to the gearbox 61,
An actuator 80, which is vertically movably incorporated into the protrusion 79 of the transmission table 61 and is biased downward, becomes operative when it corresponds to the recess 81 of the shift rod 76.

Note that the main transmission 7 is not limited to the synchromesh type.

Further, although the embodiment shows a case in which the hydraulic clutches 33 and 34 operate selectively, the same can be applied to the high-low speed switching device 6 which has a neutral state in which both the clutches 33 and 34 are disengaged. Of course,
In this case, the clutch body 32 should be
shall be fixed.

<Effects of the invention> According to the invention, the high-speed hydraulic clutch is disengaged in conjunction with the gear shifting operation of the transmission device, and the rotation of the clutch body is stopped, so that the inertial rotation during the gear shifting operation is quickly reduced. In particular, in order to suppress the inertia rotation of the clutch body, the high-speed hydraulic clutch is disconnected by switching the switching valve, so a separate inertia stopping brake etc. is required. is not required and the structure is simple. Furthermore, when the transmission is of the synchromesh type, its lifespan is improved.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing the first embodiment of the present invention, Fig. 2 is an explanatory diagram of the clutch pedal operating range, and Fig. 3 is an explanatory diagram of the clutch pedal operating range.
The figure is a sectional view of the power transmission system, FIG. 4 is a side view showing the second embodiment, and FIG. 5 is a configuration diagram showing the third embodiment. DESCRIPTION OF SYMBOLS 1... Engine, 4... Main clutch, 8... High/low speed switching device, 7... Main transmission, 12... Clutch pedal, 20... High/low speed switching valve, 26...
... Interlocking mechanism, 31 ... Planetary reduction gear, 32 ... Clutch body, 33 ... High speed hydraulic clutch, 3
4...Low speed hydraulic clutch.

Claims (1)

[Claims for Utility Model Registration] A high-low speed switching device and a transmission device are provided downstream of the main clutch, and the high-low speed switching device includes a high-speed hydraulic clutch and a low-speed hydraulic clutch that are connected and disconnected by a switching valve, respectively, in the clutch body. In a power transmission system for a vehicle, the clutch body rotates when a high-speed hydraulic clutch is engaged and stops when it is disengaged, wherein the switching valve disengages the high-speed hydraulic clutch in conjunction with a shift-related operation of the transmission. A device for reducing inertial rotation of a power transmission device for a vehicle, characterized in that an interlocking means for switching the direction is provided.