KR20170083912A - 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 the forward pedal and the reverse pedal 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, so that when the forward switch is changed from forward to reverse or from the reverse to the forward neutral position There arises a problem in that switching operation is inconvenient when the operation is required to be lifted and operated more than during 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 front / rear 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 interlocking switching plate for interrupting transmission of forward or reverse direction shifting operation force to the HST while being rotated by the shifting operation force of the interlocking switching unit and interlocking between the interlocking switching unit and the HST And an output link portion transmitting the forward or reverse direction shift operation force output from the interlocking switching portion to the HST,

Wherein the interlocking switching plate is rotated in one direction by the forward pedal link portion and is rotated in the opposite direction by the backward pedal link portion, and when the interlocking switching plate rotates in one direction, the reverse pedal link portion is rotated about the rotation behavior of the interlocking switching plate And the forward pedal link portion is free from the rotational behavior of the interlocking switching plate when the interlocking switching plate is free to rotate in the opposite direction.

The forward pedal link portion may include a forward pedal unit including a forward pedal and rotating about a pedal hinge, and a forward pivoting unit for rotating the forward pivoting link about the first pivot axis, A first operating lever unit for transmitting a forward-direction shifting operation force by the forward pedal unit to the associated switching unit, and a first connecting arm for interconnecting an output side of the forward pedal unit and an input side of the first operating lever unit Lt; / RTI >

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 An output arm may be provided.

The first operating lever unit includes a third sleeve rotatably mounted on the first pivot shaft, an input arm connecting the third sleeve and the first connecting arm, And a forward cam that is opened at a predetermined angle with respect to the input arm and contacts the first input piece on one side of the interlocking switch plate.

Further, the reverse pedal link portion applied to the present invention may include a reverse pedal unit including a reverse pedal and rotating about a pedal hinge, and a second pivot shaft biased toward a second side from a rotation center of the interlocking switchboard A second operating lever unit for transmitting a backward shift operation force by the forward pedal unit to the associated switching unit, an intermediate lever provided between the backward pedal unit and the second operating lever unit for changing the direction of transmission of force, A second connecting arm for interconnecting the input side of the intermediate lever and the output side of the reverse pedal unit and a third connecting arm for interconnecting the output side of the intermediate lever and the input side of the second operating lever 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.

And the second operating lever unit includes a fourth sleeve rotatably mounted on the second pivot shaft, an input arm connecting the fourth sleeve and the third connecting arm, And a rear cam which is opened at a predetermined angle with respect to the input arm and contacts the second input piece on the other side of the interlocking switching plate.

Further, the interlocking switching unit applied to the present invention includes the interlocking switching plate which rotates within a predetermined angular range around the switching hinge, and a control unit which is integrally formed with the central rotation axis of the interlocking switching plate, And the output side of the forward pedal link portion and the output side of the backward pedal link portion transmit force only in one direction to one side of the interlocking switching plate and the opposite side of the interlocking switching plate about the switching hinge The first input unit and the second input unit may be provided.

The output link unit includes a first output link connected to the 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 for interlocking the output side of the first output link and the input side of the third output link in a linkable manner.

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 traveling operation 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.
7 is a view for explaining an operation of the interlocking switching portion shown in 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.

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 travel control device of Fig.

3 to 5, the traveling manipulation apparatus according to the present invention is a traveling manipulator having a hydraulic system such as a hydrostatic transmission (Hydrostatic Transmission, hereinafter referred to as 'HST') mounted on a tractor, The forward pedal link portion FL, the backward 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 set to the direction of rotation of the power output from the engine in accordance with the alternative operation of the forward or reverse pedals 61, 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 transmits the forward direction shifting operation force inputted through the forward pedal 61 to the interlocking switching portion C. The forward pedal link portion FL largely comprises a first operation for transmitting the shift operation force transmitted from the forward pedal unit 60 including the forward pedal 61 and the forward pedal unit 60 to the interlock switching portion C And the forward pedal unit 60 and the first operation lever unit 66 are linked by the first connection arm 65 in a linkable manner.

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 mounted on 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 operation lever unit 66 is rotated about the first pivot axis P1 which is biased to one side from the rotation center of the interlocking switch plate 80 to be described later, And transmits the shifting operation force to the interlocking switching portion (C). To this end, the first operating lever unit 66 includes a third sleeve 67 rotating on the first pivot axis P1, an input arm 68 attached to the outer surface of the third sleeve 67, (69).

The third sleeve 67 is rotatably mounted on the first pivot axis P1 as mentioned above. The input arm 68 and the forward cam 69 are integrally formed on the outer surface of the third sleeve 67 through welding so that the input arm 68 and the forward arm 69 can be moved forward and backward relative to the center of the third sleeve 67, The cam 69 is attached at a predetermined angle. At this time, the angle between the input arm 68 and the forward cam 69 may be an obtuse angle.

The input arm 68 is connected to the output side of the forward pedal link portion FL through the first connecting arm 65 and preferably to the output arm 64 and the forward cam 69 is connected to the interlocking switching plate 80 (Forward direction, counterclockwise in the drawing) to the first input piece 84 on one side so as to transmit the operation force. That is, the forward-direction shifting operation force transmitted by the forward cam 69 is transmitted to the interlocking switch plate 80 only through the first input piece 84.

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

The reverse pedal link portion RL transmits the backward shift operation force inputted through the reverse pedal 71 to the interlock switching portion C. The rearward pedal link portion RL includes a rearward pedal unit 70 including the rearward pedal 71 and a second operating lever 71 for transmitting the shift operation force transmitted from the rearward pedal unit 70 to the interlock switching portion C, Unit 76 as shown in FIG. And an intermediate lever 75b and second and third connecting arms 75a and 75c for transmitting a shifting operation force between the reverse pedal unit 70 and the second operating lever unit 76. [

The forward pedal unit 70 is provided to rotate about the above-described pedal hinge PH in the same manner as the forward pedal unit 60. Specifically, the reverse pedal unit 70 includes 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 connects the second sleeve 73 and the reverse pedal 71 do.

One end of the pedal arm 72 and one end of the output arm 74 are fixed to the outer surface of the second sleeve 73 and the pedal arm 72 and the output arm 74 are pivoted about a pedal hinge PH at a predetermined angle . The 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 second actuating lever unit 76 rotates about the second pivot axis P2 deflected from the rotation center of the interlocking switch plate 80 to be described later to the other side, And transmits the shifting operation force to the interlocking switching portion (C). To this end, the second operating lever unit 76 includes a fourth sleeve 77 which rotates on the second pivot axis P2, an input arm 78 attached to the outer surface of the fourth sleeve 77, (79).

The fourth sleeve 77 is rotatably mounted on the second pivot axis P2 as mentioned above. The second pivot axis P2 may be symmetrical with the first pivot axis P1 described above and the input arm 68 and the backward cam 79 may be welded to each other by welding And is attached to the outer surface of the fourth sleeve 77 at a predetermined angle with reference to the center of the fourth sleeve 77.

The intermediate lever 75b serves to change the transmission direction of the force between the reverse pedal unit 70 and the second operation lever unit 76. [ Specifically, the intermediate lever 75b is rotatably mounted on the central third pivotal axis P3, and the lower end thereof is an input side receiving a reverse direction shift operation force transmitted from the reverse pedal unit 70, And the upper end is an output side for outputting a shifting operation force to the side of the interlocking switching portion (C).

The second connecting arm interlocks with the lower input side of the intermediate lever 75b and the output arm 64 of the reverse pedal unit 70 so that the third connecting arm 75c can be connected to the intermediate lever 75b, And the input side of the second actuating lever unit 76, preferably the input arm 68, in a linkable manner. The backward cam 79 contacts the second input piece 86 on the other side of the interlocking switching plate 80 so as to be interlocked.

The backward cam 79 is provided with the second input piece 86 so as to transmit the operating force only in the direction opposite to the rotation of the interlocking switching plate 80 by the forward cam 69 (the backward direction, . The backward shift operation force inputted through the reverse pedal 71 and transmitted through the reverse cam 79 can be transmitted to the interlock switch 80 only through the second input piece 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 the cable extending from the swash plate control lever of the HST are interlockingly connected.

The output link portion OL may be 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 fourth covering axis P4 in the approximate center of the second output link 92 can be rotatably engaged at the proper position of the gas frame so that the interlocking switching plate 80 can be rotated by the forward or reverse pedal 71 The second output link 92 rotates about the fourth pivot axis while pulling or pushing the third output link 94 to perform forward and reverse shift and output adjustment.

Although not specifically shown in the figure, the pedal hinge PH is provided with a 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, we will look at the interlocking switch.

FIG. 6 is an enlarged view of the interlocking switch, and FIG. 7 is a view for explaining the operation of the interlocking switch shown in FIG.

6 to 7, the interlocking switching unit C includes the interlocking switching board 80 and the output rod 88. The interlocking switching plate 80 rotates about the switching hinge H1 by a forward cam 69 or a reverse cam 79 within a predetermined angular range and an output rod 88 is connected to the interlocking switching plate 80 to the output link unit OL while performing pendulum movement according to the forward / reverse rotation of the output link unit OL

The interlocking switching plate 80 may be a substantially rectangular plate shaped member as shown in the drawing. However, the interlocking switching plate 80 is not limited as long as the left and right sides are symmetrical with respect to the switching hinge H1. The interlocking switching plate 80 is sandwiched between the switching hinges H1 And a central rotation axis in the form of a hollow tube is integrally provided so as to be rotatable about the center axis. And the output rod 88 is provided integrally with the central rotary shaft.

The first input piece 84 and the second input piece 86 are provided at one end portion and the other end portion of the opposite portion of the interlocking switching plate 80 with the switching hinge H1 as a center. A forward cam 69 corresponding to the output side of the forward pedal link portion FL is interlockingly contacted with the first input piece 84 and an output of the reverse pedal link portion RL is connected to the second input piece 86. [ The backward cam 79 corresponding to the rear side is brought into interlocking contact.

A cam surface 690 having a curved line inclined with a predetermined curvature is formed on the surface of the forward cam 69 contacting with the first input piece 84 in contact with the outer surface of the first input piece 84, 79, similarly, a curved cam surface 790 is formed on the surface of the second input piece 86, which is in contact with the outer surface of the second input piece 86, with a predetermined curvature. At this time, the first and second input pieces 84 and 86 may be provided with rollers 840 and 860 so as to roll along the cam surfaces 690 and 790.

With this configuration, when the forward-direction shifting operation force is inputted through the forward pedal 61, as shown in Fig. 7 (a), by the rotation of the forward cam 69 about the first pivot axis P1 The first input piece 84 is pushed downward so that the interlocking switch 80 rotates about the switching hinge H1 79 along the cam surface 790 of the cam follower.

Conversely, when the backward shift operation force is input through the reverse pedal 71, the reverse rotation cam 79 is rotated about the second pivot axis P2 as shown in FIG. 7 (b) The first input piece 84 on the opposite side rotates about the switching hinge H1 while the interlocking switching plate 80 rotates about the switching hinge H1 (690).

The first input piece 84 is subjected to the motion of the advancing cam 69 so that the interlocking switch 80 rotates and the second input piece 86 on the opposite side is moved to the cam surface 79 of the reverse cam 79, The second input piece 86 is subjected to the backward cam 79 and the opposite second input piece 86 is in the release state for moving along the cam surface 790 of the advancing cam 69 690, as shown in Fig.

When the interlocking switch board 80 receives the force from the cam on the side of the shift operation force input and rotates about the switching hinge H1, the output rod 88 Moves in the same direction and the pendulum motion of the output rod 88 is converted into a linear motion through the output link unit OL and transmitted to the HST side so that the rotational direction and speed of the HST output shaft can be adjusted .

The operation of the HST output implemented through the work vehicle travel control apparatus according to the embodiment of the present invention will be briefly described in connection with the overall operation of the travel control apparatus.

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.

First, let's look at the forward shift operation.

8, when the forward pedal 61 is depressed, the force is transmitted to the first operation lever unit 66 through the forward pedal unit 60 and the first connection arm 65. [ Specifically, when the forward pedal 61 is depressed, the forward pedal unit 60 is rotated in the clockwise direction around the pedal hinge PH, and the forward pedal unit 60 is rotated in the clockwise direction about the pedal hinge PH, The operation lever unit 66 is also rotated in the clockwise direction about the first pivot axis P1.

Of the interlocking switch plate 80 connected to the advancing cam 69 of the first actuating lever unit 66 is pivoted in accordance with the rotation of the first actuating lever unit 66 about the first pivot axis P1 The input piece 84 is pushed downward so that the interlocking switching plate 80 rotates counterclockwise about the switching hinge H1 and the second input piece 84, (86) slides along the cam surface (790) of the reverse cam (79).

Subsequently, when the interlocking switching plate 80 is rotated by the force transmitted from the forward cam 69, the output rod 88 performs pendulum movement in the same direction, and the pendulum movement of the output rod 88 is transmitted to the output link 88. [ The swash plate angle is adjusted in accordance with the amount of displacement of the forward pedal 61 so that the output, that is, the rotational speed is adjusted.

Next, we will look at the reverse shift operation.

9, when the reverse pedal 71 is depressed, the force is transmitted to the first operation lever unit 66 through the reverse pedal unit 70 and the second connection arm, the intermediate lever 75b, and the third connection arm 75c . Specifically, when the reverse pedal 71 is operated, the reverse pedal unit 70 is rotated counterclockwise about the pedal hinge PH, and the second operation lever unit 76 connected to the reverse pedal unit 70 And is rotated counterclockwise about the second pivot axis P2.

Of the interlocking switching plate 80 connected to the backward cam 79 of the second operating lever unit 76 is rotated in accordance with the rotation of the second operating lever unit 76 about the second pivot axis P2, The input piece 86 is pushed downward so that the interlocking switch 80 rotates clockwise about the switching hinge H1 and the first input piece 84 opposite to the second input piece 86 Is caused to slide along the cam surface (690) of the advancing cam (69).

Subsequently, as the interlocking switching plate 80 rotates, the output rod 88 moves in the same direction and the pendulum motion of the output rod 88 is converted into a linear motion through the output link portion OL And the swash plate angle is adjusted in accordance with the amount of displacement of the reverse pedal 71 so that the output, that is, the rotational speed is adjusted.

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.

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 65: first connection arm
66: first operating lever unit 67: third sleeve
68: input aa 69: forward cam
70: Reverse pedal unit 71: Reverse pedal
72: pedal arm 73: second sleeve
74: output arm 75a: second connecting arm
75b: intermediate lever 75c: third connecting arm
76: second operating lever unit 77: fourth sleeve
78: input arm 79: reverse cam
80: interlocking switching plate 82:
84: first input unit 86: second input unit
88: output load 90: first output link
92: second output link 94: third output link
PH: Pedal hinge P1: First pivot axis
P2: second pivot axis P3: third pivot axis
P4: fourth pivot axis
H1: Switching hinge

Claims (9)

An apparatus for front / rear 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 portion interposed between the forward pedal link portion and the reverse pedal link portion to intermittently transmit forward or reverse direction shift operation force to the HST while being rotated by a shift operation force transmitted from the forward pedal link portion or the reverse pedal link portion; And
And an output link unit operatively connecting the interlocking switching unit and the HST.
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;
A first operating lever unit for transmitting a forward-direction shifting operation force by the forward pedal unit to the interlocking switching unit while rotating about a first pivot axis deflected to one side from a rotation center of the interlocking switching plate;
And a first connection arm for interconnecting the output side of the forward pedal unit and the input side of the first operation lever unit.
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.
3. The method of claim 2,
The first operation lever unit includes:
A third sleeve rotatably mounted on the first pivot shaft;
An input arm connecting the third sleeve and the first connection arm;
And a forward cam which is opened at a predetermined angle with respect to the input arm about the third sleeve and contacts a first input piece on one side of the interlocking switching plate.
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;
A second operating lever unit that rotates about a second pivot axis deflected from the rotation center of the interlocking switch plate to the other side and transmits a reverse direction shift operation force by the reverse pedal unit to the interlock switch section;
An intermediate lever provided between the rearward pedal unit and the second operating lever unit to change a direction of transmission of force;
A second connecting arm interconnecting the input side of the intermediate lever and the output side of the reverse pedal unit; And
And a third connecting arm for interconnecting the output side of the intermediate lever and the input side of the second operating lever unit.
6. The method of claim 5,
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.
6. The method of claim 5,
The second operation lever unit includes:
A fourth sleeve rotatably mounted on the second pivot shaft;
An input arm connecting the fourth sleeve and the third connection arm;
And a backward cam that extends from the fourth sleeve at a predetermined angle with respect to the input arm and contacts the second input piece on the other side of the interlocking switching plate.
The method according to claim 1,
Wherein the interlocking switching unit comprises:
Said interlocking switching plate rotating in a predetermined angular range around a switching hinge;
And an output rod which is integrally formed with the central rotary shaft of the interlocking switching plate and performs pendulum movement in accordance with the forward / reverse rotation of the interlocking switching plate,
A first inputting part and a second inputting part are provided on one side of the interlocking switching plate and on the other side of the opposite side with respect to the switching hinge so that the output side of the forward pedal link part and the output side of the reverse pedal link part can transmit force only in one direction A driving control device for a work vehicle.
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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