KR20170083911A - Driving control apparatus of agriculture vehicle - Google Patents

Abstract

A traveling control device for a forward or backward traveling operation of a work vehicle equipped with a hydrostatic stepless transmission (HST) is disclosed. The traveling operation device according to the embodiment of the present invention allows the shifting operation force to be transmitted only to the forward speed change side when the forward pedal is operated and allows the forward shift pedal to be transmitted to the reverse shift side only when the reverse pedal is operated, This is to ensure that the inconvenience caused by the mutual linkage can be solved.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a traveling control apparatus for a work vehicle, and particularly to a traveling control apparatus for a work vehicle equipped with a hydrostatic continuously variable transmission (HST) for transmitting an engine output to a traveling apparatus, And a traveling operation device.

The agricultural work vehicle called 'Tractor' is structurally similar to a general automobile, but it is equipped with a powerful engine, so it is mainly used as a tractor with strong pulling force and strong, and for the purpose of cultivation, And has a structure in which various types of working machines can be selectively attached to or detached from the front or rear or both the front and rear sides.

In the agricultural work vehicle, the power for driving the working machine or the power for driving is generated from the engine, and the power generated by the engine is transmitted to the traveling wheel and / or the working machine after being shifted to a power suitable for traveling or work via the transmission . At this time, the engine speed can be adjusted by operating the accelerator installed around the driver's seat.

In order to facilitate the shifting operation and to facilitate the operation of the gas, a work vehicle employing a hydrostatic transmission (hereinafter referred to as 'HST') instead of a multistage transmission system of a general mechanical structure is well known. HST is mainly applied to a low-horsepower, low-cost, compact airframe.

The HST is composed of a variable capacity hydraulic pump that is directly connected to the engine output shaft and a constant capacity hydraulic motor that rotates by the pressure supplied from the hydraulic pump and outputs substantial driving power. The angle of the swash plate of the variable displacement hydraulic pump is adjusted So that the rotation speed (traveling speed) and the rotating direction (forward / backward switching) of the constant capacity hydraulic motor can be changed.

In the case of a HST type work vehicle, the output operation of the HST, that is, the continuously-variable shifting control related to the traveling speed and the traveling direction is performed by selectively operating the HST pedal of the stepped structure provided on the driver's footstool, Generally has a structure in which a forward pedal for a forward operation and a reverse pedal for a backward operation are interlocked with each other.

FIG. 1 is a plan view and a side view of a legged HST pedal link apparatus according to the related art, and FIG. 2 shows an operating state of the pedal link apparatus shown in FIG.

Referring to FIGS. 1 and 2, a conventional step-up HST pedal link device includes a stepped forward pedal 11 for a forward operation and a stepped backward pedal for a backward operation 21. The forward pedal 11 and the reverse pedal 21 are provided on a driver's seat footplate (usually provided on the right footboard side of the driver's seat steering unit) at a position where the driver can easily operate the vehicle.

A first sleeve 13 and a second sleeve 23 are rotatably and coaxially arranged on a fixed shaft 40 fixed to a vehicle body and are rotatably and coaxially arranged on a fixed shaft 40 fixed to a vehicle body, The forward pedal 11 and the reverse pedal 21 are connected to the first sleeve 13 and the second sleeve 23, respectively. The first and second actuating arms 19 and 29 are provided on the other side of the outer surface of the first and second sleeves 13 and 23, respectively.

A first connecting part 51 and a second connecting part 52 which are rotated about the rotating shaft 50 are provided on a rotating shaft 50 at a position spaced a predetermined distance forward of the first and second operating arms 19, And the first and second link members 31 and 32 are interlocked with each other between the first and second operation arms 19 and 29 and the first and second connection portions 51 and 52 .

The first connecting arm 12 connected to the forward pedal 11 is rotated downward about the axis of the fixed shaft 40 when the forward pedal 11 is depressed and the first connecting arm 12 is rotated through the first sleeve 13, The first link member 31 is pulled by the displacement of the first operating arm 19 and the first connecting portion 51 is rotated so that the rotating shaft 50 is rotated in one direction Clockwise in the drawing).

The second connecting portion 52 on the opposite side of the first connecting portion 51 is also rotated in the same direction with respect to the rotating shaft 50 by the unidirectional rotation of the rotating shaft 50, And the second sleeve 23 is rotated in the direction opposite to the first sleeve 13 so that the reverse pedal 21 is protruded upward.

Of course, although not specifically exemplified, in the case of operating the reverse pedal 21, the reverse pedal 21 moves toward the foot side on which the foot power acts, as in the case of the operation of the forward pedal 11 described above, The pedal 11 is moved in the opposite direction from the foot plate by the amount of displacement of the backward pedal 21.

In other words, in the related art, the forward pedal and the reverse pedal are interlocked with each other, so that the amount of displacement of the two pedals is the same, but the directions of operation are opposite to each other due to the stepping force inputted alternatively. As a result, there is a problem that when a pedal is touched, the pedal is injured by another pedal that is bouncing, or a dangerous situation occurs in which a foot is caught between the pedals during operation.

In addition, when one pedal is depressed, the other pedal relatively bounces up to a position higher than the original neutral position. Thus, when the pedal is moved forward or backward, There is a problem that the user is required to further lift the legs to operate the device, thereby causing inconvenience in the switching operation.

Korean Published Patent Application No. 2009-0080263 (published on July 24, 2009)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a driving control apparatus of a non-interlocked structure in which a forward pedal and a reverse pedal are not dependent on each other's movement.

As a means for solving the above problems,

An apparatus for forward / reverse shift operation of an HST (hydrostatic stepless speed changer)

A forward pedal link portion for transmitting a forward direction shift operation force inputted through a forward pedal, a reverse pedal link portion for transmitting a reverse direction shift operation force input through a reverse pedal, and a forward pedal link portion for transmitting forward forward pedal link portion And an output link portion interconnecting the interlocking switching portion and the HST so as to be interlocked with each other, wherein the interlocking switching portion interrupts intermittently transmission of the shifting operation force to the HST,

Wherein the interlocking switching unit includes a ratchet wheel that rotates about a pivot axis, a first pole (1 ^st Pawl) that rotates the ratchet wheel in a first direction by operation of the forward pedal link portion, ^And a second pole (2nd Pawl) for rotating the ratchet wheel in a second direction by operation of a backward pedal link portion.

In the present invention, the forward pedal link portion includes a forward pedal unit including a forward pedal and rotating about a pedal hinge, and a first connecting arm interlockably connecting an output side of the first pawl and the forward pedal unit .

The forward pedal unit includes a first sleeve rotatably mounted on the pedal hinge, a pedal arm connecting the first sleeve and the forward pedal, and a second sleeve extending from the first sleeve to the pedal arm at a predetermined angle Output arm.

The rear pedal link portion includes a forward pedal unit including a forward pedal and rotating about a pedal hinge, and a second connecting arm interlockably connecting an output side of the second pawl and the reverse pedal unit Lt; / RTI >

The rearward pedal unit includes a second sleeve rotatably mounted on the pedal hinge, a pedal arm connecting the second sleeve and the backward pedal, and a second sleeve extending from the second sleeve to the pedal arm at a predetermined angle Output arm.

Further, a circumferential surface of the ratchet wheel according to an embodiment of the present invention is formed with a second tooth row in which a first tooth row and a second pole row are engaged with each other, the first and second pawls being axially And the second pole arm is spaced apart from the corresponding row of teeth by a predetermined distance.

Preferably, the first toothed rows and the second toothed rows may be formed to have different axial and arcuate positions with respect to an axis passing through the rotation center of the ratchet wheel.

Further, the first and second pawls are provided with engaging pieces which are to be engaged with teeth on the surfaces facing to the respective tooth rows, and the engaging pieces are spaced apart from the hinge points (H1, H2) of the respective pawls by a predetermined distance, Force operation points P1 and P2 where a force for shifting operation is applied can be formed at positions which are spaced apart from the engaging pieces by a predetermined angle around the points H1 and H2.

An output rod that pivots about the pivot axis in response to rotation of the ratchet wheel in a first direction or a second direction may be integrally provided with the ratchet wheel.

The output link portion may include a first output link connected to the output side of the cooperative switching portion so as to be operatively connected to the input side, a third output link connected to the swash plate control lever of the HST by a cable or a link mechanism, And a second output link operatively connecting the output side of the first output link and the input side of the third output link.

According to the embodiment of the present invention, since the forward pedal and the reverse pedal are not interlocked, even if one pedal is depressed, the other pedal remains in its original position (neutral position) without moving. That is, the conventional problem that the pedal is injured by another pedal protruding when the pedal is depressed or the foot is caught between the pedals during operation can be clearly solved.

In addition, since the two pedals are not dependent on each other relative to each other, when the one pedal is depressed as in the prior art, the opposite pedal jumps above the original neutral position and is located at a higher position. It is possible to eliminate the operational inconvenience of lifting up, thereby making it possible to increase the convenience of operation and greatly reduce the operational fatigue.

1 is a plan view and a side view of a pedal link device for a conventional HST shift operation.
Fig. 2 is an operational state diagram of a pedal link according to the prior art shown in Fig. 1. Fig.
3 is a perspective view of a traveling control apparatus according to an embodiment of the present invention;
Fig. 4 is a plan view of the travel control device of Fig. 3; Fig.
Fig. 5 is a side view of the travel control device of Fig. 3; Fig.
FIG. 6 is an enlarged view of the essential portion of the present invention, showing an enlarged view of the interlocking switching portion of FIG. 5; FIG.
FIG. 7 is an enlarged view showing the arrangement and coupling relationship between the pole, the pole arm, and the ratchet wheel shown in FIG. 6; FIG.
Fig. 8 and Fig. 9 are operational states showing an operating state of the travel control apparatus according to the embodiment of the present invention; Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the present invention, the terminology used herein is used only to describe a specific embodiment and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly dictates otherwise.

It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, parts or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The first direction is defined as a rotation direction of the ratchet wheel (clockwise rotation with reference to the side view of FIG. 5) in the forward direction shift operation, and the second direction is defined as a rotation direction of the ratchet wheel (Counterclockwise rotation with reference to the side view of FIG. 5).

FIG. 3 is a perspective view of a traveling control apparatus according to an embodiment of the present invention, and FIG. 4 is a plan view of the traveling control apparatus of FIG. And Fig. 5 is a side view of the traveling operation device of Fig.

3 to 5, the traveling operation device according to the present invention is a traveling operation vehicle equipped with a hydrostatic transmission (Hydrostatic Transmission, hereinafter referred to as 'HST'), The forward pedal link portion FL, the reverse pedal link portion RL, the interlocking switching portion C, and the output link portion OL.

The pedal (forward pedal and reverse pedal) for the HST shift operation may be provided on the bottom of the driver's seat and the HST may be controlled by the forward pedal 61 or the reverse pedal 71, And the rotation speed is changed to output to the negative speed side. At this time, the HST may be a known configuration including a variable capacity hydraulic pump and a constant capacity hydraulic motor.

The angle of the swash plate of the variable displacement type hydraulic pump is adjusted by operating the traveling control device so that the rotation speed (traveling speed) and the rotating direction (forward / backward switching) of the constant capacity hydraulic motor can be changed. To this end, the output side of the output link part OL may be connected to the swash plate control lever of the variable displacement hydraulic pump through a cable wire or a link mechanism.

The configuration of the main part of the traveling control apparatus of the working vehicle according to the embodiment of the present invention will be described in detail.

First, look at the forward pedal link.

The forward pedal link portion FL includes a first connecting arm 66 connecting the forward pedal unit 60 and the forward pedal unit 60 to the interlocking switching portion C. [ The forward pedal unit 60 includes a forward pedal 61 to which forward shifting operation force is inputted and a first connecting arm 66 is connected to the first pole arm 84 of the interlocking switching unit C 1 pawl 80 and the output side of the forward pedal unit 60 in a linkable manner.

The forward direction shifting operation force is inputted to the forward pedal 61 of the forward pedal link portion FL by the driver and the forward direction shifting operation force is inputted to the forward pedal unit 60 and the first connecting arm 66 To the interlocking switching portion (C). Specifically, it is transmitted to the ratchet wheel 85 through the first pawl 80 of the cooperative switching portion C to rotate the ratchet wheel 85 in the first direction.

The forward pedal unit 60 is provided so as to rotate about a pedal hinge PH fixed on the gas side. Specifically, the advancing pedal unit 60 includes a forward pedal 61 and a first sleeve 63, a pedal arm 62, and an output arm 64. The first sleeve 63 is rotatably fitted to the pedal hinge PH and the pedal arm 62 connects the first sleeve 63 and the forward pedal 61.

One end of the pedal arm 62 and one end of the output arm 64 are attached to the outer surface of the first sleeve 63 so that the inclined angle between the two arms becomes a predetermined angle around the pedal hinge PH . The depressed angle between the pedal arm 62 and the output arm 64 may be an acute angle and the length of the pedal arm 62 and the output arm 64 is not limited to a specific value.

The first connecting arm 66 connects the first pawl 80 of the interlocking switching portion C described later and the output side of the forward pedal unit 60 in a linkable manner. Concretely, one end and the other end are hingedly connected to the distal end of the output arm 64 of the advancing pedal unit 60 and the force application point P1 of one side of the first pawl 80. Wherein the first pole 80 is disposed proximate to the periphery of the ratchet wheel 85 via a first pole arm 84 with the pivot axis PA as the center of rotation.

When the forward pedal 61 is operated, a predetermined force is exerted on the force application point P1 by the first connection arm 66, and the first pawl 80 is moved by the force to the outer surface of the ratchet wheel 85 Respectively. As a result, the ratchet wheel 85 and the first pole arm 84 are constrained to each other via the first pawl 80, so that the first and second pawl axes PA, The ratchet wheel 85 is also rotated in the same direction in the rotation of the pole arm 84. [

Next, look at the configuration of the rearward pedal link.

The reverse pedal link portion RL includes a second connecting arm 76 connecting the reverse pedal unit 70 and the reverse pedal unit 70 to the interlocking switching portion C, The rearward pedal unit 70 includes a reverse pedal 71 to which a rearward shift operation force is inputted and a second connecting arm 76 is connected to the second pole arm 86 supported by the second pole arm 86 of the interlocking switching portion C. 2 pawl 82 and the output side of the reverse pedal unit 70 are interlockingly connected.

The reverse direction shift operation force is inputted to the reverse pedal 71 of the reverse pedal link portion RL by the driver and the input reverse shift operation force is transmitted to the reverse pedal unit 70 and the second connection arm 76 To the interlocking switching portion (C). Specifically, the reverse direction shift operation force is transmitted to the ratchet wheel 85 via the second pawl 82 to rotate the ratchet wheel 85 in the second direction.

The reverse pedal unit 70 is provided to rotate about the pedal hinge PH fixed to the base side. Specifically, it is constituted by a reverse pedal 71 and a second sleeve 73, a pedal arm 72 and an output arm 74. The second sleeve 73 is coaxially disposed with the first sleeve 63 on the pedal hinge PH and rotates while the pedal arm 72 is moved between the second sleeve 73 and the reverse pedal 71 Connect.

One end of the pedal arm 72 and one end of the output arm 74 are fixedly attached to the outer surface of the second sleeve 73 so that the inclined angle between the two arms becomes a predetermined angle around the pedal hinge PH do. The depression angle between the pedal arm 72 and the output arm 74 may be an acute angle and the length of the pedal arm 72 and the output arm 74 is not limited to a specific value.

The second connecting arm 76 connects the second pole 82 of the interlocking switching portion C and the output side of the reverse pedal unit 70 in a linkable manner. Concretely, one end and the other end are hingedly connected to the distal end of the output arm 74 of the reverse pedal unit 70 and the force application point P2 of one side of the second pawl 82. Wherein the second pole 82 is disposed proximate the second pole arm 86 about the ratchet wheel 85 in a position opposite the first pole 80. [

When the reverse pedal 71 is operated, a predetermined force acts on the force application point P2 by the second connection arm 76, and the second pawl 82 is moved by the force to the outer surface of the ratchet wheel 85 Respectively. As a result, the ratchet wheel 85 and the second pole arm 86 are constrained to each other via the second pawl 82, The ratchet wheel 85 is also rotated in the same direction in the rotation of the pole arm 86. [

Let's look at the next output link section.

The output link unit OL finally outputs the shifting intention of the operator input through the forward pedal 61 or the reverse pedal 71 and transmits it to the HST side. To this end, the output link unit OL interlockably connects the interlocking switching unit C, which will be described later, and the HST. Preferably, the output side of the interlocking switching portion C and the input side of the link mechanism or cable extending from the swash plate control lever of the HST are interlockingly connected.

The output link portion OL is composed of three links of a rod-like structure, specifically, a first output link 90, a second output link 92, and a third output link 94. The output side of the third output link 94 is connected to the swash plate control lever of the HST by a cable or a link mechanism Lt; / RTI >

The input side opposite to the output side of the third output link 94 interlockably connected to the swash plate control lever side of the HST is relatively flexibly connected to the output side of the second output link 92, And the input side of the first output link 92 is relatively bendably connected to the output side of the first output link 90. That is, the second output link 92 serves as an intermediate medium for interlocking the first output link 90 and the third output link 94 together.

The hinge portion H3 at the approximate center of the second output link 92 can be rotatably engaged at the proper position of the frame so that the ratchet wheel 85 is rotated in the forward and reverse directions by the operation of the forward or reverse pedal 71 The second output link 92 rotates about the hinge portion while pulling or pushing the third output link 94 to perform forward and reverse shift and output control.

Although not shown in the drawings, the pedal hinge PH may be provided with one spring member corresponding to the forward pedal unit 60 and the reverse pedal unit 70, respectively. The spring member may preferably be a torsion spring, wherein the torsion spring provides resiliency to each of the forward pedal unit 60 and the backward pedal unit 70 so that they can be restored to their neutral position.

Next, the interlocking switching unit will be described with reference to FIG. 6 and FIG.

FIG. 6 is a view showing an interlocking switching portion, and FIG. 7 is an enlarged view showing the arrangement and coupling relationship between the pole, the pole arm and the ratchet wheel shown in FIG.

6 to 7, the interlocking switching portion C includes a ratchet wheel 85, and a ratchet wheel 85, which includes two pawls 80, (Ratchet) structure. The ratchet wheel 85 rotates around the pivot axis PA and the pawls are pivoted to the first pawl 1 ^st Pawl 80 and the backward pedal link portion RL interlocked with the forward pedal link portion FL ^And a second pole (2 ^nd Pawl, 82) interlocked with each other.

The first pawl 80 is supported by a first pole arm 84 pivoted about the pivot axis PA and is supported on the circumferential surface of the ratchet wheel 85 by operation of the forward pedal link portion FL The second pawl 82 is supported by the second pole arm 86 pivoting about the pivot axis PA and the second pawl 82 is supported by the backward pedal link RL, The ratchet wheel 85 is brought into close contact with the ratchet wheel 85 to rotate the ratchet wheel 85 in the second direction.

A first tooth array 850 is formed on a part of the circumferential surface of the ratchet wheel 85 to engage with the first pawl 80 to generate a frictional force and a second pole 82 is engaged with another portion of the circumferential surface And the second tooth row 852 is formed so that a frictional force is generated. An output rod 88 pivoting about the pivot axis PA is integrally provided with the ratchet wheel 85 in accordance with rotation of the ratchet wheel 85 in the first or second direction.

The first pawl 80 is connected to the ratchet wheel 85 so as to be spaced apart from the first tooth row 850 by a predetermined distance through a first pole arm 84 rotatably coupled to the pivot axis PA, And the second pole 82 is spaced a predetermined distance from the second tooth row 852 through the second pole arm 86 that is rotatably engaged with the pivot axis PA And is disposed close to the ratchet wheel 85 so as to be spaced apart.

The first toothed row 850 and the second toothed row 852 may be formed to have different axial and arcuate positions with respect to the axis A1 passing through the center of rotation of the ratchet wheel 85. In other words, the operating range of the first pole 80 and the second pole 82, and the first pole arm 84 and the second pole arm 86 supporting the first pole 80 and the second pole 82, And may be formed over a predetermined interval in an area where the arc position is different.

The engaging pieces 81 and 83 are formed on the surfaces of the first and second pawls 80 and 82 facing the teeth rows 850 and 852 so as to engage with the teeth. At this time, the latching pieces 81 and 83 are spaced apart from the hinge points H1 and H2 of the respective pawls by a predetermined distance, and are positioned at a predetermined angle with the latching pieces 81 and 83 around the hinge points H1 and H2 Force action points P1 and P2 on which a force for shifting operation is applied are formed.

The ends of the first and second connection arms 76 are hingedly connected to the first and second force application points P1 and P2, respectively. When the force acts on P1 or P2 through the first or second connecting arms 66 and 76, the engaging pieces 81 and 83 of the first pawl 80 or the second pawl 82 are engaged with the corresponding teeth So that the ratchet wheel 85 is constrained to the first or second pole arm 86 via the first pole 80 or the second pole 82 to rotate with the pole arm 86 .

For example, when a predetermined force is applied to P1 by the operation of the advancing pedal 61, the first pawl 80 rotates around H1 and rubs against the ratchet wheel 85 by this force, (85) is subjected to the rotation of the first pole arm (84) through the first pole (80). Accordingly, when the first pole arm 84 rotates about the pivot axis PA in the first direction by the force, the ratchet wheel 85 also rotates in the same direction (see FIG. 7).

A brief description will be made in connection with the operation of the traveling control apparatus with respect to the adjustment of the HST output implemented through the working vehicle traveling control apparatus having the above-described configuration.

FIG. 8 is an operating state view of the present invention when the forward shift operation is performed. FIG. 9 is a flowchart showing the operation of the present invention in the forward shift operation. Fig.

Referring to FIG. 8, when the forward pedal 61 is depressed, the force is transmitted to the first pole 80 through the forward pedal unit 60 and the first connecting arm 66. The first pole 80 rotates about H1 and rubs against the ratchet wheel 85 and the ratchet wheel 85 is constrained to the first pole arm 84 through the first pole 80. [ Accordingly, when the first pole arm 84 rotates about the pivot axis PA in the first direction by the force, the ratchet wheel 85 rotates together

As the ratchet wheel 85 rotates in the first direction together with the first pole arm 84, the output rod 88 also pivots in the same direction and the pendulum motion of the output rod 88 causes the output link 88 OL, and is transmitted to the HST side, thereby realizing a shift in the forward direction. At this time, the swash plate angle is adjusted corresponding to the amount of displacement of the forward pedal 61, so that the output, that is, the rotational speed is adjusted.

On the other hand, in the forward operation, the opposite second pawl 82 is kept in the release state away from the ratchet wheel 85. [

Referring to FIG. 9, when the reverse pedal 71 is depressed, the force is transmitted to the second pole 82 through the reverse pedal unit 70 and the second connecting arm 76. [ The second pole 82 rotates about H2 and rubs against the ratchet wheel 85 and the ratchet wheel 85 is constrained to the second pole arm 86 through the second pole 82. [ Accordingly, when the second pole arm 86 rotates about the pivot axis PA in the second direction by the force, the ratchet wheel 85 rotates together

As the ratchet wheel 85 rotates in the second direction together with the second pole arm 86, the output rod 88 also pivots in the same direction, and the pendulum movement of the output rod 88 causes the output link 88 OL, and transmitted to the HST side, thereby realizing a shift in the reverse direction. At this time, the swash plate angle is adjusted corresponding to the amount of displacement of the reverse pedal 71, so that the output, that is, the rotational speed is adjusted.

On the other hand, in the reverse operation, the opposite first pawl 80 is held in the release state away from the ratchet wheel 85, like the second pawl 82 in the above-described forward operation.

That is, in forward operation, the ratchet wheel 85 rotates in the same direction depending on the rotation of the first pole arm 84 in the first direction through the first pole 80, The ratchet wheel 85 is held in the released state away from the ratchet wheel 85 and conversely the ratchet wheel 85 is rotated in the same direction depending on the second directional rotation of the second pole arm 86 via the second pawl 82, 1 pole 80 is maintained in the released state.

According to the embodiment of the present invention described above, since the forward pedal and the reverse pedal are not interlocked, even if one pedal is depressed, the other pedal remains in its original position (neutral position) without moving. That is, the conventional problem that the pedal is injured by another pedal protruding when the pedal is depressed or the foot is caught between the pedals during operation can be clearly solved.

In addition, since the two pedals are not dependent on each other relative to each other, when the one pedal is depressed as in the prior art, the opposite pedal jumps above the original neutral position and is located at a higher position. It is possible to eliminate the operational inconvenience of lifting up, thereby making it possible to increase the convenience of operation and greatly reduce the operational fatigue.

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

FL: forward pedal link portion RL: reverse pedal link portion
C: interlocking switching part OL: output link part
60: forward pedal unit 61: forward pedal
62: pedal arm 63: first sleeve
64: output arm 66: first connecting arm
70: Reverse pedal unit 71: Reverse pedal
72: pedal arm 73: second sleeve
74: output arm 76: second connection arm
80: first pole 82: second pole
84: first pole arm 85: ratchet wheel
86: second pole arm 88: output rod
90: first output link 92: second output link
94: Third output link PH: Pedal hinge
P1, P2: Force point of action H1: Hinge point of 1st pole
H2: Hinge point of the second pole

Claims (10)

An apparatus for forward / reverse shift operation of an HST (hydrostatic stepless speed changer)
A forward pedal link portion for transmitting a forward direction shift operation force inputted through a forward pedal;
A reverse pedal link portion for transmitting a reverse direction shift operation force inputted through the reverse pedal;
An interlocking switching unit for interrupting transmission of the shift operation force transmitted from the forward pedal link portion or the reverse pedal link portion to the HST; And
And an output link unit interconnecting the interlocking switching unit and the HST so as to be interlocked with each other,
Wherein the interlocking switch comprises a ratchet wheel for rotating about a pivot axis, a first pole for rotating the ratchet wheel in a first direction by operation of the forward pedal link, And a second pole (2nd Pawl) for rotating the ratchet wheel in a second direction by operation of a pedal link portion.
The method according to claim 1,
Wherein the forward pedal link portion includes:
A forward pedal unit including a forward pedal and rotating about a pedal hinge; And
And a first connection arm for connecting the output side of the forward pedal unit and the first pole in a linkable manner.
3. The method of claim 2,
Wherein the forward pedal unit comprises:
A first sleeve rotatably mounted on the pedal hinge;
A pedal arm connecting the first sleeve and the forward pedal;
And an output arm disposed at a predetermined angle with respect to the pedal arm about the first sleeve.
The method according to claim 1,
The reverse pedal link portion
A reverse pedal unit including a reverse pedal and rotating about a pedal hinge; And
And a second connecting arm for connecting the output side of the second pawl unit and the second pawl in a linkable manner.
5. The method of claim 4,
The reverse pedal unit includes:
A second sleeve rotatably mounted on the pedal hinge;
A pedal arm connecting the second sleeve and the reverse pedal;
And an output arm disposed at a predetermined angle with respect to the pedal arm about the second sleeve.
The method according to claim 1,
Wherein the ratchet wheel is formed on a circumferential surface of the ratchet wheel with a second tooth row in which a first tooth row and a second pole tooth are meshed with each other and the first and second pawls rotate about the pivot axis Wherein the second arm is supported by the pole arm and the second pole arm and is spaced apart from the corresponding row of teeth by a predetermined distance.
The method according to claim 6,
Wherein the first toothed row and the second toothed row are different in axial position and arcuate position with respect to an axis passing through the rotation center of the ratchet wheel.
The method according to claim 6,
Wherein the first and second pawls are provided with retaining pieces which are to be engaged with the teeth on the surfaces facing the respective saw teeth, the retaining pieces being spaced apart from the hinge points (H1, H2) of the respective pawls by a predetermined distance, (P1, P2), in which a force for shifting operation is applied, is formed at a position spaced apart from the engaging piece by a predetermined angle around the center axis (H1, H2).
The method according to claim 6,
And an output rod for pendulum movement about the pivot axis in accordance with rotation of the ratchet wheel in a first direction or a second direction is integrally provided to the ratchet wheel.
The method according to claim 1,
Wherein the output link portion includes:
A first output link connected to an output side of the cooperative switching unit so as to be operatively connected to the input side;
A third output link connected to the swash plate control lever of the HST by a cable or a link mechanism;
And a second output link operatively connecting the output side of the first output link and the input side of the third output link of the first output link.

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