JPS621479Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vehicle speed change device for changing the running speed of an agricultural or other self-propelled working vehicle.

In order to change the speed in the backward direction of the vehicle in this type of vehicle speed change device, conventionally, an idler gear is used which meshes with two gears on the driving side and the driven side to give rotation in the backward direction of the vehicle to the gear on the driven side. I was using it. However, the idler gear that meshes with the two gears is unstable, and the two meshing portions are placed under different meshing frequencies, causing problems such as generation of noise.

The purpose of this invention is to provide a new vehicle speed change device for a self-propelled work vehicle that eliminates the idler gear that causes the above-mentioned problems.

The configuration of the vehicle speed change device according to the present invention will be explained with reference to the illustrated embodiment.This embodiment relates to an example in which the present invention is implemented in a frame type tractor as shown in FIG. The frame-type tractor shown in FIG. 1 has an engine 2 supported on a body frame 1, an engine 2 installed at the front of the body, and a transmission case 3 installed at the rear of the body, and supported by the body frame 1 so as to be able to swing left and right. The left and right front wheels 5 are supported by a front axle housing 4 which is mounted on the rear axle housing 4, and the left and right rear wheels 7 are supported by rear axle housings 6 on both sides of the rear part of the transmission case 3. There is. The power of the engine 2 is transmitted to the transmission case 3 through a transmission shaft 8 having a universal joint mechanism at both ends, and is transmitted to the left and right rear wheels 7 through a driving transmission (described later) inside the transmission case 3. It is also transmitted to the left and right front wheels 5 as necessary to allow the vehicle to run in two-wheel or four-wheel drive.
The power is transmitted to the PTO shaft 9 extending to the rear of the machine via a PTO transmission (described later) inside the transmission case, and the driving force of the working machine connected to the rear of the machine is transferred to the PTO shaft 9. It is designed to be obtained from A hydraulic lift device 10 and a passenger seat 11 for raising and lowering the working machine are installed on the rear upper surface of the mission case 3.
The vehicle is steered by turning the left and right front wheels 5 using a steering handle 12 in front of a passenger seat 11.

2 and 3 show a first embodiment, in which an input shaft 13, an intermediate shaft 14, and a hollow transmission shaft 15 shown in FIGS. 2 and 3 are installed at the front inside the transmission case 3. They are provided parallel to each other along the longitudinal direction of the aircraft, and furthermore, as shown in FIG. 2, intermediate shafts 14
The hollow transmission shaft 16 placed on the rear half of the machine and the transmission output shaft 17 on which the hollow transmission shaft 15 is placed on the front half are arranged along the longitudinal direction of the aircraft in the same manner as each of the shafts 13, 14, 15 described above. It is also provided. Of these shafts 13-17, the input shaft 13 is operatively connected to the engine 2 via a main clutch 18. Further, the transmission output shaft 17 is operatively connected to the left and right rear wheels 7 via a differential device 19 for the left and right rear wheels 7, a final gear reduction device 20 on the left and right, etc., and a front wheel drive clutch 21, a front wheel drive clutch 21, 5 differential gear 22, left and right final bevel gear reduction gears 23, etc., the front wheels 5 are interlocked and connected to the left and right front wheels 5.
The vehicle speed change mechanism inside the transmission case 3 is composed of a front speed change mechanism and a rear speed change mechanism, of which the front speed change mechanism is constructed in accordance with this invention. There is.

The front speed change mechanism is configured to selectively interlock the input shaft 13 and the hollow speed change shaft 15 at an appropriate speed ratio, and first, the input shaft 13 and the intermediate shaft 14 are By meshing the gears 26 and 27 fitted onto the shafts 13 and 14,
It is constantly linked to deceleration. As a result, the intermediate shaft 14 is rotated in the opposite direction to the input shaft 13. On the intermediate shaft 14, a transmission gear 28 for the forward gear is fixedly installed, and from the transmission gear 28 Shift gear 29 for large diameter forward gear
is provided so that it can only slide freely relative to the intermediate shaft 14. Further, a speed change gear 30 for a reverse gear stage is fixedly installed on the input shaft 13. Furthermore, the above-mentioned speed change gear 30 on the input shaft 13 is disposed on the hollow speed change shaft 15.
A shift gear 31 for a reverse gear that can be selectively engaged with the gear 28 on the intermediate shaft 14 and a shift gear 32 for a forward gear that can be selectively engaged with the gear 28 on the intermediate shaft 14 are connected to each other by boss portions. Unify as a common,
It is provided so as to be slidable relative to the hollow transmission shaft 15, and is fixedly provided with a transmission gear 33 for a forward gear position which can selectively mesh with the shift gear 29 on the intermediate shaft 14.

As a result of the above, the hollow speed change shaft 1
When the hollow transmission shaft 15 is rotated via the intermediate shaft 14, the hollow transmission shaft 15 is rotated in the forward direction of the vehicle.
The shift gears 29, 31, and 32 are selectively slidably displaced to change the rotational speed of the first forward gear when the shift gear 32 is engaged with the transmission gear 28, change the rotational speed of the second forward gear when the shift gear 29 is engaged with the transmission gear 33, and change the rotational speed of the second forward gear when the shift gear 31 is engaged with the transmission gear 34.
0, a rotation speed for first reverse gear can be selectively obtained for the hollow speed change shaft 15. In other words, the hollow speed change shaft 15 can be given a speed change rotation in the forward direction of the vehicle and a speed change rotation in the reverse direction of the vehicle without using an idler gear for giving rotation in the reverse direction.

To explain the vehicle speed change mechanism on the rear stage side, the hollow transmission shaft 16 has a large diameter gear 35 fixedly installed on the front end thereof, a small diameter gear 36 fixedly installed on the rear end of the hollow transmission shaft 15, and a small diameter gear 36 fixedly installed on the rear end of the hollow transmission shaft 15. By meshing, they are connected to the hollow transmission shaft 15 in a deceleration-interlocking manner.
A speed change gear 37 is fixedly installed on the hollow transmission shaft 16. Furthermore, two gears 39 and 40 having different diameters are fitted onto a reduction shaft 38 which is provided parallel to the hollow transmission shaft 16 and the transmission output shaft 17, and furthermore, two gears 39 and 40 having different diameters are fitted onto the reduction shaft 38, which is provided parallel to the hollow transmission shaft 16 and the transmission output shaft 17. Two gears 41 and 42 having mutually different diameters and a common boss are loosely fitted to the transmission gear 3 on the hollow transmission shaft 16.
7 is meshed with the gear 39 on the large diameter side on the reduction shaft 38, and the gear 40 on the small diameter side on the reduction shaft 38 is meshed with the gear 41 on the large diameter side on the input shaft 13. The gear 42 on the small diameter side is configured as a shift gear for a creep gear that receives input from the shift gear 36 and is rotated at a very low speed. On the transmission output shaft 17, each of the transmission gears 37, 4 described above is provided.
A shift gear 43 that can be selectively engaged with the transmission gear 2 is provided so as to be slidable only relative to the transmission output shaft 17. Further, the large diameter gear 35 on the front end of the hollow transmission shaft 16 has the shift gear 2 on the intermediate shaft 14.
9 is formed, and the shift gear 29 is engaged with the internal teeth 44a to form a clutch 44 that connects the intermediate shaft 14 and the hollow transmission shaft 16. In addition, the hollow gear shift shaft 1
5 the small diameter gear 36 on the rear end and the transmission output shaft 1
A pawl 45 that can be mutually engaged with the shift gear 43 on 7.
a, 45b are formed to constitute a clutch 45 which engages the clutch by meshing between the pawls 45a, 45b due to the displacement of the shift gear 43, and connects the hollow transmission shaft 15 and the transmission output shaft 17.

As a result of the above, in addition to the speed change by the previous speed change mechanism described above, the shift gear 4 on the speed change output shaft 17
3 by selectively operating the sliding displacement of gears 42 and 43.
The meshing between the gears 37 and 43, and the engagement of the clutch 45 are selectively obtained.
By selectively sliding and displacing the shift gear 29 above, the clutch 44 is selectively engaged, thereby making it possible to change the vehicle speed in multiple stages.

In FIG. 2, 47 is a pair of left and right rear wheel brakes, 48 is a differential clutch that releases the function of the differential device 19 by selectively connecting the left and right rear wheel axles, and 49 is a clutch. 50
The PTO pulley is connected to the engine 2 via the PTO pulley to extract the driving force for the work equipment, etc. toward the front of the machine. Further, the input shaft 13 is connected to a one-way clutch 51 and a one-way clutch 51 as shown in FIG.
It is also operatively connected to the PTO shaft 9 via a PTO clutch 52 and the like.

Next, a second embodiment shown in FIG. 4 will be described. In this second embodiment, a shift gear corresponding to the shift gear 28 on the intermediate shaft 14 in the first embodiment is replaced with a shift gear that can freely slide. 28' and
The transmission gears corresponding to the shift gears 31 and 32 on the hollow transmission shaft 15 in the first embodiment are fixed transmission gears 31' and 32'. Further, a shift gear 30' corresponding to the transmission gear 30 on the input shaft 13 in the first embodiment is provided on the input shaft 13 so as to be relatively rotatable and slidable, and the shift gear 30' is meshed with the gear 26 similar to the above. The shift gear 30' is engaged with the internal teeth 54a by the displacement of the shift gear 30'.
0' to the input shaft 13, and the shift gear 30' on the hollow gear shaft 15 at the position where the shift gear 30' meshes with the internal gear 54a.
1'.

As described above, in the second embodiment, when the shift gears 28', 29, and 30' are selectively operated to slide and displace, and the shift gear 28' is engaged with the transmission gear 32', the rotation of the first forward speed is achieved. When the shift gear 29 is engaged with the transmission gear 33, the rotation speed of the second forward speed increases, and when the shift gear 30' is engaged with the internal gear 54a and the transmission gear 3
1', the rotational speed for reverse first speed can be selectively obtained on the hollow transmission shaft 15.

In the second embodiment, a pair of integral gears 55, 5 are provided on the transmission output shaft 17 and the input shaft 13.
6, 57, and 58 are loosely installed, and the hollow transmission shaft 16
The upper speed change gear 37 and the gear 55 on the large diameter side on the speed change section output shaft 17 mesh with each other, and the speed change section output shaft 17
The small-diameter gear 56 on the upper side and the large-diameter gear 57 on the input shaft 13 are meshed, and the shift gear 43 on the transmission output shaft 17 is connected to the small-diameter gear 5 on the input shaft 13.
8, the gear 58 on the small diameter side on the input shaft 13 is constructed as a speed change gear for creep gear. Further, unlike the case of the first embodiment, the structure in which the shift gear 43 on the transmission output shaft 17 is selectively engaged with the transmission gear 37 on the hollow transmission shaft 16 is not adopted;
By forming internal teeth 59a that can mesh with the gear 56, the internal teeth 59a are engaged with the gear 56 by the displacement of the shift gear 43, and the gear 55 is connected to the transmission output shaft 17.
A structure is adopted in which a clutch 59 is coupled to the clutch 59.

As is clear from the above description of the two embodiments, the vehicle speed change device for a self-propelled work vehicle of this invention has the input shaft 13, the intermediate shaft 14, and the speed change shaft 15 parallel to each other. The input shaft 13 and the intermediate shaft 14 are always interlocked and connected, and the intermediate shaft 14
By selectively meshing the upper transmission gears 28, 28', 29 with the transmission gears 32, 32', 33 on the output shaft 17, the gears can be changed in the forward direction of the vehicle.
The gears 30, 30' on the transmission shaft 15 are selectively engaged with the transmission gears 31, 31' on the transmission shaft 15 to obtain a transmission in the backward direction of the vehicle, respectively. Shifting in the reverse direction,
It is said to be obtained by a structure that eliminates the idler gear for imparting reverse rotation, so the conventional problem of noise generation from the idler gear meshed with two gears is eliminated. be done.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a frame type tractor equipped with an embodiment of this invention, Fig. 2 is a mechanical diagram of a transmission mechanism including the first embodiment, and Fig. 3 is a transmission shaft in the first embodiment. A schematic diagram showing the arrangement of and gears,
FIG. 4 is a mechanical diagram showing the second embodiment. 13...Input shaft, 14...Intermediate shaft, 15...Hollow gear shift shaft, 26, 27...Gear, 28...Shift gear, 29...Shift gear, 30...Shift gear, 3
1...Shift gear, 32...Shift gear, 33...
...Speed gear, 28'...Shift gear, 30'...Shift gear, 31', 32'...Speed gear, 54...
Clutch.

Claims (1)

[Scope of utility model registration request] The input shaft 13, the intermediate shaft 14, and the transmission shaft 15 are provided parallel to each other, and the input shaft 13 and the intermediate shaft 14 are constantly dynamically connected, and the transmission gears 28, 28', and 29 on the intermediate shaft 14 are connected to each other. Speed change gear 3 on output shaft 17
The gears 30, 30' on the input shaft 13 and the gears 31, 31 on the gear shaft 15 can be selectively engaged with the gears 30, 32', 33 on the input shaft 13 and the gears 31, 33 on the gear shaft 15, respectively.
A vehicle speed change device for a self-propelled work vehicle, characterized in that the speed change in the backward direction of the vehicle is obtained through selective engagement with the work vehicle 31'.