JP2007289070A - Operation vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation vehicle capable of simply constituting a mounting structure of a tension panel and simply practicing assembly operation, etc., of tension spring. <P>SOLUTION: The operation vehicle is equipped with an engine loaded on a traveling machine body equipped with a machine body frame 3, a transmission case 19 for changing speed of power of engine and transmitting the speed to a traveling part, an input belt 35 for inputting power of the engine to the transmission case 19, a tension roller 62 for tensing the input belt 35 and a tension spring 66 for energizing the tension roller 62 in a tense direction. The operation vehicle has a structure fastening the transmission case 19 through a transmission-mounting bolt 50a to a machine body frame. In the operation vehicle, a spring-attaching part 51 for fixing one end side of the tension spring 66 is installed on the transmission-mounting bolt 50a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a work vehicle such as a lawn mower equipped with a mower device for cutting turf grass planted on the ground, and more specifically, through an input belt that tensions engine power by a tension roller and a tension spring. This is related to the work vehicle that is transmitted to the mission case.

  2. Description of the Related Art Conventionally, a work vehicle such as a lawn mower is generally connected to a mower device with a rotary cutting blade mounted on a traveling machine body so as to be movable up and down, a substantially cylindrical discharge duct extending rearward from the mower device, and the exhaust duct. And a grass collection box. Further, when power is transmitted to the traveling parts such as the left and right traveling wheels or traveling crawlers, the power is transmitted from the engine mounted on the traveling body of the work vehicle to the transmission case, and the left and right traveling parts are transmitted via the transmission mechanism of the transmission case. Is configured to output the output.

In this case, in the conventional work vehicle, in order to increase the cross-sectional area of the exhaust duct, a transmission case is disposed above the exhaust duct, and the output of the engine is transmitted from one transmission shaft to the transmission relay case and the transmission. A configuration has been adopted in which power is transmitted to the transmission case via an endless belt disposed above the case (see, for example, Patent Document 1).
JP 2004-105112 A

  In general, when a tension spring is used as a tension spring for applying a belt tension force to a tension arm of a tension roller that is brought into contact with the middle part of the endless belt, the tension direction of the tension spring, and thus the tension arm and the tension spring. Is preferably a plane that is substantially parallel to or close to the winding plane of the endless belt. Therefore, it is necessary to provide a special spring mounting part for mounting the other end locking part (fixed side) of the tension spring to the mission case or the steering body side, and a tension spring is provided between the tension arm and the spring mounting part. Since they are connected, there is a problem that the tension spring mounting structure cannot be easily configured.

  An object of the present invention is to provide a work vehicle in which a tension spring mounting structure can be easily configured and a tension spring assembly operation and the like can be easily performed.

  In order to achieve the object, a work vehicle according to a first aspect of the present invention includes an engine mounted on a traveling machine body including a traveling unit, a transmission case that shifts power of the engine and transmits the engine power to the traveling unit, In a work vehicle comprising an input belt for inputting engine power to a transmission case, a tension roller for tensioning the input belt, and a tension spring for biasing the tension roller in the tension direction, the transmission is attached to the traveling machine body. In this structure, the transmission case is fastened via a bolt, and the transmission mounting bolt is provided with a spring mounting portion for locking one end side of the tension spring.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, a gearshift output bearing portion of the transmission case is provided on the upper surface of the traveling machine body via the transmission mounting bolt fastened from above. It is fixed, the head side of the mission mounting bolt is protruded above the bearing part, and the spring mounting part is arranged on the head side of the mission mounting bolt.

  According to a third aspect of the present invention, in the work vehicle according to the second aspect, the spring mounting portion is formed by a cylindrical body and a casing that are fitted on the transmission mounting bolt.

  According to a fourth aspect of the present invention, in the work vehicle according to the first, second, or third aspect, between the mowing unit disposed on the lower surface side of the traveling machine body and the grass collecting unit disposed on the rear side of the traveling machine body. In addition, a discharge duct for conveying the cut turfgrass is extended, and the transmission case is inclined to the front, lower, and rear heights above the discharge duct, and the transmission case is inclined to the front, lower, and rear heights. The transmission relay case is disposed on the traveling machine body on the front side of the transmission case, and a relay pulley that transmits the power of the engine is attached to the relay output shaft that protrudes upward on the upper surface of the transmission relay case. A transmission input pulley is attached to a transmission input shaft that protrudes upward on the upper surface of the transmission case, and the tension roller is disposed on a tension arm that can rotate about the relay output shaft, The tension spring connected to Yon'amu, between the relay pulleys and the transmission input pulley, in which stretched the input belt through said tension roller.

  According to the first aspect of the present invention, an engine mounted on a traveling machine body including a traveling unit, a transmission case that shifts the power of the engine and transmits the power to the traveling unit, and the power of the engine to the transmission case. In a work vehicle comprising an input input belt, a tension roller that tensions the input belt, and a tension spring that biases the tension roller in the tension direction, the transmission case is connected to the traveling case via a transmission mounting bolt. Since it has a fastened structure and is provided with a spring mounting portion for locking one end of the tension spring on the mission mounting bolt, it is necessary to assemble the spring mounting portion to the mission case or the like. The transmission structure of the tension spring can be easily configured using the transmission mounting bolt. And it reduces the attachment components of the tension spring, in which the assembly work and the like can be easily performed.

  According to the invention according to claim 2, the transmission output bearing portion of the transmission case is fixed to the upper surface of the traveling machine body via the transmission mounting bolt fastened from above, and above the bearing portion. Since the head portion of the mission mounting bolt protrudes and the spring mounting portion is arranged on the head side of the mission mounting bolt, the tension is provided on the upper surface side of the mission case via the mission mounting bolt. The spring can be easily assembled.

  According to the invention of claim 3, since the spring mounting portion is formed by a cylindrical body and a casing that are fitted on the transmission mounting bolt, the spring mounting portion is configured at a low cost with a simple structure. It can be done.

  According to the invention which concerns on Claim 4, between the grass cutting part arrange | positioned in the lower surface side of the said traveling body, and the grass collection part arrange | positioned at the back of the said traveling body, the discharge duct for conveying the cut turf grass The transmission case is supported on the traveling vehicle body, which is inclined to the front low rear high shape above the discharge duct, and is inclined to the front low rear high shape to support the traveling on the front side of the transmission case. A transmission relay case is arranged on the fuselage, a relay output shaft that projects upward from the upper surface of the transmission relay case is attached to a relay pulley that transmits power of the engine, and a transmission input shaft that projects upward from the upper surface of the transmission case. A transmission input pulley is attached, the tension roller is disposed on a tension arm that is rotatable around the relay output shaft, and the tension spring is connected to the tension arm, Since the input belt is stretched between the transmission input pulley and the relay pulley via the tension roller, the transmission case can be compactly arranged above the duct, and the traveling machine body The tension spring can be supported with high rigidity via the mission mounting bolt.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings (FIGS. 1 to 9). First, an outline of a lawn mower will be described with reference to FIGS. 1 is a side view of the entire lawn mower, FIG. 2 is a plan view thereof, FIG. 3 is a side view showing a traveling machine body of the lawn mower, and FIG. 4 is a plan view thereof.

  As shown in FIGS. 1 and 2, in the lawn mower according to this embodiment, the traveling machine body 1 includes left and right machine body frames 3 and 4 that are integrally connected via a plurality of horizontal rail frames 2. . The body frames 3 and 4 are supported by left and right front wheels 5 and left and right rear wheels 6 arranged in front and rear of the left and right sides.

  An engine 9 as a power source is built in the hood 8 on the upper side of the front cowl 7 that covers the front upper surface of the traveling machine body 1. A steering column portion 11 having a round steering handle 10 is mounted on the upper side of the rear portion of the bonnet 8. A shift pedal 12 for appropriately adjusting the vehicle speed and a brake pedal 13 for braking the traveling machine body 1 are disposed below the right side in the traveling direction of the steering column unit 11.

  A driver seat 15 is provided on the rear cowl 14 that covers the rear upper surface of the traveling machine body 1. When the operator sitting on the driver's seat 15 rotates the steering handle 10, the steering angle (steering angle) of the left and right front wheels 5 is changed according to the operation amount (rotation amount). ing. On the left side of the driver's seat 15, a mower elevating lever 17 for elevating and lowering a mower device 16 described later is provided so as to be able to rotate back and forth. A PTO clutch lever 18 for driving or stopping the mower device 16 is provided on the right side of the driver seat 10 so as to be able to rotate back and forth.

  In the rear cowl 12, a mission case 19 having a hydrostatic continuously variable transmission (HST type) and the like is disposed. An inclined portion having a front, low, rear, and high shape is formed at the rear of the body frames 3 and 4, and the mission case 19 is supported at an intermediate portion of the front and rear width of the inclined portions of the body frames 3 and 4. The mission case 19 is configured to transmit power from the engine 9 to the left and right rear wheels 6 by appropriately shifting power from the engine case 19. A fuel tank 20 that supplies fuel to the engine 9 is mounted at the rear end of the inclined portion of the body frames 3 and 4. An oil tank 21 that supplies hydraulic oil to the hydrostatic continuously variable transmission 100 of the mission case 19 is mounted outside the inclined portion of the right body frame 4. On the side opposite to the oil tank 21, a battery 22 used for starting the engine 9 is mounted outside the inclined portion of the left body frame 3 so as to sandwich the fuel tank 20.

  A mower device 16 for lawn mowing is mounted on the lower surface of the body frame 2 between the left and right front wheels 5 and the left and right rear wheels 6 through a front and rear link rods 23 and 24. . The mower device 15 is provided with a pair of left and right rotary cutting blades (not shown) that can rotate horizontally in a mower case 25 having a downward opening shape. Further, on the front and rear sides of the left and right sides of the mower case 25, four front and rear gauge wheels 26 and 27 for adjusting the height of the mower device 16 when lowered are attached. A duct portion 28 that opens rearward is provided on the upper surface of the mower case 25.

  The duct portion 28 communicates with a grass collection box 30 disposed at the rear portion of the traveling vehicle body 1 via a discharge duct 29 disposed between the left and right rear wheels 6 on the lower surfaces of the body frames 3 and 4. The grass collection box 30 is formed by stretching a net-like sheet in a square box shape, and the upper surface of the grass collection box 30 is covered with a dust-proof cover 31. The turf grass cut by the rotary cutting blade in the mower case 25 is conveyed from the duct portion 28 to the inside of the grass collection box 30 through the discharge duct 29 by the wind of the rotary cutting blade, and is cut by the mower device 16. Are collected in the grass collection box 30.

  Next, the power transmission system of the lawn mower will be described with reference to FIGS. In the lawn mower of this embodiment, a two-wheel drive system is adopted in which a part of the rotational power of the engine 9 is distributed to the left and right rear wheels 6.

  That is, a part of the rotational power of the engine 9 is forward from the rear end portion of the output shaft 32 protruding forward and backward outward from the engine 9 and the propulsion shaft 33 having universal joints at both front and rear ends, and the transmission case 19. Is transmitted to the transmission case 19 via a traveling transmission relay case 34 disposed at the above-described portion and an endless input belt 35 described later. Then, from the horizontal rear wheel drive shaft 36 projecting outward in the left and right directions on the transmission case 9, the left and right longitudinal portions provided on the rear side portion of the traveling machine body 1 through the endless rear wheel drive chain 37 and the sprockets 38 and 39. It is transmitted to the axle 40. As a result, the rear wheels 6 attached to the left and right ends of the axle 40 are driven to rotate.

  On the other hand, the other rotational power of the engine 9 is transmitted from the front end portion of the output shaft 32 to the PTO shaft 42 pivotally supported on the front portion of the body frame 4 via the endless PTO transmission belt 41 for PTO power transmission. . Next, power is transmitted from the PTO shaft 42 to a mower gear box 44 disposed on the right side of the body frame 4 on the upper surface of the mower case 25 through an intermediate shaft 43 having universal joints at both front and rear ends. . As a result, the left rotary cutting blade (not shown) in the mower case 25 is driven to rotate clockwise in plan view, and the right rotary cutting blade (not shown) is driven to rotate counterclockwise in plan view. Thus, while cutting the turf grass, the cut turf grass is collected at the center of the left and right width of the mower case 25 and discharged from the duct portion 28 to the discharge duct 29.

  Next, the mounting structure and power input structure of the transmission case 19 and the traveling transmission relay case 34 will be described with reference to FIGS. As shown in FIGS. 6 and 7, the left side of the front portion of the mission case 19 is fastened to the cradle 45 of the left airframe frame 3 with bolts 46. Similarly, the right side of the front portion of the mission case 19 is fastened to the cradle 47 of the right airframe frame 4 with bolts 48.

  As shown in FIGS. 6 and 9, left and right shift output bearings 19 a for supporting the left and right rear wheel drive shafts 36 are respectively protruded on the left and right sides of the rear portion of the transmission case 19, respectively. The left and right gearshift output bearings 19a are fastened to the cradle 49 of the body frames 3 and 4 with two transmission mounting bolts 50, respectively. That is, above the discharge duct 29, the body frames 3, 4 of the traveling machine body 1 are inclined in a front, rear, and rear shape along the upper surface of the discharge duct 29, and the front and rear inclined portions of the body frames 3, 4 are arranged. In the middle, the mission case 19 is supported by being inclined in a front-rear-rear-high shape (forward-inclined shape).

  Of the two transmission mounting bolts 50 for fastening the left shift output bearing 19a, the transmission mounting bolt 50a on the front side of the machine body is formed longer than the other transmission mounting bolts 50. A cylinder body 51a and a casing 51b as a spring mounting portion 51 described later are fitted on the head side of the mission mounting bolt 50a on the front side of the machine body. The outer diameter of the casing 51b is formed larger than the outer diameter of the cylindrical body 51a.

  The bearing 19a is fastened by the mission mounting bolt 50a so that the cylindrical body 51a and the housing 51b are sandwiched between the head of the mission mounting bolt 50a and the left shift output bearing 19a. That is, the cylindrical body 51a and the casing 51b are fastened to the cradle 49 by the transmission mounting bolt 50a together with the left shift output bearing 19a.

  On the other hand, as shown in FIGS. 6 to 8, the left and right connecting brackets 2b are fastened to the left and right body frames 3 and 4 with bolts 53, respectively, and both ends of the pipe-shaped horizontal rail frame 2a are connected to the left and right connecting brackets 2b. The parts are connected together. The front side of the traveling transmission relay case 34 is fastened to the pedestal 52 of the cross rail frame 2 a by two bolts 54. Further, the bottom of the traveling transmission relay case 34 is fastened with two bolts 55 to the inner side surface of the left body frame 3 whose end face is a square pipe shape. That is, the traveling transmission relay case 34 is supported in a posture that is inclined forwardly (front low, rear high) on the front end side (inclined lower end side) of the inclined portion in the front-rear direction of the body frames 3 and 4. It will be.

  As shown in FIGS. 7 and 8, the relay input shaft 56 projects forward from the front surface of the transmission relay case 34, and the relay input shaft 56 is connected to the rear end side of the propulsion shaft 33 via the universal joint 33 a. . A relay output shaft 57 protrudes upward from the upper surface of the transmission relay case 34, and a relay pulley 58 that transmits the power of the engine 9 is fitted on the relay output shaft 57. The relay input shaft 56 and the relay output shaft 57 are connected via a bevel gear (not shown) or the like built in the transmission relay case 34.

  A transmission input shaft 59 protrudes upward from the upper surface of the transmission case 19, and a transmission input pulley 61 having an air cooling fan 60 is fitted on the transmission input shaft 59. The relay pulley 58 and the transmission input pulley 61 are disposed on a plane substantially parallel to the body frames 3 and 4.

  A V-belt type input belt 35 is stretched between the relay pulley 58 and the transmission input pulley 61 via a tension roller 62. A fulcrum shaft body 64a projects upward on the top surface of the tip end side of the tension arm 64, and the tension roller 62 is rotatably supported on the fulcrum shaft body 64a. The proximal end side of the tension arm 64 is pivotally supported by the transmission relay case 34 so as to be rotatable around the relay output shaft 57. The tension arm 64 rotates around the relay output shaft 57 below the relay pulley 58.

  A locking shaft body 65 projects downward on the lower surface side of the tension arm 64, and a spring hook 66 a on one end side of the tension spring 66 is connected to the locking shaft body 65. A spring hook 66b on the other end side of the tension spring 66 is connected to the spring mounting portion 51 having the cylindrical body 51a and the casing 51b described above. The spring hook 66b is locked to the cylindrical body 51a. The spring hook 66b is prevented from being detached from the cylindrical body 51a by the housing 51b, and the tension spring 66 is locked and maintained on the spring mounting portion 51. The tension spring 66 is formed by a tension spring.

  With the above configuration, the tension spring 66 extends substantially parallel to the left machine frame 3 and the input belt 35 between the left machine frame 3 and the input belt 35 in a side view. Further, the tension spring 66 extends in a direction crossing the left machine frame 3 and the input belt 35 in a plan view. Then, the tension roller 66 is pressed against the input belt 35 by the tension spring 66, the tension of the input belt 35 is maintained at a set value, and the power from the engine 9 is transmitted via the transmission relay case 34 and the input belt 35. It is reported to the mission case 19. Therefore, the travel driving force shifted from the rear wheel drive shaft 36 of the transmission case 19 is output, the rear wheel 6 is driven by the travel driving force, and the traveling machine body 1 moves forward or backward.

  As is apparent from the above description and FIGS. 7, 8, and 9, the engine 9 mounted on the traveling machine body 1 including the front wheel 3 and the rear wheel 4 as a traveling unit, and the power of the engine 9 are shifted. The transmission case 19 transmitted to the rear wheel 4, the transmission input belt 35 that inputs the power of the engine 9 to the transmission case 19, the tension roller 62 that tensions the transmission input belt 35, and the tension roller 62 is urged in the tension direction. A work vehicle including a tension spring 66 has a structure in which a transmission case 19 is fastened to a traveling body 1 via a mission mounting bolt 50a, and one end of the tension spring 66 is locked to the mission mounting bolt 50a. Since the spring mounting portion 51 is provided, the spring mounting portion 51 must be specially assembled to the mission case 19 or the like. Without using the transmission mounting bolt 50a, the mounting structure of the tension spring 66 can easily configure, and reduces the attachment components of the tension spring 66 can easily perform assembly work and the like.

  As is clear from the above description and FIGS. 8 and 9, the shift output bearing portion 19 a of the transmission case 19 is fixed to the upper surface of the traveling machine body 1 via the mission mounting bolt 50 a fastened from above. Since the head side of the mission mounting bolt 50a is protruded on the upper side of the bearing portion 19a and the spring mounting portion 51 is arranged on the head side of the mission mounting bolt 50a, the mission is mounted on the upper surface side of the mission case 19. The tension spring 66 can be easily assembled via the mounting bolt 50a.

  As is apparent from the above description and FIGS. 8 and 9, the spring mounting portion 51 is formed by the cylindrical body 51 a and the casing 51 b that are fitted on the transmission mounting bolt 66. It can be configured at low cost with a simple structure.

  As is clear from the above description and FIGS. 7 and 8, the mower device 16 as a mowing unit disposed on the lower surface side of the traveling machine body 1, and the grass collection box 30 as a grass collecting part disposed behind the traveling machine body 1. A discharge duct 29 for conveying the cut turfgrass is extended between the vehicle body 1 and the traveling case 1 which is inclined above and below the discharge duct 29 in a front, low, and high shape. The traveling transmission relay case 34 is disposed on the traveling machine body 1 on the front side of the transmission case 19, and the engine 9 is connected to the relay output shaft 57 projecting upward from the upper surface of the traveling transmission relay case 34. The transmission pulley 58 is attached to the transmission case 19 and the transmission input pulley 61 is attached to the transmission input shaft 59 protruding upward on the upper surface of the transmission case 19. A tension roller 62 is connected to the tension arm 64, and a speed change input belt 35 is stretched between the speed change input pulley 60 and the relay pulley 58 via the tension roller 62. Therefore, the transmission case 19 can be compactly arranged above the discharge duct 29, and the tension spring 66 can be supported on the traveling machine body 1 with the transmission attachment bolt 50a with high rigidity.

  In addition, with the above configuration, the power of the engine 9 is transmitted to the transmission case 19 by one propulsion shaft 33, and the ventilation cross-sectional area (vertical width dimension and horizontal width dimension) of the discharge duct 29 is set to a predetermined value. In order to ensure the size, the propulsion shaft 33 can be disposed low by the vertical transmission dimension of the transmission relay case 34 in a state where the transmission case 19 is disposed at a high part of the traveling machine body 1. Even if the propulsion shaft 33 is disposed below the floor (step) of the traveling machine body 1 on which the operator who sits on the driver's seat 15 puts his / her foot, the floor (step) of the traveling machine body 1 can be formed low. . Therefore, the power transmission mechanism to the transmission case 19 can be simply configured, the large discharge duct 29 is arranged at the center of the left and right width of the traveling machine body to facilitate the discharge of the cut grass to the rear, and There is an effect that the operator can easily get on and off the driver seat 15 at the same time. The step as the floor surface of the traveling machine body 1 is formed on the upper surface of each cowl 7, 14 at the connecting portion between the rear end side of the front cowl 7 and the front end side of the rear cowl 14.

  Further, the above-described hydraulic oil in the oil tank 21 is supplied to the continuously variable transmission 100 built in the mission case 19 through the charge oil pipe 70. A bypass lever 71 for maintaining the rotation of the output side (hydraulic motor) of the continuously variable transmission 100 at substantially zero regardless of whether the input side (hydraulic pump) of the continuously variable transmission 100 is rotated or not. It is disposed on the upper surface of the mission case 19 (see FIG. 6). That is, by switching the bypass lever 71, the input side (hydraulic pump) of the continuously variable transmission 100 can be short-circuited, and the output side (hydraulic motor) of the continuously variable transmission 100 can be unloaded.

  One end side of a switching lever 72 that switches the bypass lever 71 is connected to the bypass lever 71. The other end side of the switching lever 72 extends between the left and right body frames 3 and 4 at the rear end portions thereof (see FIG. 6). For example, when the rear wheel 6 cannot be driven by the power of the engine 9 due to a failure such as the lack of fuel in the fuel tank 20, the grass collection box 30 is removed from the traveling machine 1, and the operator pulls the switching lever 72. By switching the bypass lever 71, the continuously variable transmission 100 in the mission case 19 is kept in an unloaded state, and the operator can move by pushing the traveling machine body 1.

  Note that the continuously variable transmission 100 in the transmission case 19 can be returned to the operating state by the operator pressing the switching lever 72 and returning the bypass lever 71 to the initial position.

  Next, referring to FIGS. 7 and 8, the protection structure of the connecting portion between the relay input shaft 56 and the propulsion shaft 33 of the traveling transmission relay case 34 will be described. A first protective cover body 80 made of sheet metal bent into an L shape in front view is provided. The first protective cover body 80 has a vertical wall 80a and a horizontal wall 80b, and is formed in an L shape in which the left edge of the horizontal wall 80b is connected to the upper edge of the vertical wall 80a.

  The lower end side of the vertical wall 80 a is bent and extended on the upper surface of the left airframe frame 3, and the lower end side of the vertical wall 80 a is fastened to the upper surface of the left airframe frame 3 with a bolt 53. Further, the rear end side of the horizontal wall 80 b is fastened to the cradle 52 described above with a bolt 54. The upper surface side and the left side surface side of the universal joint 33 a for connecting the relay input shaft 56 and the propulsion shaft 33 are blocked by the first protective cover body 80.

  On the other hand, as shown in FIGS. 7 and 8, a second protective cover body 82 made of sheet metal for closing the right side surface of the universal joint 33 a is provided. The second protective cover body 82 is formed by a vertical wall standing on the right side of the universal joint 33a, and the rear end side of the L-shaped second view of the second protective cover body 82 is fastened to the cradle 52 with bolts 54. . That is, the connection bracket 2 b and the first protective cover body 80 are fastened by the bolt 53. Further, the transmission relay case 34, the first protective cover body 80, and the second protective cover body 82 are fastened to the pedestal 52 with bolts 54. Since the first protective cover body 80 and the second protective cover body 82 are fixed using bolts 53 and 54 for attaching other components, the first protective cover body 80 and the second protective cover body 82 are attached. When assembling, it is not necessary to specially provide a support member and a mounting bolt for the first protective cover body 80 or the second protective cover body 82.

  With the above configuration, the upper surface side, the left side surface side, and the right side surface side of the universal joint 33a are blocked by the first protective cover body 80 and the second protective cover body 82. While the propulsion shaft 33 is rotating by the power of the engine 9, even if the propulsion shaft 33 is detached from the relay input shaft 56 due to, for example, damage to the universal joint 33a or the like, the propulsion shaft 33 moves upward or left and right side first. It can be blocked by the protective cover body 80 and the second protective cover body 82. Therefore, it is possible to prevent the propulsion shaft 33 from colliding with the upper or left and right side components and damaging the components.

It is the whole lawn mower side view. It is the same top view. It is a side view of the traveling body of a lawn mower. It is a top view of the traveling body. It is an enlarged side view of the second half part of the traveling machine body. It is an enlarged plan view of the latter half part of the traveling machine body. It is a side view of the attaching part of the mission case. It is a top view of the attaching part of the mission case. It is the elements on larger scale of FIG.

Explanation of symbols

1 traveling body 5 front wheel (traveling part)
6 Rear wheels (traveling part)
9 Engine 16 Mower device (mowing unit)
19 Mission case 19a Bearing part 29 Exhaust duct 30 Grass collection box (grass part)
34 Transmission relay case 35 Input belt 50a Transmission mounting bolt 51 Spring mounting portion 51a Cylindrical body 51b Housing 57 Relay output shaft 58 Relay pulley 59 Shifting input shaft 62 Tension roller 64 Tension arm 66 Tension spring

Claims (4)

An engine mounted on a traveling machine body including a traveling unit, a transmission case that shifts the power of the engine and transmits the engine power to the traveling unit, an input belt that inputs the power of the engine to the transmission case, and the input belt In a work vehicle comprising a tension roller that tensions and a tension spring that biases the tension roller in the tension direction,
A structure in which the transmission case is fastened to the traveling body via a mission mounting bolt,
A work vehicle characterized in that a spring mounting portion for locking one end side of the tension spring is provided on the transmission mounting bolt.   A transmission output bearing portion of the transmission case is fixed to the upper surface of the traveling machine body via the transmission mounting bolt fastened from above, and the head side of the transmission mounting bolt protrudes above the bearing portion. The work vehicle according to claim 1, wherein the spring mounting portion is arranged on a head side of the transmission mounting bolt.   The work vehicle according to claim 2, wherein the spring mounting portion is formed of a cylindrical body and a casing that are fitted on the transmission mounting bolt. Between the grass cutting part disposed on the lower surface side of the traveling machine body and a grass collecting part disposed on the rear side of the traveling machine body, a discharge duct for conveying the cut grass is extended.
The mission case is supported by inclining in the front low, rear, and high shape on the traveling machine body that is inclined in the front low rear high shape above the discharge duct,
A transmission relay case is disposed on the traveling machine body on the front side of the transmission case, and a relay pulley that transmits the power of the engine is attached to a relay output shaft that protrudes upward on the upper surface of the transmission relay case.
A transmission input pulley is attached to a transmission input shaft protruding upward on the upper surface of the transmission case,
Placing the tension roller on a tension arm rotatable around the relay output shaft, connecting the tension spring to the tension arm;
The work vehicle according to claim 1, wherein the input belt is stretched between the transmission input pulley and the relay pulley via the tension roller.

Images