JPS635053Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a shifter fork device for sliding gears in a sliding gear transmission.

(b) Prior Art The technology of configuring a shifter shaft, fork lever, etc. integrally with a shifter fork has been known for some time.

For example, Utility Model Publication No. 57-99223, Utility Model Publication No. 48-
As in Publication No. 23380.

(c) Problems that the invention aims to solve This invention consists of a short transmission case,
The width should also be as narrow as before, and in such a case, multiple gear shifters are inserted within a narrow range, making it difficult to position the gear shifter shaft and making assembly complicated.

In order to eliminate these drawbacks, we took advantage of the fact that the shaft center is located near the wall of the transmission case, and inserted and supported the shifter fork, which is an integral part of the fork and shifter shaft, into the wall to facilitate assembly and save space. In addition, since the detent device does not have a shifter shaft, it is difficult to remove the detent device, but the detent engagement surface is provided integrally with the shifter fork, thereby simplifying the structure.

In addition, the detent device is constructed in the shape of a bolt, with a spring and a detent protrusion installed inside the bolt, the head of the bolt is hexagonal, and a threaded portion is also provided, and it is assembled by screwing it into the wall of the mission case. It is something.

In addition, the shifter shaft portion 5 of the shifter fork 53
The retaining ring 70 engaged with the portion 3a and the detent case 62 restrict the left and right positions of the shifter fork 53, and the lever portions 53c and 53c are in a floating state with respect to the sliding groove of the sliding gear. It was supported as such.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

A shifter shaft portion 53a, a U-shaped fork portion 53b, and a lever portion 53 are integrated into the shifter fork 53.
c. 53c, and a detent engagement surface 53d is formed on the outer surface of the lever portions 53c, 53c, where the shifter shaft portion 53a inserted from the inside of the mission case protrudes from the mission case, A fitting groove 53i for locking the retaining ring 70 is formed, and a detent case 62 holding a spring 64 and a detent protrusion 63 is screwed in from the outside of the transmission case toward the detent engagement surface 53d of the shifter fork 53. , the left and right positioning of the shifter fork 53 is regulated by a retaining ring 70 and the inner end of the detent case 62.

(E) Embodiment The purpose and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is an overall side view of the agricultural tractor, and FIG. 2 is a drawing showing the internal structure of the transmission case.

An engine 2 is disposed on a bonnet 1, and a front axle bracket 3 protrudes forward from the engine 2. A front differential case 6 is supported by the front axle bracket 3, and front wheels 5 are supported by a front axle that projects laterally from the front differential case 6. The front differential case 6 is driven by a front wheel drive shaft inside the front wheel drive shaft cover 4.

A clutch housing 7 is fixed to the rear surface of the engine 2, and a transmission case 8 is fixed to the rear surface of the clutch housing 7. A rear axle housing protrudes from the side surface of the transmission case 8 or the rear axle case, and the rear wheel 9 is supported by the rear axle housing.

A PTO shaft 10 protrudes from the rear surface of the transmission case 8, and power is transmitted to the working machine via a universal joint. Operation levers protrude from the left and right sides of the transmission case 8. On the left side is the PTO gear shift lever 11, on the right side is the front clutch lever 12 and the auxiliary gear/creep gear lever 13.
Further, a main shift lever 14 is provided protruding from the top surface.

PTO gear shift lever 11 on the side, front clutch lever 12, auxiliary gear shift/creep gear shift lever 1
3, the 16 sides of the fenders on both sides of the seat also serve as shift guide plates. 17 is a hydraulic case, and 18 is a steering handle.

FIG. 2 is an axially developed sectional view showing a gear train of the transmission device. While explaining this configuration, I will also explain its function at the same time.

The driving force of the engine 2 is connected and disconnected by a main clutch device within a clutch housing 7, and is transmitted to an input shaft 19 protruding from a transmission case 8.
A main shaft 20 whose front end is supported by a bearing in a rear end face hole of the input shaft 14 is supported at the rear on the same axis as the input shaft 19 .

Shafts are arranged at respective positions of a ▼ shape with the input shaft 19 and the main shaft 20 as vertices. A pinion shaft 22 with a pinion 21 carved on the right side facing the direction of travel is located below the front power take-off shaft 2.
3 and the creep shaft 24 are arranged on the same axis.

Further, a counter shaft 25 and a PTO speed change shaft 26 are arranged on the left side surface when facing the direction of travel.

The power input from the input shaft 19 is transferred to the fixed gear 41.
from the fixed gear 27 on the counter shaft 25 to the counter shaft, and further from the fixed gear 27 to the PTO
Power is transmitted to the PTO transmission shaft 26 via a fixed gear 28 on the transmission shaft 26. The aforementioned main shift lever 14 allows for three forward speeds and one reverse speed change.

The main gear shift lever 14 has two shifter forks 5
0.51 is configured to selectively slide on the shifter shafts 50a and 51a. shifter fork 51
slides the sliding gear 31 on the main shaft 20 back and forth to change gears into one reverse and one forward gear, and the shifter fork 50 also moves two sliding gears 33 and 34 on the main shaft 20 back and forth to shift into two forward gears. Performs three forward gear shifts.

In the reverse gear, the rotation of the counter shaft 25 is the fixed gear 3.
5, the sliding gear 31 is always meshed with the other one of the two loosely fitted reverse gears 29 and 30 on the pinion shaft 22, and the sliding gear 31 is in mesh with the other one of the two loosely fitted reverse gears 29 and 30.
By engaging with the gear, it becomes a reverse gear.

In the first forward stage, the same sliding gear 31 is the counter shaft 2.
This is achieved by meshing with the fixed gear 32 on the top of the gear.

The second forward stage is one of the two sliding gears 33 and 34.
is obtained by meshing with a part of the fixed gear 35.

Three forward speeds are obtained by the other two sliding gears 34 meshing with the fixed gear 42 on the countershaft.

The rotation after the main shift is transmitted from the carved gear 43 of the main shaft 20 to the larger diameter one of the two loosely fitted gears 36 and 47 on the pinion shaft 22.

This loosely fitted gear 36 is divided into a normal sub-shift and a creep shift.

When the wide sliding gear 37 on the creep shaft 24 is slid to the right, it meshes with the fixed loose fit gear 36 and another loose fit gear 38 at the same time, resulting in a sub-shift.

In this state, the auxiliary transmission sliding gear 39 is connected to the loosely fitted gear 3.
By meshing with the internal gear No. 8, the sub-shift becomes a low speed. The sliding gear 39 is the fixed gear 4 on the main shaft 20.
By meshing with 0, a high speed sub-shift can be obtained.

This sub-shift operation is achieved by sliding the sliding gear 39 back and forth by operating the sub-shift/creep shift lever 13 shown in FIG.

Further, by operating the sub-shift/creep shift lever 13, the wide sliding gear 37 on the creep shaft 24 is also slid back and forth, thereby switching between the creep state and the sub-shift state.

When the wide sliding gear 37 is slid forward, it disengages from the loose-fit gear 36, remains engaged with the loose-fit gear 38, and the front end engaging portion 44 of the wide sliding gear 37 engages with the creep shaft. It engages with the integrated engagement portion 45 and transmits the rotation of the creep shaft 24 to the loosely fitted gear 38.

Let me explain the power transmission system in a creep shift state.

Engraved gear 43 on main shaft 20 and double loose fit gear 3
One 36 of the 6 and 47 meshes, and this rotation is transmitted from the other 47 to the fixed gear 46 on the creep shaft 24, causing the creep shaft 24 to rotate.
The rotation of the creep shaft 24 is transmitted from the engaging portion 45 to the wide sliding gear 37, and from 37 to the loose fit gear 38.

As will be described later, the auxiliary transmission shifter fork 52 and the creep transmission shifter fork 53 are operated in association with one auxiliary transmission/creep transmission lever 13, so that double meshing is prevented.

The front power take-off shaft 23 is driven only when the pinion shaft 22 is rotating to drive the rear wheels, and the rotation of the pinion shaft 22 is driven by the fixed gear 54.
Loosely fitted gear 49 on the front power take-off shaft 23
can be conveyed to.

By engaging the engaging portion 48a of the clutch slider 48 with the engaging portion 49a of the loosely fitted gear 49,
The front wheels 5 are driven from the front power take-off shaft 23 via the front drive shaft inside the front drive shaft case 4 .

PTO shifting is achieved by the sliding of the sliding gear 55 for PTO shifting, low speed PTO shifting is achieved by the engaging portion 55a engaging with the engaging portion 28a of the loosely fitted gear 28, and middle speed PTO shifting is achieved by sliding. A high speed PTO shift is obtained by the gear 55 meshing with the fixed gear 35 on the counter shaft 25, and a high speed PTO shift is obtained by the engaging portion 55b engaging with the loosely fitted gear 56 on the PTO shift shaft 26.

FIG. 3 is a cross-sectional view of the mission case 8.
1 shows a diagram of a variable speed shifter fork device.

The shifter shafts 50a and 5 are controlled by the main gear lever 14.
The shifter forks 50 and 51 on 1a are moved to selectively slide the double sliding gears 33 and 34 on the main shaft 20 and the sliding gear 31, thereby performing a speed change of one reverse speed and three forward speeds.

In addition, the shifter fork 58 is rotated by the PTO speed change lever 11, and the sliding gear 55 on the PTO speed change shaft 26 is slid, thereby changing the PTO speed from low to medium to high.

Furthermore, the sliding gear 39 on the pinion shaft 22 is slid back and forth to obtain the height of the sub-shift, and the wide sliding gear 37 on the creep shaft 24 is moved back and forth to switch between creep and sub-shift. Since these are related, the sub-shift/creep shift lever 13 is used to shift the two in a related manner.

When the lever 13 is tilted to the left in the direction of travel, it engages with the sub-shift arm 59, slides the shifter fork 52 from the shaft 66, and slides the sliding gear 39. Furthermore, when the lever 13 is tilted to the right to tilt the creep shift arm 60, the shifter fork 53 is rotated via the link 68 since it is loosely fitted onto the shaft 66.

Figure 4 shows front clutch levers 12 and 12.
FIG. 5 is a front view showing the relationship between the shifter fork 57 and the shifter fork 57.

Shifter fork 53 and shifter fork 57
are located in overlapping positions in the front-rear direction, with the same axis 2
The wide sliding gear 37 on 3.24 and the clutch slider 48 are made to slide.

Figure 5 is a front view of shifter fork 53, Figure 6 is a front view of shifter fork 53;
The figure is the same external view, and Figure 7 is the same internal view.
Fig. 8 is a bottom view, Fig. 9 is a sectional view showing the engagement relationship with the detent device, Fig. 10 is an exploded view of the detent device, Fig. 11 is a diagram of the protruding state of the detent projection, and Fig. 12 is a storage It is a drawing showing a state.

Conventionally, the sliding width of the sliding gear was wide, making it difficult to use such a shifter fork and a fork shaft that were integrated, but in this proposal, the sliding width was reduced and the shaft By placing the core close to the wall of the transmission case, it is constructed as a simple shifter fork.

The shifter fork 53 is a U-shaped fork portion 5
3b and lever portions 53c and 53c that engage with the engagement groove,
The shifter shaft portion 53a and the detent engagement surface 53d are integrally formed therein.

The detent engagement surface 53d has engagement holes 53e and 53f opened outward, and the detent protrusion 63 of the detent device is located between the creep device and the width change position.
is inserted.

An oil seal fitting groove 53g and a retaining ring 70 fitting groove 53i are provided in the middle of the shifter shaft 53a, and an insertion hole 53h for the arm 61 is provided in the external protrusion.

Insertion groove 53i provided in the shifter fork 53
By fitting the retaining ring 70 into the holder and bringing the retaining ring 70 into contact with the outer wall surface 8a of the transmission case,
This positions the shifter fork 53 to move inward.

Further, the shifter fork 53 is positioned outward by the portion of the detent engaging surface 53d coming into contact with the detent case 62 when the detent protrusion 63 inside the detent case 62 is completely retracted. be.

Also, the structure of the detent device is shown in Figures 10 and 11.
As shown in FIG.

The case 62 of the detent device is made of a bolt, and includes a hexagonal head 62c, a threaded portion 62b, and a guide hole 62a into which the detent protrusion is inserted. A spring 64 is inserted into the insertion hole 62a of this detent protrusion.
is inserted first, then the detent protrusion 63 is inserted, and then screwed onto the wall surface 8a of the mission case 8. An oil groove 63 is provided inside the detent protrusion 63 to prevent rust and fixation due to poor lubrication.
It passes through a. Assembling the shifter fork 53 and detent device is done using the shifter fork 53.
The retaining ring 70 is engaged and fitted by protruding from the inside of the transmission case to the outside, and the arm 61 is inserted for inward positioning, and then the half-assembled assembly is inserted toward the detent engagement surface of the shifter fork 53. Screw on the detent device from the outside and install the detent case 6.
The position where 2 hits the surface of the detent engagement surface 53d constitutes outward positioning.

By changing the thickness of the washer shim 65 interposed between the detent case 62 and the outer wall of the transmission case 8, the amount of protrusion of the detent projection can be changed.

(f) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, the left and right positioning of the shifter fork 53 is controlled by the retaining ring 70 to prevent it from moving inward, and by applying the detent engagement surface 53d to the inner end of the detent case 62 to prevent it from moving outward. ,
The lever portions 53c, 53c do not continue to be in frictional contact with the sliding groove of the sliding gear in a biased state, and can always maintain a floating state within the sliding groove. It is something.

This makes it possible to prevent abnormal wear of the sliding groove and the lever portions 53c.

Second, a spring 64 that presses the detent protrusion 63
, the shifter fork 53 is elastically pressed inward, and the retaining ring 70 is pressed against the transmission case wall surface 8a in the elastically biased state.
The position of the detent engagement surface 53d is determined by the retaining ring 70, and the detent protrusion 63
Since the gear lever protrudes and retreats, the operating feeling caused by operating the gear shift lever is always stable, and the detent effect can be reliably exerted.

[Brief explanation of the drawing]

FIG. 1 is an overall side view of the agricultural tractor, FIG. 2 is a side sectional view showing the internal structure of the transmission case, and FIG. 3 is a front sectional view of the transmission case 8.
Figure 4 is a front sectional view of the front clutch shifter fork, Figure 5 is a front view of the shifter fork 53, Figure 6 is an outside view, Figure 7 is an inside view, and Figure 8 is a bottom view. , FIG. 9 is a sectional view showing the engagement relationship with the detent device, FIG. 10 is an exploded view of the detent device, FIG. 11 is a drawing of the detent projection in a protruding state, and FIG. 12 is a drawing of the same in the retracted state. . 8...Mission case, 8a...Mission case wall, 53...Shifter fork, 53a...
...Shifter shaft, 53b...Fork part, 53c...
...Lever, 53d...Detent engagement surface, 53e.5
3f...Engagement hole, 62...Detent case, 62
a... Fitting guide hole, 63... Detent protrusion, 6
3a...Oil groove, 64...Spring.

Claims (1)

[Scope of utility model registration request] A shifter shaft portion 53a, a U-shaped fork portion 53b, and a lever portion 53 are integrated into the shifter fork 53.
c. 53c, and a detent engagement surface 53d is formed on the outer surface of the lever portions 53c, 53c, where the shifter shaft portion 53a inserted from the inside of the mission case protrudes from the mission case, A fitting groove 53i for locking the retaining ring 70 is formed, and a detent case 62 holding a spring 64 and a detent protrusion 63 is screwed in from the outside of the transmission case toward the detent engagement surface 53d of the shifter fork 53. , a speed change shifter device characterized in that the left and right positioning of the shifter fork 53 is regulated by a retaining ring 70 and an inner end of a detent case 62.