JP5037426B2 - Work vehicle - Google Patents

Description

  The present invention relates to a work vehicle in which a clutch piston is slidably and slidably attached to a friction plate so that a PTO clutch is turned on and off, and power of a PTO input shaft is transmitted to or cut off from a PTO intermediate shaft. The PTO brake is composed of a brake plate provided at the rear part of the clutch cylinder via a pin connected to the clutch piston and slidable in the axial direction, and a brake disk provided at the front end part of the brake body. The present invention relates to a work vehicle characterized in that a brake plate is brought into contact with a brake disk to brake rotation of a PTO intermediate shaft, and a brake disk and a brake body of a PTO brake are installed on a clutch cylinder.

In a conventional work vehicle such as a wheel tractor, for example, the power from the engine is transmitted from the input shaft provided in the clutch housing to one of the drive shafts via the main auxiliary transmission, and the front wheel drive device and the rear wheel drive device. The device is operable, and the other from the input shaft is transmitted to the PTO intermediate shaft connected by turning on and off of the PTO hydraulic clutch constituting the PTO power transmission device provided in the transmission case, and the PTO transmission is Is transmitted to the PTO shaft, and drives a working machine mounted on the rear part of the vehicle (for example, Patent Document 1).
JP-A-11-34679

  However, in such a PTO power transmission device for a work vehicle, an inertia brake that brakes the rotation of the clutch piston and the clutch cylinder that rotate integrally with the PTO intermediate shaft and that constitutes the PTO power transmission device in the vehicle manufacturing process. The mechanism (PTO brake) is provided in a configuration in which a brake plate is disposed between steel plates in a brake holder that rotates behind the clutch cylinder and rotates integrally with the PTO intermediate shaft provided on the PTO intermediate shaft. Since the PTO brake and the PTO clutch cannot be efficiently assembled in the transmission case because they are assembled separately from the PTO clutch and assembled in the transmission case, there is a problem that productivity is lowered. there were. In addition to using a steel plate in addition to the brake plate, the shielded bearing was used to dampen the PTO brake lubricating oil to the rear side of the PTO brake, resulting in an increase in cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a work vehicle having a PTO power transmission device that reduces costs and improves productivity.

For this reason, the invention according to claim 1 is integrated with the PTO input shaft in the vicinity of the PTO intermediate shaft constituting the PTO power transmission mechanism in the transmission case and transmitting the power from the engine to the work machine. A PTO clutch comprising a clutch cylinder fitted with a plurality of friction plates and a clutch piston that rotates integrally with the PTO intermediate shaft, and a PTO brake that brakes rotation of the PTO clutch, In a work vehicle in which the PTO clutch is detachably slid on and off the PTO clutch and the power of the PTO input shaft is transmitted to or cut off from the PTO intermediate shaft, the PTO brake is connected to the clutch cylinder. Brake play that is slidable in the axial direction, provided on the rear via a pin connected to the clutch piston And a brake disk provided at the front end of the brake body, the brake plate is brought into contact with the brake disk to brake the rotation of the PTO intermediate shaft, and the brake disk of the PTO brake and the brake body are was placed on the clutch cylinder, the PTO brake, said clutch cylinder, between said brake disc, characterized Rukoto includes a gap portion of the labyrinth structure for storing lubricating oil.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, the brake disk and the brake main body are fixed to a rear portion of the clutch cylinder, which is a rear portion of a bearing provided on the PTO intermediate shaft. It is fixed by a ring.

According to the first aspect of the present invention, in the transmission case, integrally with the PTO input shaft, in the vicinity of the PTO intermediate shaft constituting the PTO power transmission mechanism that transmits the power from the engine to the work machine. A PTO clutch comprising a clutch cylinder fitted with a plurality of rotating friction plates and a clutch piston that rotates integrally with the PTO intermediate shaft, and a PTO brake that brakes the rotation of the PTO clutch. The clutch piston is attached to and detached from the friction plate. In a working vehicle that slides freely to turn on and off the PTO clutch and transmit or cut off the power of the PTO input shaft to the PTO intermediate shaft, the PTO brake has a pin connected to the clutch piston at the rear of the clutch cylinder. A brake plate that is slidable in the axial direction, and a brake device provided at the front end of the brake body. It consists disk, contacting the brake plate to the brake disc, with braking the rotation of the PTO intermediate shaft, a brake disk and brake body of the PTO brake, installed on the clutch cylinder, PTO brake, a clutch cylinder, brake between the disc, Runode includes a gap portion of the labyrinth structure which stores lubricating oil, without using a lining, such as a conventional steel plate, such as, as well as enabling a reduction in assembly, PTO clutch and PTO brake Can be efficiently assembled in the mission case. Also, the lubricating oil is temporarily stored in the gap where the storage volume is increased by the labyrinth structure without using expensive parts such as shielded bearings to dam the lubricating oil of the PTO brake to the rear side of the PTO brake. Thus, it is possible to prevent the lubricating oil from flowing out to the rear side of the PTO brake. Therefore, it is possible to provide a work vehicle with reduced cost and improved productivity.

  According to the second aspect of the present invention, the brake disc and the brake main body are fixed to the rear portion of the bearing on the PTO intermediate shaft by the retaining ring at the rear portion of the clutch cylinder. The brake disc and brake body of the PTO brake can be fixed on the clutch cylinder with a simple configuration without using many parts. Therefore, it is possible to provide a work vehicle with reduced cost and improved productivity.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a left side view of a wheel tractor as a work vehicle according to an embodiment of the present invention, and FIG. 2 is a plan view of the tractor.

  As shown in FIGS. 1 and 2, the tractor 1, which is a working vehicle of this example, includes a front wheel 3 and a rear wheel 4 before and after the body frame 2, and forms a hood 5 above the front wheel 3. An engine 6 as a prime mover section and a clutch housing 7 are disposed behind the engine 6, and a transmission case 8 is disposed behind the clutch housing 7. Power from the engine 6 is transmitted to the front wheels 3 and the rear wheels. 4 is transmitted. A cabin 9 is provided on the body frame 2 continuously to the rear part of the bonnet 5. The drive unit of the tractor 1 is not limited to the wheel type as described above, and may be a crawler type.

  Next, an operating pedal such as a brake pedal and a clutch pedal 10, a steering handle 11, a seat 12, and the like are provided in the cabin 9 as a vehicle control unit. Further, various operation levers 14 such as a main transmission lever, a sub transmission lever, and a PTO transmission lever are provided on the left and right fenders 13 provided on both sides of the seat 12 in a protruding manner. And the windshield 15, the rear glass 16, the door 17, the roof 18, etc. may be attached to the outer periphery of the cabin 9, respectively. Note that the tractor 1 is not limited to the cabin specification described above, and may be a lops specification.

  The power from the engine 6 is transmitted to a PTO shaft 60, which will be described later, protruding from the rear end of the transmission case 8, and from the PTO shaft 60 via a work implement mounting device 20 such as a universal joint or a three-point link type not shown. Then, the work machine 21 mounted on the rear end of the vehicle is driven.

  Next, the configuration of power transmission will be described. 3 is a skeleton diagram of the power transmission system, FIG. 4 is a developed sectional view of the inside of the mission case, and FIG. 5 is a side view of the PTO power transmission mechanism provided in the rear part of the mission case. As shown in FIGS. 3 to 4, a multi-plate main clutch 43 is accommodated in the clutch housing 41 and linked to the clutch pedal 10. The rotation of the output shaft 44 of the engine 6 is input to the main clutch 43, and the output shaft 45 of the main clutch 43 is provided on the same axis as the PTO input shaft 46 extending rearward of the vehicle. 3 to 4, the PTO power transmission mechanism 59 is simply described or omitted.

  Next, a transmission gear 47 and a PTO third speed claw 47a are arranged at the rear end of the output shaft 45. A PTO first speed gear 48, a PTO second speed gear 49, and a PTO reverse gear are arranged on the PTO input shaft 46. 50 and are respectively loosely fitted. The PTO first speed gear 48, the PTO second speed gear 49, and the transmission gear 47 are engaged with transmission gears 52, 53, and 54 provided on the main shaft 51, respectively, and the PTO reverse gear 50 is a counter gear 55. The power from the engine 40 transmitted to the PTO input shaft 46 from the transmission gears 52, 53, 56 and the PTO third speed claw 47a by the sliding of the PTO clutch sliders 57, 58 is shown in FIG. As shown in 4 to 5, the work machine 21 is driven by being transmitted to the PTO shaft 60 through a PTO power transmission mechanism 59 described later such as the PTO intermediate shaft 90 and the PTO transmission shaft 91.

  Note that the PTO transmission is not limited to the above-described method, and a PTO transmission (not shown) may be provided between the PTO transmission shaft 91 and the PTO shaft 60. In this case, for example, a plurality of PTO transmission shafts 91 may be provided on the PTO transmission shaft 91. A drive gear with different number of teeth is provided, a driven gear meshing with the drive gear is rotatably provided on the PTO shaft 60, a shifter is provided on the PTO shaft 60 between the driven gears so as to be slidable and relatively non-rotatable. It is also possible to perform the PTO speed change by switching the shifter by operating a PTO speed change lever (not shown) and selectively engaging with the driven gear.

  Next, transmission gears 52, 53, 54, 56 fixed to the main shaft 51 are loosely fitted to the main transmission shaft 61, a main transmission first speed gear 62, a main transmission second speed gear 63, and a main transmission third speed gear. 64 and the main transmission fourth speed gear 65 are respectively meshed. Two main transmission clutch sliders 66 and 67 that are spline-fitted so as to be slidable in the axial direction of the main transmission shaft 61 are linked to a main transmission lever (not shown) provided in the cabin 9. Claws formed on the main transmission clutch sliders 66 and 67, the main transmission first speed gear 62, the main transmission second speed gear 63, the main transmission third speed gear 64, and the main transmission fourth speed gear 65 by the operation of the main transmission lever. And the power is transmitted from the main shaft 51 to the main transmission shaft 61 via any one of the selected main transmission gears 62, 63, 64, 65.

  Further, a forward rotation side gear 68 and a reverse rotation side gear 69 are loosely fitted on the same shaft center in a forward extension portion of the main transmission shaft 61 in the vehicle traveling direction. Then, by operating a reverser lever (not shown) provided in the cabin 9, the reverser clutch 70 is selectively connected to either the forward side or the reverse side, and the rotation of the main transmission shaft 61 is rotated in the forward rotation side gear 68 or the reverse rotation side gear 69. Communicated to either. However, when the reverser lever is in the neutral position, the rotation is not transmitted to either the forward rotation side gear 68 or the reverse rotation side gear 69.

  The forward rotation side gear 68 is engaged with a gear 72 fitted to the transmission shaft 71, and the reverse rotation side gear 69 is engaged with a counter gear 74 fitted to the counter shaft 73. The counter gear 74 is transmitted. It meshes with a gear 75 fitted to the shaft 71.

  As a result, when the reverser clutch 70 is connected to the forward side, the rotational power of the main transmission shaft 61 is transmitted to the transmission shaft 71 via the forward rotation side gear 68, and the reverser clutch 70 is connected to the reverse side. The rotational power of the main transmission shaft 61 allows the transmission shaft 71 to rotate in the reverse rotation direction from the reverse rotation side gear 69 via the counter shaft 73.

  A gear 72 fitted to the transmission shaft 71 meshes with the forward rotation side gear 68 and meshes with a gear 77 provided on the coaxial line of the auxiliary transmission shaft 76 and in front of the vehicle traveling direction. A sub-transmission shifter 78 is fitted to the sub-transmission shaft 76 so that it can freely slide between the front portion of the sub-transmission shaft 76 and the rear portion of the gear 77.

  The auxiliary transmission shifter 78 is operated by an auxiliary transmission lever (not shown) provided in the cabin 27, and the auxiliary transmission shifter tooth 78 a formed at the front of the auxiliary transmission shifter 78 is positioned at the rear position 77 a of the gear 77. A third speed (sub-speed), a sub-speed second speed in a state where the sub-shift shifter teeth 78 a and a tooth 77 b provided at the rear end of the gear 77 mesh with each other, and a tooth 78 b formed at the upper center of the sub-shift shifter 78. And the gear 79 provided in the vicinity of the center of the transmission shaft 71, the sub-shift first speed, the state where the rotational power is not transmitted to the sub-shift shifter 78 (neutral), and the teeth 78c of the rear portion of the sub-shift shifter 78 A sub-transmission device that can be switched to a sub-transmission ultra-low speed (C speed) in a state in which the illustrated ultra-low speed gear meshes with each other is configured.

  By selecting the gear meshing by sliding of the auxiliary transmission shifter 78, the rotation of the transmission shaft 71 is output through three speeds, and the rotational power input to the auxiliary transmission shaft 76 is provided to the auxiliary transmission shaft 76. The three gears 80, 81, 82, etc. output in two directions, the rear wheel drive system and the front wheel drive system.

  A rear wheel differential device 83 is disposed behind the transmission case 42, and the rotation of the auxiliary transmission shaft 76 is input to the rear wheel differential device 83 via a gear 82 formed at the rear end of the auxiliary transmission shaft 76. The rear wheel 3 is driven via an axle or the like in a rear axle case (not shown). Reference numeral 84 denotes a brake device.

  Next, a specific configuration of the PTO power transmission mechanism 59, which is a feature of the present invention, will be described. FIG. 6 is a cross-sectional side view of the periphery of the PTO intermediate shaft showing the PTO clutch and the PTO brake, and FIG. 7 shows the contact between the brake plate of the PTO brake and the brake disc by the operation of the PTO brake accompanying the disconnection of the PTO clutch. FIG. 8 is an enlarged side view of the upper part of the PTO clutch and the PTO brake. FIG. 8 shows the separation between the brake plate of the PTO brake and the brake disc when the PTO brake is released due to the connection of the PTO clutch. It is a top enlarged side view.

  As shown in FIGS. 5 to 6, the PTO power transmission mechanism 59 includes a PTO intermediate shaft 90 disposed behind the PTO input shaft 46 in the transmission case 8 and a PTO transmission shaft linked to the PTO intermediate shaft 90. 91, and further, a PTO brake 100 and a PTO clutch 101 disposed between the PTO input shaft 46 and the PTO intermediate shaft 90 and around the PTO intermediate shaft 90.

  First, the PTO clutch 101 includes a cylindrical member 102 that is rotatably fitted integrally with the PTO input shaft 46 at the rear end portion of the PTO input shaft 46, and a PTO intermediate shaft 90 in the middle of the PTO intermediate shaft 90. The clutch cylinder 103 is rotatably fitted integrally with the shaft 90. The clutch cylinder 103 has an inner cylinder part 104 and an outer cylinder part 105 formed in a double cylinder shape. In a space formed between the inner cylinder part 104 and the outer cylinder part 105, The rear part of the cylindrical member 102 is inserted.

  A plurality of driving friction plates 106 and driven friction plates 107 are alternately arranged between the outer cylinder portion 105 of the clutch cylinder 103 and the cylinder member 102. In the space between the inner cylinder part 104 and the outer cylinder part 105, a clutch piston 108 linked to an operation member (not shown) provided in the vehicle control part is slidably fitted. In FIG. 2, since the elastic body 109 such as a spring is urged backward, the PTO clutch 101 is disconnected (power is not transmitted from the PTO input shaft 46 to the PTO intermediate shaft 90). The clutch piston 108 slides forward against the urging force of the elastic body 109 by hydraulic drive, and presses the friction plates 106 and 107 to connect the PTO clutch 101 (from the PTO input shaft 46 to the PTO intermediate shaft). Power is transmitted to 90). Note that the sliding of the clutch piston 108 by the operation of the operation member is a well-known technique, and a detailed description thereof will be omitted.

  Next, the present invention is characterized in that the PTO brake 100 is mounted on the clutch cylinder 103. The PTO brake 100 includes a brake plate 110 and a brake main body 111.

  First, a brake plate 110 constituting the PTO brake 100 is disposed at the rear portion of the clutch cylinder 103. The brake plate 110 is connected to the clutch piston 108 by a pin 112 that is attached through the clutch cylinder 103 between a front end portion of the brake plate 110 and a rear portion of the clutch piston 108. Accordingly, as the clutch piston 108 slides as described above, the brake plate 110 can also slide in the front-rear direction in conjunction with the clutch piston 108.

  The brake plate 110 is configured such that the brake plate 110 and a brake disk 113 described later are spaced apart when the PTO clutch 101 is connected.

  Next, the brake body 111 has an appropriate length in the axial direction including a brake disk 113 at the front end, and a middle part of the brake body 111 is a bearing 114 disposed on the rear part of the clutch cylinder 103. In addition, the brake body 111 is fixed on the clutch cylinder 103 by being indirectly fixed by the retaining ring 115. Therefore, the brake main body 111 including the brake disk 113 does not rotate with the rotation of the PTO input shaft 46 and the PTO intermediate shaft 90.

  The brake disc 113 is preferably a front end surface of the brake disc 113 and has a diameter r1 at a portion in contact with the brake plate 110 that is equal to or larger than ½ of the diameter r2 of the brake plate 110.

  Furthermore, a gap s is provided between the brake plate 110 and the clutch cylinder 103 and the brake disk 113. The gap portion s is, for example, a side surface that is cut so as to curve downward from the gap between the upper brake plate 110 and the brake disc 113 toward the rear side of the brake disc 113 and the front side of the clutch cylinder 103. It is provided with a labyrinth structure such as a substantially S-shape.

  Here, when the PTO clutch 101 is operated to be disconnected by the operation member included in the vehicle control unit described above while the PTO clutch 101 is being connected, in which power is transmitted from the PTO input shaft 46 to the PTO intermediate shaft 90, FIG. As shown, the clutch piston 108 is slid rearward by the urging force of the elastic body 109, and the friction plates 106, 107 and the clutch piston 108 are separated from each other, whereby the power from the PTO input shaft 46 to the PTO intermediate shaft 90 is shown. Transmission is interrupted.

  At this time, the brake plate 110 is also slid rearward via the pin 112 in conjunction with the sliding of the clutch piston 108, so that the rear end surface of the brake plate 110 contacts the front end surface of the brake disc 113. As a result, the rotation of the clutch piston 108 and the clutch cylinder 103 is braked by the frictional force of both, and the rotation of the PTO intermediate shaft 90 after the power is disconnected from the PTO input shaft 46 is fitted to the PTO intermediate shaft 90. The clutch cylinder 103 is stopped by braking.

  At this time, the diameter r1 of the portion of the front end surface of the brake disk 113 that contacts the brake plate 110 is set to be 1/2 or more of the diameter r2 of the brake plate 110, so that the contact surface of the brake disk 113 with the brake plate 110 is sufficient Therefore, the frictional force between the two can be increased, and the rotation of the PTO intermediate shaft 90 can be easily braked without using a lining such as a steel plate as in the prior art.

  When the PTO clutch 101 is connected, the operation of the operation member causes the clutch piston 108 to slide forward against the urging force of the elastic body 109 as shown in FIG. Since the plate 110 is also linked, the brake plate 110 is separated from the brake disk 113, so that the PTO intermediate shaft 90 is rotated by the rotational drive of the PTO input shaft 46 via the friction plates 106, 107, the clutch piston 108, the clutch cylinder 103, and the like. Is done.

  Thus, by configuring the PTO brake 100 from the brake plate 110 and the brake body 111, it is possible to reduce assembly parts without using a lining such as a steel plate as in the prior art, and to reduce costs. Can be achieved. In addition, since the PTO brake 100 has a simple configuration as described above, the brake body 111 can be easily placed and fixed on the clutch cylinder 103 with the retaining ring 115, and the PTO brake is a PTO clutch as in the past. The PTO clutch 101 and the PTO brake 100 can be efficiently assembled as one assembly unit in the mission case 8 without being assembled separately and assembled in the mission case 8.

  Furthermore, in the present invention, as described above, since the gap portion s having a labyrinth structure such as a substantially S shape in a side view is provided between the brake plate 110 and the clutch cylinder 103 and the brake disc 113, the bearing 114 is conventionally provided. Thus, there is no need to block the lubricating oil supplied from within the intermediate shaft by using an expensive shielded bearing, and even if a normal bearing 114 is used, this lubricating oil is temporarily stored in the gap s. Thus, it is possible to prevent the lubricating oil from flowing out to the rear of the bearing 114, thereby reducing the cost.

  As described above in detail, the tractor 1 of this example is in the mission case 8 and in the vicinity of the PTO intermediate shaft 90 constituting the PTO power transmission mechanism 59 that transmits the power from the engine 6 to the work implement 21. , A PTO clutch 101 comprising a plurality of friction plates 106, 107 rotating integrally with the PTO input shaft 46 and a clutch cylinder 103 fitted with a clutch piston 108 rotating integrally with the PTO intermediate shaft 90, and rotation of the PTO clutch 101 And a PTO brake 100 that detachably slides the clutch piston 108 on the friction plates 106 and 107 to turn the PTO clutch 101 on and off, and the power of the PTO input shaft 46 is transferred to the PTO intermediate shaft 90. In the work vehicle that transmits or shuts off, the PTO brake 100 is placed at the rear of the clutch cylinder 103. The brake plate 110 is provided via a pin 112 connected to the latch piston 108 and is slidable in the axial direction, and a brake disk 113 provided at the front end of the brake body 111. The brake plate 110 is connected to the brake disk 113. The brake disc 113 and the brake body 111 of the PTO brake 100 are installed on the clutch cylinder 103 while the rotation of the PTO intermediate shaft 90 is braked.

  In addition, the brake disc 113 and the brake body 111 are fixed to the rear portion of the bearing 114 on the PTO intermediate shaft 90 by the retaining ring 115 at the rear portion of the clutch cylinder 103, and the brake disc 113 is fixed to the brake disc 113. The diameter of the contact surface of the brake plate 110 is set to be 1/2 or more of the diameter of the brake plate 110, and the PTO brake 100 supplies lubricating oil between the clutch cylinder 103 and the brake disc 113. A gap s for storing is provided.

  In the above-described example, the wheel type tractor (agricultural working machine) has been described as an example of the work vehicle. However, the present invention is not limited to this, and any work including a PTO power transmission mechanism such as a crawler type tractor. It can be applied to vehicles.

It is a left view of the wheel type tractor as a work vehicle concerning one example of the present invention. It is a top view of the tractor. It is a skeleton figure of a power transmission system. It is a section development figure inside a mission case. It is a side view of the PTO power transmission mechanism which has in a mission case rear part. It is a cross-sectional side view around the PTO intermediate shaft showing the PTO clutch and the PTO brake. It is the upper part expansion side view of a PTO clutch and a PTO brake which shows contact with a brake plate of a PTO brake by operation of a PTO brake, and a brake disc accompanying disconnection of a PTO clutch. FIG. 6 is an enlarged side view of the upper part of the PTO clutch and the PTO brake, showing the separation between the brake plate of the PTO brake and the brake disk when the PTO brake is released according to the connection of the PTO clutch.

Explanation of symbols

46 PTO input shaft 46
59 PTO power transmission mechanism 59
90 PTO intermediate shaft 100 PTO brake 101 PTO clutch 103 Clutch cylinder 106, 107 Friction plate 108 Clutch piston 110 Brake plate 111 Brake body 112 Pin 113 Brake disc 114 Bearing 115 Retaining ring r1, r2 Diameter s Gap

Claims (2)

A plurality of friction plates that rotate integrally with a PTO input shaft in the vicinity of a PTO intermediate shaft that constitutes a PTO power transmission mechanism in a transmission case and transmits power from an engine to a work machine, and the PTO intermediate shaft A PTO clutch composed of a clutch cylinder fitted with a clutch piston that rotates integrally with the PTO brake, and a PTO brake that brakes the rotation of the PTO clutch. In a working vehicle that turns on and off the PTO clutch and transmits or shuts off the power of the PTO input shaft to the PTO intermediate shaft, the PTO brake is connected to the rear portion of the clutch cylinder via a pin connected to the clutch piston. A brake plate that is slidable in the axial direction and provided at the front end of the brake body Consists rake disc, said brake plate into contact with the brake disc, with braking the rotation of the PTO intermediate shaft, the brake disc and the brake body of the PTO brake, installed on the clutch cylinder, the PTO brake, working vehicle to said clutch cylinder, between said brake disc, wherein Rukoto includes a gap portion of the labyrinth structure for storing lubricating oil.   2. The work vehicle according to claim 1, wherein the brake disk and the brake main body are fixed to a rear portion of the clutch cylinder at a rear portion of a bearing provided on the PTO intermediate shaft by a retaining ring.

Images