JPH07293670A - Fixing structure of operation lever fulcrum shaft on transmission case - Google Patents

Abstract

PURPOSE:To reduce manufacturing cost by providing a fitting-in hole in which one end of an operation lever fulcrum shaft is fitted and a member for preventing coming-off which prevents coming-off of the operation lever support point shaft from the fitting-in hole in a transmission case. CONSTITUTION:A fitting-in lateral hole 31 in which an operation fulcrum shaft 30 can be fitted freely from a side is formed in a front part and on a side of a cylinder case 5d, and one end of the operation lever fulcrum shaft 30 is fitted in the fitting-in lateral hole 31. Moreover, a member 33 for preventing coming-off which is locked in a locking portion 32 formed in a section which is exposed from the fitting-in lateral hole 31 of the operation lever fulcrum shaft 30 and prevents coming-off of the operation lever fulcrum shaft 30 from the fitting-in lateral hole 31 is mounted in the front part and on the side of the cylinder case 5d by bolts. Consequently, it is possible to omit a welding process and a process in which welding distortion is removed. In addition, operation levers R1 R3 do not bend easily, and it is possible to increase the strength in supporting the operation levers R1 R3. Consequently, it is possible to reduce manufacturing cost and obtain a fixing structure which excels in durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating lever fulcrum so that the operating lever can be supported by the operating lever fulcrum shaft in a state where the operating lever is swingably fitted to one end of the operating lever fulcrum shaft. The present invention relates to a structure for fixing an operation lever fulcrum shaft to a transmission case in which the other end of the shaft is fixed to the transmission case.

[0002]

2. Description of the Related Art Conventionally, a structure for fixing an operation lever fulcrum shaft to a transmission case has been constructed by fixing a bracket welded and fixed to the other end of the operation lever fulcrum shaft to the transmission case with a bolt. It was

[0003]

However, according to the above-mentioned conventional structure, the step of welding the bracket to the other end of the operation lever fulcrum shaft and the step of removing the welding distortion caused by the welding are necessary. Moreover, the production cost was high.

An object of the present invention is to provide a structure for fixing the operation lever fulcrum shaft to the transmission case, which can reduce the manufacturing cost.

[0005]

According to a characteristic construction of the present invention, an insertion hole into which an operation lever fulcrum shaft can be inserted is formed in a transmission case, and the other end of the operation lever fulcrum shaft is inserted into the insertion hole. The transmission case is provided with a retaining member for locking the operation lever fulcrum shaft from the insertion hole by engaging with a locking portion formed at a portion exposed from the insertion hole of the operation lever fulcrum shaft. It is installed in.

[0006]

In other words, in the above structure, the end portion of the operation lever fulcrum shaft is fitted in the fitting hole formed in the transmission case, and the operation lever fulcrum shaft is formed in a portion exposed from the fitting hole. It is only necessary to attach the retaining member to the transmission case in a state where the retaining member is retained in the retaining portion, and the conventional welding process and the process of removing welding distortion as in the conventional case can be omitted. Moreover, by inserting the other end of the operation lever fulcrum shaft into the insertion hole formed in the transmission case, the operation lever is less likely to bend, and the support strength for supporting the operation lever can be increased.

[0007]

Therefore, since the welding process and the process for removing welding distortion can be omitted, the manufacturing cost can be reduced, and the supporting strength for supporting the operation lever can be increased. It was possible to provide a structure for fixing the operation lever fulcrum shaft to the transmission case, which has excellent properties.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an engine 3 is provided at the front of a body supported by front wheels 1 and rear wheels 2, a control section 4 is provided at the center of the body, and a mission case 5 (an example of a transmission case) is provided below a driver seat 4a of the control section 4. ) Is arranged to constitute a four-wheel drive agricultural tractor.

The transmission case 5 will be described in detail, as shown in FIGS. 1 and 4, a front case 5a in which a front wheel transmission 6 is housed, a hydrostatic continuously variable transmission 7 (hereinafter referred to as HS).
(Hereinafter referred to as "T"), a middle case 5b, and a rear case 5c, which houses a gear type auxiliary transmission and a diff mechanism (above, not shown), are sequentially connected from the front side of the machine body, and a cylinder case is provided on the upper surface of the rear case 5c. 5d has a PTO shaft case 5 on the rear surface
e is connected to each other to form a mission case 5. The HST 7 is composed of a hydraulic pump 9 that is output-operated by a swash plate 8, a hydraulic motor 10 that is driven by hydraulic oil from the hydraulic pump 9, and the like. Power from the engine 3 is transmitted from the hydraulic pump 9 via a first transmission shaft 11. It is transmitted to the input shaft 12 and is output from the output shaft 13 of the hydraulic motor 10 to the rear case 5c.
It is transmitted to the sub-transmission device in the inside, and the gear is operated to be transmitted to the rear wheel 2.

The power branched from the sub transmission is transmitted to the front wheel transmission 6 through the second transmission shaft 14 penetrating from the rear case 5c into the middle case 5b and inserted into the front case 5a. . The front wheel transmission 6 includes a multi-plate hydraulic clutch 15, a gear meshing meshing clutch 16 and a shift member 1 for selectively engaging and operating both clutches 15, 16.
It is composed of 7 etc., and the occlusal clutch 1 in the straight traveling state.
When 6 is in the on state, the power from the second transmission shaft 14 is transmitted to the front wheels 1 via the output shaft 18 and the third transmission shaft 19 while the front wheels 1 and the rear wheels 2 are driven at substantially the same speed. It Then, when the steering handle 20 is steered over the set angle, the hydraulic pressure causes the shift member 17 to move from the side of the articulation clutch 16 to the side of the hydraulic clutch 15 (to the right in FIG. 1).
The slide operation is performed. As a result, power is transmitted to the front wheels 1 in a state in which the front wheels 1 are accelerated more than the rear wheels 2.

As shown in FIG. 4, the partition wall 21 is concentric with the second transmission shaft 14 in the middle case 5b.
As a pipe member is externally attached, and the front case 5a
And the notch 2 in the bearing support 22 of the rear case 5c.
3 is provided, and the lubricating oil in the front case 5a and the rear case 5c passes through the ring-shaped passage formed by the notches 23 and the inner surface of the pipe member 21 and the outer surface of the second transmission shaft 14. It allows people to come and go. As shown in FIG. 7, the pipe member 21 has a large diameter portion 21a at both ends.
And an O-ring 38 is interposed between the large diameter portion 21a and the inner wall of the case.

In the normal straight traveling state, the lubricating oil in the rear case 5c is the oil passage 24, the pump 25, the switching valve 26 and the oil passage 2.
It is sent into the front case 5a via 7 and circulated. On the other hand, when the steering handle 20 is steered over the set angle, the switching valve 26 is operated and the lubricating oil is supplied as hydraulic fluid from the oil passage 28 to the shift member 17, and the shift member 17 is operated toward the hydraulic clutch 15 entry side. As a result, the front wheels 1 are accelerated and the surplus lubricating oil from the relief valve 29 is fed into the front case 5a.

As shown in FIG. 2, the cylinder case 5
One end of the operation lever fulcrum shaft 30 is fixed to the side surface of d, and is fixed to one ends of the PTO disguise operation operation lever R1, the traveling auxiliary shift operation lever R2, and the mid PTO on / off operation lever R3. A ring member is loosely fitted in this order to the other end of the operation lever fulcrum shaft 30 from the lateral outside of the machine body. On the operation lever fulcrum shaft 30,
A pair of left and right retaining rings 37 are mounted in the groove portion so as to sandwich the ring members of these three operating levers R1, R2, R3 to prevent movement of the operating lever in the axial direction. Also, the operation levers R1, R2, R3 are
The intermediate portion is bent and formed outward in the lateral direction of the machine body when viewed from the front, and the operation portion thereof extends above the driver seat 4a so that the driver can easily operate it.

The structure for fixing the operation lever fulcrum shaft 30 to the cylinder case 5d will be described. As shown in FIG. 2, a lateral insertion hole 31 into which the operation lever fulcrum shaft 30 can be fitted from the side is formed on the side surface of the cylinder case 5d. Formed in the front part, one end of the operation lever fulcrum shaft 30 is inserted into this insertion lateral hole 31, and as shown in FIGS. 2 and 3, at a portion exposed from the insertion lateral hole 31 of the operation lever fulcrum shaft 30. The operation lever fulcrum shaft 3 is engaged with the formed groove portion 32 (an example of an engagement portion).
A retaining plate 33 (an example of a retaining member) for preventing the 0 from slipping out of the fitting lateral hole 31 is attached to the front side surface of the cylinder case 5d through a bolt.

The stopper plate 33 has a bolt insertion hole 33a.
And a cutout portion 33b which is fitted into the groove portion 32 and which can be externally fitted from above in the reduced diameter portion of the operation lever fulcrum shaft 30.

As shown in FIG. 5, the PTO shaft case 5 is
The PTO shaft 34 extends rearward from e, and
Rearward-facing ring-shaped boss portion 3 protruding from the O-axis case 5e
5, a resin cap 36 for internally covering the PTO shaft 34 when not in use is fitted and mounted. The connecting portion between the boss portion 35 and the cap 36 will be described. As shown in FIG. 6, an engaging hole 35a and an engaging claw that can be engaged with each other are provided in the peripheral wall of the boss portion 35 and the opening peripheral portion of the cap 36. 36a and a pair of cutout grooves 36b are formed on the cap 36 with the locking claws 36a interposed therebetween, and the opening peripheral portion of the cap 36 is fitted into the boss portion 35.
The locking claw 36a is configured to be locked in the locking hole 35a from the radially inner side by the elastic restoring force of the cap 36. The pair of locking holes 35a and the pair of locking claws 36a are arranged so as to face each other in the radial direction.

The PTO shaft case 5e is made of aluminum die cast. Therefore, the size of the material can be accurately finished as it is by casting, and the pair of locking holes 35a can be finished by casting without machining. Therefore,
It is possible to save the labor of machining the locking hole 35a and reduce the manufacturing cost.

[Other Embodiment] As shown in FIG. 8, instead of the groove portion as the engaging portion 32, the operating lever fulcrum shaft 30 is used.
In addition, a step portion capable of locking the stop plate 33 may be formed.

As shown in FIG. 9, three operating levers R
The operation lever fulcrum shaft 30 may be formed with a step portion 30a that prevents the movement of 1, R2, R3 toward the transmission case 5 side. According to this configuration, the retaining ring on the transmission case 5 side can be omitted, and the mounting work of the retaining ring 37 can be reduced.

The retaining member 33 may be a rod-shaped member instead of the retaining plate.

It should be noted that reference numerals are given in the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a side view of an agricultural tractor.

FIG. 2 is a vertical sectional front view showing a structure for fixing an operation lever fulcrum shaft to a cylinder case.

FIG. 3 is a perspective view of an operation lever fulcrum shaft and a stopper plate.

FIG. 4 is a vertical sectional side view of a mission case and a diagram showing a hydraulic piping system.

FIG. 5 is a vertical sectional side view showing a state in which a cap for covering the PTO shaft is attached to a boss portion of the PTO shaft case.

FIG. 6 is a perspective view of a PTO shaft case and a cap for covering the PTO shaft.

FIG. 7 is a vertical sectional side view showing a pipe member and a connecting portion of the pipe member.

FIG. 8 is a vertical sectional side view around an operation lever fulcrum axis according to another embodiment.

FIG. 9 is a vertical sectional side view around an operation lever fulcrum shaft of another embodiment.

[Explanation of symbols]

 5 Transmission case 30 Operation lever fulcrum shaft 31 Fitting hole 32 Locking part 33 Locking part R1 operating lever R2 operating lever R3 operating lever

Claims (1)

[Claims] 1. The operation lever fulcrum shaft (30) with the operation levers (R1), (R2), (R3) loosely fitted to one end of the operation lever fulcrum shaft (30). The other end of the operation lever fulcrum shaft (30) is fixed to the transmission case (5) so that the operation levers (R1), (R2), (R3) can be supported. It has a fixed structure, and the operation lever fulcrum shaft (30) can be freely inserted into the insertion hole (3
1) is formed on the transmission case (5), the other end of the operation lever fulcrum shaft (30) is inserted into the insertion hole (31), and the insertion hole (30) of the operation lever fulcrum shaft (30) is formed. Three
1) A retaining member (33) for retaining the operating lever fulcrum shaft (30) from the fitting hole (31) by locking the locking portion (32) formed in the exposed portion.
Is a structure for fixing the operation lever fulcrum shaft to the transmission case attached to the transmission case (5).