JPH0478726A - Lever restraint structure of gear shift operation part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an operation lever restraining structure for biasing a shift operation lever having an H-type shift operation path or the like to a neutral position. is provided with an operating shaft that allows one of a plurality of shift forks to be selected by rotating around the axis and to shift the selected shift fork by sliding in the axial direction, and an operating shaft formed at the lower end. Relating to a lever restraining structure for a speed change operation section, wherein a speed change operation lever is spherically supported at an upper position of the speed change operation section, and a tip of a protrusion erected from the operation shaft and the action section are engaged in an interlocking state. .

[Conventional technology]

Conventionally, this type of lever restraint structure of the gear shift operation part is
The one shown in the figure is known. In other words, two shift forks (21), (see 23X Figure 3), and an operating shaft (1
7), operation levers (20) each having an operating portion (20a) at the lower end that is ball-fitted with the protrusion (17a) of the operation shaft (17) are provided to constitute a speed change operation section; 2
0) is shifted along an H-shaped operating path (W) as shown in FIG.

In order to prevent an unexpected shift operation of the operating lever (20), the operating path (13) is placed in a neutral position that is oriented sideways.
The operating lever (20) is biased to return to the intermediate portion thereof, and the biasing force is generated by a trapezoidal coil spring (27).

[Problem to be solved by the invention]

Normally, a vertical transmission shift path (14) shown in FIG.
(15) is equipped with a detent mechanism (not shown) in order to maintain the operating lever (20) in the shift engaged state, and the operating lever is placed in a position where the action of the detent mechanism does not work, that is, in the neutral position (N). (20) is manually moved to release the gear shift, and the operating lever (20) automatically returns to the intermediate portion (Nc) of the neutral operating path (13) by the action of the trapezoidal coil spring (27).

However, due to the nature of the trapezoidal coil spring, its bias return force, or restoring force, acts to increase not only by the neutral operation path (13) but also by the shift operation on the transmission shift paths (14) and (15). As a result, the gear shift operation tends to become heavier due to the restoring force, and since the restoring force reaches its maximum at the gear shift position, the holding force of the detent mechanism has to be strong as well. The shift operation was heavy and tiring, which had a negative impact on the operating feel, so there was still room for improvement.

An object of the present invention is to solve the above-mentioned disadvantages by devising a structure that focuses on the linkage structure between the operating lever and the operating shaft.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a lever restraining structure for a speed change operating section described at the beginning, in which each of the operating shafts near the operating section and the protrusion is arranged so as to be orthogonal to the axis and horizontally. A restoring mechanism is constructed by fixing protrusions extending in different directions so as to face the same direction, and constructing an elastic body across both protrusions, and connecting the elastic bodies in both protrusions. A feature of the present invention is that the restoring mechanism is provided to bias the opposing distance between the parts back to a set value.

[For production]

To explain using FIGS. 1 to 4, the operation shaft (17)
The sliding movement of the operating shaft (17) is performed when the operating lever (20) performs a shift operation on the transmission shift paths (14) and (15), and the rotational movement of the operating shaft (17) is performed using the operating lever (20).
This is performed in conjunction with the swinging operation on the neutral operation path (13).

According to the configuration, the restoring mechanism (B
) are projecting pieces (C) extending from the operating shaft (17) and the action portion (20a) in a direction perpendicular to the axis of the operating shaft (17) and facing sideways; an elastic body (10),
(10) is constructed to connect the operating part (20a) and the operating shaft (17).
), that is, the operation lever (20) and the operation shaft (17) are restored to a predetermined relative posture. ) so that the control lever (20) is in the center position (Nc).
As before, a diversion mechanism that always positions the neutral operating path (13) at the center of the neutral operating path (13) occurs.

Then, when the operating lever (20) is moved along the gear shift path (14 or 15) to shift the gear, the operating shaft (17) slides. , (C) are almost parallel to each other and move in the same direction, so both protruding pieces (C), (C
) The facing distance (L) between the connecting portions (11) and (12) of the elastic body (10) remains almost unchanged, and the operation in the transmission shift paths (14) and (15) as in the conventional method is not possible. This effectively eliminates the phenomenon in which the restoring force is further strengthened by the shift operation of shifting the lever (20).

In other words, the restoring force acting on the operating lever (20) acts only in the longitudinal direction of the neutral operating path (13) and does not occur in the longitudinal direction of the gear shift paths (14) and (15). Compared to the conventional technology, the force required for gear shift operation can be reduced, and the operating force of the detent mechanism that maintains the gear shift position can also be reduced.

〔Effect of the invention〕

Therefore, even if the lever cannot be restrained from shifting easily even if the lever is accidentally moved, such as by accidentally touching the lever when getting on or off the control section, it is possible to shift lightly. In addition, it has been possible to provide a lever restraining structure for the gear shift operation part, which has a great practical advantage of improving the operational feeling.

Furthermore, the restoring mechanism, which is a means for this purpose, can be constructed with a relatively simple structure by utilizing the structure of the speed change operation section.

〔Example〕

In the following, a case will be described in which the lever check structure of the speed change operation section of the present invention is applied to the main speed change mechanism of a tractor.

Figure 6 shows a tractor, which connects the engine (1), clutch housing (2), intermediate transmission case (3), and transmission case (4) in this order from the front to the rear of the machine. The driver's seat (5) is located above the transmission case (4), and the hydraulic lift arm (6) for raising and lowering the work equipment and the work equipment drive are located at the rear of the mission case (4). A PTO shaft (7) for use is provided.

A main transmission mechanism (A) for the traveling system and a PT○ transmission mechanism (not shown) are installed in the transmission chamber in the clutch housing (2).Next, the transmission operation in the main transmission mechanism (A) is Explain the structure of the section.

As shown in FIG. 5, the first shift fork (21) engaged with the first shift gear (not shown) of the main transmission mechanism (A)
The support shaft (22) of the second shift fork (23) engaged with the second shift gear (not shown) and the support shaft (24) of the second shift fork (23) are connected to the bearing front wall of the clutch housing (2) and the rear end of the clutch housing. Each shift fork (21), (2
3) the engagement recesses (21a) and (23a) formed at the base of the
) with an operating arm (16) that selectively engages with the operating shaft (
17) is attached to a bracket (18) attached to the left outer surface of the clutch housing (2) so that it can slide back and forth and rotate. As shown in Figure 3, this operating shaft (17) is extended to the rear of the aircraft and is attached to the left side of the mission case (4) via a ball fulcrum (19) so that it can swing forward, backward, left, and right. The two protrusions (17a) attached to the rear end of the operating shaft (17) are engaged with the lower end cylindrical part (20a), which is the operating part of the main shift operating lever (20), so that the main shift lever (20) By rotating the operating shaft (17) by the left and right rocking of the
21) or (23) and push or pull the operating shaft (17) back and forth by swinging the main shift lever (20) back and forth to shift the selected shift fork (21) or (23) back and forth. It is configured. By the way, do you not show the diagram?
The shift forks (21) and (23) have their support shafts (22) on the rear walls of their bearings.

(24) A check ball that prevents simultaneous gear shifting operations and prevents double engagement, and a gear shift detent mechanism that maintains the gear shifting state are incorporated. The reason there are two protrusions (17a) is to prevent the lever (20) from rotating.

As shown in FIGS. 1 and 2, the lower end cylinder part (20a)
The tongue pieces (8), (8) are fixed to the left and right sides of the holder, and a mounting plate (9) extending left and right is fixed to the lower surface of the operating shaft (17) of the protrusion (17a). Board (9
) and the left and right tongue pieces (8), (8), respectively, with tension springs (10), (10) installed to constitute the restoring mechanism (B).

This restoring mechanism (B) includes upper and lower connecting portions (11) in each spring (10), (10) in a free state.

(12) so that the facing distance (L) between them is equal, and each spring (
10) and (10) are set to be the same, and at this time, the operating lever (20) in the neutral position (N)
is the neutral operation path (W) in the H-type operation path (W).
13) is at the center position (Nc).

When the operating lever (20) is swung from the center position (Nc) to the right gear shift path (14), the right spring (
10) is compressed, but the left spring (10) is stretched,
A difference occurs between these tensile forces, and a restoring force is generated that tries to return to the free state. The same is true even if the operating lever (20) is swung to the left speed change shift path (15).

By the way, as shown in FIG. 3, the upper and lower connecting parts (11) and (12) of the spring (10) are at the same position in the axial direction of the operating shaft (17), so the operating shaft (
17), that is, even if the operating lever (20) is operated to shift the gear, the upper and lower connecting portions (11), (12)
) there is almost no change in the facing distance. (
(It is possible to make the change zero by properly aligning the upper connecting part (11) with the center position of the spherical part at the upper end of the protrusion (17a). 2 springs (10) when in.

(10) The inner guide edge (
14a or 15a), but the operation lever (20) is returned to the neutral position (N) in this gear shift path (14 or 15). There is no force to do so.

[Another example]

As shown in FIG. 7, a bidirectional spring (25) having elasticity in both compression and tension directions from a free state is prepared,
A tongue piece (8) on one side and a mounting plate (26) that extends only on one side.
The restoring mechanism (B) may be constructed by installing the bidirectional spring (25) over the above.

In addition, there are three shift forks, and the operation path (W
), and in that case, when the restoring mechanism (B) is in the free state, the operation lever (20) or any adjacent transmission shift path (14),
It is sufficient to set the position to be an intermediate position in (15).

In the present invention, the tongue piece (8) and the mounting plates (9), (26) are collectively called the projecting piece (C), and the tension spring (lO), bidirectional spring (25), etc. are collectively called the elastic body (10). )
It is called.

It should be noted that the present invention is not limited to the structure shown in the accompanying drawings by adding reference numerals in the claims for convenient comparison with the drawings.

[Brief explanation of drawings]

The drawings show an embodiment of the lever restraining structure of the gear shift operation part according to the present invention, FIG. 1 is a diagram of the main parts of the structure during neutral operation, and FIG. 3 is a partially cutaway side view showing the entire gear shift operation section, FIG. 4 is a diagram showing the operating path, FIG. 5 is a sectional view showing the gear shift section, and FIG. 6 is a side view of the tractor. FIG. 7 is a main part view showing another embodiment of the lever check structure, and FIG. 8 is a side view of a shift operation section showing a conventional example. (10)...Elastic body, (11), (12)
...Connection part, (17) ...Operation axis, (1
7a)... Protrusion, (20)... Operation lever, (20a)... Acting part, (B)...
...Restoration mechanism, (C) ... protrusion.

Claims (1)

[Claims] an operating shaft (17) capable of selecting one of the plurality of shift forks by rotating around the axis and shifting the selected shift fork by sliding in the axial direction;
and a shift operation lever (20) supported spherically at a position above the action part (20a) formed at the lower end.
and a protrusion (17a) erected from the operating shaft (17).
) is a lever check structure for a speed change operating section in which a tip of the operating section (20a) is engaged in an interlocking manner with the operating section (20a), the operating shaft (20a) near the operating section (20a) and the protrusion (17a). 17), protrusions (C) and (C) extending in a direction perpendicular to the axis and laterally facing each other are fixed in a state facing the same direction, and both of these protrusions (C ), (C
) to constitute a restoring mechanism (B), and connecting portions (11), (12) of the elastic body (10) in both protrusions (C), (C). ) A lever check structure for a speed change operating section, wherein the restoring mechanism (B) is provided in a state where the opposing distance between the two is biased back to a set value.