JPH0749128Y2 - Gearbox - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a transmission that can be applied to a transmission mechanism such as a PTO shaft mounted in a transmission case such as a tractor. The present invention relates to a transmission in which an arm provided on a dual operation shaft is operably connected by a double rod.

[Prior art]

There are various types of power transmission types installed in the transmission case of the tractor. For example, the standard type in which the running power and the extraction power can be connected / disconnected by one clutch is the power transmission shown in FIGS. 5 to 6. The PTO shaft 20 that is projected from the end to the rear and drives the work machine is as shown in the system diagram, and the PTO shaft 20 of the pair of front and rear forks that switches the PTO shaft transmission mechanism 19 installed on the rear side of the case 13 is used. By moving
It is configured such that the speed is changed over four rotation speeds so that the rotation speed matches the rotation speed of each work machine centered on the neutral position.

In this PTO shaft speed change mechanism, as shown in FIG. 9, a fork 2 on the front side and a fork 3 on the rear side, which are slidably provided on a fork shaft 1 arranged in the front-rear direction, are different from each other in the speed change direction. Is generally connected to the operation arms 4 and 5 adjacent to each other at a long distance in the orthogonal direction via two connecting rods 6 and 7 provided along the shifting direction.

Further, as shown in Japanese Utility Model Laid-Open No. 56-100722, the shift fork shaft having a fixed shift fork at the end may have a double shaft structure so that the respective shift fork shafts are relatively movable. It is known.

[Problems to be solved by the invention]

By the way, in the former one of the above-mentioned conventional structures, the two connecting rods 6 and 7 adjacent to each other are independently arranged with a wide interval, so that the installation space of the connecting rod is minimized. In addition to this, there is a problem that the reinforcing effect of preventing the bending of one connecting rod from being prevented by the other connecting rod cannot be expected. Further, if both connecting rods 6 and 7 are provided close to each other, they interfere with other members such as the diff lock fork 56 shown in FIG. 2, so that the degree of freedom in the case is increased and the connecting lever cannot be connected. There was a point. In the latter case, the former problem of the installation space and the fact that the shift fork shaft is prevented from being bent by one of the shift forks can be solved, but the bearing portion supporting the shift fork shaft is replaced by the mission case. However, there is a problem that the arrangement of the shift fork shaft is restricted and the degree of freedom of the arrangement position of the operation lever for operating the shift fork shaft is impaired, and there is room for improvement.

[Means for solving problems]

Therefore, the present invention was devised to solve the above-mentioned problems, and the front and rear forks 30, 31 mounted slidably along the shift rail 29 are disengaged from the transmission mechanism. In the transmission thus configured, a double rod 40 in which the inner shaft 37 and the outer shaft 39 are relatively slidably fitted is provided in parallel with the shift rail 29 in a plan view, and is orthogonal to the double rod 40. In the direction, a double operation shaft 34 in which an inner shaft 32 and an outer shaft 33 are relatively rotatably fitted is provided, and the inner shaft 32 and the outer shaft 33 of the double operation shaft 34 are selected by a shift lever 41. Each of them is configured to rotate independently by a switching operation, and the double operation shaft 34
A pair of arms 35 and 36 hung and attached at predetermined intervals are arranged at the side ends of the inner shaft 32 and the outer shaft 33, and the inner shaft 37 of the double rod 40 is attached to the pair of arms 35 and 36. And connecting members 37b, 39b integrally provided at one end of the outer shaft 39, respectively, are arranged to face each other,
The pair of arms 35, 36 and the connecting members 39b, 37b are pivotally connected by the horizontal connecting pins 45, 46 orthogonal to the double rod 40, while the inner shaft 37 and the outer shaft 39 of the double rod 40 are The connecting members 37a, 39a integrally provided at the ends are pivotally connected to the front and rear forks 30, 31 by horizontal connecting pins 43, 44 orthogonal to the double rod 40. And

[Action]

The present invention is configured as described above, and the inner shaft 32 and the outer shaft 33 of the dual operation shaft 34 are independently rotated by the gear shift lever 41, and the inner shaft 32 and the outer shaft 33 are rotated by this rotation. The arm 35 or the arm 36 connected to the end also rotates, and the inner shaft of the double rod 40 via the horizontal connecting pin 45 or the connecting pin 46 and the connecting member 39b or 37b of the double rod 40.
Either the 37 or the outer shaft 39 reciprocates, and the movement of the coupling member 37a or 39a coupled to the other end of the double rod 40 is accompanied by this movement via the horizontal coupling pin 43 or 44. Is transmitted to the front and rear forks 30 or 31, and either the front fork 30 or the rear fork 31 slides along the shift rail 29.

〔Example〕

Hereinafter, the drawings showing the present invention as an embodiment will be described.

In the power transmission system diagram of the tractor shown in FIGS. 5 to 6, a clutch housing 12 is fixed to the rear of the engine 11, and a transmission case 13 extending rearward is fixed to the rear of the clutch housing 12. Thus, the monocoque body 10 of the tractor T is constructed.

In the front of the transmission case 13, a main transmission mechanism 14 capable of shifting in four stages is installed.
A forward switching mechanism 15 capable of switching between forward and reverse is installed in the rear of the. Behind this forward / reverse switching mechanism 15, there is a first
Sub-transmission mechanism 16 including sub-transmission mechanism and second sub-transmission mechanism
A rear wheel drive mechanism 17 having a differential mechanism for driving the rear wheels 66 is installed behind the sub transmission mechanism 16. Behind the rear wheel drive mechanism 17, a PTO shaft speed change mechanism 19 is installed, and a PTO shaft driven by the PTO shaft speed change mechanism 19.
20 penetrates the rear wall of the transmission case 13 and projects rearward.

Further, as shown in FIG. 6, the drive shaft 21 of the rear wheel drive mechanism 17 is
And the PTO shaft drive shaft 22 are interlockingly connected to the front wheel drive shaft 24 via the speed reduction mechanism on the ultra-low speed drive shaft 23 so that the front wheels 67 are driven. A power take-off gear train 25 is configured.

As shown in FIG. 4, the PTO shaft speed change mechanism 19 includes a PTO shaft.
PTO shaft 2 by selectively meshing with four gears arranged on 20
A front sleeve 26 and a rear sleeve 27 for shifting 0 to four steps are provided so as to be movable along the axial center direction of the PTO shaft 20, and are arranged in parallel above the PTO shaft 20. Sliding parts of a front fork 30 and a rear fork 31 whose lower ends are fitted in grooves provided in the front sleeve 26 and the rear sleeve 27 are slidably fitted to the shift rail 29. Has been done.

As shown in FIGS. 1 and 2, both forks 30, 31 are shown.
And a double operation shaft 34 that is arranged in a direction orthogonal to the speed change direction (sliding direction) of both forks 30 and 31 and that includes an inner shaft 32 and a pipe-shaped outer shaft 33 that is fitted onto the inner shaft 32. Both arms 35 and 36, which are individually fixed to the inner side portions (side end portions) of the double shaft, are double arms each having an inner shaft 37 and a pipe-shaped outer shaft 39 which is fitted on the inner shaft 37 along the shifting direction. The forks 30 and 31 are individually pivotally connected by a rod 40, and the forks 30 and 31 are slid to the shift positions separately by a selection operation of a shift lever 41 provided on the double operation shaft 34 protruding to the outside of the transmission case 13. Is configured to.

That is, above the rear fork 31, the connecting member 37a fixed downward to the rear end (the other end side) of the inner shaft 37 is pivotally connected by the connecting pin 43, and the front end of the outer shaft 39 (one end side)
The connecting member 39b fixed to the inner end of the double operation shaft 34 is pivotally connected to the lower end of the arm 35 fixed to the shaft end of the inner shaft 32 by a connecting pin 45, and the connecting member 37b fixed to the front end of the inner shaft 37. Is
The lower end of an arm 36 fixed to the shaft end of the outer shaft 33 of the double operation shaft 34 is pivotally connected by a connecting pin 46.

The arms 35, 36 are hung at a predetermined interval, and the pair of arms 35, 36 are opposed to the connecting members 37b, 39b integrally provided at the front ends of the inner shaft 37 and the outer shaft 39 of the double rod 40. It is arranged. The double rod 40 and the shift rail 29 are arranged in parallel in a plan view. Further, the pair of arms 35, 36 and the connecting members 39b, 37b are pivotally connected by the horizontal connecting pins 45, 46 orthogonal to the double rod 40, while the inner shaft 37 and the outer shaft 39 of the double rod 40 are connected. The connecting members 37a, 39a integrally provided at the ends and the front and rear forks 30, 31 are pivotally connected by connecting pins 43, 44 in the horizontal direction orthogonal to the double rod 40.

As shown in FIG. 3, the dual operation shaft 34 is rotatably supported by a bearing case 47 fixed to the right outer wall of the transmission case 13, and is rotatably fitted in the inner shaft 32.
A gear shift lever 41 is provided in 49 so as to be swingable in the left-right direction about a fulcrum shaft 51, and the gear shift lever 41 engages and disengages with a boss 52 fixed to the outer shaft end of the outer shaft 33. An interlocking arm 53 having a groove is fixed, and an interlocking arm 55 having a groove with which the shift lever 41 engages and disengages is fixed to a boss 54 fixed to an outer shaft end of the inner shaft 32.

The inner shaft 32 and the outer shaft 33 that form the double operation shaft are relatively rotatably fitted. Therefore, when the speed change lever 41 is tilted from the neutral position to the right side in FIG. 3 around the fulcrum shaft 51, it engages with the groove of the interlocking arm 53 and interlocks with the outer shaft 33. By swinging backward, the arm 36 fixed to the outer shaft 33 moves in the front-rear direction (shift direction), and the rear fork 31 is moved to a predetermined shift position via the inner shaft 37 connected to the arm 36. You can shift.

Further, when the speed change lever 41 is tilted to the left side in FIG. 3 from the neutral position about the fulcrum shaft 51, it engages with the groove of the interlocking arm 55 and interlocks with the inner shaft 32. By swinging backward, the arm 35 fixed to the inner shaft 32 moves in the front-rear direction (shift direction), and the front fork 30 is shifted to a predetermined shift position via the outer shaft 39 connected to the arm 35. it can.

In this case, the linking holes of the arms 35 and 36 are made to have a flexible mechanism including elongated holes extending in the up-and-down direction, so that one side of the double rod 40 moves to the shift position and the neutral position. The side interlocking with the other arm can always be kept concentric.

Even if another member such as a diff lock foam 56 that locks the differential device of the rear wheel drive mechanism 17 is arranged in front of the PTO shaft speed change mechanism 19, it does not interfere with the other member 56 and is small. By using the double rod 40 that linearly overlaps in space, both forks 30, 31 are rotated around the axis of the bearing case 47 which is provided at a distance in front of the transmission case 13 as shown in FIG. Each arm 35,3 of the moving double operating shaft 34
6 to the driver seat 6 from the dual operating shaft 34
5 can be operably connected to a shift lever 41 extending in the vicinity of the shift lever 29, but the double rod 40 does not necessarily have to be provided in a state in which both directions in plan view and side view are parallel to the shift rail 29. Can be provided in a non-parallel state in the side view direction, that is, in the vertical direction as long as the parallel state is maintained only in the plan view direction. The operation lever 41 can be provided at any position where it can be easily operated from the driver's seat 65 in a position avoiding members, and the position selection of the dual operation shaft 34 that changes according to the configuration and size of the aircraft becomes extremely easy. Therefore, the degree of freedom in selecting the position can be increased.

As shown in FIG. 4, the PTO shaft drive shaft 22 is a PTO shaft transmission mechanism.
A PTO shaft drive shaft 22a disposed on the front side by a shaft joint 57 at a lower portion of the rear wheel drive mechanism 17 installed in front of 19
Is spline-connected, and the shaft joint 57 is positioned by a fixing member 60 attached using a hole for supporting a ball bearing 59 opened on a side wall in the transmission case 13, and these linear joints are linear to each other. The positioning structure of the shaft joint 57 provided to connect the shafts facing each other in the shape of
It may be configured as shown in the figure.

That is, as shown in FIG. 7B, the contracted inner diameter of the C-shaped ring 62 made of spring steel shown in FIG. 7C is arranged along the circumference at the end of the spline provided at the front of the PTO shaft drive shaft 22. A groove 61 having a depth for accommodating is engraved, and a groove having a depth capable of accommodating the expanded outer diameter of the C-shaped ring 62 on the inner periphery near the end face of the shaft joint 57.
63 is engraved. When positioning the shaft joint 57 on the PTO shaft drive shaft 22, the C-shaped ring 62 is housed in the groove 63 of the shaft joint 57 in a contracted state, and then the PTO shaft drive shaft 22 is accommodated as shown in FIG. 7B. When inserted into the spline part and pushed in, the C-shaped ring 62 expands in the groove 63 and slides down the outer diameter of the spline part to drop into the groove 61 at the position where it reaches the groove 61, and at the same time, the shaft joint 57 drives the PTO shaft. Positioned on shaft 22.

By positioning the shaft joint 57 with the elastic C-shaped ring 62 in this way, flexibility is given to the positioning of the shaft joint 57, so that insertion and extraction of the PTO shaft drive shaft 22a performed from the opposite side can be easily performed. Although it can be performed, by setting the relationship between the outer diameter d of the shaft joint 57 and the outer diameter D of the PTO shaft drive shaft 22 fitted to the inner diameter of the ball bearing 59 as outer diameter d <outer diameter D, It is possible to insert the shaft joint 57 through the inner diameter of the ball bearing 59 together with the PTO shaft speed change mechanism 19 from the PTO shaft speed change mechanism side 19 side or pull it out to the PTO shaft speed change mechanism 19 side. Assembling and disassembling can be easily performed without dropping into the case 13.

[Effect of device]

The present invention configured as described above has the following excellent effects.

(1). The dual operation shaft 34 and the front and rear forks 30, 31 slidably mounted along the shift rail 29 are perpendicular to the dual operation shaft 34 and parallel to the shift rail 29 in a plan view. In connecting with the heavy rod 40, connecting members 37b, 39b, 37a, 39a integrally provided at one end and the other end of the inner shaft 37 and the outer shaft 39 that form the double rod 40 are respectively provided at one end. Double operating axis 34
A pair of arms 3 suspended from the side ends of the inner and outer shafts 32 and 33
5,36 pivotally connected via horizontal connecting pins 45,46,
Since the other end is pivotally connected to the front and rear forks 30 and 31 via horizontal connecting pins 44 and 43, respectively, the double rod 40 is connected to one end while the structure is simple. Since it can be reliably supported with the other end, it is a double rod.
It is possible to eliminate the need for a bearing portion for supporting.

(2). Further, even with the double rod 40 pivotally connected in the direction orthogonal to the double operation shaft 34, the pair of arms 35 and 36 of the double operation shaft 34 and one end of the double rod 40 are integrally formed. The connecting members 39b, 37b provided and the connecting members 39a, 37a integrally provided at the other end of the double rod 40 and the front and rear forks 30, 31 are both horizontal connecting pins 39b, 37b. , 39a, 37a, it is possible not only to arrange the double rod 40 in an inclined state in side view, but also to rotate the inner shaft 32 or the outer shaft 33 of the double operation shaft 34. The vertical movement of the arm 35 or the arm 36 due to the movement can be easily released by the pivotal connecting portion by, for example, a long hole.

(3). Moreover, a double rod in which the outer shaft 39 is fitted to the inner shaft 37
Because of the 40 configuration, inner shaft 37 or outer shaft 39 during operation
Of the double rod 40 by minimizing the thickness of the inner shaft 37 and the outer shaft 39.
The outer diameter of the double rod 40 can be further reduced to reduce the arrangement space, and the pair of arms 35 and 36 and the forks 30 and 31 provided at the side end portions of the double operation shaft 34 can be installed in the double rod 40. The shifter operation is linked to the shifter because it has a configuration in which it is pivotally connected by the horizontal connecting pins 45, 46, 43, 44 via the connecting members 39b, 37b, 39a, 37a between the one end and the other end. Compared to the conventional type in which the combined operating rod is used, the degree of freedom in design of the arrangement of the double operating shaft 34 and the arrangement of the double rod 40 is increased in combination with the fact that the bearing portion is unnecessary. You can

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an exploded perspective view showing the relationship between a double rod and a double operating shaft, and FIG. 2 is an enlarged transmission case in which gears are omitted and only essential parts are shown. Longitudinal sectional view, FIG. 3 is a sectional view taken along the line AA of FIG. 2, 4
Fig. 5 is a vertical cross-sectional view of the PTO shaft transmission, Fig. 5 is a power transmission system diagram of the tractor showing the entire transmission case, and Fig. 6 is a power transmission system diagram showing the ultra-low speed and front wheel drive power take-out gear trains in a plane deployment. FIG. 7 shows another example of the shaft coupling, and FIG. 7A is a longitudinal sectional view showing a state after the connection is completed.
FIG. B is an operation explanatory view, FIG. 7C is a plan view of a C-shaped ring, FIG. 8 is a schematic side view of a tractor showing only essential parts, and FIG. 9 is an exploded perspective view showing a conventional example. 13 …… Transmission case, 19 …… PTO shaft speed change mechanism, 29 …… Shift rail, 30 …… Front fork, 31…
… Rear fork, 32 …… inner shaft, 33 …… outer shaft, 34 …… double operation shaft, 35 …… arm, 36 …… arm, 37 …… inner shaft,
37a, 37b, 39a, 39b ...... Connection member, 39 ...... Outer shaft, 40 ...... Double rod, 41 ...... Shift lever, 43, 44, 45, 46 ...... Connection pin

Claims (1)

[Scope of utility model registration request] 1. A transmission device in which front and rear forks 30, 31 slidably mounted along a shift rail 29 are engaged with and disengaged from a transmission mechanism, and are parallel to the shift rail 29 in a plan view. Is provided with a double rod 40 in which an inner shaft 37 and an outer shaft 39 are slidably fitted to each other, and an inner shaft 32 and an outer shaft 33 are relatively rotatable in a direction orthogonal to the double rod 40. A double operation shaft 34 fitted to the inner shaft 32 and an outer shaft of the double operation shaft 34.
33 and 33 are configured to rotate independently by a selective switching operation of the shift lever 41, and are respectively attached to the side ends of the inner shaft 32 and the outer shaft 33 of the dual operation shaft 34 at predetermined intervals. A pair of arms 35 and 36 are arranged, and the pair of arms 3
Connection members 37b and 39b integrally provided at the one ends of the inner shaft 37 and the outer shaft 39 of the double rod 40 are arranged so as to oppose to each other at 5, 36, and the pair of arms 35, 36 and the connection member 39b are arranged. , 37b are pivotally connected by connecting pins 45, 46 in the horizontal direction orthogonal to the double rod 40, while connecting members integrally provided on the other ends of the inner shaft 37 and the outer shaft 39 of the double rod 40, respectively. 37a, 39a and the front and rear forks 30, 31 are pivotally connected by horizontal connecting pins 43, 44 orthogonal to the double rod 40.