JP2005104227A - Hst mount unit of working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a configuration at a working vehicle having a mid-mount type working machine in which a space at the berry part of the vehicle is kept as wide as possible, the working machine is raised high to reduce its contact with any hindrance item during its running operation and a fixing or removing work of the working machine and further a maintenance work of a transmission device can be easily performed. <P>SOLUTION: A pump shaft 4 of an HST pump 3 and a motor shaft of an HST motor are arranged in parallel below an operating floor 2 in a forward or rearward direction of a vehicle body. A trunnion shaft 7 is arranged above an upper surface of the floor 2 by protruding from the upper surface of the HST pump 3. The trunnion shaft 7 and a neutral setting link 8 connected to the trunnion shaft 7 are covered by a cover 11 constructed to be fixed to or removed from the operating floor 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a configuration of an HST (hydrostatic continuously variable transmission) mounting device for various work vehicles such as a tractor and a riding lawn mower.

2. Description of the Related Art Conventionally, in a tractor or the like, when an HST is mounted as a travel transmission, a configuration in which the HST pump is disposed in the transmission case along the front-rear direction of the vehicle body with the HST pump on the front side and the HST motor on the rear side, A configuration is known in which a motor is arranged and mounted vertically in a transmission case. (For example, refer to Patent Document 1).
JP 63-263136 A

  As described above, in a tractor or the like equipped with an HST as a transmission for traveling, the weight of the vehicle body can be reduced and the vehicle speed can be adjusted steplessly compared to the configuration of a gear type transmission. It is suitable for a small tractor or the like that performs load work.

  However, if this type of vehicle is equipped with a midmore work machine, the space in the abdomen of the vehicle cannot be taken wide, the work machine cannot be raised high, and it is easy to contact the ground surface during traveling, Furthermore, there was a problem that it was difficult to perform HST maintenance work.

In view of the above problems, the present invention has the following HST mounting configuration.
In other words, the invention of claim 1 is characterized in that the pump shaft (4) of the HST pump (3) and the motor shaft (6) of the HST motor (5) are provided below the control floor (2) of the vehicle body (1). The trunnion shaft (7) is arranged in the front-rear direction and in parallel and projects from the upper surface of the HST pump (3) to a position higher than the upper surface (L2) of the floor (2). ) Is provided with a link mechanism (8) for urging the output rotation of the HST pump (3) without rotation, and the trunnion shaft (7) and the link mechanism (8) are configured to be detachable from the floor (2). It was set as the HST mounting apparatus of the working vehicle characterized by having covered with the cover (11).
(Operation of claim 1)
In the HST mounting apparatus for a work vehicle configured as described above, by rotating the trunnion shaft (7) on the upper side of the floor (2), the output shaft rotates forward and backward or increases and decreases, while the vehicle moves forward and backward. In a state where the trunnion shaft (7) is not operated, the rotation of the motor shaft (6) is set to non-rotation by the link mechanism (8).

  In the invention of claim 1 configured as described above, since the motor shaft (6) of the HST motor (5) is arranged in parallel in the longitudinal direction of the vehicle body, the longitudinal length of the entire transmission device is shortened. Thus, the wheel base can be shortened, the height of the transmission can be set as high as possible, and the space in the vehicle abdomen can be widened and increased. Therefore, it is easy to perform the work of attaching / detaching the work implement and the maintenance work of the HST by preventing contact with an obstacle during movement when not working.

  Further, the trunnion shaft (3) for controlling the output rotation of the HST and the link mechanism (8) for setting the output rotation to no rotation are set above the floor (2) and are covered with the cover (11). Since it is a thing, the maintenance regarding HST is easily performed only by removing the cover (11).

Hereinafter, the form which mounted this invention in the riding lawn mower which mounts the mid mower 15 is demonstrated.
As shown in FIGS. 2 and 3, the riding lawn mower 1 has a pair of left and right body frames 9 and 9 arranged at the front and rear, and left and right front wheels 17 and 17 steered by a steering handle 16 at the front end. The rear axle housing 19 is supported from the left and right sides of the transmission case 18 toward the rear lower side. The left and right rear wheels 20 and 20 are mounted on the rear axle housing 19. An engine 21 covered with a bonnet 24 is mounted on the front portion of the vehicle body frame 9, and a handle post 23 is disposed on the rear portion. A seat cover 25 and a cockpit 26 are mounted on the upper side of the transmission case 18 behind the steering handle 16. Further, as will be described later, between the lower portion of the handle post 23 and the seat cover 25, there is provided a resin-made control floor 2 and an iron plate floor cover 11 detachably attached to the floor 2. It has become.

  The mower deck 15 is mounted on the abdomen of the vehicle body between the front wheel 17 and the rear wheel 20 in a side view, and the mower deck 15 is driven by a lift cylinder 30 through a pair of front and rear parallel links 29, 29. It is configured to be attached to the frame 9 so as to be movable up and down.

  Further, the mower deck 15 is configured to be interlocked and rotated by a power take-off shaft from the engine 21 or the like from an input shaft at the front of the deck. Further, on the rear side of the moor deck 15, a discharge port 34 for discharging the cut turf grass is provided, and the turf grass is collected in a collector 35 at the rear end of the vehicle body.

Next, the HST type traveling transmission of the riding lawn mower 1 will be described.
As shown in FIGS. 4 to 6, an HST (hydrostatic continuously variable transmission) is provided in the space 10 between the left and right vehicle body frames 9 on the front side of the transmission case 18. The HST is arranged in a laterally arranged manner so that the HST pump 3 is positioned at a substantially central portion on the left and right sides of the spacing portion 10 and the HST motor 5 is positioned on the left side. The pump shaft 4 of the HST pump 3 and the motor shaft 6 of the HST motor 5 are both oriented in the front-rear direction of the vehicle body and arranged in parallel. A universal joint 41 connects the front end of the pump shaft 4 to the crankshaft of the front engine 21. The pump shaft 4 has a fan 42 to cool the HST by this rotation.

  In the HST, a pump case in which the HST pump 3 is housed and a motor case in which an HST motor that is hydraulically driven by the HST pump 3 is integrally formed in a single mounting case 43. It is attached to the rear end surface of the front transmission case 18 with bolts 44 or the like. At this time, the motor shaft 6 can be configured to be interlocked by being fitted to an input shaft, an input gear, or the like in the mission case 18 at a position on the left side. The transmission case 18 has a sub-transmission gear, a differential gear, and the like as a transmission mechanism, and transmits a rear axle 45 projecting left and right of the case. The rear axle housing 19 has a structure in which a chain that interlocks between the rear axle 45 and the rear wheel shaft 46 is hung so as to transmit and rotate the left and right rear wheels 20 and 20.

  Above the HST, a trunnion shaft 7 for changing the output rotation of the HST, a link mechanism for returning the trunnion shaft 7 to a neutral position (hereinafter referred to as a neutral link 8), and the like are disposed. The HST or the like attaches the transmission case 18 to the mounting bracket 48 of the vehicle body frame while keeping it as high as possible so as not to protrude downward from the lower side position L1 of the vehicle body frame 9. For this reason, although it changes with the height of the vehicle body frame 9, the upper part of HST becomes a form which protrudes upwards rather than the upper surface position L2 of the control floor 2 of the said position.

  As shown in FIGS. 4 and 5, the trunnion shaft 7 is erected along the vertical direction on the upper side of the pump shaft 4 of the HST pump 3, and a trunnion arm for rotating the trunnion shaft 7. 51 is provided at the upper end. Further, on the left side of the trunnion shaft 7 and the HST motor 5 side, each member of the neutral link 8 is provided so as to be rotatable around the vertical arm shaft 52, that is, horizontally. The neutral link 8 includes a rotating arm 53 that rotates around the arm shaft 52 and a cam roller 54 that is rotatably provided on the rotating arm 53. The neutral cam 55 has a bifurcated shape at the base of the trunnion arm 51. , A spring 57 that repels toward the 56-part side, and a regulating plate 62 that regulates the rotation area of the rotating arm 53.

  Further, bifurcated neutral cams 55 and 56 are provided at the left end portion of the trunnion arm 51. When the cam roller 54 is pressed between them, the trunnion arm 51 and the trunnion shaft 7 are in the neutral position N of the HST. Is set to

  Specifically, when the trunnion arm 51 is operated to the neutral position N or the forward shift position F, the neutral cam 55 pushes the cam roller 54 outward against the spring 57. Since the trunnion arm 51 receives the pressure of the cam roller 54 by the spring 57, the trunnion arm 51 returns to the neutral position N when the operating force is loosened. Similarly, the neutral cam 56 operated to the reverse shift position R side pushes the cam roller 54 outward and returns to the neutral position N. A guide pin 61 is provided at the left end of the rotating arm 53 of the neutral link 8, and the guide pin 61 is fitted into a guide hole 63 of a restriction plate 62 fixed on the transmission case 18 side. The rotation of the rotation arm 53 around the arm shaft 52 can be restricted between the restriction plate 62 and the restriction plate 62.

  Further, the trunnion shaft 7 and the trunnion arm 51 are operated and rotated by a forward petal 66 and a backward petal 67 arranged at the right foot portion of the control floor 2 as shown in FIGS. The left and right vehicle body frames 9 are provided with bearing pipes 69 and 69 respectively close to the front lower side of the HST, and the lateral brake petal shaft 12 extends between the left and right bearing pipes 69 and 69. Is rotatably supported. A brake petal 70 is provided on the right end portion of the brake petal shaft 12 on the outer side of the vehicle body frame 9 so as to rotate integrally therewith, and on both left and right sides of the brake petal 70 with respect to the brake petal shaft 12. Thus, the forward petal 66 and the reverse petal 67 are rotatably provided.

  A bearing pipe 71 is provided on the right body frame 9 behind the petal shaft 12, a rotatable trunnion interlocking shaft 72 is supported on the bearing pipe 71, and arms 73 projecting above and below the trunnion interlocking shaft 72. Interlock rods 77 and 78 connect 74 and arms 75 and 76 projecting on the forward pedal 66 and reverse petal 67 bases and on the brake pedal shaft 12 core.

  Therefore, the trunnion interlocking shaft 72 rotated by depressing the backward petal 67 is in the reverse rotation direction with respect to the forward rotation direction of the trunnion interlocking shaft 72 rotated by depressing the forward petal 66. An interlocking arm 79 is integrally attached to the inner end of the trunnion interlocking shaft 72, and the upper end of the interlocking arm 79 and the trunnion arm 51 are connected by a link rod 80 in the form of a turnbuckle. The trunnion shaft 7 is rotated toward the forward shift position F by the forward rotation of the trunnion shaft 72, and is rotated toward the reverse shift position R by the reverse rotation.

  In such a continuously variable transmission by the HST trunnion shaft 7, the HST motor 5 and the motor shaft 6 are not rotated when the cam roller 54 of the rotating arm 53 is in a neutral position between the neutral cams 55 and 56. When the forward petal 66 is stepped on and the trunnion arm 51 is turned to the forward shift position, the HST pump 3 causes the motor 5 and the motor shaft 6 to rotate at an increased speed in the forward direction to increase the speed steplessly. When the forward petal 66 is stepped back, the trunnion arm 51 is returned from the forward shift position side to the neutral position side and decelerated steplessly.

Further, when the trunnion arm 51 is turned to the reverse shift position R by depressing the reverse petal 67, the reverse continuously variable transmission can be increased or decreased in substantially the same manner.
Reference numeral 81 in the figure denotes an air damper having the lower end portion of the arm 73 provided between the vehicle body frame 9 and serves to brake the rotation of the trunnion arm 51 and maintain the rotation position.

  The control floor 2 is configured to extend from the lower portion of the front handle post 23 to the left and right side portions of the cockpit 26. The left and right central portions, specifically, the HST and the mission case disposed in the spacing portion 10 are provided. The upper portion of 18 is cut out. Then, a floor cover 11 (left cover 11L, right cover 11R) divided into left and right is attached to the cutout portion of the floor 2, and the HST and some constituent members of the neutral link 8 provided on the HST, and further the mission The upper and side portions of the case 18 are covered.

  Therefore, the floor cover 11 has a shape that protrudes one step above the control floor 2. The right cover 11R is provided with an opening 97 above the fuel filler opening 14 of the mission case 18, and a rubber lid member 13 is attached to the opening 97 for opening and closing.

  Thereby, since the motor shaft 6 of the HST motor 5 is arranged in the vehicle longitudinal direction and in parallel, the longitudinal length of the entire transmission case 18 can be shortened, and the wheel base can be shortened. The height of the mission case can be set at a high position, and the space of the vehicle abdomen can be set wide and high. Therefore, the mower deck 15 to be mounted on the abdomen of the vehicle body can be raised as high as possible to avoid contact with obstacles during non-working and the space for the abdomen of the vehicle body is wide so that the mower deck 15 itself can be easily attached and detached. It becomes.

  The trunnion shaft 3 that controls the output rotation of the HST and a part of the neutral link 8 that sets the output rotation to non-rotation are set above the control floor 2 and covered with the floor cover 11. Therefore, simply removing the cover 11 reveals the parts related to the HST and facilitates maintenance. In addition, the floor cover 11 is divided into left and right parts and can be attached and detached one by one, so that only the appropriate places requiring maintenance can be exposed, and the heavy or bulky cover is not attached or detached. Can reduce the labor involved.

  Furthermore, the right cover 11R is configured to include an opening 98 for refueling the mission case 18, and when maintenance of the HST, the transmission case, and the like is performed, working members related to these are concentrated on the cover 11. Therefore, the maintenance property can be improved as described above.

The side view of a HST mounting part. The perspective view of a floor part. The side view of a riding lawn mower. The top view which shows a vehicle body rear part. The front view of a HST mounting part. The top view of a vehicle body rear part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 2 Control floor 3 HST pump 4 Pump shaft 5 HST motor 6 Motor shaft 7 Trunnion shaft 8 Neutral link 9 Body frame 10 Frame space part 11 Floor cover 11L Left cover 11R Right cover

Claims (1)

Under the control floor (2) of the vehicle body (1), the pump shaft (4) of the HST pump (3) and the motor shaft (6) of the HST motor (5) are directed parallel to the vehicle longitudinal direction. The trunnion shaft (7) protrudes from the upper surface of the HST pump (3) to a position higher than the upper surface (L2) of the floor (2), and the output of the HST pump (3) is coaxially (7). A link mechanism (8) for energizing rotation without rotation is provided, and the trunnion shaft (7) and the link mechanism (8) are covered with a cover (11) configured to be detachable from the floor (2). The HST mounting apparatus of the working vehicle characterized by these.

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