JP2005083488A - Working power transmission structure for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working power transmission structure with a working device having great output and connectedly mounted thereon for improving the working capability with no disadvantage in cost and manufacture by mounting a PTO brake having great braking force for preventing the inertial action and accompanying rotation of the working device having great output with no great change in the arrangement of a power transmission system. <P>SOLUTION: The working power transmission structure for a working vehicle comprises a working power transmission system 25 for transmitting power from an engine 1 to a PTO shaft 21 and a hydraulic PTO clutch 32 and PTO brake 33 mounted thereacross. The braking operation of the PTO brake 33 is performed in linkage with the off-operation of the PTO clutch 32, and the braking cancelling operation of the PTO brake 33 is performed in linkage with the on-operation of the PTO clutch 32. The PTO clutch 32 and the PTO brake 33 are of an integrated multiplate type with an number of friction plates 35, 38, 40, 42 for sharing a single housing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, a hydraulic PTO clutch and a PTO brake are interposed in a work transmission system that transmits power from the engine to the PTO shaft, and the PTO brake is braked in conjunction with the disengagement operation of the PTO clutch. The present invention relates to a work transmission structure for a work vehicle configured to release a brake of the PTO brake in conjunction with a PTO clutch engagement operation.

  In a work transmission structure of a work vehicle, when only a hydraulic PTO clutch is interposed in a work transmission system that transmits power from an engine to a PTO shaft, the work device connected to the PTO shaft when the PTO clutch is operated to be disconnected However, there is a disadvantage that the operation is continued due to the inertia. Further, when the PTO clutch is configured as a multi-plate type, when the PTO clutch is disengaged, the inconvenience that the working device rotates with the PTO clutch is likely to occur.

  Therefore, a hydraulic PTO clutch and a PTO brake are installed in the work transmission system, the PTO brake is braked in conjunction with the PTO clutch disengagement operation, and the PTO brake is interlocked with the PTO clutch engagement operation. Is configured so that the PTO clutch can be released, so that in a working state in which the PTO clutch is engaged, the working device connected to the PTO shaft can be driven satisfactorily while the PTO clutch is disengaged. In this case, it is possible to prevent the work apparatus from causing the inconvenience of continuing the operation due to its inertia and the inconvenience of being accompanied by the multi-plate PTO clutch.

By the way, in order to prevent inertial operation and accompanying rotation of the working device during the PTO clutch disengagement operation as described above, conventionally, the PTO brake is linked to the PTO clutch disengagement operation in a simple manner as a braking action unit. One friction member is configured to be a single plate type that presses against a fixed braking member to brake (see, for example, Patent Document 1).
JP-A-6-297971 (paragraph number 0009, FIG. 3, FIG. 4, FIG. 13)

  In recent years, in order to improve work ability, it is desirable to connect and equip work devices driven by a PTO shaft with a large work device such as a tiller device having a wide work width or a three-blade mower. In order to meet such a demand, it is necessary to equip a PTO brake having a large braking force that can surely prevent the inertial operation of a working device having a large output.

  However, in order to improve the braking force in the single plate type PTO brake described above, it is necessary to adopt a large-diameter friction member and a fixed-side braking member, but it is interposed in the work transmission system. Around the PTO brake, the components of the work transmission system and the components of the traveling transmission system that transmit the power from the engine to the drive wheels are arranged in close proximity. It is difficult to adopt a large-diameter member, and when a large-diameter member is used, the transmission shaft of the work transmission system equipped with the PTO brake and the work transmission system or traveling transmission adjacent to this transmission shaft. It is necessary to make major changes to the arrangement of the transmission system, such as increasing the distance between each transmission axis of the system, and many new parts corresponding to the change must be arranged and assembled using a new assembly procedure. Since cormorants needs, which is disadvantageous in terms of cost and production with take considerable effort to such arrangement setting of the transmission system.

  An object of the present invention is to provide a PTO brake having a large braking force capable of preventing inertial operation and accompanying rotation of a work device having a large output without greatly changing the arrangement of the transmission system, and thus, cost, manufacturing, etc. Therefore, it is possible to improve work ability by connecting and equipping a work device having a large output without being disadvantageous.

  As means for solving the above-mentioned problems, in the present invention, a hydraulic PTO clutch and a PTO brake are interposed in a work transmission system for transmitting power from the engine to the PTO shaft. In the work transmission structure for a work vehicle, wherein the PTO brake is braked and the PTO brake is braked and released in conjunction with the PTO clutch engagement operation, The PTO brake is a multi-plate type having a large number of friction plates, and is configured as an integrated type sharing a single housing.

  According to this configuration, the PTO brake is braked in conjunction with the PTO clutch disengagement operation, and the PTO brake is released in conjunction with the PTO clutch engagement operation. In this state, the working device connected to the PTO shaft can be driven satisfactorily, and in the non-working state in which the PTO clutch is turned off, the working device continues to operate with its inertia, and the multi-plate type PTO clutch It is possible to prevent the occurrence of inconvenience that is accompanied by the user.

  In addition, since the PTO brake is a multi-plate type, work equipment driven by the PTO shaft, such as a tiller device with a wide work width or a 3-blade mower, can be used to improve work capacity. Even when the equipment is connected, the number of friction plates equipped on the PTO brake is increased, so that the transmission shaft of the work transmission system equipped with the PTO brake, the work transmission system adjacent to the transmission shaft, and traveling It is possible to obtain a large braking force that can reliably prevent inertial operation of a work device having a large output without greatly changing the arrangement of the transmission system such as increasing the distance between each transmission shaft of the transmission system. .

  Moreover, since the PTO clutch and the PTO brake are configured as an integrated type that shares a single housing, the number of parts can be reduced compared to the case where each has a dedicated housing, and parts management and manufacturing are made correspondingly. This makes it easier to reduce costs. In addition, the PTO clutch and PTO brake can be assembled in a wide work area by attaching a plurality of friction plates of the PTO clutch and a plurality of friction plates of the PTO brake to a single housing in advance. The PTO clutch and PTO brake can be relatively easily assembled by assembling them into the work transmission system. In addition, the PTO clutch and PTO brake can be linked smoothly compared to the case where the PTO clutch and PTO brake are assembled separately. Can be easily linked.

  In other words, in order to prevent the inertial operation and accompanying rotation of the working device in the non-working state in which the PTO clutch is turned off, the PTO brake is not only equipped with a PTO brake but also configured in a multi-plate type together with the PTO clutch, In addition, by integrating the PTO clutch and the PTO clutch that shares the housing, it is possible to reduce the number of parts and improve the assemblability, which can be advantageous in terms of parts management, cost and manufacturing. Even when working equipment with high output is connected to improve work capacity, it is possible to reliably prevent inertial operation and rotation of the work equipment with high output without making major changes to the transmission system layout. it can.

  As one of means for making the present invention more suitable, each PTO clutch and the PTO brake are moved by moving the piston in the energizing direction by energizing a spring, and each friction plate of the PTO clutch. While the friction plates of the PTO brake are pressed against each other, and the pistons move in a direction against the urging of the spring by hydraulic pressure, and the friction plates of the PTO clutch are pressed against each other The friction plates of the PTO brake are separated from each other.

  According to this configuration, when the hydraulic pressure decreases due to leakage of hydraulic oil or the like, the PTO clutch is disengaged by the biasing of the spring, and the working device is stopped because the PTO brake is braked. . On the other hand, when the PTO clutch is engaged and operated by the bias of the spring, and the PTO brake is operated to release the brake, if the hydraulic pressure decreases due to hydraulic oil leakage or the like, Since the PTO clutch is engaged and operated by urging, and the PTO brake is released, the work device operates.

  That is, it is possible to prevent the working device from operating unexpectedly due to leakage of hydraulic oil or the like.

  Also, since the spring and piston are shared by the PTO clutch and the PTO brake, the number of parts can be reduced compared to the case where each is equipped with a dedicated one. Reduction can be achieved.

  That is, it can be further advantageous in terms of component management, cost, and manufacturing.

  As one of means for making the present invention more suitable, the friction plate of the PTO clutch and the friction plate of the PTO brake are set in the same shape.

  According to this configuration, a common friction plate can be used for the PTO clutch and the PTO brake, and it becomes easier to manage components and reduce costs compared to the case where friction plates having different shapes are used.

  Therefore, it can be further advantageous in terms of parts management and cost.

  FIG. 1 shows an entire side surface of a tractor which is an example of a work vehicle. The tractor forms a main frame 4 by connecting a front frame 2, a mission case 3, and the like to an engine 1, and the main frame. 4 is equipped with a pair of left and right front wheels 5 and rear wheels 6 driven by the power from the engine 1, and a steering wheel 7 for driving the front wheels and a driver seat 8 are arranged between the front and rear wheels 5 and 6. The boarding operation part 9 is formed.

  As shown in FIG. 2, the power from the engine 1 is transmitted to an input shaft 12 of a hydrostatic continuously variable transmission 11 provided as a main transmission for traveling via a main clutch 10 and the like. The power after the shift by the hydrostatic continuously variable transmission 11 output from the output shaft 13 of the continuously variable transmission 11 is transmitted to the gear transmission 14 provided as a sub-transmission for traveling, and the gear-type shift is performed. The power after the shift by the device 14 is transmitted to the left and right rear wheels 6 through the rear wheel differential device 15 and the like, and through the hydraulic front wheel transmission device 16 and the front wheel differential device 17 and the like. To the left and right front wheels 5.

  In other words, the hydrostatic continuously variable transmission 11, the gear transmission 14 for traveling, the differential 15 for the rear wheels, the front transmission 16, the differential 17 for the front wheels, etc. A traveling transmission system 18 is configured to transmit to the left and right front wheels 5 and rear wheels 6 for traveling.

  A gear type speed reducer 19 is connected to the input shaft 12 of the hydrostatic continuously variable transmission 11, and the power from the engine 1 transmitted to the input shaft 12 of the hydrostatic continuously variable transmission 11 is input as it is. Power transmitted from the shaft 12 to the gear type speed reducer 19 and power after deceleration by the gear type speed reducer 19 are transmitted to the working gear type speed change device 20, and power after speed change by the gear type speed change device 20 is the work power. As an example of the PTO shaft 21 for taking out, the high-speed power transmitted from the gear-type transmission 20 to the rear PTO shaft 22 provided at the rear end portion of the mission case 3 is used as an example of the PTO shaft 21. It is transmitted to the mid PTO shaft 23 provided at the rear bottom portion via a working auxiliary clutch 24.

  That is, from the input shaft 12 of the hydrostatic continuously variable transmission 11 by the input shaft 12 of the hydrostatic continuously variable transmission 11, the gear type reduction gear 19, the working gear transmission 20, the auxiliary clutch 24, and the like. A work transmission system 25 is configured to transmit the output non-transmission power to the rear PTO shaft 22 and the mid PTO shaft 23 as work power.

  As shown in FIGS. 2 and 3, the gear reduction device 19 includes a first gear 26 that is splined to the input shaft 12 of the hydrostatic continuously variable transmission 11, and a second gear that meshes with the first gear 26. 27, a first shaft 28 that supports the second gear 27 in a relatively rotatable manner, a third gear 29 that is spline-fitted to the first shaft 28, and a first gear 26 that are supported in a relatively rotatable manner. The fourth shaft 30 is integrally formed with a fourth gear 30 that meshes with the third gear 29. The hydraulic PTO clutch 32 is provided between the second gear 27 and the third gear 29 on the first shaft 28. And a PTO brake 33 are interposed.

  The PTO clutch 32 includes a drive-side friction plate 35 that is spline-fitted to an inner drum 34 that is integrally formed with the second gear 27, and an outer drum 37 that is integrally formed with a housing 36 that rotates integrally with the first shaft 28. And a plurality of driven friction plates 38 that are spline-fitted to each other. The PTO brake 33 is a brake-side friction plate 40 that is spline-fitted to an inner drum 39 that is rotatably supported by the housing 36, and a braked that is spline-fitted to an outer drum 41 that is integrally formed with the housing 36. A plurality of friction plates 42 on the side are provided in a multi-plate type.

  The housing 36 is integrally formed with an inner cylinder 43 that is spline-fitted to the first shaft 28, an outer cylinder 44 in which the outer drums 37 and 41 are formed, and a partition wall 45 that divides them into a clutch side and a brake side. In this structure, the outer drum 37 on the clutch side and the outer drum 41 on the brake side have the same shape in the radial direction, and the piston is fitted on the clutch side so as to be relatively slidable in the axial direction. An oil chamber 48 through which hydraulic oil is supplied and discharged through an oil passage 47 formed in the first shaft 28 is formed between the inner wall 43 and the partition wall 45. A push spring 49 that urges toward the outside is fitted.

The piston 46 is formed so that its outer peripheral portion 50 acts on each of the friction plates 35 and 38 of the PTO clutch 32, and the outer peripheral portion 50 is opposed to the plurality of communication holes 51 formed in the partition wall 45. A plurality of pins 52 that are slidably fitted and inserted are integrally provided, and these pins 52 act on the friction plates 40 and 42 of the PTO brake 33.

  The inner drum 34 of the PTO clutch 32 and the inner drum 39 of the PTO brake 33 are formed to have the same shape in the radial direction.

  From the above configuration, when the piston 46 moves in the biasing direction of the PTO clutch 32 and the PTO brake 33 by the biasing of the pressing spring 49, the friction plates 35 and 38 of the PTO clutch 32 are caused by the pressing of the piston 46. The friction plates 40 and 42 of the PTO brake 33 are pressed by the pins 52 of the piston 46 so as to be unable to rotate relative to each other while the pressure contact is released and the friction plates 40 and 42 are separated so as to be relatively rotatable. On the contrary, when the piston 46 moves in a direction against the urging force of the push spring 49 by the pressure increase by supplying the hydraulic oil to the oil chamber 48, the friction plates 35 and 38 of the PTO clutch 32 are pressed by the piston 46. Thus, the friction plates 40 and 42 of the PTO brake 33 are released from the press contact by the pins 52 and are separated so as to be relatively rotatable.

  That is, since the PTO brake 33 is braked in conjunction with the disengagement operation of the PTO clutch 32, and the PTO brake 33 is released in conjunction with the engagement operation of the PTO clutch 32, the PTO clutch 32 is engaged. In this working state, a working device such as an unillustrated tillage device connected to the rear PTO shaft 22 and an unillustrated working device such as a mower connected to the mid PTO shaft 23 can be driven well. In a non-working state in which the PTO clutch 32 is turned off, a working device such as an unillustrated tillage device connected to the rear PTO shaft 22 or an unillustrated working device such as a mower connected to the mid PTO shaft 23 is used. It is possible to prevent the occurrence of inconveniences such as continuing the operation with the inertia or rotating with the multi-plate type PTO clutch 32.

  In addition, when the hydraulic pressure is reduced due to leakage of hydraulic oil or the like, the PTO clutch 32 is disengaged and the PTO brake 33 is braked by the urging of the push spring 49 so that the work device is stopped. As a result, the hydraulic oil leaks that may occur when the PTO clutch 32 is engaged by the urging of the push spring 49 and the PTO brake 33 is released. Therefore, when the hydraulic pressure is reduced, it is possible to avoid the inconvenience that the operation device unexpectedly operates due to the operation of engaging the PTO clutch 32 and the operation of releasing the brake of the PTO brake 33 due to the urging of the spring.

  Further, by making the PTO clutch 32 and the PTO brake 33 multi-plate type, they can be configured to have high transmission ability and braking force while suppressing their enlargement in the radial direction. It is possible to easily equip the first shaft 28 of the speed reducer 19 without changing the distance between the first shaft 28 and the second shaft 31 in the gear speed reducer 19 and to improve the work capacity. In order to improve, even when a working device driven by each PTO shaft 22, 23 is connected to a working device having a large output such as a wide working width tiller or a three blade mower, The working devices can be driven well, and the inertial operation of the working devices can be reliably prevented.

  In addition, the PTO clutch 32 and the PTO brake 33 are integrated so as to share a single housing 36, and are configured to share a single piston 46 and a push spring 49. The number of parts can be reduced as compared with the case where the outer drums 37 and 41 and the inner drums 34 and 39 of the PTO clutch 32 and the PTO brake 33 are formed in the same shape having the same radial size. A common friction plate can be used for the drive-side friction plate 35 of the PTO clutch 32 and the brake-side friction plate 40 of the PTO brake 33, and the driven-side friction plate 38 of the PTO clutch 32 and the PTO brake 33 A common friction plate can be used for the brake-side friction plate 42. As a result, it is easy to perform component management, manufacturing, and the like, and to reduce costs.

  The PTO clutch 32 and the PTO brake 33 are, in a wide work area, a single housing 36, a piston 46, friction plates 35, 38, 40, 42, a push spring 49, a second gear 27, an inner drum 39, The first shaft 28 and the like can be attached relatively easily. After the third gear 29 is mounted on the first shaft 28, the second gear 27 meshes with the first gear 26 on the transmission case 3 side. The first shaft 28 is supported by the transmission case 3 in a state where the third gear 29 is engaged with the fourth gear 30 on the transmission case 3 side, so that the work transmission system 25 can be assembled relatively easily. This also improves the workability when replacing the friction plates 35, 38, 40, 42, and the like.

  As shown in FIGS. 3 and 4, the inner drum 39 of the PTO brake 33 is provided with an arm 53 extending toward the mission case 3, and the arm 53 is in contact with the mission case 3. Along with this, a locking portion 54 that prevents the inner drum 39 from rotating in the contact direction and allows the inner drum 39 to rotate within a set angle range until the arm 53 contacts is projected. Is formed.

  In other words, by providing the PTO brake 33, the inertia of the working device connected to the rear PTO shaft 22 and the mid PTO shaft 23 and the accompanying rotation are prevented, but the arm of the inner drum 39 is in the braking state of the PTO brake 33. The rear PTO shaft 22 and the mid PTO shaft 23 can be rotated within a set angle range until 53 contacts the locking portion 54 of the transmission case 3. When connecting the input shaft of the work device to the mid PTO shaft 23, even if the rotational phases thereof do not match and the rotation operation of the input shaft of the work device is difficult, the rear PTO shaft 22 and By rotating the mid PTO shaft 23, the rotation phase of the rear PTO shaft 22 and the mid PTO shaft 23 can be matched with the rotation phase of the input shaft of the work device, and the rear Because it can easily be connected to the input shaft of the working device in the TO axis 22 and the mid PTO shaft 23, facilitates the mounting of the working device.

  As shown in FIGS. 2, 3, and 5, the electromagnetic valve 55 for switching the hydraulic fluid flow state with respect to the PTO clutch 32 is a front-wheel shift electromagnetic valve for switching the hydraulic fluid flow state with respect to the front wheel transmission 16. 56 and an unloading solenoid valve 57 are integrally formed. When the PTO switch 58 provided in the boarding operation unit 9 is turned on, the solenoid 59 is energized, and the PTO clutch 32 is The state is switched to a state where hydraulic oil is supplied to the oil chamber 48. When the PTO switch 58 is turned on, the solenoid 61 of the unloading solenoid valve 57 is also energized via the relay 60, and the unloading solenoid valve 57 is connected to the PTO clutch 32 and the front wheel speed change. It is switched to a state in which the pressure in the hydraulic circuit for the device 16 is increased. As a result, hydraulic oil is supplied to the oil chamber 48 of the PTO clutch 32, and the PTO clutch 32 is turned on and the PTO brake 33 is released.

  On the other hand, when the steering angle sensor 62 that detects the steering angle of the front wheels 5 detects steering more than the set angle of the front wheels 5, the front-wheel shift electromagnetic valve 56 is controlled by the control device 63 based on the detection. The solenoid 64 is energized and switched to a state where hydraulic oil is supplied to the front wheel transmission 16. When the solenoid 64 of the front-wheel shifting solenoid valve 56 is energized, the solenoid 61 of the unloading solenoid valve 57 is also energized via the relay 60, and the unloading solenoid valve 57 is It is switched to a state in which the pressure in the hydraulic circuit for the PTO clutch 32 and the front wheel transmission 16 is increased. As a result, hydraulic oil is supplied to the front wheel transmission 16 and the front wheel transmission 16 is switched to a state in which the front wheels 5 are accelerated.

  That is, the electromagnetic valves 55 to 57 for working, front wheel shifting and unloading are integrated, and a single unloading electromagnetic valve 57 and relay 60 are used for operating the PTO clutch and operating the front wheel transmission. Thus, the electromagnetic valves 55 to 57 for working, front wheel shifting and unloading are independent structures, and the electromagnetic valves 57 for unloading respectively dedicated for PTO clutch operation and front wheel transmission operation are used. Compared with the case where the relay 60 is provided, the number of parts can be reduced and the assemblability can be improved, which is advantageous in terms of parts management, cost and manufacturing.

  Incidentally, as shown in FIG. 2, the front wheel transmission 16 is configured such that the acceleration clutch 66 is disengaged by the urging of the push spring 65 and the shift member 67 is engaged with the first gear 68, so that the first gear is engaged. The shift member 67 and the first gear 68 are meshed against the biasing force of the push spring 65 by hydraulic pressure, and switched to the normal state where the power is transmitted to the left and right front wheels 5 through the second gear 69 and the second gear 69. Is released, and the speed increasing clutch 66 is engaged and operated, so that the speed increasing state is transmitted to the left and right front wheels 5 via the speed increasing third gear 70 and the fourth gear 71. ing.

[Another Example]
Other embodiments of the present invention will be listed below.
[1] The working vehicle may be a mower or a rice transplanter.
[2] The work vehicle may be equipped with only the rear PTO shaft 22 or the mid PTO shaft 23. As an example of the PTO shaft 21, a front PTO shaft provided at the front of the work vehicle may be used. It may be equipped.
[3] The PTO clutch 32 and the PTO brake 33 may be provided at a location other than the first shaft 28 of the gear type reduction gear 19 in the work transmission system 25.
[4] The PTO clutch 32 may be disconnected and the PTO brake 33 may be braked hydraulically.
[5] The friction plate 35 on the drive side of the PTO clutch 32, the friction plate 40 on the braking side of the PTO brake 33, the friction plate 38 on the driven side of the PTO clutch 32, and the friction plate 42 on the brake side of the PTO brake 33 In addition, friction plates having different shapes may be used.

Overall side view of tractor Vertical side view of the main part showing the transmission configuration of the tractor Longitudinal side view of the main part showing the configuration of the PTO clutch and PTO brake Longitudinal front view of the main part showing the configuration of the PTO brake Electric circuit diagram for each solenoid valve for PTO clutch and front wheel transmission operation

Explanation of symbols

1 Engine 21 PTO Shaft 25 Work Transmission System 32 PTO Clutch 33 PTO Brake 35 Friction Plate 36 Housing 38 Friction Plate 40 Friction Plate 42 Friction Plate 46 Piston 49 Spring

Claims (3)

A hydraulic PTO clutch and a PTO brake are interposed in a work transmission system that transmits the power from the engine to the PTO shaft, and the PTO brake is braked in conjunction with the disengagement operation of the PTO clutch. A work transmission structure for a work vehicle configured to release the braking of the PTO brake in conjunction with an entry operation,
A working power transmission structure for a work vehicle, wherein the PTO clutch and the PTO brake are a multi-plate type including a plurality of friction plates and are configured as an integrated type sharing a single housing.   The movement of the piston in the biasing direction of the PTO clutch and the PTO brake by biasing of the spring causes the friction plates of the PTO clutch to be separated while the friction plates of the PTO brake are pressed against each other, and The friction plate of the PTO brake is separated from the friction plate of the PTO brake while the friction plate of the PTO clutch is pressed by the movement of the piston in a direction against the urging of the spring by hydraulic pressure. Item 2. A work transmission structure for a work vehicle according to Item 1.   The work transmission structure for a work vehicle according to claim 1 or 2, wherein the friction plate of the PTO clutch and the friction plate of the PTO brake are set in the same shape.

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