JPH01169158A - Transmission for tractor - 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 relates to a tractor transmission.

[Conventional technology]

As a transmission for a tractor, for example, one described in Japanese Utility Model Application Publication No. 58-45450 is known. This transmission consists of a 4-speed main transmission and a 2-speed main transmission.
It was equipped with a step-change sub-transmission device and a two-step creep transmission device, and was capable of changing the vehicle speed into 16 forward speeds.

For each of the 16 vehicle speeds, first, a required minimum vehicle speed and a maximum vehicle speed were determined, and the 16 vehicle speeds were determined so that the vehicle speed between them was divided by a substantially equal vehicle speed ratio.

[Problem that the invention seeks to solve]

In the conventional transmission, since the vehicle speed ratios of adjacent gears are approximately equal, for example, when performing rotary plowing work, fine gear shifting operations are performed in the medium speed range of 1.0 to 4 km/h. There are times when it is desired to perform optimal tilling work, but conventional vehicles can only be shifted in five to six gears, making it difficult to select the optimum vehicle speed for the tilling work conditions.

Therefore, in the present invention, the vehicle speed ratio of the gear is large in the low speed range and the high speed range, and the vehicle speed ratio is small in the middle speed range,
The purpose of the present invention is to provide a tractor transmission capable of performing optimal work by increasing the number of gears in the medium speed range.

[Means for solving problems]

In order to solve the above problems, the present invention has taken the following measures. That is, the features of the present invention include a main transmission that changes the engine speed in multiple stages in the rotational power transmission path of the engine, an auxiliary transmission that changes the engine speed into two stages (low and high speed), and a transmission that changes the engine speed to very low speed. In a tractor transmission having a creep transmission, the auxiliary transmission is on the high speed side, the creep transmission is on the main transmission, and the auxiliary transmission is on the low speed side and the creep transmission is off. The gear ratio of each transmission is set so that the transmission range overlaps with that of the main transmission.

[For production]

According to the conventional example, when the auxiliary transmission is "low speed" and the creep transmission is "on", it is a low speed region, and the auxiliary transmission is "low speed".
When the creep transmission is in the "on" state when the auxiliary transmission is on the low speed range, the creep transmission is on.
When the auxiliary transmission is in the ``high speed'' position, the creep transmission is in the medium-high speed range, and when the auxiliary transmission is in the ``high speed'' position, the creep transmission is in the high speed range. The shifting ranges when the transmission is "on" and when the auxiliary transmission is "low speed" and the creep transmission is "off" are considered to be overlapping regions, so fine shifting of 8 steps in the medium speed region is possible. It is something that can be taken.

〔Example〕

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

What is shown in FIG. 2 is the overall configuration of a tractor transmission. In the figure, 1 is an engine, and the rotational power of the engine 1 is transmitted through a main clutch 2 to a main transmission 3, a creep transmission 4, Rear wheel 9 via forward/reverse switching device 5, auxiliary transmission 6, differential gear device 7, final reduction device 8
transmitted to.

The main transmission 3 includes a first shaft 10 connected to the main clutch 2 and a second shaft 11 arranged parallel to the first shaft 10.
and the first to fourth gears Zl+Z on the first axis lO.
t, 23. Za is fixed, and the second shaft 11d is connected to the fifth to eighth gears ZS+Z6 that mesh with the respective gears.
．． Ztl Ze is fitted to be movable in the axial direction, and these fifth to eighth gears Z, , Z, , Zt, Z are the first
The second shaft 11 is removably engaged with the second shaft 11 through fourth shifter clutches 12, 13, 14, and 15.

The creep transmission device 4 includes a ninth gear 2. and a tenth gear Z provided at the tip of the third shaft 16 coaxially arranged with the second shaft 11.
,. and a pair of eleventh and twelfth gears ZII+z, □, which are freely rotatably provided at the rear end of the first shaft 10, and the ninth gear Z9 and the eleventh gear Zll mesh with each other, and,
1st O gear Z. The twelfth gears z and t are in mesh with each other.

10th gear Z. is spline-fitted to the third shaft 16 and is movable in the axial direction, and the tenth gear 2. . and 12th gear z
1□ are removably engaged with each other, and the tenth gear z1° and the ninth gear Z are removably engaged via the fifth shock clutch 17.

The forward/reverse switching device 5 includes a first
3.14 gear Z11+ZI4 and 15.16th gear Z+s provided on the fourth shaft 18 which is arranged parallel to the third shaft 16
, Zt&, and the 17th gear Z provided on the counter shaft 19
l? a forward clutch 21 that has a forward clutch 21 that directly connects a fifth shaft 20 disposed coaxially with the third shaft 16 and the third shaft 16 in a detachable manner; It has a reverse clutch 22 that connects and disconnects the reverse clutch 22.

The sub-transmission device 6 includes an 18th gearbox provided on the fifth shaft 20.
19 gear Zllll + Z19 and the fifth gear to mesh with the gear.
A second shaft arranged on the sixth shaft 23 arranged parallel to the shaft 20
0, 21 gear zzo, zt+, and 20.21
The gear 220°Ztl is detachably engaged with the sixth shaft 23 via the high speed clutch 24 and the low speed clutch 25.

The differential gear device 7 includes a pinion gear z0 provided at the rear end of the sixth shaft 23 and a differential case bevel gear Zzz that meshes with the pinion gear Z2□.
A yoke shaft 27 protrudes from the.

The final reduction gear 8 has a pair of gears h4+Z2s provided on a yoke shaft 27 and a rear axle 28 and meshing with each other.

The number of teeth of each gear is set as shown in the table below.

FIG. 3 is a shift diagram of the gear change lever of the main transmission 3. In the figure, the first shift clutch 12 is engaged with the second shaft 11 at the "1" position, and the power of the engine 1 is transferred to the first shaft 11.
to the second shaft 11 via the fourth gear z4 and the eighth gear z6.
transmitted to. Similarly, at the "2" position, the second shifter clutch 13 engages the second shaft 11, and the power of the engine 1 is transmitted from the first shaft 0 to the third gear z3 to the seventh gear Z1 to the second shaft 11. , at the "3" position, the transmission is transmitted from the first shaft 10 to the first gear Z, to the fifth gear Z, to the second shaft 11, and at the "4" position.
At the position, the first shaft 10-second gear Z2-sixth gear Z6
- transmitted to the second shaft 11;

What is shown in FIG. 4 is a shift diagram of the shift operation levers of the auxiliary transmission and the creep transmission. In this embodiment, the auxiliary transmission 6 and the creep transmission 4 are simultaneously operated by one operation lever. Ru. In the “H/on” position in the figure, the high-speed clutch 24 of the sub-transmission device 6 engages with the sixth shaft 23,
And the fifth shifter clutch 17 of the creep transmission 4 engages the third shaft 16, and the engine power is transferred from the second shaft 11→
9th gear Z9 - 11th gear z, → 12th gear 2+2 - 10th gear Z,.

→3rd axis 16-forward crunch 21-5th axis 20-19th axis
The signal is transmitted from gear 219 to 21st gear Ztl to sixth shaft 23.

Also, in the "L/on" position, the second shaft 11-9th gear 'r
' Z q - 11th gear z, → 12th gear zl! →1st
Power is transmitted from the 0th gear Z1° to the third shaft 16 to the forward clutch 21 to the fifth shaft 2o to the 18th gear Z111 to the 20th gear Z2° to the sixth shaft 23.

In the "H-off" position, the fifth shifter clutch 17 is
The shaft 11 and the third shaft 16 are directly connected. Therefore, the rotational power is generated from the second shaft 11-third shaft 16-fifth shaft 2o-19th gear z
0→21st gear 2!1→transmitted to the sixth shaft 23.

"For L-cutting, the second shaft 11 → the third shaft 16 → the fifth shaft 20
- 18th gear Z111 = 20th gear Z2° - 6th shaft 23
transmitted to.

Therefore, the vehicle speed in each shift state is as shown in FIG.

As is clear from Fig. 1, in the "H-on" and "L-off" shift ranges, the two shift ranges overlap, and l k
The vehicle speed is shifted in 8 steps from In/h to 4 km/h.

In this way, the number of teeth of each of the gears is set so that the shift ranges in the medium speed range overlap.

That is, the vehicle speed range for "H/ON" and the vehicle speed range for "L/OFF" are set to be midway between the other vehicle speed range.

Therefore, for example, 3.17 km/h in the "L/off" range
If you are doing plowing work and there is a lack of horsepower, the
・By downshifting to 2.72 km/h in the "on" range, you can perform fine gear shifting operations.

Conventionally, the next stage of 3.17 km/h is 2.02 km/h.
/h, and the gear ratio was too large, but according to the present invention,
2.721 m/h, and no large change in vehicle speed occurs.

What is shown in FIGS. 5 and 6 is a temperature detection device within the clutch housing 29 of the transmission.

Conventionally, there has been a problem that the clutch 2 is prematurely worn and damaged. The cause of this is thought to be insufficient clutch capacity, but there have also been cases where the vehicle was driven in a half-clutch state with the foot still on the clutch pedal. If the clutch is operated for a long period of time in a half-clutch state, the temperature of the clutch plate 30 will rise and the clutch notch 2 will wear out and break. However, operators often do not notice this.

Therefore, we decided to issue a warning if the car is operated with the clutch partially engaged for a long period of time.

That is, a temperature sensor 31 is provided at the bottom of the clutch housing 29 and near the clutch 2, and when the room temperature rises in the half-clutch state, the temperature sensor 31 detects the temperature rise, and an alarm means 32 notifies the operator. I made it.

〔Effect of the invention〕

According to the present invention, the rotational power transmission path of the engine includes a main transmission that changes the engine speed in multiple stages, a sub-transmission that changes the engine speed into two stages, low and high speed, and a creep transmission that changes to ultra-low speed. In the interposed tractor transmission, there is a shift range of the main transmission when the auxiliary transmission is on the high speed side and the creep transmission is on, and a shift range of the main transmission when the auxiliary transmission is on the low speed side and the creep transmission is off. Since the gear ratio of each transmission device is set so that the range overlaps with the range, it is possible to perform fine gear changes in the medium speed range, and it is possible to perform work under optimal conditions in rotary plowing work, etc.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing vehicle speed in an embodiment of the present invention, Fig. 2 is an overall configuration diagram of a transmission in an embodiment of the present invention, Fig. 3 is a shift pattern diagram of the main transmission, and Fig. 4 is a sub-transmission diagram. FIG. 5 is a cross-sectional view of the Crabchi housing, and FIG. 6 is a wiring diagram of the alarm device. DESCRIPTION OF SYMBOLS 1... Engine, 3... Main transmission, 4... Creep transmission, 6... Sub-transmission. Patent applicant: Kubota Iron Works Co., Ltd. Agent: Patent attorney: Yasu 1) Toshi Yuuuuuuuuuuuuuuu-u-o. Figure 7

Claims (1)

[Claims] (1) A main transmission that changes the engine speed into multiple stages, a sub-transmission that changes into two stages (low and high speed), and a creep transmission that changes to ultra-low speed are interposed in the rotational power transmission path of the engine. In the tractor transmission, there is a shift range of the main transmission when the sub-transmission is on the high-speed side and the creep transmission is on, and a shift range of the main transmission when the sub-transmission is on the low-speed side and the creep transmission is off. A tractor transmission characterized in that the gear ratios of each transmission are set so that the areas overlap.