JPH089484Y2 - Device for restricting meshing between super-low speed gear and auxiliary speed change gear of transmission in tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a transmission of a tractor having a high-low two-stage sub-transmission unit and an ultra-low-speed transmission unit. The present invention relates to a simultaneous meshing restriction device for an ultra-low speed gear and a sub transmission gear of a transmission of a tractor, which prohibits simultaneous conversion of an input side of a transmission section.

[Problems to be solved by conventional techniques and devices]

Conventionally, an agricultural tractor has a main speed change gear, a sub speed change gear, and an ultra-low speed speed change gear part in order to adapt to a wide variety of work, and by combining these various gear change parts, it is possible to perform extremely multi-speed gear change. There is.

However, for example, in a transmission having a main transmission unit having three forward gears and one reverse gear, an auxiliary transmission unit having two high and low gears, and an ultra-low speed transmission unit having one turn-on / off, the sub-transmission unit is set to a high speed and an ultra-low speed is adopted. The final gear ratio is the combination of the gear ratio when the speed change unit is turned on and the speed ratio when the sub speed change unit is set to low speed and the ultra-low speed speed change unit is turned off. Is practically meaningless, and complicated simultaneous conversion operations of the main, sub, and ultra-low speed gear shift levers are required to obtain the required gear ratio. Also, if the sub-transmission unit is set to high speed and the ultra-low speed transmission unit is turned on, the reaction force of the torque from the wheel side becomes excessive.Therefore, widen the gear width of the ultra-low speed transmission unit to secure strength. It is necessary to keep the gear width wide, and increasing the gear tooth width causes the transmission to become larger, and it is useless to widen the gear tooth width in the ultra-low-speed transmission section in order to obtain a gear ratio that is rarely used. .

Therefore, conventionally, it is considered to prevent the sub-transmission unit from entering at high speed when the ultra-low speed transmission unit is turned on, and as a means for that, a link mechanism attached to the outside of the transmission is used to convert the sub-transmission unit to the high-speed side. The one that prohibits the simultaneous conversion with the input side conversion of the ultra-low speed transmission is generally adopted.

The above-mentioned conventional mechanism connects the auxiliary shift lever and the ultra-low speed shift lever with additional parts to prohibit simultaneous conversion of the auxiliary shift lever at the high speed side and the conversion of the ultra-low speed shift lever at the incoming side. It is a little complicated and costly, and since it is an external mechanism, there is a risk of foreign matter being caught in the parts and interfering with the lever operation.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to improve the problems, without using a special additional component, and without an externally exposed component such as a foreign object being bitten,
An object of the present invention is to provide a meshing restricting device for a transmission ultra-low speed gear and an auxiliary transmission gear in a tractor that can prohibit simultaneous conversion of the high speed side of the auxiliary transmission section and the input side conversion of the ultra low speed transmission section.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a transmission of a tractor having two high and low sub-transmission parts and an ultra-low speed transmission part, in which an ultra-low speed gear shifter rotatable about an ultra-low speed gear shifter shaft is provided in the transmission, The working end of the ultra-low speed gear shifter is interlocked with the on / off switching operation of the ultra-low speed transmission section, and the reaction end of the shifter is extended toward the sub-transmission section. The extension of the low-speed gear shifter shifts between the high-speed shift position at the working end of the auxiliary transmission gear shifter and the position withdrawn from this position, and the auxiliary transmission shifts to the high-speed shift position only when the ultra-low speed transmission is turned off. It is characterized by a meshing restricting device for an ultra-low speed gear and a sub-transmission gear of a transmission in a tractor configured to be shiftable.

[Action]

In the device of the present invention, the working end portion of the ultra-low speed gear shifter provided in the transmission is interlocked with the on / off switching operation of the ultra-low speed transmission portion, and the extension portion of the shifter allows the auxiliary transmission portion when the ultra-low speed transmission portion is turned on. Prohibits shifting to the high speed side, and the sub-transmission portion can be shifted to the high speed side only when the ultra-low speed transmission portion is turned off. It is possible to achieve the intended purpose with a simple structure that only extends the end side, there is no obstacle such as foreign matter biting due to externally exposed parts, it is inexpensive, and it is an ultra-low speed transmission gear in a compact tractor. A device for restricting meshing between the auxiliary transmission gear and the auxiliary transmission gear is provided.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

FIG. 1 is a side sectional view of a main part of the present invention, FIG. 2 is a front sectional view of the same part, and FIG. 3 is an explanatory view of a power transmission system of a tractor.
The figure is an overall side view of the tractor.

In FIG. 4, 1 is a tractor, 2 is a main shift lever,
Reference numeral 3 is an auxiliary gear shift lever, 4 is an ultra-low speed gear shift lever, and 5 is a mission case. As shown in FIG. 3, the power of the engine 6 is transmitted to the PTO shaft 8 via the clutch 7, and the main gear shift portion 9 After entering the transmission 12 having the sub-transmission unit 10 and the ultra-low speed transmission unit 11, the gear is transmitted and output to the final bevel pinion shaft 13 of the transmission 12, and the power is transmitted from the bevel pinion shaft 13 to the final drive shaft 14 to the axle shaft 15. It is transmitted and the rear wheels 16 are driven. 17 is a one-way clutch, PTO
When a reverse driving force is applied from the working machine side connected to the shaft 8,
It works to release the overload of the engine 6.

The main transmission portion 9 of the transmission 12 includes a first speed input gear 19, a second speed input gear 20, and a third speed gear 3, which are fixed to a main transmission portion input shaft 18.
High speed input gear 21, reverse input gear 22, and main transmission section output shaft
First gear change gear 24 mounted on 23, second gear change gear
The gear change with the 25th, 3rd speed change gear 26 and the reverse change gear 27 makes it possible to obtain 3 forward speeds and 1 reverse speed.

That is, the first speed change gear 24 and the reverse change gear 27
Is fixed to the output shaft 23 of the main transmission portion and is rotatably mounted. The first speed change gear 24 is a first speed input gear 19, and the reverse change gear 27 is a reverse intermediate gear 28 that meshes with the reverse input gear 22. It is always meshed and is installed between the first speed change gear 24 and the reverse change gear 27.
When the tooth profile clutch 30 slidable on the main transmission section output shaft 23 by engagement with 29 is engaged with the tooth profile 31 formed on the first speed change gear 24, a first speed (1) gear change is performed, and the reverse change gear 27 If it engages with the tooth profile 32 formed in the above, it becomes a reverse (R) gear change. 2nd speed change gear 25 and 3
The speed change gear 26 is formed integrally, and the main transmission unit output shaft 23
Spline that can rotate integrally with and slide on shaft 23
33 is engaged, and if the second speed change gear 25 is meshed with the second speed input gear 20, it becomes the second speed (2) gear change, and if the third speed change gear 26 is meshed with the third speed input gear 21, the third speed (3)
Gear change.

The third speed input gear 21 is meshed with the output gear 34 of the PTO shaft 8 to input the rotation of the engine 6 to the main transmission unit input shaft 18 of the main transmission unit 9, and the gear change of the main transmission unit 9 is performed by the main transmission. It is operated by the lever 2.

The ultra-low-speed transmission section 11 includes an ultra-low-speed transmission section input gear 35 fixed to the rear end of the main-transmission section output shaft 23 and an ultra-low-speed transmission section output shaft 36 provided on the axial extension of the main-transmission section output shaft 23. An ultra-low speed transmission output gear 38 slidably engaged with the spline 37, and a large-diameter intermediate gear 40 and a small-diameter intermediate gear 41 integrally formed and rotatably mounted on the intermediate shaft 39. The ultra-low-speed transmission section input gear 35 and the large-diameter intermediate gear 41 are constantly meshed with each other, and the ultra-low-speed transmission section output gear 38 is selectively meshed with the small-diameter intermediate gear 41. When shifting to a position where it meshes with the gear 41, the ultra-low speed transmission section 11 is turned on (ON) and the main transmission section output shaft 23 rotates in the ultra-low speed transmission section input gear 35, large diameter intermediate gear 40, small diameter intermediate gear 41. , Is transmitted to the ultra-low speed transmission unit output shaft 36 via the ultra-low speed transmission unit output gear 38 at an ultra-low speed transmission ratio, If the gear 38 is shifted to the input gear 35 side of the ultra-low speed transmission unit and the tooth profiles 42 and 43 formed on the facing surfaces of the both gears 38 and 35 are engaged, the ultra-low speed transmission unit 11 is turned off (OFF). The main transmission unit output shaft 23 is directly connected to the ultra-low speed transmission unit output shaft 36, and the rotation of the main transmission unit output shaft 23 is transmitted to the ultra-low speed transmission unit output shaft 36 as it is.

The sub-transmission unit 10 is a small-diameter input gear 45 and a large-diameter input gear fixed to the sub-transmission unit input shaft 44 that is an extension of the ultra-low-speed transmission unit output shaft 36.
46, a large-diameter output gear 47 and a small-diameter output gear, which are engaged with a spline 49 slidably on the bevel pinion shaft 13 described above.
Neutral (N) gear in which the auxiliary transmission section input shaft 44 idles if the large-diameter output gear 47 and the small-diameter output gear 48, which are integrally formed of 48, are positioned intermediately between the small-diameter input gear 45 and the large-diameter input gear 46. When the large diameter output gear 47 is meshed with the small diameter input gear 45, a low speed (L) gear change with a large gear ratio is made. When the small diameter output gear 48 is meshed with the large diameter input gear 46, a small gear ratio is high speed (H). ) It will be a gear change.

The L, N, H gear changes of the sub-transmission unit 10 are performed by the sub-transmission lever 3, and as the sub-transmission lever 3 is operated to the L, N, H positions, the sub-transmission lever 3 is interlocked. , Second
The sub-transmission gear shifter shaft 50 shown in the figure rotates, and the working end portion 51a of the sub-transmission gear shifter 51 in the transmission case 5 fixed to the sub-transmission gear shifter shaft 50 shifts to each shift position of L, N, H, The large-diameter output gear 47 and the small-diameter output gear 48 are integrally shifted to the L, N, and H change positions by the shift piece 53 attached to the working end 51a via the shifter pin 52. Incidentally, 54 in FIG. 2 is an auxiliary transmission gear shifter.
This is a detent mechanism that locks 51 at L, N, and H shift positions.

The ON / OFF operation of the ultra-low speed shift unit 11 is performed by the ultra-low speed shift lever 4
When the ultra low speed gear shift lever 4 is operated to the ON side, the ultra low speed gear shifter shaft 55 rotates counterclockwise in FIG. 1, and together with this, the ultra low speed gear shifter shaft 55 inside the mission case 5 is fixed. The working end portion 56a of the ultra-low speed gear shifter 56 moves the ultra-low speed gear shift rail 57 to the right in FIG. 1, and the shift fork 58 fixed to the end portion of the ultra-low speed gear shift rail 57 causes the output shaft 36 of the ultra-low speed transmission section 36 to move.
The ultra-low speed transmission section output gear 38 engaged with the spline 37 is shifted to the small diameter intermediate gear 41 side, and the ultra-low speed transmission section input gear 35 connecting the main transmission section output shaft 23 and the ultra-low speed transmission section output shaft 36 is connected.
And the engagement of both tooth shapes 43, 42 of the ultra-low speed transmission section output gear 38 with the small diameter intermediate gear 41 to engage the main transmission section output shaft 23 to rotate the ultra-low speed transmission section input gear 35, large diameter intermediate gear 40, It is transmitted to the ultra-low speed transmission section output shaft 36 via the small diameter intermediate gear 41 and the ultra-low speed transmission section output gear 38, and the ultra-low speed output shaft 36 is rotated at the ultra-low speed transmission ratio.

When the ultra-low speed gear shift lever 4 is operated to the OFF side, the ultra-low speed gear shifter shaft 55 rotates clockwise in FIG. 1, and the working end 56a of the ultra-low speed gear shifter 56 moves the ultra-low speed gear shift rail 57 along with it. When the shift fork 58 fixed to the end of the shift rail 57 is moved to the upper left, the mesh between the ultra-low speed transmission section output gear 38 and the small diameter intermediate gear 41 is released, and the ultra-low speed transmission section output gear 38 is released. Tooth profile 42
And the tooth profile 43 of the ultra-low speed transmission section input gear 35 are engaged, and the main transmission section output shaft 23 and the ultra-low speed transmission section output shaft 36 are directly connected.

The ultra-low speed gear shifter 56 has its reaction end side extended toward the sub-transmission section 10 and when the ultra-low speed transmission section 11 is turned on,
The extension portion 56b of the ultra-low speed gear shifter 56 shifts the auxiliary transmission portion 10 to H
The extended portion 56b is adapted to retreat from the position when the operating end portion 51a of the auxiliary transmission gear shifter 51 is shifted to the position of the auxiliary shift gear shifter 51 and the ultra-low speed transmission portion 11 is turned off. Therefore, when the ultra-low speed transmission is turned off, the auxiliary transmission gear shifter 5
The working end portion 51a of 1 can be shifted to each of the L, N, and H positions, and the sub-transmission unit 10 can perform high and low two-speed gear shifting.

Here, operate the ultra-low speed shift lever 4 to set the OF
When it is turned from F to ON, the extension portion 56b of the ultra-low speed gear shifter 56 pushes the working end portion 51b of the auxiliary transmission gear shifter 51 from the H position to the N side, and when the ultra-low speed transmission portion 11 is ON, the auxiliary transmission When the gear lever 3 is operated to try to gear change the sub transmission portion 10 from L to H, the working end portion 51a of the sub transmission gear shifter 51 pushes the extension portion 56b of the super low speed gear shifter 56 to the OFF side, and the super low speed transmission portion 11 Turn it off. That is, the sub-transmission unit can shift to the high speed side only when the ultra-low speed transmission unit 11 is turned off.

As described above, in the transmission 12, the main transmission unit 9 has three forward gears, the reverse gear has one, the auxiliary transmission unit 10 has two high and low gears, and an ultra-low speed transmission unit.
Since 11 has one speed, and simultaneous conversion of the H side of the sub-transmission unit 10 and the ON side of the ultra-low speed transmission unit 11 is prohibited, a convenient shift of 9 speeds and a reverse speed of 3 speeds can be obtained. Will be done.

[Effect of device]

As described above, the meshing restriction device for the ultra-low speed gear and the auxiliary transmission gear of the transmission of the tractor of the present invention is an ultra-low speed gear shifter for a transmission of a tractor having two high-low sub-transmission parts and an ultra-low speed transmission part. An ultra-low speed gear shifter, which is rotatable around a shaft, is provided in the transmission, and the working end of the above-mentioned ultra-low speed gear shifter is interlocked with the on / off switching operation of the ultra-low-speed shifting section, and the reaction end of the shifter is the sub-shifting section. The extension part of the ultra-low speed gear shifter shifts between the high-speed shift position of the working end part of the sub-shift gear shifter and the position withdrawn from this position as the ultra-low speed gear shift part is turned on and off. Since the sub-transmission unit can be shifted to the high-speed shift position only when the low-speed transmission unit is turned off,
In addition to eliminating practically meaningless gears, the gear change operation becomes simpler, and it is not necessary to widen the tooth width of the gears of the ultra-low speed transmission section to secure particular strength, thus avoiding an increase in size of the transmission. Then, the simultaneous conversion of the high speed side conversion of the sub transmission section and the input side conversion of the ultra low speed transmission section is prohibited by the extension portion on the reaction end side of the ultra low speed Kayaf footer provided in the transmission. Provided with an ultra-low speed gear shifter device for a transmission that is inexpensive, compact, and operates reliably with a link mechanism without obstacles such as foreign matter biting due to exposed parts. Regulation of meshing between ultra-low speed gear and auxiliary transmission gear of transmission. A device is provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a sectional side view of a main portion of the present invention, FIG. 2 is a front sectional view of the same portion, and FIG. 3 is an explanatory view of a power transmission system of a tractor. FIG. 4 is an overall side view of the tractor. 1 ... tractor, 9 ... main transmission, 10 ... sub transmission,
11 …… Ultra-low speed transmission section, 12 …… Transmission, 51…
... Sub-transmission gear shifter, 51a ... Operating end of sub-transmission gear shifter, 55 ... Ultra-low speed gear shifter shaft, 56 ... Ultra-low speed gear shifter, 56a. Department.

Claims (1)

[Scope of utility model registration request] 1. In a transmission of a tractor having a high-low two-stage sub-transmission unit and an ultra-low speed transmission unit, an ultra-low speed gear shifter rotatable about an ultra-low speed gear shifter shaft is provided in the transmission, and the ultra-low-speed gear shifter is provided. The working end is linked to the on / off switching operation of the ultra-low speed transmission, and the reaction end of the shifter is extended toward the sub-transmission part. Shifts between the high speed shift position at the working end of the auxiliary transmission gear shifter and the position withdrawn from this position, and the auxiliary transmission unit can shift to the high speed shift position only when the ultra-low speed transmission unit is turned off. A device for restricting meshing between an ultra-low speed gear and a sub-transmission gear of a transmission in a tractor characterized by the above.