JP5764074B2 - Brake control tool for work vehicle - Google Patents

Description

  The present invention relates to a brake operating tool for a work vehicle.

  A pair of left and right brake pedals that are individually linked to the left and right traveling brakes, and an interlocking means for interlocking the pair of brake pedals so that the other brake pedal is depressed by depressing one brake pedal. The means comprises a locking piece provided on one brake pedal and a lock piece provided rotatably on the other brake pedal, and the brake pedal is engaged by engaging the locking piece with the locking piece. A brake operating tool for a work vehicle shown in Patent Literature 1 that releases the connection between brake pedals by connecting the brake pieces to each other and releasing the engagement of the lock pieces with the locking pieces is known.

Japanese Utility Model Publication No. 52-94632

If the brake operating tool of the work vehicle in the above document is in a state in which the lock piece is engaged with the locking piece and the brake pedals are connected to each other, both brake operations for operating both the left and right traveling brakes are performed by the operator. Can be done unconsciously.
However, when the operator who misunderstood that the brake pedals are connected to each other when the engagement between the locking piece and the locking piece is released, when the operator depresses only the brake pedal on one side, There is an inconvenience such as an erroneous operation of a single brake that is braked only by the traveling brake, and the aircraft suddenly turning against the operator's intention.
In addition, when the operator intentionally performs one-brake operation from the state where the brake pedals are connected to each other, after releasing the engagement between the lock piece and the locking piece and releasing the connection between the brake pedals, Since it is necessary to depress one brake pedal, it takes time to operate one brake.

  An object of the present invention is to provide a brake operating tool for a work vehicle that can smoothly perform one-brake operation of left and right brake pedals and both brake operations without erroneous operation.

  In order to solve the above-mentioned problem, first, a pair of left and right brake pedals 19L and 19R respectively linked to the left and right traveling brakes, and the other brake pedal 19L and 19R are operated by depressing one brake pedal 19L and 19R. A brake operating tool for a work vehicle having interlocking means for interlocking a pair of brake pedals 19L and 19R so as to be depressed, and an interlocking mechanism by connecting pieces 34 and 47 for connecting the pair of brake pedals 19L and 19R to each other The release pedals 38, 38L, 38R for releasing the connection between the brake pedals 19L, 19R by the connecting pieces 34, 47 are provided facing the upper side of the tread surface 24a of the brake pedals 19L, 19R. , 38L, 38R and one brake pedal 19L When the pedal 19R is depressed, the connection with the other brake pedals 19L and 19R via the connection pieces 34 and 47 is released, and only the traveling brake on the one brake pedal 19L and 19R side is braked. It is characterized by that.

  Secondly, left and right release pedals 38L and 38R facing each other are provided above the treads 24a of the left and right brake pedals 19L and 19R.

  Third, the release arm 36 is rotatably supported on the support shaft 22 that rotatably supports the brake pedals 19L and 19R, and the treads of the left and right brake pedals 19L and 19R are provided at the distal ends of the release arms 36. The left and right release pedals 38L and 38R that face each other above 24a and 24a and the left and right connecting pieces 34 and 34 for connecting the left and right brake pedals 19L and 19R are mounted and connected to the left and right brake pedals 19L and 19R. Locking portions 44, 44 for locking the pieces 34, 34 are formed, and when the release pedals 38L, 38R on one brake pedal 19L, 19R side are depressed, the locking portions of the other brake pedal 19L, 19R 44, the connecting piece 34 is detached, and the connection between the other brake pedal 19L, 19R and the one brake pedal 19L, 19R is released. It is characterized in Rukoto.

  Fourthly, the connecting piece 34 on the other brake pedal 19L, 19R side is integrally formed at the end of the release pedal 38L, 38R arranged on the one brake pedal 19L, 19R side opposite to the stepped portion, An elastic member 46 that biases the connecting piece 34 toward the side locked by the locking portion 44 is provided.

  Fifth, a cover plate 37 is disposed below the tread surface 24a of the brake pedals 19L and 19R, the cover plate 37 is fixed to the tip of the release arm 36, and the left and right release pedals 38L and 38R are attached to the cover plate 37. It is characterized by pivotally supporting on the back side.

  Sixth, the locking portions 44 formed on the brake pedals 19L and 19R are arranged so that the recess 44a into which the connecting piece 34 is inserted and the connecting piece 34 detached from the recess 44a is inserted into the recess 44a again. And a guide portion 44b for guiding the connecting piece 34.

  Since the release pedal that releases the connection between the brake pedals is provided above the tread surface of the brake pedal, the left and right brake pedals can be operated by unconsciously pressing the left and right brake pedals or one of the brake pedals in an emergency or emergency situation. Since they are connected and both brake operations are performed, it is possible to prevent an erroneous operation such as a sudden turn caused by one brake. In addition, when the release pedal and one brake pedal are consciously stepped on at one time with one foot, the connection between the brake pedals is released, and a small turn of the aircraft can be performed. Since the release pedal can be operated by depressing the release pedal in the same way as the brake pedal, the left and right brakes can be connected securely without forcibly damaging or damaging the foot. The brake can be released and a one-brake operation can be performed.

  In addition, a release arm is rotatably supported on a support shaft that rotatably supports the brake pedal, and left and right release pedals respectively facing above the treads of the left and right brake pedals at the distal end of the release arm; Attaching left and right connecting pieces that connect the left and right brake pedals together, and forming a locking part that locks the connecting pieces to the left and right brake pedals, along with the depressing operation of the release pedal on one brake pedal side The connecting piece is disengaged from the latching portion of the other brake pedal, the connection between the other brake pedal and the one brake pedal is released, and is opposite to the stepped portion of the release pedal arranged on the one brake pedal side. If the connecting piece on the other brake pedal side is integrally formed at the end on the side, and an elastic member is provided to urge the connecting piece to the side that is locked by the locking portion, the depression by the release pedal When the operation is released, the brake pedals are automatically connected by the urging force of the elastic member, so that the interlocking mechanism of the brake pedal can be configured relatively inexpensively, but the transition from the released state to the connected state is possible. It can be done reliably.

  If a cover plate is arranged below the tread surface of the brake pedal, the cover plate is fixed to the tip of the release arm, and the left and right release pedals are pivotally supported on the back side of the cover plate, the cover The pivot support portion of the release pedal is protected by the plate, and malfunction due to mud adhesion to the portion can be prevented.

  Furthermore, the latching part formed in each brake pedal has a recessed part into which the connecting piece is inserted, and a guide part that guides the connecting piece so that the connecting piece detached from the recessed part is inserted into the recessed part again. As a result, even when the release pedal operation is released during one-brake operation, the left and right brake pedals can be reliably returned to the connected state by the subsequent release of the brake pedal. It is not necessary to consider the operation for returning to the state, and the handleability can be improved.

1 is a side view of an agricultural tractor to which the present invention is applied. It is a principal part perspective view which shows the structure of the brake operation tool provided in the tractor of FIG. (A) is a side view of a brake pedal and a connection / release mechanism, and (B) is a view taken in the direction of arrow B in (A). (A), (B) is the front side perspective view and back side perspective view of a brake pedal and a connection / release mechanism. It is a principal part side view which shows the structure of a latching | locking part and a connection piece. (A) thru | or (C) is the front view, side view, and back side perspective view which show the state which stepped on and operated the release pedal of the right-and-left one side. (A) thru | or (C) is the front view, side view, and back side perspective view which show the state which stepped on the brake pedal of this release pedal side with the release pedal of the right-and-left one side. (A) thru | or (C) are the front view, side view, and back side perspective view which show the operation state at the time of canceling | pressing depressing operation of the release pedal and brake pedal of one side on either side. It is a perspective view which shows the structure of another embodiment of a brake operation tool. (A) is sectional drawing of the principal part which shows the state with which brake pedals were connected, (B) is sectional drawing of the principal part which shows the state with which brake pedals are not connected. (A) is sectional drawing of the principal part which shows the state with which brake pedals were connected, (B) is sectional drawing of the principal part which shows the state with which the connection of brake pedals was cancelled | released. It is a front view of a steering handle.

  FIG. 1 is a side view of an agricultural tractor to which the present invention is applied, and FIG. 2 is a main part perspective view showing a configuration of a brake operating tool provided in the tractor of FIG. A tractor of FIG. 1 which is a kind of work vehicle includes a traveling unit 3 constituted by a pair of left and right front wheels 1, 1 and a pair of left and right rear wheels 2, 2, a traveling machine body 4 supported by the traveling unit 3, and a traveling A rotary tiller device (working machine) 7 connected to the rear part of the machine body 4 through a lifting link 6 so as to freely move up and down, and the traveling machine body 4 is caused to travel forward in a state where the lowered rotary tiller device 7 is driven. As a result, the farming work (work) is performed.

  A cabin 8 is erected on the rear half of the traveling machine body 4, and a bonnet 11 is provided in front of the cabin 8 so as to open and close the engine 9 so that the engine 9 can be opened and closed. 8 Transmission is transmitted to the traveling unit 3 and the rotary tiller 7 by the transmission in the transmission case 12 arranged below.

  In the cabin 8, a control unit 13 on which an operator gets is installed. The control unit 13 is provided with a seat 14 on which the operator is seated and a steering handle 16 disposed in front of the seat 14. A floor step 17 serving as a floor surface is formed between the seat 16 and the seat 14. A single unit for intermittently transmitting power to the traveling unit 3 is provided at the front of the floor step 17 and directly below the steering handle 16. The clutch pedal 18 and a pair of left and right brake pedals 19L, 19R are suspended and arranged side by side.

  The left and right brake pedals 19L and 19R are arranged on the right side (hereinafter simply referred to as “right”) in the aircraft traveling direction opposite to the clutch pedal 18 so that the right pedal of the operator can be depressed. The left and right brake pedals 19L and 19R are mechanically coupled to left and right traveling brakes (not shown) via left and right linkage mechanisms 21L and 21R, respectively. The left and right traveling brakes are configured to individually brake the corresponding traveling units 3 and 3 to decelerate or stop traveling. In short, the left and right brake pedals 19L and 19R individually perform the brake operation of the left and right traveling units 3 and 3 via the left and right traveling brakes.

  A specific configuration will be described. A support shaft 22 in the left-right direction is supported on the front side of the floor step 17 via a bracket so as to be rotatable about its own axis, and the left and right brake pedals 19L. , 19R is composed of support arms 23, 23 extending downward from the support shaft 22 side, and treads 24, 24 provided integrally at the lower ends (tip portions) of the support arms 23, 23. Yes. Each support arm 23, 23 has a lower portion bent backward with respect to the upper portion and the middle portion. Each tread 24, 24 is installed at the tip of the support arm 23, 23 so as to incline downward toward the rear in side view, and the upper surface of the tread 24 becomes a tread 24a on which the operator's feet are placed.

  The upper end portion of each support arm 23 is integrally attached and fixed to a support tube 26 fitted on the support shaft 22 by welding or the like. One (left side) of the left and right support cylinders 26, 26 is fixed to the support shaft 22 with a pin, and the other is supported so as to be rotatable around the support shaft 22. For this reason, the left and right support arms 23 rotate back and forth integrally with the support shaft 22, but the other support arm 23 rotates back and forth around the support shaft 22 separately from the support shaft 22. .

  The linkage mechanism 21L on the brake pedal 19L side that rotates back and forth integrally with the support shaft 22 corresponds to the rotation of the support shaft 22, the linkage arm 27 that rotates together with the support shaft 22, and the linkage arm 27. It comprises a link mechanism 28 that transmits to the traveling brake. On the other hand, the linkage mechanism 21R on the side of the brake pedal 19R supported by the support shaft 22 so as to be freely pivotable back and forth is a linkage arm 29 that rotates integrally with the support cylinder 26, and a traveling brake that corresponds to the turning of the connecting arm 29. It is comprised from the link mechanism 31 which transmits to.

  The brake pedals 19L, 19R (support arms 23) are urged toward the rear rotation side by the elastic members 32, 32 formed of tension springs provided on the support cylinders 26, 26 side, and this elastic force is applied. The brake pedals 19L and 19R in an unoperated state are turned to the rear position by the force, and in this state, the traveling brake is inactive.

  That is, the brake pedals 19L and 19R are always urged toward the traveling brake off side by the elastic members 32 and 32. On the other hand, when the right foot is placed on the tread surface 24a and the brake pedals 19L and 19R are depressed against the urging force of the elastic member 32, the traveling brake mechanically linked to the brake pedals 19L and 19R is braked, Brake is applied to the traveling parts 3 and 3 on the traveling brake side.

  The brake pedals 19L and 19R configured as described above are connected to and released from the left and right brake pedals 19L and 19R by connecting and releasing the brake pedals 19L and 19R (see FIG. 3 to FIG. 3). 8), and the connecting / releasing mechanism 33 and the left and right brake pedals 19L and 19R constitute the brake operating tool of the present invention. According to this brake operating tool, both the left and right traveling brakes are applied. It is possible to smoothly perform both brake operations for braking operation and one-brake operation for braking only one of the left and right traveling brakes in a state where erroneous operation is prevented.

Next, the structure of the connection / release mechanism 33 will be described with reference to FIGS.
3A is a side view of the brake pedal and the connection / release mechanism, FIG. 3B is a view taken along the arrow B in FIG. 4A, and FIGS. 4A and 4B are the brake pedal and the connection / release mechanism. It is the front side perspective view and back side perspective view of a mechanism. Incidentally, since the brake pedals 19L and 19R are members facing the operator side (rear side in the traveling direction), the rear side surfaces of the brake pedals 19L and 19R are set to the front. The connection / release mechanism 33 includes a pair of left and right connection pieces 34, 34 for connecting the brake pedals 19L, 19R, and a release arm 36 that protrudes downward from the support shaft 22 side and is supported by the support shaft 22 so as to be able to rotate back and forth. And a cover plate 37 fixed to the lower end (front end) of the release arm 36, and a pair of left and right release pedals 38L and 38R rotatably supported on the back side (back side) of the cover plate 37. ing.

  The release arm 36 is disposed between the left and right brake pedals 19L, 19R, and a lower portion of the release arm 36 is bent rearward with respect to the upper and middle portions along the side view support arm 23. The upper end of the release arm 36 is attached and fixed by welding or the like to a support sleeve 39 that is externally fitted to the support shaft 22 so as to be rotatable about the axis. An elastic member 41 (see FIG. 2) is attached to the support sleeve 39 sandwiched between the left and right support cylinders 26, 26, thereby urging the release arm 36 to always rotate backward. Has been.

  The cover plate 37 has a distal end portion of the release arm 36 so as to be positioned below the brake pedals 38L and 38R on both the left and right sides (specifically, a lower surface side opposite to the tread surface 24a of the tread plate 24). It is attached and fixed to the front edge side. The cover plate 37 has a lateral width from the left tread plate 24 to the right tread plate 24. Incidentally, the attachment structure of the cover plate 37 to the release arm 36 will be described. A reverse L-shaped attachment bracket 40 is fixed to the lower part of the rear surface (front surface) of the release arm 36, and the attachment bracket 40 is seen in a side view. The cover plate 37 bent in an L shape is fixed by welding or the like so as to form a box shape, and the distal end portion of the release arm 36 is accommodated in the box shape.

  The release pedals 38 </ b> L and 38 </ b> R include a balance arm 42 bent in a U-shape and a release side tread plate 43. The left and right balance arms 42 are crossed in the rear view, and a bent portion of the U-shape is pivotally supported (pivotally supported) on the back side of the cover plate 37 via the mounting bracket 40 so as to be rotatable left and right. Yes. One side portion of each balance arm 42 is bent rearward, and at the end portion (tip portion) of this one side portion, the release side tread plate 43 whose upper surface becomes the tread surface 43a is provided on the tread surface 24a of the brake pedals 19L and 19R. It is attached integrally so that it may face the upper side.

  That is, the release side step plates 43 (stepping portions) of the release pedals 38L and 38R face close to the upper side of the tread surface 24a of the one side brake pedals 19L and 19R, while being opposite to the stepped portions of the release pedals 38L and 38R. The end portion (connection side end portion) is located in front of and below the tread plate 24 of the other side brake pedals 19L, 19R.

  The left and right connecting pieces 34 are integrally formed at the connecting side ends of the left and right release pedals 38L and 38R, respectively. On the other hand, a locking portion 44 extending forward is integrally projected from the distal end portion of the support arm 23, 23 of each brake pedal 19L, 19R. When the corresponding connecting piece 34 is detachably engaged with the locking portion 44 of the brake pedal 19L, 19R, the brake pedal 19L, 19R is connected to the release arm 36 via the mounting bracket 40, The release arm 36 and the brake pedals 19L and 19R are integrally rotated back and forth.

  Then, the left connecting piece 34 is engaged with the right engaging portion 44 and the right connecting piece 34 is engaged with the left engaging portion 44, whereby the mounting bracket 40 and the release arm 37 are interposed. The left and right brake pedals 19L, 19R are connected to each other. As a result, the left and right brake pedals 19L, 19R and the release arm 36 are rotated together. Incidentally, an elastic member 46 such as a tension spring that elastically biases the end of the balance arm 42 on the side of the connecting piece 34 toward the locking portion 44 is provided between each balance arm 42 and the cover plate 37. The left and right connecting pieces 34 are elastically urged toward the side engaging with the corresponding locking portion 44 by the left and right elastic members 46, 46.

  FIG. 5 is a principal side view showing the configuration of the locking portion 44 and the connecting piece 34. The structure of the locking portion 44 and the connecting piece 34 will be described in more detail. The locking portion 44 has a concave portion 44a for engaging and locking the corresponding connecting piece 34 with a concave and convex portion, and is detached from the concave portion 44a. A guide portion 44b is formed as a guide edge for guiding the non-engaged connection piece 44 biased toward the locking portion 44 by the elastic member 46 to the recess 44a.

  FIGS. 6A to 6C are a front view, a side view, and a rear perspective view showing a state where the release pedal on one of the left and right sides is depressed, and FIGS. 7A to 7C are left and right ones. FIGS. 8A to 8C are a front view, a side view, and a rear perspective view showing a state in which the brake pedal on the release pedal side is depressed together with the release pedal on the side, and FIGS. It is the front view, side view, and back side perspective view which show the operation state at the time of canceling the depression operation of a brake pedal.

  A case will be described in which the operator seated on the seat 14 performs a one-brake operation in which only the brake pedal 19L on one side (left side in the illustrated example) is depressed with the right foot.

  First, the operator places his right foot on the tread surface 43a of the release side tread plate 43 (release pedal 38L) on the left and right one side and steps forward diagonally downward against the elastic force of the elastic member 46. Then, the connecting piece 34 is disengaged upward from the recess 44a provided in the locking portion 44 of the brake pedal 19R on the left and right other side, the engagement between both is released, and the brake pedal 38R and the mounting bracket 40 on the other side are released. Is released (that is, the connection between the one-side brake pedal 38L and the other-side brake pedal 38R is released) (see FIG. 6).

  Subsequently, a right foot is placed on the tread surface 43a of the release side tread plate 43 on the one side and the tread surface 24a of the brake pedal 19L on the side close to the release side tread plate 43, and the release pedal 38L and the brake pedal 19L are stepped on together. Then, a one-brake operation in which only the brake pedal 19L on one side is depressed is performed, and a braking force acts only on the traveling unit 3 on the one side via the traveling brake (see FIG. 7).

  Finally, when the right foot is released from the release pedal 38L and the brake pedal 19L on the one side, the connecting piece 34 is guided toward the recess 44a along the guide portion 44b by the elastic force of the elastic member 46. 34 and the recess 44a are automatically engaged with each other, and the brake pedal 19R on the other side and the mounting bracket 40 (and the brake pedal 19L on the one side) are connected again (see FIG. 8).

  In addition, a case will be described in which the operator seated on the seat 14 performs both brake operations by depressing the left and right brake pedals 19L and 19R with the right foot.

  If the operator depresses the brake pedals 19L and 19R on at least one side without being aware of it, the brake pedals 19L and 19R are connected to each other by the left and right connecting pieces 34 and 34. The pedals are operated together and both brake operations are performed.

  According to the brake operation tool configured as described above, one brake operation is performed by depressing and operating the release pedals 38L and 38R and the brake pedals 19L and 19R on one side of the left and right sides consciously and naturally. One-brake operation can be performed quickly and smoothly, and it is also efficiently prevented that one-brake operation is mistaken for both-brake operations.

  Further, when the one-brake operation is finished, the two brake operations can be performed quickly and smoothly because the operation of the guide portion 44b and the elastic member 46 automatically returns the state where both the brakes can be operated. . The cover plate 37 is disposed below the tread surface 24a of the brake pedals 19L and 19R, and the left and right release pedals 38L and 38R are pivotally supported on the back side of the cover plate 37 via the mounting bracket 40. Even when the brake pedals 19L and 19R are treaded with the mud-attached shoes, the pivot portions of the left and right release pedals 38L and 38R are protected by the cover plate 37, preventing malfunction due to mud adhesion of the pivot portions. can do.

Next, a different part from the above-mentioned example is demonstrated about another embodiment of a brake operation tool based on FIG.9 and FIG.10.
FIG. 9 is a perspective view showing the configuration of another embodiment of the brake operating tool, FIG. 10A is a cross-sectional view showing a state in which the brake pedals are connected to each other, and FIG. It is sectional drawing which shows the state which is not made. In the example described above, the pair of left and right release pedals 38L and 38R face the upper side of the left and right brake pedals 19L and 19L, respectively, but in this example, a single upper side of the left and right brake pedals 19L and 19R is single. The release pedal 38 is configured to face.

  More specifically, in the illustrated brake operation tool, a single release pedal 38 (release side tread 43) facing the upper surfaces of the treads 24a and 24a of the left and right brake pedals 19L and 19R is fixed to the tip of the release arm 36. A left and right connecting rod 47 functioning as the connecting piece is movable in the axial direction via a support member 48 on the support cylinder 26 of the brake pedal 19R on the left and right side (right side in the illustrated example). The support cylinder 26 of the brake pedal 19L on the left and right side is provided with a plate-like locking portion 49 having a connection hole 49a into which the connection rod 47 is removably inserted. An elastic member 51 that urges the rod 47 toward the side to be inserted into the coupling hole 49a is mounted on the outer periphery of the coupling rod 47, and the release pedal 38 is depressed on the side where the locking portion 49 and the coupling rod 47 are located. And tread Actuating mechanism 52 for moving actuating the connecting rod 47 with the vertical pivot by viewing released in the axial direction is provided.

  The operating mechanism 52 includes a cam 53 that rotates together with the support sleeve 39 and a contact portion 54 that moves integrally with the connecting rod 47 in the axial direction. When the release pedal 38 is depressed, the cam 53 comes into contact with the contact portion 54 and resists the elastic force of the elastic member 51 so that the connection rod 47 is pulled out from the connection hole 49a. As a result, the connection between the brake pedals 19L and 19R is released, and a one-brake operation is possible. On the other hand, when the depression of the release pedal 38 is released, the cam 53 becomes inoperative with respect to the contact portion 54, and the connecting rod 47 is reinserted into the connecting hole 49a by the elastic force of the elastic member 51. .

  By the way, when the left and right brake pedals 19L and 19R and the release pedal 38 are released, the left and right brake pedals 19L and 19R are rotated to the rearmost position by the urging force of the elastic member 51, and the connecting rod 47 and The positions of the connecting holes 49a coincide in side view, the connecting rod 47 is smoothly inserted into the connecting hole 49a, and the left and right brake pedals 19L, 19R are automatically and smoothly connected.

  According to the brake operating tool having such a configuration, one brake pedal 19L, 19R is consciously depressed together with the release pedal 38 to perform one-brake operation, and at least one brake pedal 19L, 19R in normal or emergency situations. By depressing, both brakes are operated.

Next, based on FIG.11 and FIG.12, a different part from the above-mentioned example is demonstrated about the modification of the brake operation tool shown in FIG.9 and FIG.10.
FIG. 11A is a cross-sectional view showing a state where the brake pedals are connected to each other, and FIG. 11B is a cross-sectional view showing a state where the connection between the brake pedals is released.

  In this example, without providing the release arm 36 and the release pedal 38, the left and right support cylinders 26, 26 are directly adjacent to each other, and the connection hole 49 a A solenoid 57 having a left / right engaging / disengaging shaft 56 that is removably inserted into the housing is provided.

  When the solenoid 57 is not driven, the connecting rod 47 is inserted into the connecting hole 49a by the urging force of the elastic member 51, and the brake pedals 19L and 19R are connected to each other (see FIG. 12A). On the other hand, when the solenoid 57 is driven, the engagement / disengagement shaft 56 is inserted into the connection hole 49a, and the connection rod 47 is pulled out from the connection hole 49a, and the connection between the brake pedals 19L and 19R is released. (Refer to FIG. 5B). By switching between non-driving and driving of the solenoid 57 in this way, it is possible to switch between both brake operation states and one-brake operation possible states.

  FIG. 12 is a rear view of the steering handle. An operation lever 58 for raising and lowering the rotary tiller 7 is provided toward the side of the steering handle 16 from the side of the steering shaft (not shown). The operation lever 58 is swung in a direction away from or close to the steering handle 16 to move the rotary tiller 7 up and down, and the operation lever 58 is rotated around the steering shaft to operate as described above. The solenoid 57 is turned on and off.

  Specifically, when the operation lever 58 is turned to one side around the steering shaft (front side in the illustrated example), the solenoid 57 is driven, and the brake pedals 19L and 19R are connected to each other. Then, when the other side is turned, the solenoid 57 is stopped and the brake pedals 19L and 19R are disconnected. That is, the operation lever 58 switches the operation position between the rear drive stop position and the front drive position by a turning operation around the steering shaft, thereby driving and stopping the solenoid 57.

  In addition, steering operation (steering operation) is performed by turning the steering handle 16. However, when the steering operation is performed so that the aircraft travels straight after turning left and right, it is provided on the base end side of the operation lever 58. The operation lever 58 is automatically returned to the drive stop position by the function of the conventionally known cancel rotor (not shown). That is, after a single brake operation is performed together with the steering operation and the aircraft is turned slightly, the two brake operation states are automatically restored.

19L Left brake pedal (brake pedal)
19R Right brake pedal (brake pedal)
22 Support shaft 24a Tread surface 34 Connecting piece 36 Release arm 37 Cover plate 38 Release pedal 38L Left release pedal 38R Right release pedal 44 Locking portion 44a Recess 44b Guide portion 47 Connection piece

Claims (6)

  A pair of left and right brake pedals (19L), (19R) individually linked to the left and right traveling brakes, and the other brake pedal (19L), (19R) by depressing one of the brake pedals (19L), (19R) Is a brake operating tool for a work vehicle having interlocking means for interlocking the pair of brake pedals (19L) and (19R) so that the pedals are stepped on. The pair of brake pedals (19L) and (19R) are coupled to each other. The connecting pieces (34) and (47) to be operated constitute a linkage mechanism, and the release pedals (38) and (19) for releasing the connection between the brake pedals (19L) and (19R) by the connecting pieces (34) and (47). 38L) and (38R) are provided above the tread surface (24a) of the brake pedals (19L) and (19R), and the release pedals (38) and (3 L), (38R) and when one brake pedal (19L), (19R) is depressed, the other brake pedal (19L) via the connecting pieces (34), (47), A brake operating tool for a work vehicle in which the connection with (19R) is released and only the traveling brake on the one brake pedal (19L), (19R) side is braked.   The brake operating tool for a work vehicle according to claim 1, wherein left and right release pedals (38L) and (38R) facing each other are provided above the treads (24a) of the left and right brake pedals (19L) and (19R).   The release arm (36) is rotatably supported on a support shaft (22) that rotatably supports the brake pedals (19L) and (19R), and left and right brakes are mounted on the distal end of the release arm (36). The left and right release pedals (38L) and (38R) respectively facing the tread surfaces (24a) and (24a) of the pedals (19L) and (19R) and the left and right brake pedals (19L) and (19R) are connected to each other. The left and right connecting pieces (34) and (34) are mounted, and the left and right brake pedals (19L) and (19R) are engaged with the engaging portions (44) and (44) for engaging the connecting pieces (34) and (34). 44), and when the release pedals (38L) and (38R) on one side of the brake pedals (19L) and (19R) are stepped on, the locking parts of the other brake pedals (19L) and (19R) (44) to connecting piece ( 4) is disengaged, said other of the brake pedal (19L), (19R) and the one brake pedal (19L), (19R) and the brake operation member of the working vehicle according to claim 2, wherein the coupling is released.   The other brake pedal (19L), (19R) side connection to the end of the release pedal (38L), (38R) disposed on the one brake pedal (19L), (19R) side opposite to the stepped portion The brake operation of the work vehicle according to claim 3, wherein the piece (34) is integrally formed, and an elastic member (46) for urging the connecting piece (34) toward the side locked by the locking portion (44) is provided. Ingredients.   A cover plate (37) is disposed on the lower side of the tread surface (24a) of the brake pedals (19L) and (19R), and the cover plate (37) is fixed to the tip of the release arm (36). The brake operating tool for a work vehicle according to claim 4, wherein (38L) and (38R) are pivotally supported on the back side of the cover plate (37).   The locking portion (44) formed in each brake pedal (19L), (19R) includes a recess (44a) into which the connecting piece (34) is inserted, and a connecting piece (34) detached from the recess (44a). The brake operating tool for a work vehicle according to any one of claims 4 and 5, further comprising a guide portion (44b) for guiding the connecting piece (34) so that the connecting piece (34a) is reinserted into the recess (44a).

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