JP6181439B2 - Working vehicle - Google Patents

Description

  The present invention relates to a work vehicle such as a passenger rice transplanter.

  A working vehicle having a main transmission mechanism including a continuously variable transmission mechanism such as a hydrostatic continuously variable transmission mechanism (HST) and capable of continuously changing a traveling speed based on a shift operation of the main transmission mechanism by a main transmission lever. Are known. Some types of working vehicles of this type include a main transmission neutral return mechanism that returns a main transmission lever to a neutral position when a brake pedal is depressed during operation. For example, the working vehicle of Patent Document 1 has a structure in which when the brake pedal is depressed, the hydrostatic continuously variable transmission mechanism is neutralized and the brake is applied in response to the neutral return of the main transmission lever. In addition, this type of work vehicle usually includes a parking brake mechanism that selectively locks the brake pedal at the depressed position, and in a parking brake state that selectively locks the brake pedal at the depressed position, The hydrostatic continuously variable transmission mechanism is also maintained in a neutral state.

JP 2011-194948 A

  By the way, in this type of working vehicle, there is a case where a shifting operation of a traveling power system (for example, a sub-transmission mechanism) or a working power system (for example, a stock transmission mechanism) is performed in a parking brake state. However, when these speed change mechanisms are sliding mesh type (selective sliding type) gear speed change mechanisms, if the meshing positions of the driving side gear and the driven side gear do not match, the side surfaces of the gears interfere with each other to make a speed change. there is a possibility. Conventionally, in such a case, the parking brake is once released and the main speed change lever is operated to rotate the upstream side of the gear speed change mechanism while performing the speed change operation. There was a risk that the aircraft would move during the shifting operation by releasing the parking brake.

The present invention has been created in view of the above circumstances and has been created for the purpose of solving these problems. The invention of claim 1 includes a main transmission mechanism for continuously changing the power of a prime mover, and a main transmission. A main transmission lever that shifts the mechanism, a sliding mesh gear transmission mechanism that is provided on the downstream side of the transmission of the main transmission mechanism and that shifts the traveling power or working power, and brakes the traveling according to the depression operation of the brake pedal. Work traveling provided with a travel brake mechanism, a parking brake mechanism that selectively locks the brake pedal in the depressed position, and a main shift neutral return mechanism that returns the main transmission lever to the neutral position in response to the depression operation of the brake pedal Even if the vehicle is in a parking brake state in which the main shift neutral return mechanism is selectively locked at a position where the brake pedal is depressed, Comprising a flexible means for allowing the shifting operation of the main speed change mechanism by the main shift lever, the flexibility range of the melting communication means, even in the parking brake state main shift lever is flexible operation angle to be returned to the neutral position This is a featured working vehicle.

  According to the first aspect of the invention, even in the parking brake state, the shift operation of the main transmission mechanism by the main transmission lever is allowed within a predetermined interchangeable range, so that the main transmission lever can be operated without releasing the parking brake. The gear shifting mechanism can be shifted while operating to rotate the downstream side of the main transmission mechanism. As a result, not only can the shifting operation of the gear shifting mechanism in the parking brake state be simplified, but also during the shifting operation. Inconveniences that cause the aircraft to move can also be eliminated.

It is a left view of a riding rice transplanter. It is a top view of a riding rice transplanter. It is a transmission diagram of a riding rice transplanter. It is a top view which shows the brake operation system and main transmission operation system of a riding rice transplanter. It is a front view which shows the brake operation system and main transmission operation system of a riding rice transplanter. It is a left view which shows the brake operation system and main transmission operation system of a riding rice transplanter. It is a right view which shows the brake operation system and main transmission operation system of a riding rice transplanter. It is a perspective view which shows the main transmission operating system and main transmission neutral return mechanism of a riding rice transplanter. It is a disassembled perspective view which shows the main transmission operating system and main transmission neutral return mechanism of a riding rice transplanter. It is a principal part expanded side view which shows the main transmission operating system and main transmission neutral return mechanism of a riding rice transplanter.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a traveling machine body of a passenger rice transplanter (working traveling vehicle). The traveling machine body 1 includes an engine 2 mounted on a front portion of the machine body, a transmission case 3 for shifting engine power, and a front axle. A pair of left and right front wheels 5 supported by the case 4 and a pair of left and right rear wheels 7 supported by the rear axle case 6 are provided. Engine power is input to the transmission case 3 via a main transmission mechanism 8 comprising a hydrostatic continuously variable transmission mechanism, and the power shifted here is output to the front axle case 4, the rear axle case 6, and the planted PTO shaft 9. Is done.

  A planting work part 11 is connected to the rear part of the traveling machine body 1 via a lifting link mechanism 10. The planting work unit 11 includes a work unit frame 12 that is connected to the lifting link mechanism 10 so as to be able to roll, a seedling stage 13 that is provided so as to be able to reciprocate left and right above the work unit frame 12, and a rear side from the work unit frame 12 A plurality of planting transmission cases 14, a planting mechanism 15 provided at the rear end of the planting transmission case 14, and a float 16 provided below the planting transmission case 14 so as to be swingable up and down. It is prepared for.

  As shown in FIG. 3, the transmission case 3 includes an input shaft 17 that inputs power from the main transmission mechanism 8, and a front wheel power output shaft 19 and a rear wheel power output shaft that transmit the power of the input shaft 17 via the auxiliary transmission mechanism 18. And a planting power transmission path 25 that transmits the power of the input shaft 17 to the planting PTO shaft 9 via the inter-strain transmission mechanism 22, the torque limiter 23, and the planting clutch mechanism 24. Prepare.

  The sub-transmission mechanism 18 is a sliding mesh type gear transmission mechanism that changes the driving power stepwise, and includes two fixed gears 26 and 27 on the drive side and two slide gears 28 and 29 on the driven side. By selective engagement by sliding operation of the gears 28 and 29, a two-stage shift (running and working) via the neutral position becomes possible.

  The inter-strain transmission mechanism 22 is a sliding mesh type gear transmission mechanism that changes the relative operation speed of the planting mechanism 15 with respect to the vehicle speed in stages, and includes four fixed gears 30 to 33 on the drive side and two on the driven side. Four slide gears 34 and 35 are provided, and a four-stage speed change is possible by selective engagement by sliding operation of the slide gears 34 and 35.

  As shown in FIGS. 1 and 2, the traveling machine body 1 includes a driving unit 37 on which an operator rides behind an engine mounting unit 36 on which the engine 2 is mounted. The driving unit 37 includes various operating tools such as a steering handle 39, a brake pedal 40, and a main transmission lever 41 in addition to the driving seat 38.

  As shown in FIGS. 4 to 7, the brake pedal 40 includes a pedal arm 43 that pivots up and down with the pedal shaft 42 as a fulcrum in response to an operator's stepping operation. A pair of protruding connection arms 44 and 45 are integrally provided. One connecting arm 44 is connected to a brake arm 46 a that operates a traveling brake mechanism 46 provided in the rear axle case 6 via a rod 47, a rotating plate 48, and a connecting plate 49. The traveling brake mechanism 46 is operated according to the operation.

  Further, a parking brake mechanism 50 that selectively locks the brake pedal 40 at a depressed position is provided in the vicinity of the brake pedal 40. The parking brake mechanism 50 according to the present embodiment includes a pin 51 protruding laterally from the pedal arm 43 and a parking brake hook that is provided in the vicinity of the brake pedal 40 so as to be pivotable back and forth and can selectively engage with the pin 51. 52 and a spring 53 that urges the parking brake hook 52 in the disengagement direction (forward). While depressing the brake pedal 40, the parking brake hook 52 is pulled forward, and the parking brake hook 52 By engaging the hook groove 52a with the pin 51, the brake pedal 40 can be selectively locked at the depressed position, and the parking brake state can be revealed. When the brake pedal 40 is depressed in the parking brake state, the pin 51 is disengaged from the hook groove 52a of the parking brake hook 52, and the parking brake state is released.

  As shown in FIGS. 4 to 10, the main transmission lever 41 has a pivoting operation in the front-rear direction with the first lever support shaft 54 facing left and right as a fulcrum and a second lever support shaft 55 facing in the front-rear direction. Rotation operation in the left-right direction is allowed, and the forward / reverse operation is performed forward / backward by the guide of the linear shift guide portion 56a of the lever guide 56 and the forward / backward guide portion 56b of the lever guide 56 is operated forward / backward. And a forward / reverse switching operation for selectively switching between the forward shift operation and the reverse shift operation, which are operated to the left and right by the guide of the neutral guide portion 56c of the lever guide 56.

  An arm 57 and a cam plate 58 that integrally rotate in the front-rear direction in response to a rotation operation in the front-rear direction of the main speed-change lever 41 are provided at the base of the main speed-change lever 41. The arm 57 is connected to the trunnion arm 60 of the main transmission mechanism 8 via a rod 59, and pushes and pulls the trunnion arm 60 in accordance with the rotation operation of the main transmission lever 41 in the front-rear direction. 8 is shifted.

  The cam plate 58 is a component of the position holding mechanism 61 that positions and holds the main speed change lever 41 at a plurality of preset speed change operation positions (for example, neutral, forward 5 steps, reverse 3 steps). While having a fan shape centering on the shaft 54, a plurality of positioning grooves 58a are provided in the arc portion. The position holding mechanism 61 includes, in addition to the cam plate 58, a roller arm 63 that is rotatable up and down with an arm support shaft 62 as a fulcrum, a roller 64 provided on the roller arm 63, and a spring that urges the roller arm 63 upward. 65, and the roller 64 is engaged with each positioning groove 58a of the cam plate 58 while receiving the urging force of the spring 65, whereby the main transmission lever 41 is positioned at a plurality of preset transmission operation positions. Retained.

  Further, the main transmission lever 41 is linked to a main transmission neutral return mechanism 66 that returns the main transmission lever 41 to the neutral position in accordance with the depression operation of the brake pedal 40. The main shift neutral return mechanism 66 of the present embodiment is integrally provided at one end of the first lever support shaft 54, and a plate 67 that overlaps with the cam plate 58, and a projection that protrudes from the plate 67 to engage the cam plate 58. A pin 68 that engages with the joint hole 58b, an arm 69 that is integrally provided at the other end of the first lever support shaft 54 and protrudes in the left-right direction, and pins 69a that protrude from the left and right ends of the arm 69 , 69b are connected to a pair of front and rear rods 70, 71 engaged through the long holes 70a, 71a and the other end of the rods 70, 71, and to the connecting arm 45 through the rod 72. A rotating member 73 to be connected is provided.

  When the brake pedal 40 is depressed, as the connecting arm 45 pulls the rod 72 rearward, the rotating member 73 rotates and pulls the rods 70 and 71 downward. The rods 70 and 71 pull the pins 69a and 69b downward at the upper ends of the long holes 70a and 71a, and rotate the arm 69 to a predetermined angle. When the arm 69 reaches a predetermined angle, the plate 67 is integrally connected to the arm 69 via the first lever support shaft 54, and the cam plate is engaged to the plate 67 via the pin 68 and the engagement hole 58b. 58, and the main transmission lever 41 that rotates back and forth integrally with the cam plate 58 is also at a predetermined angle. Therefore, by setting the predetermined angle so as to coincide with the neutral position, it becomes possible to automatically return the main transmission lever 41 to the neutral position in accordance with the depression operation of the brake pedal 40.

  The main shift neutral return mechanism 66 is an accommodation that allows a shift operation of the main transmission mechanism 8 by the main transmission lever 41 within a predetermined accommodation range even in a parking brake state in which the brake pedal 40 is selectively locked at the depressed position. Means. The accommodation means of this embodiment is a gap 74 provided between the pin 68 of the plate 67 and the engagement hole 58b of the cam plate 58, and a parking brake that selectively locks the brake pedal 40 in the depressed position. Even in this state, the main transmission lever 41 can be rotated back and forth within the gap 74 to change the speed of the main transmission mechanism 8. Therefore, when the sub-transmission mechanism 18 or the inter-gear transmission mechanism 22 that is a sliding mesh type gear transmission mechanism is operated in the parking brake state, the main transmission lever 41 is operated within the range of the accommodation means without releasing the parking brake. Thus, the sub-transmission mechanism 18 and the inter-company transmission mechanism 22 can be shifted while rotating the downstream side of the main transmission mechanism 8, and as a result, the sub-transmission mechanism 18 and the inter-mechanism transmission mechanism 22 in the parking brake state can be operated. Not only can the speed change operation be simplified, but also the inconvenience of the airframe moving during the speed change operation by releasing the parking brake can be eliminated.

The accommodation operation angle α of the main transmission lever 41 that is the accommodation range of the accommodation means is preferably smaller than the angle β at which the roller 64 deviates from the neutral positioning groove 58 a of the cam plate 58. The reason for this is that even if the main transmission lever 41 is operated without shifting the main transmission lever 41 to the neutral position after operating the main transmission lever 41 while operating the main transmission lever 41 in the parking brake state, This is because the main transmission lever 41 is automatically returned to the neutral position by the position holding mechanism 61. If it does in this way, it can prevent that an airframe starts suddenly simultaneously with cancellation of a parking brake by forgetting to return to the neutral position of main shift lever 41.

  According to the present embodiment configured as described, the main transmission mechanism 8 for continuously changing the power of the engine 2, the main transmission lever 41 for shifting the main transmission mechanism 8, and the transmission downstream side of the main transmission mechanism 8. The sliding mesh type sub-transmission mechanism 18 and the inter-company transmission mechanism 22 for shifting the traveling power and the working power, the traveling brake mechanism 46 for braking the traveling in response to the depression operation of the brake pedal 40, and the brake pedal 40 are provided. A riding rice transplanter comprising a parking brake mechanism 50 that selectively locks in a depressed position, and a main shift neutral return mechanism 66 that returns a main shift lever 41 to a neutral position in response to a depression operation of the brake pedal 40, The main shift neutral return mechanism 66 is capable of shifting the main shift within a predetermined range even in a parking brake state in which the brake pedal 40 is selectively locked at the depressed position. Since there is provided a means for allowing the speed change operation of the main speed change mechanism 8 by the bar 41, the sub speed change mechanism is operated while operating the main speed change lever 41 and rotating the downstream side of the main speed change mechanism 8 without releasing the parking brake. 18 and the inter-gear transmission mechanism 22 can be changed. As a result, the speed change operation of the auxiliary transmission mechanism 18 and the inter-gear transmission mechanism 22 in the parking brake state can be simplified. Inconveniences such as moving can be solved.

DESCRIPTION OF SYMBOLS 1 Traveling machine body 2 Engine 3 Transmission case 8 Main transmission mechanism 18 Subtransmission mechanism 22 Stock transmission mechanism 40 Brake pedal 41 Main transmission lever 46 Traveling brake mechanism 50 Parking brake mechanism 58 Cam plate 58b Engagement hole 59 Rod 60 Trunnion arm 61 Position holding Mechanism 66 Main shift neutral return mechanism 67 Plate 68 Pin 74 Clearance (conversation means)

Claims (1)

A main transmission mechanism for continuously changing the power of the prime mover;
A main transmission lever for shifting the main transmission mechanism;
A sliding mesh type gear transmission mechanism that is provided on the downstream side of the transmission of the main transmission mechanism and that changes the traveling power or working power;
A travel brake mechanism that brakes the travel in response to the depression of the brake pedal;
A parking brake mechanism that selectively locks the brake pedal in the depressed position;
A working vehicle including a main shift neutral return mechanism that returns a main shift lever to a neutral position in response to a depression operation of a brake pedal;
The main shift neutral return mechanism includes accommodation means for allowing a shift operation of the main transmission mechanism by the main transmission lever within a predetermined accommodation range even in a parking brake state in which the brake pedal is selectively locked at the depressed position. ,
The working vehicle according to claim 1, wherein the accommodation range by the accommodation means is an accommodation operation angle at which the main transmission lever is returned to the neutral position even in a parking brake state .

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