JP2021096601A - Work vehicle - Google Patents

Abstract

To provide a work vehicle provided with a forward/reverse lever that can prevent erroneous operation by a simple structure and simple operation.SOLUTION: A work vehicle (1) is provided with a forward/reverse lever 14, which is operable to be rotated in a forward/reverse direction (C1,C2) around an operation transmission shaft 51 to switch between forward and reverse traveling, and is mounted to be rotatable in a vertical direction D1,D2 with respect to the operation transmission shaft 51, a protruding portion 81 protruding in a lower part of the forward/reverse lever 14 in the downward direction D2, and a locking mechanism 80 having a regulating member 82 composed of a shape which is present at a destination when the protruding portion 81 is about to move from a switching position to at least one of the forward/reverse directions (C1, C2) when the forward/reverse lever 14 is rotated in the downward direction D2 and prevents such movement, while being absent at a destination when the protruding portion 81 is about to move in the forward/reverse direction (C1, C2) when the forward/reverse lever 14 is rotated in the upward direction D1 and does not prevent such movement.SELECTED DRAWING: Figure 10

Description

The present invention relates to a work vehicle such as a tractor.

Conventionally, as a technique for preventing erroneous operation of an operation lever, a shift lever supported so as to be swingable, a push knob formed on the tip side of the shift lever that can be pressed, and a push knob extended in the shift lever are pushed. A rod lock pin that descends when the knob is pressed, an erroneous operation prevention window that is placed near the lower end of the shift lever and has an opening that corresponds to the shift position and movement space, and an erroneous operation prevention window. It is provided with a locking means that allows the shift lever to swing by disengaging the engagement when the rod lock pin is lowered, and the locking means is rotatable at the lower end of the shift lever. For vehicles that are urged to the side that regulates the swinging motion of the shift lever and have a protrusion that can be engaged or disengaged from the erroneous operation prevention window by rotation. An automatic transmission operating device is known (Patent Document 1).

JP-A-2015-119394

When an attempt is made to apply a conventional automatic transmission operation device for a vehicle to a work vehicle, the configuration is complicated and the number of parts is large, which may increase the cost, and it is difficult to adopt the conventional automatic transmission operation device.

An object of the present invention is to provide a work vehicle provided with a forward / backward lever capable of preventing erroneous operation with a simple configuration and by a simple operation.

The above object of the present invention is solved by the following means.

That is, the invention according to claim 1 is
Work provided with a forward / backward lever (14) that switches between forward travel and reverse travel by operating so as to rotate in the front-rear direction (C1, C2) around an operation transmission shaft (51) that transmits the movement of the operation downward. In the vehicle
The forward / backward lever (14) is rotatably attached in the vertical direction (D1, D2) with respect to the upper end portion of the operation transmission shaft (51).
The protrusion (81) provided at the lower part of the forward / backward lever (14) so as to project downward (D2), and the forward / backward lever (14) in a state of being rotated downward (D2). The protrusion (81) exists at the destination when trying to move from the switching position to at least one of the front-rear directions (C1 and C2) to prevent the movement, while raising the front-rear lever (14). The protrusion (81) does not exist at the destination when it tries to move in the front-rear direction (C1, C2) when it is rotated in the direction (D1), and has a shape that does not prevent the movement. It is a work vehicle characterized in that a lock mechanism (80) having a regulating member (82) is provided.

According to the second aspect of the present invention, the forward / backward lever is located in a portion where the regulation member (82) is arranged so as to exist at an intermediate position between the position for switching to the forward travel and the position for switching to the reverse travel. A shape having a recess (83) in which the protruding portion (81) enters when the (14) is rotated downward (D2) and is prevented from moving in the front-rear direction (C1, C2). The work vehicle according to claim 1, wherein the work vehicle is made of a member.

The invention according to claim 3 is characterized in that the locking mechanism (80) has an urging member (86) for urging the forward / backward lever (14) to rotate downward (D2). The work vehicle according to claim 1 or 2.

According to the fourth aspect of the present invention, a connecting portion (51a) having a shaft through hole (53) through which the rotating shaft (62) is passed is provided at the upper end portion of the operation transmission shaft (51). A claim comprising a connecting member (61) rotatably attached to and connected to the connecting portion (51a) via a rotating shaft (62) at a lower portion of the advancing lever (14). The work vehicle according to any one of items 1 to 3.

The invention according to claim 5 is a fixing member (56) having an upper surface (56a) orthogonal to the operation transmission shaft (51) at a portion of the operation transmission shaft (51) below the connecting portion (51a). ) Is attached, and the upper surface (56a) of the fixing member (56) is attached to the lower part of the connecting member (61) when the forward / backward lever (14) is rotated in the vertical direction (D1, D2). The work vehicle according to claim 4, wherein a first contact portion (66) and a second contact portion (67) are provided in contact with each other to limit the range of rotation.

According to the sixth aspect of the present invention, the urging member (86) is located on a portion of the fixing member (56) opposite to the forward / backward lever (14) with the operation transmission shaft (51) interposed therebetween. An urging member mounting portion (87) for mounting the lower end portion is provided, and the connecting member (61) faces the urging member mounting portion (87) at intervals and the upper end portion of the urging member (86). An urging member holding portion (88) having a contact surface (88a) for contacting the lever is provided.
The lower end of the urging member (86) is held by the urging member mounting portion (87), while the upper end thereof contacts the contact surface (88a) of the urging member holding portion (88). The work vehicle according to claim 5, wherein the work vehicle is attached in a capable state and elastically deforms so as to contract when the forward / backward lever (14) is rotated at least in the upward direction (D1).

According to a seventh aspect of the present invention, the forward / backward lever (14) is rotatably attached to an upper end portion of the operation transmission shaft (51) at a position below the steering wheel (12). The work vehicle according to any one of claims 1 to 6, wherein the member (82) is arranged adjacent to the vicinity of the upper end portion of the operation transmission shaft (51).

In the invention according to claim 1, the forward / backward lever (14) is moved downward (D2) with respect to the operation transmission shaft (51) by the lock mechanism (80) having the protruding portion (81) and the regulating member (82). While the switching operation is not possible when the lever (14) is rotated to, the forward / backward lever (14) is rotated upward (D1) with respect to the operation transmission shaft (51). Sometimes the switching operation becomes possible.
Therefore, according to the present invention, erroneous operation of the forward / backward lever (14) can be prevented by a simple configuration and a simple operation.

According to the second aspect of the present invention, the restricting member (82) in the lock mechanism (80) has a recess (83) for preventing the protrusion (81) from moving in the front-rear direction (C1, C2). Since it is configured as a member having a different shape, it is possible to prevent erroneous operation of the forward / backward lever (14) with a simpler configuration.

According to the third aspect of the present invention, the locking mechanism (80) is configured to urge the forward / backward lever (14) to rotate downward (D2) by the urging member (86). , The state in which the switching operation by the forward / backward lever (14) cannot be performed is easily maintained in a stable manner, and erroneous operation of the forward / backward lever (14) can be prevented more reliably.

According to the invention of claim 4, the forward / backward lever (14) has a simple structure with respect to the operation transmission shaft (51) via a connecting member (61) and a rotation shaft (62) in the vertical direction (D1). , D2) is rotatably connected, so that erroneous operation of the forward / backward lever (14) can be prevented with a simpler configuration.
According to the fifth aspect of the invention, the first contact portion (66) and the second contact portion in the connecting member (61) when the forward / backward lever (14) is rotated in the vertical direction (D1, D2). Since (67) comes into contact with the upper surface (56a) of the fixing member (56) to limit the range of rotation, the switching operation is performed under the restricted state, and the forward / backward lever (14) ) Wrong operation can be prevented by simple operation without unnecessary movement.
According to the invention of claim 6, the urging member (86) is elastically deformed so as to contract when the forward / backward lever (14) is rotated at least in the upward direction (D1). Since it is mounted while being sandwiched between the portion (87) and the urging member holding portion (88), it is possible to prevent erroneous operation of the forward / backward lever (14) with a simpler configuration.

According to the invention of claim 7, the forward / backward lever (14) below the steering wheel (12) that the driver puts his / her hand on during driving is grasped by his / her hand (finger) and moves upward ( It is easy to rotate it to D1) to enable the switching operation, or release it and rotate it downward (D2) to disable the switching operation, and erroneously operate the forward / backward lever (14). Can be prevented by a simpler operation. Further, since the regulating member (82) of the lock mechanism (80) is arranged near the upper end portion of the operation transmission shaft (51), erroneous operation of the forward / backward lever (14) can be prevented with a simpler configuration. ..

It is a left side view of the tractor which concerns on embodiment of this invention. It is a perspective view which shows the structure in front of a cockpit. It is a perspective view which shows the structure related to the forward / backward lever. FIG. 3 is a perspective view showing a configuration related to the forward / backward lever of FIG. 3 with some parts removed. FIG. 6 is a perspective view of another angle showing a configuration related to the forward / backward lever of FIG. 4 with another component removed. It is an exploded perspective view which shows the structure related to the forward / backward lever. (A) is a perspective view showing a portion where the forward / backward lever is arranged, and (B) is a perspective view showing a part of (A) taken out. It is explanatory drawing which shows the structure of the connection part of the forward / backward lever, the operation transmission shaft, and the lock mechanism partially in perspective and cross section. It is a side view which shows the structure of the forward / backward lever. (A) is an explanatory view showing one state of the protruding portion and the regulating member when the forward / backward lever is rotating downward, and (B) is an explanatory diagram when the forward / backward lever is rotating upward. It is explanatory drawing of one state of a protrusion and a regulation member. It is a top view which superimposes the state when it is moving to three switching positions of a forward / backward lever. (A) is a conceptual diagram showing the configuration of the protruding portion and the regulating member in the lock mechanism as viewed from above, and (B) is a schematic cross-sectional view substantially along the QQ line of (A).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a tractor 1 which is an example of a work vehicle according to an embodiment of the present invention.
In this tractor 1, devices such as an engine 3, a power transmission device 4, and a driver's seat 7 are mounted or provided on a vehicle body 2 having a pair of left and right front wheels 5 and rear wheels 6. Of these, the engine 3 is covered with a bonnet cover 11 provided so as to be openable and closable. The power transmission device 4 includes a clutch mechanism (not shown), a main transmission, an auxiliary transmission, a forward / backward switching mechanism, a differential device, and the like, which are arranged in the transmission case 40.

Further, the tractor 1 is driven by four-wheel drive (4WD) in which the rotational power of the engine 3 is transmitted to the left and right front wheels 5 and the left and right rear wheels 6 via a power transmission device 4 and the like, and the left and right rear wheels 6. The drive system can be switched between the two-wheel drive (2WD), which is transmitted and driven, and the vehicle travels by any of the drive systems.
Further, the tractor 1 can perform a desired work by mounting a work machine (not shown) such as a rotary tiller on the rear part of the vehicle body 2 via a mounting portion such as a lower link 29. A PTO shaft 49 for outputting the rotational power of the engine 3 to the mounted work machine is provided at the rear portion of the vehicle body 2 (rear portion of the mission case 40).

The cockpit 7 is provided inside the cabin 20, which is a cockpit including a roof, windows, opening / closing doors, a frame, and the like.
A steering wheel 12 for steering the front wheels 5 is provided in front of the cockpit 7. As shown in FIGS. 2 to 4, the steering wheel 12 is a hydraulic steering assist device 25 (FIG. 4) such as an orbit roll (registered trademark) arranged in the column cover 22 at the upper end of the dashboard 21. It is supported via a column shaft.
A meter panel 13 for displaying information on maneuvering (running speed, operating state, etc.) to the driver is provided diagonally downward in front of the steering wheel 12. For example, a speedometer 13a, a liquid crystal display unit 13b, and the like are arranged on the meter panel 13.

On the left side surface of the column cover 22 below the steering wheel 12, a forward / backward lever 14 that operates to switch between forward travel and reverse travel is provided.
Further, on the right side surface of the column cover 22 below the steering wheel 12, a throttle lever 15 for changing the rotation speed of the engine 3, a blinker lever 16, and the like are provided.

As shown in FIG. 2 and the like, the floor surface side 20b of the cabin 20 is provided with an accelerator pedal 25, left and right brake pedals 26L and 26R, a PTO shift lever 17, a clutch pedal 27 and the like.
A main shift lever 18, an auxiliary shift lever (not shown), a position lever, and the like are provided around the driver's seat 7 in the cabin 20.

In this tractor 1, a forward / backward lever 14 having the following configuration is adopted.

First, as shown in FIGS. 2 to 4, the forward / backward lever 14 is operated so as to rotate in the front-rear direction C1 and C2 with respect to the forward direction of the tractor 1 about the operation transmission shaft 51, thereby moving forward. It is designed to switch between running and reverse running.

The forward / backward lever 14 in the present embodiment is rotated in the front-rear direction C1 and C2, and as shown in FIG. 12 (A), the forward / backward lever 14 is positioned at any of the three switching positions of the forward position, the neutral position, and the reverse position. It is configured to be moved and fastened to.
The forward position is a position to be selected and moved when switching to forward running, and the reverse position is a position to be selected and moved when switching to reverse running. The neutral position is a position to be selected and moved when neither forward running nor reverse running is performed. Further, the forward position, the neutral position, and the reverse position are arranged in this order so as to be arranged in a substantially row from the front to the rear in the forward direction with a required interval. Strictly speaking, the forward position, the neutral position, and the reverse position are set as positions corresponding to the forward position, the neutral position, and the reverse position, which are switched by the forward / backward switching mechanism (not shown) in the power transmission device 4.

The operation transmission shaft 51 moves the movement (rotational motion) when the forward / backward lever 14 is rotated in the front-rear directions C1 and C2 in the front-rear direction (not shown) in the power transmission device 4 arranged below the forward / backward lever 14. It is a columnar shaft that is directly or indirectly transmitted to the input operating shaft 45 of the advance switching mechanism.

As shown in FIGS. 3 and 4, the operation transmission shaft 51 in the present embodiment indirectly moves the operation by adding a relay transmission shaft 52 between the operation transmission shaft 51 and the input operation shaft 45 of the forward / backward switching mechanism. It is configured to be transmitted. At this time, the operation transmission shaft 51 and the relay transmission shaft 52 are rotatably connected by the first universal joint 55A. Further, the relay transmission shaft 52 and the input operation shaft 45 are also rotatably connected by the second universal joint 55B.

As a result, in the present embodiment, as shown in FIGS. 3, 4, 11, 11 and the like, when the forward / backward lever 14 is rotated and operated in the forward direction C1 or the backward direction C2, each movement is moved. It is transmitted to the input operating shaft 45 via the operation transmission shaft 51 and the relay transmission shaft 52, respectively, and the input operating shaft 45 rotates in the directions indicated by the arrows E1 or E2, respectively. Finally, the switching operation in the forward / backward switching mechanism is performed according to each position when the input operating shaft 45 rotates.

Further, the operation transmission shaft 51 is rotatably supported by a holding pipe 71 attached to one of the left and right side portions (left side plate portion 24b in this example) of the support bracket 24 that supports the steering wheel 12 from below. ..

The support bracket 24 is configured by combining, for example, an inclined plate portion 24a, left and right side plate portions 24b, 24c, an upper end mounting plate portion 24e, etc., and is attached to a panel dash (bulkhead plate) 23 that separates the engine room and the cabin 20. Has been done. Incidentally, the hydraulic steering assist device 25 is attached to the upper end mounting plate portion 24e of the support bracket 24 (FIG. 4).

The holding pipe 71 is fixed to the left side plate portion 24b of the support bracket 24 via a mounting plate 72 by welding or the like, and the upper end portion thereof is formed in a notch formed at the left end portion of the upper end mounting plate portion 24e. It is fitted and supported.

Next, as shown in FIGS. 3, 4, 8, 8 and the like, the forward / backward lever 14 is rotatably attached to the upper end portion 51a of the operation transmission shaft 51 in the vertical directions D1 and D2.
The vertical directions D1 and D2 at this time are not limited to the vertical direction along the direction of gravity, and in the present embodiment, the forward / backward lever 14 is lifted and moved along the axial direction of the operation transmission shaft 51. The direction of time is the upward direction C1, and the direction in which the forward / backward lever 14 moves so as to descend along the axial direction of the operation transmission shaft 51 when the lifting is stopped is the downward direction C2.

As shown in FIG. 6, the operation transmission shaft 51 is formed in a plate-like shape at the upper end portion of the operation transmission shaft 51 for mounting that can be rotated in the vertical directions D1 and D2, and a rotation shaft (a part thereof) is formed. It is configured as a connecting portion 51a in which a shaft through hole 53 through which the header pin) 62 is passed is formed.
Further, for mounting that can be rotated in the vertical directions D1 and D2, as shown in FIG. It includes a connecting member 61 that is rotatably attached and connected via 62.

The forward / backward lever 14 includes a main body portion 141 having an upper end portion 141a and a lower end portion 141b bent inward, a gripping core portion 142 extending from the bent upper end portion 141a of the main body portion 141, and a gripping core portion 142 thereof. It is composed of a covering member 143 that covers the above. The forward / backward lever 14 is used so that the bent lower end portion 141b of the main body portion 141 is parallel to the axial direction of the operation transmission shaft 51, and the bent upper end portion 141a is oriented outward on the left side in the forward direction. To.

The connecting member 61 is a member having a shape (fork shape) having a fitting space 61e for rotatably fitting and sandwiching the connecting portion 51a formed in the plate shape of the operation transmission shaft 51. It is a member provided with an axial through hole 63 through which a rotating shaft 62 is passed through an opposed portion forming an insertion space 61e. The connecting member 61 is fixedly attached to the bent lower end portion 141b of the main body portion 141 of the forward / backward lever 14 by means such as welding or a mounting jig.

As shown in FIGS. 6, 8 and the like, the forward / backward lever 14 has the rotating shaft 62 of FIG. 6 after fitting the connecting portion 51a of the operation transmission shaft 51 into the fitting space 61e of the connecting member 61. As shown by the alternate long and short dash line, it is attached so as to penetrate through the shaft through hole 63 in the connecting member 61 and the shaft through hole 53 in the connecting portion 51a.
As a result, the forward / backward lever 14 is rotatably attached to the connecting portion 51a of the operation transmission shaft 51 in the vertical directions D1 and D2 by rotating the connecting member 61 around the rotating shaft 62.

Next, as shown in FIGS. 3 to 8 and the like, the forward / backward lever 14 prevents the protrusion 81 provided at the lower part of the forward / backward lever 14 and the movement of the protrusion 81, which will be described later, and releases the prevention. It is provided with a lock mechanism 80 having a regulating member 82 having a shape to be bent and an urging member 86 for urging the forward / backward lever 14 to rotate downward D2.

As shown in FIGS. 6, 8, 9, 9 and the like, the protruding portion 81 of the lock mechanism 80 protrudes on the lower end surface of the bent lower end portion 141b of the forward / backward lever 14 with a diameter smaller than the outer diameter of the bent lower end portion 141b. It is a part consisting of a shape.
The protruding portion 81 may have a shape and size that can be accommodated by at least entering the recess 83 described later of the regulating member 82. Further, the protruding portion 81 is obtained, for example, by cutting a base material portion extending below the bent lower end portion 141b so as to squeeze it into a cylindrical shape and a truncated cone shape, or a member having a small diameter thereof is formed on the lower end surface of the bent lower end portion 141b. Obtained by fixing.

As shown in FIGS. 4, 7, 8, 10, 12, and the like, the regulating member 82 in the lock mechanism 80 has a protruding portion 81 when the forward / backward lever 14 is rotated downward D2. Exists at the destination when trying to move from the switching position to at least one of the front-rear directions C1 and C2 to prevent the movement, while the forward / backward advance lever 14 is rotated in the upward direction D1. It is a member having a shape that does not exist at the traveling destination when the protruding portion 81 tries to move in the front-rear direction C1 and C2 and does not prevent the movement.

The movement of the protruding portion 81 from the switching position to at least one of the front-rear directions C1 and C2 means the following in the present embodiment.
That is, moving in one of the front-rear directions C1 and C2 means that when the forward / backward lever 14 is in the switching position (forward position and reverse position in the present embodiment) arranged at both ends of the plurality of switching positions, the switching position. It corresponds to moving from the forward position of the above to the backward direction C2 and moving from the reverse position of the switching position to the forward direction C1. Further, moving in both the front-rear direction C1 and C2 means that when the forward / backward lever 14 is in the switching position (neutral position in the present embodiment) arranged inside other than both ends, the switching position is moved in the forward direction from the neutral position. It corresponds to moving to C1 or backward C2, respectively.

As the regulating member 82 in the present embodiment, as shown in FIG. 12, the forward / backward lever 14 is moved downward to the main body portion 82a arranged so as to exist at an intermediate position between the forward position and the reverse position. A member having a shape having a recess 83 in which the protruding portion 81 enters when rotated to D2 and is prevented from moving in the front-rear direction C1 and C2 is applied.

Specifically, as shown in FIGS. 7, 8 and the like, the regulating member 82 is made of a flat plate having an elongated shape having a main body portion 82a arranged so as to exist at the intermediate position.

Further, the regulating member 82 made of the plate material is provided with a recess 83 made of a through hole at an intermediate position in the front-rear direction of the main body portion 82a.
The recess 83 has a depth that allows the protrusion 81 at the lower part of the forward / backward lever 14 to enter and be accommodated, and the protrusion 81 moves integrally with the forward / backward lever 14 in the front-rear directions C1 and C2. It has front and rear inner walls 83a and 83b that can prevent the movement by contact when trying. Further, as shown in FIG. 7 and the like, the recess 83 is formed in the left-right direction in consideration of facilitating the protrusion 81 of the forward / backward lever 14 when rotating in the vertical directions D1 and D2. It is formed in the shape of a long slotted hole. The recess 83 may be composed of a recess (groove) that does not penetrate.

Further, in the regulating member 82 made of a plate material, the protruding portion 81 of the forward / backward advance lever 14 when in the forward position as the switching position moves to the rearward direction C2 at the front / rear position sandwiching the recess 83 of the main body portion 82a. A first blocking unit 84 that prevents this from happening, and a second blocking unit 85 that prevents the protruding portion 81 of the forward / backward lever 14 from moving in the forward direction C1 when it is in the reverse position as the switching position are provided. ..
The first blocking portion 84 and the second blocking portion 85 are composed of end face portions before and after sandwiching the recess 83 of the main body portion 82a. The first blocking portion 84 is formed of an end face portion that is inclined diagonally forward from left to right and extends linearly. Further, the second blocking portion 85 is formed by an end face portion extending linearly along substantially in the left-right direction.

As shown in FIGS. 7 (B), 8 and the like, the restricting member 82 has a mounting portion 82b extending from the main body portion 82a on the upper surface of the upper end mounting plate portion 24e of the support bracket 24 that supports the steering wheel 12. Of these, the operation transmission shaft 51 is fixedly attached by a fixing means such as welding so as to be arranged adjacent to the upper end portion (the upper portion excluding the connecting portion 51a in this example) of the operation transmission shaft 51. Further, in the present embodiment, the vicinity of the upper end portion of the operation transmission shaft 51 is actually next to the portion of the holding pipe 71 holding the operation transmission shaft 51 that protrudes from the upper end mounting plate portion 24e.
Further, as shown in FIG. 7A and the like, the regulating member 82 is arranged so that the main body portion 82a is exposed to the outside from the opening 22a provided on the left side surface portion of the column cover 22. Incidentally, the column cover 22 provided with the opening 22a can also be used as a column cover that does not have the configuration (lock mechanism 80) for the forward / backward lever 14 in the present embodiment.

As shown in FIGS. 6 and 8, the urging member 86 in the lock mechanism 80 is arranged at a position opposite to the forward / backward lever 14 with the operation transmission shaft 51 interposed therebetween. A coil spring is applied as the urging member 86.

First, in the present embodiment, as shown in FIGS. 6, 8, 10, 10 and the like, a fixing having an upper surface 56a orthogonal to the operation transmission shaft 51 at a portion below the connecting portion 51a of the operation transmission shaft 51. The member 56 is attached.
The fixing member 56 is formed of a flat plate having a shape that surrounds the outer circumference of the operation transmission shaft 51. The lower surface of the fixing member 56 slidably contacts the upper end portion 71a of the holding pipe 71 when the operation transmission shaft 51 is inserted into and held by the holding pipe 71, thereby positioning the operation transmission shaft 51. It is designed to be held rotatably together with.

The fixing member 56 is provided with an urging member mounting portion 87 for mounting the lower end portion 86b of the urging member 86.
The urging member mounting portion 87 is arranged so as to exist in a portion of the fixing member 56 that is opposite to the forward / backward lever 14 with the operation transmission shaft 51 interposed therebetween. Further, the urging member mounting portion 87 is formed as a cylindrical structural portion provided with a holding hole 87a at the upper portion for accommodating and holding the lower end portion 86b of the urging member 86. The urging member mounting portion 87 in the present embodiment is provided on the upper surface of the pedestal portion 89 that rises upward from the upper surface 56a of the fixing member 56 and extends in the direction opposite to the forward / backward lever 14.

On the other hand, the connecting member 61 of the forward / backward lever 14 is provided with an urging member holding portion 88 that holds the upper end portion 86a of the urging member 86 in contact with the connecting member 61.
The urging member holding portion 88 is a structural portion having a contact surface 88a that faces the urging member mounting portion 87 at a distance and that the upper end portion 86a of the urging member 86 can come into contact with. The urging member holding portion 88 in the present embodiment is a flat plate extending so as to face the urging member mounting portion 87 at the upper portion of the connecting member 61 which is opposite to the forward / backward lever 14 with the axial through hole 63 interposed therebetween. It is formed as a shaped structural part.

As shown in FIGS. 6 and 8, the urging member 86 has its lower end 86b accommodated and held in the holding hole 87a of the urging member mounting portion 87, while its upper end 86a is urged. It is attached by being in a state where it can come into contact with the contact surface 88a of the member holding portion 88.

At this time, as shown in FIG. 8, the urging member 86 is maintained in a contracted state by a required amount even when the forward / backward lever 14 rotates in the downward direction D2 and is stopped. It is attached. Therefore, even when the forward / backward lever 14 rotates in the downward direction D2 and is stopped, the urging member 86 urges the forward / backward lever 14 at that time to rotate in the downward direction D2. It has become.

Further, the urging member 86 is a contact surface of the urging member holding portion 88 that moves integrally with the forward / backward lever 14 when the forward / backward lever 14 is rotated in the upward direction D1 about the rotation shaft 62. When pushed by 88a in the direction indicated by the arrow H1, it elastically deforms to contract. As a result, the restoring force (spring force) toward the direction indicated by the arrow H2 is generated in the urging member 86 at this time as an urging force so as to rotate the forward / backward lever 14 downward D2 due to the contraction.

Further, as shown in FIGS. 8 to 10 and the like, the forward / backward lever 14 is attached to the lower portion 61b of the connecting member 61, and the upper surface of the fixing member 56 when the forward / backward lever 14 is rotated in the vertical directions D1 and D2. A first contact portion 66 and a second contact portion 67 are provided which come into contact with each of the 56a and limit the range of rotation.

The first contact portion 66 contacts the upper surface 56a of the fixing member 56 when the forward / backward lever 14 is rotated in the upward direction D1, and restricts the further rotation of the forward / backward lever 14 in the upward direction D1. Functions as a stopper. Further, the first contact portion 66 is placed on the upper surface 56a of the fixing member 56 while restricting the rotation in the upward direction D1 even when the forward / backward lever 14 is rotated in the front-rear direction (C1, C2) for switching. It also functions as a guide to guide you along. The first contact portion 66 is restricted from rotating at a position where, for example, the protruding portion 81 at the lower portion of the forward / backward lever 14 is completely ejected from the recess 83 of the regulating member 82 (FIG. 10 (B)). Is set to.

On the other hand, the second contact portion 67 comes into contact with the upper surface 56a of the fixing member 56 when the forward / backward lever 14 is rotated downward D2, and the forward / backward lever 14 is further rotated downward D2. Functions as a stopper to limit. The second contact portion 67 is in a state in which, for example, the protruding portion 81 at the lower part of the forward / backward lever 14 can enter the recess 83 of the regulating member 82 and come into contact with the inner walls 83a and 83b of the recess 83 to prevent movement (FIG. 10). The rotation is restricted at the positions (A) and 12 (B)).

Hereinafter, the switching operation of the forward / backward lever 14 will be described.

First, when neither forward travel nor reverse travel is performed, that is, when the vehicle is in the stopped state, the forward / backward lever 14 is moved to the neutral position switching position as shown in FIGS. 3 and 11. Be placed.

At this time, the forward / backward lever 14 (N) in the neutral position rotates downward D2 about the rotation shaft 62 as shown in FIGS. 8, 10 (A), 12 and the like. Then, the protruding portion 81 of the lock mechanism 80 is inserted into the recess 83 of the regulating member 82 so as to be accommodated.
At this time, as shown in FIG. 10A, the forward / backward lever 14 (N) moves downward to D2 when the second contact portion 67 of the connecting member 61 comes into contact with the upper surface 56a of the fixing member 56. Further rotation is restricted and kept in a stopped state.

Then, the driver or the like mistakenly touches the forward / backward lever 14 (N) at this time, and the forward / backward lever 14 (N) is operated to rotate and move in the forward direction C1 or backward. It is assumed that the operation is performed so as to rotate and move in the direction C2. In this case, the protruding portion 81 of the forward / backward advance lever 14 (N) also tries to move integrally in the front-rear directions C1 and C2.

However, in this case, the forward / backward lever 14 (N) is urged to rotate downward D2 by the urging force F1 (FIG. 8) of the urging member 86 via the urging member holding portion 88 of the connecting member 61. Therefore, the protruding portion 81 is held in a state of being housed in the recess 83 of the regulating member 82, and is difficult to move in the upward direction D1.
Further, in this case, even if the protruding portion 81 tries to move in the front-rear direction C1 and C2, the inner wall surface 83a on the front side or the inner wall surface 83b on the rear side of the recess 83 of the regulation member 82 existing at each of the traveling destinations thereof. Contact is blocked from its movement. As a result, the forward / backward lever 14 (N) does not move in the front-rear directions C1 and C2.

Therefore, in the tractor 1, the forward / backward lever 14 (N) when in the neutral position is prevented from being moved to the switching position of the forward position or the reverse position and switched by an erroneous operation.

Next, when traveling forward, the forward / backward lever 14 is moved from the switching position at the neutral position to the switching position at the forward position.

In this case, first, the forward / backward lever 14 (N) in the neutral position is rotated upward D1 about the rotation shaft 62 as shown in FIGS. 10B and 11. It is held by the driver's hand and lifted once.

As a result, the protruding portion 81 of the forward / backward lever 14 (N) is moved upward D1 in accordance with the rotation of the forward / backward lever 14 (N) as shown in FIGS. 10 (B) and 12 (B). The locking mechanism 80 is in a state of being pulled out of the recess 83 of the regulating member 82 (a state in which the movement is released from the recess 83). Further, since the protruding portion 81 at this time has nothing to prevent the movement of the traveling portion when moving in the forward direction C1, the protruding portion 81 is also in a state where it can freely move in the forward direction C1.

As shown in FIG. 10B, the forward / backward lever 14 (N) when lifted is moved upward by the first contact portion 66 of the connecting member 61 coming into contact with the upper surface 56a of the fixing member 56. Further rotation to D1 is kept restricted. Further, the forward / backward lever 14 (N) at this time is in a state in which the urging member 86 is further contracted due to the rotation in the upward direction D1, so that the forward / backward lever 14 (N) is strongly rotated in the downward direction D2 by the additional contraction. You will receive the force to make you.

Subsequently, the forward / backward lever 14 (N) once lifted is rotated in the forward direction C1 around the operation transmission shaft 51 while being held by the driver's hand to move forward from the neutral position. It is moved to a switching position of a certain forward position, and when it reaches the switching position of the forward position, it is released from the driver's hand.

The forward / backward lever 14 when released is moved so as to rotate downward D2 about the rotation shaft 62 while receiving the urging force of the urging member 86 at the switching position of the forward position. Further, the forward / backward lever 14 at this time is kept in a stopped state in which the second contact portion 67 of the connecting member 61 comes into contact with the upper surface 56a of the fixing member 56, so that further rotation in the downward direction D2 is restricted. Dripping.
When the forward / backward lever 14 is rotated in the forward direction (C1) in a state where the second contact portion 67 is in contact with the upper surface 56a of the fixing member 56, the forward / backward lever 14 remains stable along the upper surface 56a. It will rotate and move.

Further, the rotational movement of the forward / backward lever 14 in the forward direction C1 (arc motion toward the forward direction C1) at this time is an input operation in the forward / backward switching mechanism via the operation transmission shaft 51 and the relay transmission shaft 52. It is transmitted to the shaft 45 and rotates the input operating shaft 45 in the direction indicated by the arrow E1 (FIG. 11). As a result, the forward / backward switching mechanism is switched to the forward position.
The forward / backward lever 14 after the above operation becomes the forward / backward lever 14 (F) that has moved to the forward position switching position as shown in FIG.

Further, as shown in FIG. 12, the protruding portion 81 of the forward / backward lever 14 (F) that has moved to the switching position of the forward position is located in front of the first blocking portion 84 of the regulating member 82 in the lock mechanism 80. It moves and becomes a stopped state.

Then, it is assumed that the driver or the like mistakenly touches the forward / backward lever 14 (F) at this time, and the forward / backward lever 14 (F) is operated to rotate and move in the backward direction C2. In this case, the protruding portion 81 of the forward / backward lever 14 (F) also tries to move integrally with the rearward direction C2.

However, in this case, the forward / backward lever 14 (F) is urged to rotate downward D2 by the urging force F1 (FIG. 8) of the urging member 86 via the urging member holding portion 88 of the connecting member 61. Therefore, the protruding portion 81 is easily held in a state of being stopped at a position in front of the first blocking portion 84 of the regulating member 82, and is also in a state of being difficult to move in the upward direction D1.
Further, in this case, even if the protruding portion 81 tries to move in the rear direction C2, it comes into contact with the first blocking portion 84 of the regulation member 82 existing at the traveling destination, and the movement is blocked. As a result, the forward / backward lever 14 (F) does not move in the backward direction C2.

Therefore, in the tractor 1, the forward / backward lever 14 (F) when in the forward position may be moved to the neutral position or the reverse position switching position on the rear side of the forward position and switched due to an erroneous operation. Be prevented.

Next, when traveling backward, the forward / backward lever 14 is moved from the switching position at the neutral position to the switching position at the reverse position.

In this case as well, as in the case of switching to the forward position switching position, the forward / backward lever 14 (N) in the neutral position is centered on the rotation shaft 62 as shown in FIGS. 10 (B) and 11. Then, it is held by the driver's hand and once lifted so that it can be rotated in the upward direction D1.

Subsequently, the forward / backward lever 14 (N) once lifted is rotated in the rearward direction C2 around the operation transmission shaft 51 while being held by the driver's hand to be rearward from the neutral position. It is moved to a certain reverse position switching position, and when it reaches the backward position switching position, it is released from the driver's hand.

At this time, the rotational movement of the forward / backward lever 14 in the backward direction C2 (arc motion toward the backward direction C2) is the input operating shaft 45 in the forward / backward switching mechanism via the operation transmission shaft 51 and the relay transmission shaft 52. The input operating shaft 45 is rotated in the direction indicated by the arrow E2 (FIG. 11). As a result, the forward / backward switching mechanism is switched to the reverse position.
The forward / backward lever 14 after the above operation becomes the forward / backward lever 14 (R) that has moved to the reverse position switching position as shown in FIG.

Further, as shown in FIG. 12, the protrusion 81 of the forward / backward lever 14 (R) that has moved to the reverse position switching position is located behind the second blocking portion 85 of the regulation member 82 in the lock mechanism 80. It moves and becomes a stopped state.

Then, it is assumed that the driver or the like mistakenly touches the forward / backward lever 14 (R) at this time, and the forward / backward lever 14 (R) is operated to rotate and move in the forward direction C1. In this case, the protruding portion 81 of the forward / backward lever 14 (R) also tries to move integrally with the forward direction C1.

However, in this case, the forward / backward lever 14 (R) is urged to rotate downward D2 by the urging force F1 (FIG. 8) of the urging member 86 via the urging member holding portion 88 of the connecting member 61. Therefore, the protruding portion 81 is easily held in a state of being stopped at a position behind the second blocking portion 85 of the regulating member 82, and is also in a state of being difficult to move in the upward direction D1.
Further, in this case, even if the protruding portion 81 tries to move in the forward direction C1, it comes into contact with the second blocking portion 85 of the regulation member 82 existing at the traveling destination, and the movement is blocked. As a result, the forward / backward lever 14 (R) does not move in the forward direction C1.

Therefore, in the tractor 1, the forward / backward lever 14 (R) when in the reverse position may be moved to the neutral position or the forward position switching position on the front side of the reverse position and switched due to an erroneous operation. Be prevented.

As described above, since the forward / backward lever 14 in the tractor 1 is provided with the lock mechanism 80, the switching operation is performed in a two-step motion.
That is, as illustrated by the two-dot chain line with an arrow in FIG. 12B, the forward / backward lever 14 first moves the forward / backward lever 14 upward when moving from the current switching position to a different switching position. The operation of lifting and rotating D1 by hand (first stage motion) is performed, and then the hand to be gripped is released after rotating and moving in the forward direction C1 or the backward direction C2 which is the target switching position. The operation of rotating in the downward direction D2 (second stage motion) is performed.

<Modification example>
In the above embodiment, with respect to the urging member 86, the contact surface 88a of the urging member holding portion 88 for the first time when the forward / backward lever 14 is rotated in the upward direction D1 about the rotation shaft 62. It may be attached in a state of being elastically deformed so as to be pushed by and contracted.
In the urging member 86 attached in this way, the urging force F that elastically deforms so as to contract for the first time when the forward / backward lever 14 is rotated upward D1 and rotates the forward / backward lever 14 downward D2 is applied. Will occur.

As the urging member 86, another type of elastic member limited to the coil spring used in a state of being sandwiched between the urging member mounting portion 87 and the urging member holding portion 88 may be applied. As another urging member 86, for example, a torsion spring in which a winding portion is attached to the rotating shaft 62 can be applied.

As the regulating member 82, in addition to the recess 83 corresponding to the neutral position, a member provided with the recess 83 corresponding to a switching position (for example, a forward position or a reverse position) other than the neutral position may be applied.

The present invention is not limited to vehicles for agricultural work such as tractors, but can also be applied to vehicles for various other work.

1 ... Tractor (working vehicle)
14 ... Forward / backward lever 51 ... Operation transmission shaft 51a ... Connecting portion 53 ... Shaft through hole 56 ... Fixing member 56a ... Top surface 61 ... Connecting member 62 ... Rotating shaft 66 ... First contact portion 67 ... Second contact portion 80 ... Lock Mechanism 81 ... Protruding portion 82 ... Regulatory member 83 ... Recessed portion 86 ... Biasing member 87 ... Biasing member mounting portion 88 ... Biasing member holding portion 88a ... Contact surfaces C1, C2 ... Front-rear direction D1, D2 ... Vertical direction

Claims (7)

Work provided with a forward / backward lever (14) that switches between forward travel and reverse travel by operating so as to rotate in the front-rear direction (C1, C2) around an operation transmission shaft (51) that transmits the movement of the operation downward. In the vehicle
The forward / backward lever (14) is rotatably attached in the vertical direction (D1, D2) with respect to the upper end portion of the operation transmission shaft (51).
The protrusion (81) provided at the lower part of the forward / backward lever (14) so as to project downward (D2), and the forward / backward lever (14) in a state of being rotated downward (D2). The protrusion (81) exists at the destination when trying to move from the switching position to at least one of the front-rear directions (C1 and C2) to prevent the movement, while raising the front-rear lever (14). The protrusion (81) does not exist at the destination when it tries to move in the front-rear direction (C1, C2) when it is rotated in the direction (D1), and has a shape that does not prevent the movement. A work vehicle characterized in that a lock mechanism (80) having a regulating member (82) is provided. The restricting member (82) has the forward / backward lever (14) downward (D2) at a portion arranged so as to exist at an intermediate position between the position for switching to the forward travel and the position for switching to the reverse travel. The member is characterized by having a concave portion (83) in which the protruding portion (81) enters and is prevented from moving in the front-rear direction (C1, C2) when the member is rotated. The work vehicle according to claim 1. The lock mechanism (80) according to claim 1 or 2, wherein the lock mechanism (80) has an urging member (86) for urging the forward / backward lever (14) to rotate downward (D2). Work vehicle. A connecting portion (51a) having a shaft through hole (53) through which the rotating shaft (62) is passed is provided at the upper end portion of the operation transmission shaft (51).
The lower part of the forward / backward lever (14) is provided with a connecting member (61) that is rotatably attached to and connected to the connecting portion (51a) via a rotating shaft (62). The work vehicle according to any one of claims 1 to 3. A fixing member (56) having an upper surface (56a) orthogonal to the operation transmission shaft (51) is attached to a portion of the operation transmission shaft (51) below the connecting portion (51a).
When the forward / backward lever (14) is rotated in the vertical direction (D1, D2) at the lower part of the connecting member (61), it comes into contact with the upper surface (56a) of the fixing member (56). The work vehicle according to claim 4, wherein a first contact portion (66) and a second contact portion (67) that limit the range of motion are provided. An urging member mounting portion that attaches the lower end portion of the urging member (86) to a portion of the fixing member (56) that is on the opposite side of the operation transmission shaft (51) from the forward / backward lever (14). (87) is provided
An urging member holding portion (88a) having a contact surface (88a) that faces the connecting member (61) with a gap from the urging member mounting portion (87) and contacts the upper end portion of the urging member (86). 88) is provided,
The lower end of the urging member (86) is held by the urging member mounting portion (87), while the upper end thereof contacts the contact surface (88a) of the urging member holding portion (88). The work vehicle according to claim 5, wherein the work vehicle is attached in a capable state and elastically deforms so as to contract when the forward / backward lever (14) is rotated at least in the upward direction (D1). The forward / backward lever (14) is rotatably attached to the upper end of the operation transmission shaft (51) at a position below the steering wheel (12), and the regulation member (82) is attached to the operation transmission shaft (82). The work vehicle according to any one of claims 1 to 6, wherein the work vehicle is arranged adjacent to the upper end portion of (51).

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