JP2550931Y2 - Operation structure for working vehicle traveling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a work vehicle equipped with a continuously variable transmission mechanism for traveling and a forward / reverse switching mechanism in which a state in which a minimum speed is zero or close to the minimum speed appears. The present invention relates to an operation structure for traveling.

[Conventional technology]

This type of operation structure is a convenient one that can be switched between forward and reverse with an arbitrary running speed selected by separately providing the shift lever of the continuously variable transmission mechanism and the switching lever of the forward / reverse switching mechanism. It is. That is, there is no need to set the continuously variable transmission mechanism to the lowest speed state during the forward / backward switching operation, so that there is an advantage that the original forward speed can be maintained even if the vehicle is once switched from the reverse state to the forward state again.

[Problems to be solved by the invention]

However, when switching between forward and reverse while maintaining the traveling speed selected by the continuously variable transmission mechanism, if the selected speed is in a high speed state, the switching shock becomes large, damaging the transmission, or, for example, in a lawn tractor. There is a possibility that the driving wheels slip and the vegetation is damaged due to the switching. Therefore, it is common practice to shift back and forth between the forward and reverse when the continuously variable transmission mechanism is once shifted down to the low speed side or neutral, and then to switch back and forth. However, there was a case where the switching between forward and backward was performed inadvertently at a high speed.

SUMMARY OF THE INVENTION An object of the present invention is to realize a driving operation structure for a working vehicle that does not cause the above-described inconvenience.

[Means for solving the problem]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a traveling operation structure of a working vehicle including a traveling continuously variable transmission mechanism and a forward / reverse switching mechanism in which a state in which a minimum speed is zero or close to this appears. , With a single reciprocating shift lever,
A reciprocating mechanism for linking the speed change lever and the forward / reverse switching mechanism; and a reciprocating operation mechanism for switching the forward / reverse switching mechanism. To allow the relative position change operation of the shift lever in a range exceeding the switching operation range of the elastically deformable, and so that the shift lever is maintained at a predetermined relative position with respect to the operating member, A biasing mechanism that elastically returns and biases the shift lever, and a resistance to the relative movement between the operating member and the shift lever, such that the operating member and the shift lever move integrally within a switching operation range of the forward / reverse switching mechanism. And the operating member and the shift lever are provided in accordance with the application of an operating force by operating the shift lever to a region beyond a switching operation range of the forward / reverse switching mechanism. And a detent mechanism for removably linking the operation member and the shift lever so that resistance to relative movement with the shift lever is released. Irrespective of the shifting operation of the shift lever from the neutral position of the forward / reverse switching mechanism to any side of the forward / backward movement, they are interlockingly connected via a conversion unit that outputs a push / pull operation force under the same conditions. This is a technical measure.

[Action]

The effects of taking the above technical means are as follows.

When the continuously variable transmission mechanism and the forward / reverse switching mechanism are operated in conjunction with each other, the forward / backward switching is performed while the continuously variable transmission mechanism is on the low speed side as described above. It is desirable to keep the continuously variable transmission mechanism at the lowest speed.

Therefore, according to the above-described configuration, if the forward / reverse switching mechanism is switched by operating the shift lever, the continuously variable transmission mechanism is also shifted, but the continuously variable transmission mechanism is operated via the conversion unit. With this configuration, if the lowest speed state of the continuously variable transmission mechanism is set at a position where the forward / reverse switching mechanism is neutral, the continuously variable transmission mechanism is continuously variable even if the gearshift lever is operated in any of forward and backward directions from the neutral position. The speed increasing operation of the transmission mechanism can be performed.

Since the speed change lever and the forward / reverse switching mechanism are interlockingly connected via the flexible linking means, the ratio of the operation stroke required for the forward / reverse switching to the operation stroke of the speed change lever is reduced, so that the forward / reverse switching operation is performed. The state of the continuously variable transmission mechanism at the time point of the completion of the above-described operation can be changed to a state in which the speed is not increased as much as possible from the lowest speed state, and the vehicle can be started.

In addition, the forward / reverse switching operation is performed with a sense of moderation by the detent mechanism provided in the interchangeable linking means, and the presence of the detent mechanism allows the forward / reverse switching mechanism to be directly interlocked with the shift lever until the switching is completed. For example, as compared with a flexible linking means using only an elastic tool such as a spring, elastic deformation of the spring can be prevented from occurring until the forward / reverse switching is completed, and the rate of speed increase of the continuously variable transmission mechanism when the switching is completed is reduced. It becomes possible.

That is, in the present invention, since the detent mechanism is provided in the interchangeable linking means interposed in the operation system of the forward / reverse switching mechanism, the forward / backward switching mechanism can be directly operated by the shift lever until the switching is completed. , A compression spring is interposed in the operation system of the speed change lever and the forward / reverse switching mechanism, and the speed change lever is completed until the switching of the forward / reverse switching mechanism is completed, as compared with the operation of operating the forward / reverse switching mechanism via the compression spring. The operation stroke can be reliably performed even if the operation stroke is reduced without wasting the operation stroke. The ratio of the required operation stroke is reduced, and the speed of the continuously variable transmission mechanism is largely changed at the timing when the switching operation of the forward / reverse switching mechanism is completed. The thing that enables a speed increase of.

[Effect of the Invention] Accordingly, the stepless speed change mechanism and the forward / reverse switching mechanism can be operated by a single shift lever, and forward / backward switching can be reliably performed in a low speed range, and the speed is as close as possible to the lowest possible speed. It is possible to provide a traveling operation structure of a working vehicle that is convenient and can be easily operated by a beginner, in which a smooth start of the aircraft in a state is always expected.

〔Example〕

Hereinafter, a case in which the operation structure for traveling of a work vehicle according to the present invention is mounted on a lawn tractor will be described.

In FIG. 5, an airframe (3) equipped with a longitudinal axis type engine (1) at the front, a control unit (2) at the center, and a transmission (A) at the rear is attached to the front and rear wheels (4). ) And (5) show a lawn tractor which is configured to be able to run and has a mower (6) suspended from the lower abdomen of the fuselage. The transmission (A) and the mower (6) are both belt transmission mechanisms (7),
(8) is configured to input the power of the engine (1).

 Next, the transmission (A) will be described.

As shown in FIGS. 2 and 3, the transmission (A) is a power input unit (B) for inputting the power of the engine (1) by a belt transmission mechanism (7), and continuously changes the input power. Friction-type continuously variable transmission mechanism (hereinafter abbreviated as CVT) (C), forward / reverse switching mechanism (D) capable of switching the direction of rotation of traveling power after passing through CVT (C), differential mechanism (E), etc. It is provided with.

The power input unit (B) is configured such that a vertical axis (10) having an input pulley (9) and an input rotary body (11) of a CVT (C) described later are linked with a bevel gear, and the input rotary body is provided. The shaft (12) of (11) is extended and protrudes out of the transmission case (13) to constitute a PTO shaft (F).

CVT (C) is connected to the output shaft (1) around the output shaft (14).
A plurality of rotatable taper cones (15) revolving around the axis of the output shaft (14) by an input rotating body (11) arranged concentrically with 4) are provided. ) Is attached to the output shaft (14), and a transmission member (17) that can shift in the axial direction over the tapered cone (15) is provided. Have been. The tapered cone (15) comes into pressure contact with the output rotary body (16) pressed and urged by the cam mechanism (18), receives the reaction force of the output rotary body (16) by the disk-shaped cone support (19), and simultaneously receives the input rotary body ( The carrier (2) is formed by an outer frame (20) attached to the outer frame (11) and an inner frame (21) connected to the outer frame (20).
2) is formed, and the tapered cone (15) is rotatably supported via a support shaft (23).

The forward / reverse switching mechanism (D) includes the output shaft (14) and an intermediate shaft (25) having a brake device (24) at one end. That is, the forward and reverse rotation directions are changed by the drive gear (26) and the drive sprocket (27) of the output shaft (14), the driven gear (28) and the driven sprocket (29) of the intermediate shaft (25), and the chain (30). The rotation direction of the intermediate shaft (25) is selected using the shift rotating tool (31). The CVT (C) has a structure having a deceleration mechanism that performs a planetary motion, and is configured to have a zero speed at which the rotation of the output rotating body (16) stops in the lowest speed state. The speed change member (17) is shifted by the turning operation of (1) to change the speed.
On the other hand, the forward / reverse switching mechanism (D) has a structure in which the switching is performed by rotating the switching shaft (33) of the shift rotating tool (31).

Next, an operation system of the CVT (C) and the forward / reverse switching mechanism (D) will be described.

As shown in FIG. 1, a reciprocating swing operation type shift lever (34) is provided, and the shift lever (34) and the switching shaft (33) of the forward / reverse switching mechanism (D) are connected to an urging mechanism (39). ) And a detent mechanism (35), which are interlockingly connected via a flexible linking means (G), so that the shift lever (34) can be oscillated in the operation direction even after the forward / reverse switching operation is completed. At the same time, regardless of the operation of moving the shift lever (34) from the neutral position to the forward or backward direction from the neutral position to the forward / reverse switching mechanism (D), the conversion means (H) outputs the push / pull operation force under the same conditions. The speed change lever (34) and the speed change shaft (32) of the CVT (C) are linked to each other.

The urging mechanism (39) of the interchangeable linking means (G) includes an operating member (37) including a connecting rod integrally connected to a reciprocating switching rod (36) for switching the forward / reverse switching mechanism (D). ), A U-shaped receiving plate (38) is attached, and two compression springs are fitted into the connecting member (37) in the receiving plate (38). In other words, the compression spring allows the relative position changing operation of the shift lever (34) in a range exceeding the switching operation range of the forward / reverse switching mechanism (D) by elastic deformation, and allows the operating member (37) to operate. On the other hand, an urging mechanism (39) is configured to elastically return and urge the shift lever (34) so that the shift lever (34) is maintained at a predetermined relative position.

The detent mechanism (35) of the interchangeable linking means (G) is interposed between two compression springs constituting the urging mechanism (39). That is, the ball (41) is biased and sealed by the spring (42) into the cylindrical member (40) through which the operating member (37) formed of the connecting rod penetrates, and the operating member (37) is engaged with the ball (41). Grooves (43) are formed. In addition, cylindrical member (40)
Is pivotally connected to the shift lever (34) and is connected to the shift lever (34).
The operating member (37) and the shift lever (34) are integrally moved within a switching operation range of the forward / reverse switching mechanism (D). As a result, a resistance is given to the relative movement between the two, and the operation force of the shift lever (34) is applied to a region beyond the switching operation range of the forward / reverse switching mechanism (D). The operation member (37) and the speed change lever (34) are configured to be removably linked so that the resistance to the relative movement between the operation member (37) and the speed change lever (34) is released. It is.

The link between the shift lever (34) and the CVT (C) is performed as follows.

A cam plate (45) in which a V-shaped guide groove (44) is formed is fixed to a swing fulcrum (P) portion of the shift lever (34).
A transmission rod (46) interlocked with the transmission shaft (32) of the CVT (C) is engaged in the guide groove (44) to convert the conversion means (H).
Is composed. (47) is a support guide for restricting lateral movement of the speed change rod (46) at the cam plate (45).

To explain the operation, when the shift lever (34) is in the neutral position (N), the forward / reverse switching mechanism (D) is in the neutral state, and the CVT (C) is in the lowest speed state (zero speed). The guide end (46a) of the rod (46) with roller (46a)
Is located at the vertex of. (Solid line in FIG. 1) When the shift lever (34) is swung to the forward side, the forward switching of the forward / reverse switching mechanism (D) is completed at the forward position (F), but up to this point, the forward side compression spring ( The detent mechanism (35) is maintained in the engaged state against 39), and the shift lever (34) and the connecting rod (37) move integrally and interlockedly.
Further, the transmission rod (46) is pulled by the upper groove (44a) to slightly shift the CVT (C) to the speed increasing side.

When the shift lever (34) is still swung toward the forward side, the switching shaft (33) does not rotate.
6) also stops moving, but when the detent mechanism (35) of the accommodating mechanism (G) reaches the separated state, the forward side compression spring (39) is moved forward and backward by the urging force caused by the compression deformation (D). The shift lever (34) can continue to swing while the reverse compression spring (39) is allowed to extend while maintaining the switching state of (1), and the CVT (C) is moved to the maximum forward position (FMAX). ) (See phantom lines in FIG. 1).

Similarly, when the shift lever (34) is operated in the reverse direction,
Flexible linking means (G) and conversion means (H) operate.

FIG. 4 shows a shift state diagram according to this embodiment for reference.

(Another embodiment)

 The traveling operation structure of the working vehicle described below may be used.

The shift lever (34) moves in parallel.

A device in which the urging mechanism of the flexible linking means (G) is exposed by a rubber cushion.

The conversion means (H) is configured using a wire urged in one direction.

The continuously variable transmission mechanism (C) is of a hydrostatic type using a pump and a motor.

Apply the present invention to the binder.

Note that, in the claims of the utility model registration, reference numerals are written for convenience of comparison with the drawings, but the present invention is not limited to the structure of the attached drawings by the entry.

[Brief description of the drawings]

The drawings show an embodiment of the operating structure for traveling of a work vehicle according to the present invention, FIG. 1 is a diagram showing a main part of the structure, FIG. 2 is an exploded sectional view of the transmission, and FIG. FIG. 4 is a side view of the lawn tractor, and FIG. 4 is a side view of the lawn tractor. (32) Speed change shaft, (34) Speed change lever, (35)
Detent mechanism, (37) operating member, (39) urging mechanism, (C) continuously variable transmission mechanism, (D) forward / reverse switching mechanism, (G) flexible interlocking means, ( H) Conversion means.

Claims (1)

(57) [Scope of request for utility model registration] A traveling operation structure for a working vehicle, comprising a continuously variable transmission mechanism (C) for traveling and a forward / reverse switching mechanism (D) in which a state in which the minimum speed is zero or close to it appears. A single reciprocating shift lever (34) is provided, and a flexible linking means (G) for linking the shift lever (34) with the forward / reverse switching mechanism (D) is provided; The means (G) includes the forward / reverse switching mechanism (D).
For the reciprocating operation type operation member (37) that switches the
An operation for changing the relative position of the speed change lever (34) in a range exceeding a switching operation range of the forward / reverse switching mechanism (D) is permitted by elastic deformation, and the speed change lever (34) is moved relative to the operation member (37). ) Is maintained at a predetermined relative position, and a biasing mechanism (39) for elastically returning and biasing the shift lever (34) and a switching operation of the forward / reverse switching mechanism (D). Within the range, the operating member (37)
And the shift lever (34) so as to integrally move the shift lever and the shift lever (34), and provide the shift lever (34) to a region beyond a switching operation range of the forward / reverse switching mechanism (D). The operation member (37) is released such that the resistance to the relative movement between the operation member (37) and the shift lever (34) is released with the addition of the operation force by the operation of (1).
And a detent mechanism (35) for engaging and disengaging the transmission lever (34). The transmission lever (34) and the transmission shaft (32) of the continuously variable transmission mechanism (C). The conversion means (H) for outputting the push-pull operation force under the same condition regardless of the operation of moving the shift lever (34) from the neutral position of the forward / reverse switching mechanism (D) to any side of forward / backward travel. Operational structure for traveling of a work vehicle that is interlocked and connected via the