JP4764437B2 - Brake operation mechanism of tractor - Google Patents

Description

  The present invention relates to a brake operation mechanism using a side brake pedal and a parking brake pedal linked to a pair of left and right side brakes.

  As a conventional brake operation mechanism of a tractor, for example, as disclosed in Patent Document 1, on the left and right sides of the front part centered on the driver seat in the step floor located in front of the driver seat, A pair of left and right side brake pedals that are linked to the left and right side brakes via the first linkage mechanism are arranged close to each other, and the left and right sides When parking with a parking brake pedal for parking that is linked to the brake via the second linkage mechanism, and the left and right side brakes can be operated and held in the braking state by depressing the parking brake pedal. By depressing the parking brake pedal, the parking brake pedal is depressed to maintain the posture What was Unishi is known.

As shown in FIGS. 11 to 14 of Patent Document 1, the brake operation mechanism disclosed in Patent Document 1 moves down the tread of the parking brake pedal with the left and right side brakes being released. The left and right side brakes can be operated and held in the braking state by stepping on the left and right sides, but when releasing the left and right side brakes, the parking claws are released by pulling the release levers provided separately to remove the locking claws. Return the pedal to the upper position and release the left and right side brakes.
Alternatively, as shown in FIG. 4 to FIG. 7 and FIG. 8 to FIG. 10 of Patent Document 1, the parking brake pedal tread surface is provided to be swingable with respect to the pedal arm, and the left and right side brakes are released from braking. If the front end of the tread of the parking brake pedal is stepped strongly with a scissors while it is The left and right side brakes can be operated and held in the braking state by engaging, and when releasing the left and right side brakes, the latching claw is removed by swinging the tread surface of the pedal in the reverse direction. The left and right side brakes are released by releasing the parking brake pedal while raising the parking brake pedal.

  In the former case, when operating and holding the left and right side brakes in the braking state during parking, it is not necessary to worry about the tread surface, it is only necessary to depress the tread surface of the parking brake pedal. When releasing the brake, a manual lever different from the parking brake pedal has to be operated, and there is a problem that the left and right side brakes must be manually released. On the other hand, in the latter case, the left and right side brakes can be operated and held in the braking state, and the brakes can be released simply by depressing the foot, but the steps when operating and holding the left and right side brakes in the braking state and when releasing the brakes are possible. Since the operation position of the surface has to be changed to a position adapted to it, there is a disadvantage that the operation and holding to the braking state and the brake releasing operation are not successful unless used.

Further, in the brake operation mechanism disclosed in Patent Document 1, when the parking brake pedal is depressed while the braking state of the left and right side brakes is released, the left and right side brake pedals move together. Excessive operating force is required for the operation of depressing the pedal, and there is annoyance that an impact sound is generated when the left and right side brake pedals are raised when the left and right side brakes are released.
JP-A-11-321594

  The present invention relates to a parking brake in which the braking operation and the releasing operation of the parking brake in the tractor can be performed only by depressing the tread surface of the parking brake pedal regardless of how the parking brake pedal is depressed, and the brake is in the braking state even when the braking is released. An object of the present invention is to provide a brake operation mechanism that can release a brake by simply depressing the pedal and then returning it.

  Another object of the present invention is to eliminate the conventional inconvenience of the tractor by preventing the left and right side brake pedals in front of the driver's seat from moving when operating the parking brake pedal.

〔Constitution〕
The first feature of the present invention is that the left and right side brakes for the left and right rear wheels are respectively connected to the left and right side brakes for the left and right rear wheels via the first linkage mechanism. A pair of left and right side brake pedals that are linked in close proximity to each other, and the parking that is linked to the left and right side brakes via a second linkage mechanism at a position closer to the driver seat than the side brake pedal on the step floor In a tractor brake operation mechanism configured to be capable of operating and holding the left and right side brakes in a braking state by providing a parking brake pedal for use and depressing the parking brake pedal,
The parking brake pedal includes a tread surface fixed to a pedal arm, and the left and right side brakes are operated by depressing the tread surface of the parking brake pedal downward while the left and right side brakes are released from braking. Is provided with a pedal depression type brake release switching mechanism for releasing the braking of the side brake in the braking state by depressing the tread surface of the parking brake pedal again from the braking state of the side brake.
The pedal depression type brake release switching mechanism includes an engagement plate having a plurality of engagement recesses formed on an upper edge and a stopper member integrally attached to the pedal arm, and is engaged / disengaged from above with respect to the engagement recess. A claw swinging member provided with a locking claw, a stopper pin provided in the claw swinging member and engaging the claw swinging member with the engaging recess the release posture and positioning swinging member for attitude change, said the body-fixed portion of the pedal arm is supported, is respectively equipped to oscillatory movement is supported by another axis to another Rutotomoni, wherein A reversing spring for linking the claw swinging member and the positioning swinging member,
The positioning rocking member is fixed to the stopper pin so that the engaging recess that moves relative to the locking claw as the parking brake pedal is depressed engages the locking claw at a desired depression position. The left and right side brakes are operated to a braking state by pressing the pawl swinging member to the side where the engaging posture is maintained , and the parking brake pedal is depressed again with respect to the positioning swinging member. The stopper pin is slidably moved, and the claw swinging member is changed in posture to a posture for releasing the engagement of the engagement recess with respect to the locking claw to release the braking state of the left and right side brakes, and the operation of accompanying the stopper member to return operation after again depressing operation of the pedal arm, the positioning swinging member through the stopper pin and the reverse spring the Operating the swing member, it lies in the engagement of the locking pawl to said engagement recess is configured to return to a state as possible.

[Action]
According to the first feature of the present invention, the left and right side brake pedals in front of the driver's seat are connected to the left and right side brakes via the first linkage mechanism, and the parking brake pedal below the side of the driver's seat is connected to the left and right side brakes via the second linkage mechanism. It is linked to. As a result, the right side brake can be operated in the braking state by depressing the right side brake pedal, and the left side brake can be operated in the braking state by depressing the left side brake pedal. can do. At the time of parking, the left and right side brakes can be operated and held in a braking state only by operating the parking brake pedal, and the side brakes are used as parking brakes.

  Next, the left and right side brakes can be released by depressing the parking brake pedal again.

  According to the first feature of the present invention, the parking brake pedal is fixed to the pedal arm of the parking brake pedal when the left and right side brakes are operated and held in the braking state and the left and right side brakes are released. Therefore, the parking brake pedal can be easily depressed without having to worry about how to depress the parking brake pedal as in the prior art.

〔The invention's effect〕
According to the first feature of the present invention, the parking brake pedal can be easily operated and maintained in the braking state of the left and right side brakes and the brake can be released without worrying about how to step on the parking brake pedal.

〔Constitution〕
According to a second aspect of the present invention, in the first aspect of the invention, the pair of left and right side brake pedals are arranged on the right side of the front part centering on the driver seat on the step floor, and the main clutch pedal for the main clutch is disposed on the step floor. The parking brake pedal is disposed behind the main clutch pedal, and the parking brake pedal is disposed on the left side of the front part centering on the driver's seat.

[Action]
In tractors, getting on and off from the left is normal. In medium-sized aircraft, many control levers are arranged on the right side, and getting on and off from the right is harder than on the left side. In particular, a tractor with a mid-mount mower has a discharge port on the right, making it difficult to get on and off from the right.
According to the second feature of the present invention, since the parking brake pedal is provided on the lower left side in the vicinity of the seat, the protruding state of the parking brake pedal can be visually observed when getting on and off, and it is easy to notice if the parking brake is depressed. If you forget to operate, you can depress the parking brake pedal when you get off.
Further, by manually operating the parking brake pedal even in the state of getting off, the left and right side brakes can be easily operated and maintained in the braking state, and the braking can be released.

Further, according to the second feature of the present invention, the parking brake pedal can be depressed while operating the left and right side brake pedals in front of the driver's seat. In this case, the side brake is first applied with the left and right side brake pedals. Since the brake is operated, the parking brake pedal can be depressed with an extremely light operating force, which is convenient when the parking brake is immediately applied when the vehicle is stopped. In this way, since the simultaneous operation of the side brake pedal and the parking brake pedal when the parking brake pedal even the parking brake pedal to receive a heel while stepping Le is also possible, in accordance with both feet easily be a shorty There is an advantage that simultaneous operation can be easily performed.

〔The invention's effect〕
According to the second feature of the present invention, there is an advantage that forgetting to depress the parking brake pedal when getting off can be reduced. Further, there is an advantage that the parking brake pedal can be easily manually operated when the vehicle is alighted.

  Further, there is an advantage that the left and right side brakes can be easily operated by the both foot operations of depressing the parking brake pedal while depressing the side brake pedal.

〔Constitution〕
According to a third aspect of the present invention, in the first or second aspect of the invention, a bracket is provided on the operating arm for operating the side brake, and two through holes are formed through the bracket in the front-rear direction. The rear end side of the operation rod constituting the first linkage mechanism is inserted into one through hole of the through holes, and the first contact portion is provided at the rear end portion of the operation rod located on the rear side of the bracket. The rear end of the second rod located on the rear side of the bracket by connecting the rear end of the second rod constituting the second linkage mechanism to the other through hole of the two through holes The second connecting part is connected to the part,
When the operating rod is pulled by operating the side brake pedal, the operating arm is swung through the first contact portion without operating the parking brake pedal due to the accommodation through the other through hole. is not allowed to braking operating the side brake,
When the parking brake pedal is depressed and the second rod is pulled , the side brake pedal is not actuated by the accommodation through the one through hole , and the operating arm is swung through the second contact portion. The side brake is configured to be actuated by braking.

[Action]
According to the third feature of the present invention, the parking brake pedal is not operated when the left and right side brake pedals are depressed, and the left and right side brake pedals are not activated when the parking brake pedal is depressed. In particular, when depressing the parking brake pedal, the parking brake pedal can be depressed more easily than when using the conventional structure. It is not generated.
Further, the parking brake pedal can be depressed with the left and right side brake pedals depressed, and in this case, the parking brake pedal can be depressed with a light depression force.

In addition, it has become possible to easily operate the left and right side brakes to the braking state by operating both feet by depressing the parking brake pedal while depressing the side brake pedal.
〔The invention's effect〕
According to the third feature of the present invention, the parking brake pedal can be operated easily and lightly. In particular, when you depress the parking brake pedal immediately after operating the side brake pedal, you can operate the parking brake pedal while depressing the side brake pedal. The operation can be performed.

  FIG. 1 shows an entire side surface of the tractor. The tractor is arranged at an engine 21 mounted on the front part of the fuselage, a clutch housing 22 incorporating a main clutch connected to the rear part of the engine 21, and disposed on the rear part of the fuselage. The transmission case 23, a pair of left and right front wheels 24 that can be driven by the power after the transmission from the engine 21 through the transmission case 23, and a pair of left and right rear wheels that are driven by the power after the transmission from the engine 21 through the transmission case 23. 25, steering wheel 26 for steering operation, driver seat 1 disposed between left and right rear wheels 25, step floor 2 disposed between front wheels 24 and rear wheels 25, and step floor 2 A rear fender 29 is provided so as to cover the upper part of the left and right rear wheels 25 from the rear.

  As shown in FIG. 1 and FIG. 2, a rear axle case 30 connected to the left and right of the mission case 23 at the front portion of the right side portion of the step floor 2, which is the left and right side portion sandwiching the driver seat 1. Left and right side brakes linked to the operation arms 31 of the left and right side brakes 3 (the left side brake 3a and the right side brake 3b), respectively, via the pivot shaft 32 and the left and right operation rods 33. Brake pedals 5 (left side brake pedal 5a and right side brake pedal 5b) are arranged close to each other, and only one of the left and right side brake pedals 5a and 5b is depressed with the right foot. By operating, only the left and right side brakes 3 can be operated in the braking state. As shown in FIG. 14, the left and right side brake pedals 5a and 5b are engaged by the engagement lock member 34, and both the left and right side brake pedals 5a and 5b are simultaneously depressed with the right foot to operate the left and right side brakes 3a and 5b. 3b can be operated to the braking state at the same time. A shift pedal 35 linked to a hydrostatic continuously variable transmission HST (not shown) that shifts the power of the engine 21 is arranged in parallel on the right side of the right side brake pedal 5b. The speed control operation can be performed by adjusting the depression amount of the pedal 35 with the right foot.

  A main clutch pedal 12 linked to the main clutch is disposed at the front portion of the left side of the step floor 2 that is the left and right other side with the driver seat 1 interposed therebetween. By depressing with the left foot, the disengagement state of the main clutch that interrupts transmission from the engine 21 to the transmission case 23 can be revealed. On the other hand, the left recessed space S of the recessed spaces S between the left and right rear fenders 29 and the under-seat cover 36, which are rear portions, is linked to the left and right side brakes 3a and 3b. The parking brake pedal 8 configured to be able to be engaged and held in a braking operation range in which the left and right side brakes 3a and 3b are braked is deployed in a state where it is located behind the lower front end position of the left rear fender 29. The left and right side brakes 3a and 3b are maintained in a braking action state by depressing the parking brake pedal 8 with the left foot and engaging and holding it in the braking operation area, thereby functioning as a parking brake. The parking brake state to be displayed can be displayed.

  A lower link 38 is provided at the rear of the machine body to raise and lower the connected working machine (not shown) as the lift arm 37 swings.

  In the embodiment of the present invention, the left and right side brake pedals 5 a and 5 b are linked to the same left and right side brakes 3 a and 3 b via the first linkage mechanism 4 including the operation rod 33 and the operation arm 31. . A parking brake pedal 8 includes an operation arm 59, a first rod 62 disposed only on the left side, a left and right relay swing arm 61 linked via a rotation shaft 60, a second rod 63, and a second operation arm 31. They are linked via a linkage mechanism 7.

  Reference numeral 71 in the rear part of the rear fender 29 shown in FIGS. 1 and 2 is a brake lamp. The switch 72 of the brake lamp 71 is fixed to the side portion of the mission case 23 and is in a cut state when pressed by a bracket 73 fixed to the operation rod 33. The brake lamp 71 is connected to the left operating rod 33 constituting the first linkage mechanism 4 so that it lights up when the left side brake pedal 5a alone or the left and right side brake pedals 5a, 5b are stepped on simultaneously. The brake switch 72 for turning on and off the brake lamp 71 by operating the left operating rod 33 is linked, and the brake lamp 71 is not turned off when the parking brake pedal 8 is depressed and returned. The brake switch 72 is turned on and operated by depressing operation 5a to turn on the brake lamp 71, and the brake switch 72 is turned off and operated to turn off the brake lamp 71 by returning the left side brake pedal 5a.

The first linkage mechanism 4 and the second linkage mechanism 7 are respectively connected between the bracket 65 of the operation arm 31 and the operation rod 33 linked to the left and right side brake pedals 5a and 5b and to the bracket 65 and the parking brake pedal 8. An accommodation mechanism is provided between the two rods 63. In this accommodation mechanism, when the left and right side brake pedals 5a and 5b are depressed, the operation rod 33 moves forward and the operation arm 31 is moved via the rear end spacer 66 (corresponding to the first contact portion). 4, the second rod 63 linked to the parking brake pedal 8 does not move, and the bracket 65 is moved from the spacer 67 (corresponding to the second contact portion). It only moves away and moves forward, and there is an accommodation (an accommodation mechanism) between the bracket 65 and the spacer 67 so that the operation rod 33 can move freely. When the parking brake pedal 8 is depressed, the second rod 63 moves forward to swing the operation arm 31 clockwise through the rear end spacer 67. In this case, The operating rod 33 linked to the left and right side brake pedals 5a and 5b does not move, the bracket 65 only moves forward away from the spacer 66, and the second rod 63 is free between the bracket 65 and the spacer 66. Is provided with a flexible movement (flexibility mechanism).

  Thus, when the left side brake pedal 5a or the left and right side brake brake pedals 5a and 5b are depressed, the left or right side brakes 3a and 3b are braked without operating the parking brake pedal 8, and the brake switch 72 operates to turn on the brake lamp 71. When the parking brake pedal 8 is depressed, the left and right side brake pedals 5a and 5b are not operated, and the left and right side brakes 3a and 3b are braked.

The left and right side brake pedals 5a and 5b are arranged on the right side of the front part centering on the driver seat 1 on the step floor 2 of the driver A, and the main clutch pedal 12 for the main clutch is centered on the driver seat 1 on the step floor 2. The parking brake pedal 8 is disposed at a position behind the main clutch pedal 12.

  From the above configuration, the left and right side brake pedals 5a and 5b provided on the right side of the aircraft are simultaneously depressed with the right foot to stop the aircraft, and then the parking brake pedal 8 provided on the left side of the aircraft is The aircraft can be parked easily by depressing it with a heel.

  In addition, a parking brake pedal 8 that can operate the left and right side brakes by depressing is used to operate the left and right side brakes when parking, and the parking brake pedal is placed in the recessed space S formed on the left side of the aircraft. 8, the parking brake pedal 8 can be prevented from getting in the way when getting into and out of the tractor from the left side where the parking brake pedal 8 is deployed, and when maneuvering. It is possible to easily get on and off the tractor from the left side where the parking brake pedal is provided, and to improve the comfort of the parking brake pedal 8 provided as the parking brake pedal 8 provided below the operator's feet.

  Moreover, the parking brake pedal 8 is arranged on the opposite side of the left and right side brake pedals 5a and 5b with the driver seat 1 interposed therebetween, so that when parking on an uphill or downhill, the left and right side brake pedals 5a with the right foot are used. , 5b can be used to operate the left and right side brakes by stepping on the parking brake pedal 8 with the foot of the left foot while maintaining the travel stop state by simultaneously depressing the pedal. The stepping operation can be easily performed.

  In addition, when it is necessary to stop the aircraft urgently, the aircraft can be quickly urgently stopped by depressing the parking brake pedal 8 with the heel of the left foot.

As shown in FIGS. 3 to 8, the parking brake pedal 8 includes a pedal arm 44, a pedal arm supported on the left side portion of the transmission case 23 via a support member 43 so as to swing up and down around the first horizontal axis P <b> 1. 44, a pedal plate 45 fixed to the free end of 44, a lower end fixed to the outer surface of the intermediate portion of the pedal arm 44, and an upper portion bent to the inside of the fuselage so as to stand vertically upward with respect to the pedal arm 44, a pedal An engagement plate 48 fixed to the side surface of the body of the arm 44 and having a plurality of engagement recesses 47 formed on the upper edge, is provided between the support member 43 and the pedal arm 44 to urge the pedal arm 44 in the upward direction. An urging spring 49, a support shaft 50 fixed to the support member 43, a long hole 51 inserted through the support shaft 50, a locking claw 52 that engages with an engagement recess 47 of the engagement plate 48, and a stopper pin 53 are provided. The claw swinging member 55 to which one end of the rolling spring 54 is attached and the other end of the reversing spring 54 are attached to the support member 43 by being pushed by the stopper member 46 of the pedal arm 44 in the free state of the parking brake pedal 8. It swings around the second horizontal axis P2 by the fixed support shaft 56, engages with the stopper pin 53 of the claw swinging member 55, and moves the claw swinging member 55 around the third horizontal axis P3 by the support shaft 50. A positioning rocking member 57 that biases the claw engagement direction (counterclockwise in FIG. 7) to position the pedal arm 44 and a support shaft 58 that forms the first horizontal axis P1 on the pedal arm 44 are integrated. An operation arm 59 that is swingably connected, a pair of left and right relay swing arms 61 that are connected so as to be swingable integrally around the fourth horizontal axis P4 via a rotation shaft 60, and a relay on the left side of the operation arm 59. Built over the swing arm 61 Left and right side brakes 3a, 3b via a first rod 62 and a second rod 63 installed across the left and right relay swing arms 61 and the corresponding operation arms 31 of the side brakes 3a, 3b. It is linked to. The operating arm 31 is fixedly provided with an operating rod 33 linked to the side brake pedals 5 a and 5 b and a bracket 65 for inserting the second rod 63. The operating rod is inserted into two through holes formed in the bracket 65. The abutting position can be adjusted by double nuts 68 and 69 via spacers 66 and 67 at the rear portions of 33 and the second rod 63, respectively. In the pedal arm 44, the stopper member 46 contacts the positioning swing member 57 in the free state of the parking brake pedal 8, and the locking claw 52 of the claw swing member 55 engages with the engagement recess 47 of the engagement plate 48. Oscillation is restricted by being locked. In addition, the code | symbol 64 shown in FIG. 4 is an urging | biasing spring which returns and urges | biases the operation arm 31 of each right and left side brake 3a, 3b to a brake release position.

  When the parking brake pedal 8 is depressed, for example, the pedal plate 45 of the parking brake pedal 8 (see FIG. 9) that has returned to the free braking release posture is depressed with the left foot of the foot to lower the pedal arm 44. As shown in FIGS. 9 to 10, while the pedal plate 45 is being depressed, the engagement claw 52 of the claw swinging member 55 is moved by the reversing spring 54 to the engagement recess 47 side of the engagement plate 48. The pedal arm 44 is lowered while sequentially moving the position of the engaging recess 47 in the state of being urged by. Then, when the left foot is released from the front position of the parking brake pedal 8 when it is depressed to the desired depression position, the engagement claw 52 engaged with the engagement recess 47 by the action of the biasing spring 49 is engaged. The claw swinging that is in contact with the lower end of the support shaft 50 and the long hole 51 by the acting force that the locking claw 52 rotates in the clockwise direction about the first horizontal axis P <b> 1 is pressed against the recess 47. The member 55 swings and contacts with the upper end of the long hole 51 and is fixed in a state where the engagement between the locking claw 52 and the engagement recess 47 is held. As a result, the parking brake pedal 8 is engaged and held in the braking operation area in which the left and right side brakes 3a and 3b are braked (see FIG. 11). That is, the braking and holding operation for locking and holding the parking brake pedal 8 in the braking operation area can be performed easily and reliably by simply depressing the parking brake pedal 8 with the left foot.

  On the other hand, when the parking brake pedal 8 is locked and held in the braking operation area, when the pedal plate 45 of the parking brake pedal 8 is depressed again with the left foot heel against the urging spring 49, the pedal arm 44 is operated. With the downward movement, the locking claw 52 is separated from the engagement recess 47, and the claw swinging member 55 is lifted around the support shaft 56 by the action of the reversing spring 54, and is located above the long hole 51 with respect to the support shaft 50. The claw swinging member 55 that has been in contact abuts the lower portion of the long hole 51 [see FIG. 12]. After that, when the pedal arm 44 is raised and further raised from the state of FIG. 13 and the front edge of the positioning swing member 57 above the support shaft 56 is pressed by the stopper member 46, the positioning swing member 57 is supported. As the shaft 56 swings clockwise about the second horizontal axis P2, the claw swinging member 55 swings counterclockwise about the third horizontal axis P3 to engage the locking claw. 52 engages with the engaging recess 47, whereby the parking brake pedal 8 returns to the braking release posture at the free position (see FIG. 9). That is, the brake releasing operation for releasing the engagement and holding of the parking brake pedal 8 in the braking operation area can be easily and reliably performed only by depressing the parking brake pedal 8 with the left foot.

In short, maintaining the left and right side brakes 3a and 3b in the braking action state and maintaining the parking state of the aircraft (parking brake operation) and maintaining the left and right side brakes 3a and 3b in the braking action state Both the braking releasing operation (parking brake releasing operation) for releasing the parking state of the airframe can be easily and reliably performed simply by repeatedly depressing the parking brake pedal 8 using only the left foot.
In the present invention, an engagement / disengagement mechanism that performs braking / releasing of the left and right side brakes 3a and 3b only by repeatedly depressing the parking brake pedal 8 is referred to as a pedal depression type brake releasing switching mechanism.

[Another embodiment]
The brake switch 72 may be provided only for at least one of the left and right sides of the operating system of the left and right side brake pedals 5a and 5b, that is, the right operating rod 33 contrary to the above embodiment. A brake switch 72 provided on the rod 33 may be connected in a parallel circuit.

Overall side view of the tractor viewed from the left side of the aircraft Overall view of the tractor Plan view showing the operating system of the brake Side view showing the operating system of the brake Side view showing the action of pressing the side brake pedal Side view showing the action of pressing the parking brake pedal Side view showing details of parking brake operation system Front view of parking brake pedal and pedal depression brake release switching mechanism Side view showing action diagram of braking release posture of parking brake pedal Side view showing the action of the parking brake pedal depressed Side view showing an operation diagram of the parking brake pedal in a braking engagement state Side view showing the action diagram of the parking brake pedal depressed release state Side view showing the action diagram of the parking brake pedal in the middle of returning The perspective view which shows the latching tool of a side brake pedal Disassembled perspective view of parking brake pedal depression type brake release switching mechanism

1 driver's seat 2 step floor 3 side brake 4 first linkage mechanism 5 side brake pedal 7 second linkage mechanism 8 parking brake pedal 12 main clutch pedal 31 operation arm 33 operation rod 44 pedal arm 46 stopper member 47 engagement recess 48 engagement plate 52 Locking claw
53 Stopper pin 54 Reversing spring 55 Claw swing member
57 Positioning swing member 63 Second rod 65 Bracket 66 Spacer (first contact portion)
67 Spacer (2nd contact part)

Claims (3)

A pair of left and right sides linked to the left and right side brakes for the left and right rear wheels via the first linkage mechanism on the left and right sides of the front part of the step floor located in front of the driver seat. A parking brake pedal for parking, which is disposed close to the driver's seat at a position closer to the driver seat than the side brake pedal on the step floor, and is linked to the left and right side brakes via a second linkage mechanism; In the brake operation mechanism of the tractor configured to operate and hold the left and right side brakes in a braking state by depressing the parking brake pedal,
The parking brake pedal includes a tread surface fixed to a pedal arm, and the left and right side brakes are operated by depressing the tread surface of the parking brake pedal downward while the left and right side brakes are released from braking. Is provided with a pedal depression type brake release switching mechanism for releasing the braking of the side brake in the braking state by depressing the tread surface of the parking brake pedal again from the braking state of the side brake.
The pedal depression type brake release switching mechanism includes an engagement plate having a plurality of engagement recesses formed on an upper edge and a stopper member integrally attached to the pedal arm, and is engaged / disengaged from above with respect to the engagement recess. A claw swinging member provided with a locking claw, a stopper pin provided in the claw swinging member and engaging the claw swinging member with the engaging recess the release posture and positioning swinging member for attitude change, said the body-fixed portion of the pedal arm is supported, is respectively equipped to oscillatory movement is supported by another axis to another Rutotomoni, wherein A reversing spring for linking the claw swinging member and the positioning swinging member,
The positioning rocking member is fixed to the stopper pin so that the engaging recess that moves relative to the locking claw as the parking brake pedal is depressed engages the locking claw at a desired depression position. The left and right side brakes are operated to a braking state by pressing the pawl swinging member to the side where the engaging posture is maintained , and the parking brake pedal is depressed again with respect to the positioning swinging member. The stopper pin is slidably moved, and the claw swinging member is changed in posture to a posture for releasing the engagement of the engagement recess with respect to the locking claw to release the braking state of the left and right side brakes, and the operation of accompanying the stopper member to return operation after again depressing operation of the pedal arm, the positioning swinging member through the stopper pin and the reverse spring the Operating the swing member, the engaging recess the locking pawl of the engagement of the tractor that is configured to return to the state capable brake operating mechanism for.   The pair of left and right side brake pedals are arranged on the right side of the front part centered on the driver seat on the step floor, and the main clutch pedal for the main clutch is arranged on the left side of the front part centered on the driver seat on the step floor. The tractor brake operating mechanism according to claim 1, wherein the parking brake pedal is disposed behind the main clutch pedal. A bracket is provided on the operating arm for operating the side brake, two through holes are formed through the bracket in the front-rear direction, and the first linkage mechanism is configured in one of the two through-holes. A rear end side of the operation rod is inserted, a first contact portion is connected to a rear end portion of the operation rod located on the rear side of the bracket, and the first through hole is connected to the other through hole of the two through holes. Inserting the rear end side of the second rod constituting the two linkage mechanism, and connecting the second contact portion to the rear end portion of the second rod located on the rear side of the bracket;
When the operating rod is pulled by operating the side brake pedal, the operating arm is swung through the first contact portion without operating the parking brake pedal due to the accommodation through the other through hole. To actuate the side brake,
When the parking brake pedal is depressed and the second rod is pulled, the side brake pedal is not actuated by the accommodation through the one through hole, and the operating arm is swung through the second contact portion. The tractor brake operating mechanism according to claim 1 or 2, wherein the side brake is configured to be actuated by braking.

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