JP3618255B2 - Driving transmission structure of work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is configured such that the left and right traveling devices can be switched between a straight traveling state and a turning state, and one of the traveling devices is switched to a deceleration normal rotation state, a deceleration reverse rotation state, and a braking state to obtain a turning state. The present invention relates to a traveling transmission structure for a work vehicle provided with a turning mode switching mechanism capable of rotating.
[0002]
[Prior art]
For example, Japanese Patent Laid-Open No. 11-70885 discloses a turning mode switching mechanism. That is, to constitute the turning mode switching mechanism, two intermediate transmission shafts (numbers 27 and 20 in the publication) are provided to receive power transmission from the output shaft (number 15 in the publication) of the auxiliary transmission mechanism. A pair of left and right reversing gear pairs (No. 29, 26L, 29, 26R in the publication) are provided across the two intermediate transmission shafts, and an input gear that receives the straight power from the second intermediate transmission shaft (No. 20 in the publication). (Figure number 19 in the gazette) is provided. For this input gear, a side clutch is formed by turning on and off of a shift gear (numbers 21L and 21R in the publication). Further, the first intermediate transmission shaft (No. 27 in the publication) is loosely fitted with the output gear of the auxiliary transmission mechanism (No. 16 in the publication) and the input gear in the normally biting state (No. 62 in the publication). The power can be transmitted by a hydraulic clutch for reverse rotation (number 30 in the publication).
[0003]
[Problems to be solved by the invention]
In the above-described conventional configuration, in order to obtain the turning state, the side clutch for one traveling device is disengaged, or reversely decelerated or driven, or the brake is applied to perform turning. Even when the side clutch is disengaged and the vehicle turns slowly, the turning radius is smaller than that of straight traveling, so that it is not possible to solve problems such as being dragged by the traveling device outside the turning and the traveling device roughening the field.
Therefore, there is a method of setting one of the traveling devices in the normal deceleration state in order to make the turning radius larger and take a turning form that does not roughen the field, but this normal rotation deceleration state appears. Therefore, if the transmission of the conventional configuration is used, a pair of gears extends between the output shaft of the auxiliary transmission mechanism (number 15 in the publication) and the first intermediate transmission shaft (number 27 in the publication). If a pair and a clutch mechanism are added, normal deceleration power can be obtained.
However, it is necessary to make some improvement only by increasing the number of parts.
[0004]
An object of the present invention is to provide a traveling transmission structure for a working vehicle that can obtain forward deceleration power while effectively using a reverse gear pair.
[0005]
[Means for Solving the Problems]
The characteristic configuration of the present invention according to claim 1 is provided with an input gear that is always meshed with the first output gear that outputs normal rotation power, and the input gear and the side clutch that transmits power to the transmission system of the left and right traveling devices are the same. Provided on the shaft so that both can be occluded and disengaged , and apart from the input gear, a transmission mechanism for transmitting the power on the transmission upper side to the left and right side clutches via a hydraulic clutch is provided,
A first state for supplying a driving force to the input gear and the side clutch directly traveling device by bite, switched to a second state for supplying a driving force to the driving device from the side clutch via the hydraulic clutch and the transmission mechanism Thus, in the traveling transmission structure of the work vehicle configured to be able to switch the left and right traveling device between a straight traveling state and a turning state,
A turning mode switching mechanism for obtaining a turning state by switching one of the left and right traveling devices to a deceleration normal rotation state, a deceleration reverse rotation state, and a braking state,
The turning mode switching mechanism selects a second output gear that outputs a reverse output, a braking gear that displays a braking state, and any one of the second output gear, the braking gear, and the input gear. And an occlusable shift member,
While maintaining the state where the input gear and one side clutch are engaged, the shift member and the shift member are engaged with the other side clutch by engaging the other side clutch with the transmission mechanism. A forward deceleration state in which a forward deceleration output is transmitted through the input gear, the hydraulic clutch, and the transmission mechanism;
A deceleration reverse rotation state in which a deceleration reverse rotation output is transmitted to the other side clutch via the shift member, the hydraulic clutch, and the transmission mechanism by engaging the shift member with the second output gear ;
By engaging the shift member with the braking gear and bringing the hydraulic clutch into an engaged state, the braking gear is switched to a braking state in which the other traveling device is braked in conjunction with the transmission mechanism and the other side clutch. There the point you have freely configured, effects thereof are as follows.
[0006]
[Action]
The operation of the turning mode switching mechanism will be described. For one traveling device, the state in which the input gear and one side clutch are engaged with each other is maintained, and the normal rotation speed is maintained. For the other traveling device, by engaging the other side clutch with the transmission mechanism, the shift member, and the input gear with which the shift member is engaged, the hydraulic clutch, Transmits the forward deceleration output through the transmission mechanism. In other words, the decelerating forward rotation output is obtained by a method in which power on the transmission upper side is applied to the input gear and input to the side clutch through the shift member, hydraulic clutch, and transmission mechanism. Thereby, the traveling device performs a gentle turn.
In order to obtain the deceleration reverse rotation output, the power from the reverse rotation output gear is obtained by a method of inputting the power to the side clutch through the shift member, the hydraulic clutch, and the transmission mechanism. The shift member, the transmission mechanism, and the other side clutch are linked to brake the other travel device.
[0007]
〔effect〕
That is, since the method of obtaining the reverse deceleration power via the input gear that receives the straight power is adopted, the input gear can be used as a gear for generating the reverse reduction power. Further, since the speed change mechanism can be used not only for forward deceleration but also for reverse deceleration power, simplification of the equipment configuration can be achieved.
[0008]
According to a second aspect of the present invention, in the invention according to the first aspect, the portion of the brake gear other than the portion to be engaged with the shift member is engaged with the brake gear from the fixed portion and rotated. The engagement member to be blocked is engaged, and the effect is as follows.
[0009]
[Action]
In order to obtain a braking state, a gear is adopted as a member to be engaged with the shift member. Therefore, in the engagement between the shift member and the gear, a part of the gear may be engaged with the shift member. Since the engaging member for fixation can be applied to the portion other than the part to be occluded, and the number of teeth of the gear related to the engagement can be increased, each occlusion with the plurality of teeth of the gear of the engaging member The load burden on the portion can be reduced.
[0010]
〔effect〕
As an engaging member, it is not necessary to ensure the same strength as that of the braking gear, and consideration on strength can be reduced.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a self-removing combine as an example of a work vehicle having a traveling transmission structure according to the present invention. This combine has a structure in which a cutting part 3 is connected to a front part of a traveling machine body 2 having a pair of left and right crawler type traveling devices 1 by a hydraulic cylinder 4 so as to be driven up and down. The threshing device 5, the grain recovery unit 6, the engine 7, and the operation unit 8 are mounted, and the reaping unit 3 has a plurality of pulling devices 9 and a clipper type that harvests the caused culm. Cutting device 10, a supply transport device 11 for transporting the harvested cereal grains toward the threshing device 4, and the like.
[0012]
As shown in FIG. 2, the power from the engine 7 is belt-transmitted to a hydrostatic continuously variable transmission (HST) 12, and the forward or reverse power shifted by the hydrostatic continuously variable transmission 12 is a gear type. It is transmitted to the transmission 13. The gear-type transmission 13 is a gear-shift type sub-transmission mechanism 14 that can change the power after shifting from the hydrostatic continuously variable transmission 12 in three stages, and the power after shifting from the sub-transmission mechanism 14 is used for turning. Slewing mode switching mechanism 15 that can be switched and decelerated further in three stages as power of the left and right side clutches 16, 16 that can switch the transmission state for the left and right crawler type traveling device 1 between a straight transmission state and a slewing transmission state, And the like, and the like, and the like. The gear type transmission 13 is provided with a power take-off shaft 18 that outputs the power after shifting from the hydrostatic continuously variable transmission 12 as working power without passing through the sub-transmission mechanism 14. The power take-out shaft 18 is equipped with a one-way clutch 19 that transmits only normal rotation power to the cutting unit 3 whose output is transmitted to the belt.
[0013]
As shown in FIGS. 2 and 3, the side clutch 16 includes a steering shaft 20 supported by the transmission case 17, an input gear 21 externally fitted to the center of the steering shaft 20, and a steering shaft 20. Left and right steering gears 22 fitted to both ends so as to be relatively rotatable, and left and right shift members fitted between the input gear 21 and the left and right steering gears 22 so as to be relatively rotatable and relatively slidable. 23, and left and right springs 24 that slidably bias the left and right shift members 23 toward the input gear 21. The input gear 21 is meshed with the first output gear 25 of the auxiliary transmission mechanism 14. The left and right shift members 23 employ shift gears that can be engaged with the input gear 21 or the corresponding steering gear 22, and each shift member 23 corresponds to the first transmission position that meshes with the input gear 21. The second transmission position meshed with the steering gear 22 and the neutral position not meshed with either the input gear 21 or the steering gear 22, and the corresponding crawler type traveling regardless of the shift position. The meshing state with the output gear 26 that is transmission-coupled to the device 1 is maintained.
[0014]
A pair of oil passages 20 a are formed in the steering shaft 20. Between the steering shaft 20 and each shift member 23, the corresponding shift member 23 is resisted against the bias of the spring 24 by the hydraulic oil supplied through the oil passage 20 a communicated with each of the shift shafts 23. An oil chamber 27 to be shifted to the 22 side is formed. That is, the side clutch 16 is configured as a hydraulic type in which the left and right shift members 23 are shifted by switching the flow state of the hydraulic oil to each oil chamber 27.
[0015]
The turning mode switching mechanism 15 includes a second output gear 31 that outputs a reverse rotation output, a fixing member 32 that serves as a braking gear that reveals a braking state, the second output gear 31, the fixing member 32, and the input gear 21. And a shift member 30 that can be engaged with each other by selecting one of the gears, and the shift member 30 is a cylindrical shaft that is externally fitted to a rotation shaft 28 supported by the mission case 17 so as to be relatively rotatable. It is spline-fitted to rotate integrally with relative slidable state 29.
The shift member 30 is a second position of the sub-transmission mechanism 14 that functions as a decelerating forward rotation position that functions as a reverse gear and a state that meshes with the input gear 21 that functions as a normal rotation gear by operation of an operation lever (not shown) that is mechanically linked. The shift operation is shifted to the deceleration reverse rotation position where the output gear 31 is engaged, or the braking position where the fixed gear 32 is engaged.
The input gear 21 includes a large-diameter gear portion 21 a that is always meshed with the first output gear 25 of the auxiliary transmission mechanism 14 and a small-diameter gear portion 21 b that meshes with the shift member 30. The shift member 30 employs a shift gear that includes a forward rotation gear portion 30 a that can mesh with the small-diameter gear portion 21 b of the input gear 21 and a reverse rotation gear portion 30 b that can mesh with the second output gear 31.
[0016]
The fixed member 32 has the same diameter as the second output gear 31 and is loosely fitted to the output shaft 33 of the auxiliary transmission mechanism 14 so as to be freely rotatable relative to the fixed gear 32 and fixedly meshed with the transmission case 17 so as not to rotate. Has been. That is, when the shift member 30 is shifted to the braking position, the reverse gear portion 30 b is engaged with the braking gear 32.
The fixed gear is called a braking gear.
As shown in FIG. 5, a normal spur gear is used for this braking gear, and the gear 32 is engaged with the boss portion 17 </ b> A inner peripheral surface of the transmission case 17 that supports the output shaft 33. A plurality of tooth portions 17a are formed. This tooth portion 17a is referred to as an engaging member that engages with the braking gear 32. Here, although the tooth portion is directly formed on the boss portion 17A of the transmission case 17 as the engaging member, a ring-shaped member formed with an internal tooth type tooth portion may be fitted into the boss portion 17A.
Engaging site for the brake gear 32 of the engaging member 17a is and have set against a portion other than the occlusal target site of the braking gear 32 and the shifting member 30, the engagement portion between the shift member 30 and the brake gear 32 is Since the gear is limited to one or two teeth, a braking force can be applied to the remaining many teeth.
In the auxiliary transmission mechanism 14, the first output gear 25 and the second output gear 31 are spline-fitted so as to rotate integrally with the output shaft 33.
[0017]
The rotary shaft 28 is splined at both ends so that the reduction gears 34 rotate together, and each reduction gear 34 meshes with the corresponding steering gears 22, 22 of the side clutches 16, 16. Yes. Between the rotary shaft 28 and the cylindrical shaft 29 of the turning mode switching mechanism 15, that is, on the lower transmission side of the turning mode switching mechanism 15, the spring 35 is urged in the transmission cutting direction and formed on the rotating shaft 28. A hydraulic multi-plate clutch 36 that is operated in the transmission entering direction against the urging of the spring 35 by hydraulic oil supplied through the oil passage 28a is interposed.
Here, the reduction gear 34 and the steering gear 22 are referred to as a transmission mechanism A.
[0018]
As shown in FIG. 4, the hydraulic fluid pumped by the hydraulic pump 37 driven by the engine 7 is selectively supplied to and discharged from the oil chambers 27 of the left and right side clutches 16 and 16 via the steering valve 38. The supply pressure to each oil chamber 27 is set by a sequence valve 39. The steering valve 38 includes a discharge state in which hydraulic oil is discharged from each oil chamber 27 of the side clutch 16, a left supply state in which hydraulic oil is supplied to the left oil chamber 27 of the side clutch 16, and a right side of the side clutch 16. A three-position switching type that can be switched to a right supply state in which hydraulic oil is supplied to the oil chamber 27 is employed. A multi-plate clutch 36 and a variable relief valve 41 are connected to the lower oil passage 40 with respect to the sequence valve 39, and the supply hydraulic pressure can be adjusted by changing the operating pressure of the relief valve 41. Yes. The steering valve 38, the sequence valve 39, and the relief valve 41 are provided in a hydraulic unit 42 that is connected to each oil passage 20 a of the steering shaft 20 and the oil passage 28 a of the rotary shaft 28.
[0019]
The steering valve 38 is wire-coupled to a single steering lever 43 provided in the operating unit 8 so as to be swingable left and right, and the steering lever 43 and the relief valve 41 are wire-coupled with a predetermined flexibility. When the steering lever 43 is operated to the neutral position N, the steering valve 38 is switched to the discharge state, and when the steering lever 43 is operated to the first left operation position L1 to the left of the neutral position N, the steering valve 38 is switched. Is switched to the left supply state, and when the steering lever 43 is operated to the first right operation position R1 to the right of the neutral position N, the steering valve 38 is switched to the right supply state. In these operation positions, the relief valve 41 is not affected by the operation of the steering lever 43 due to the linkage accommodation, so that the operating pressure is maintained at zero or an extremely low pressure close thereto. When the steering lever 43 is swung in an operation region extending from the first left operation position L1 to the second left operation position L2 to the left of the first operation position L1, the steering valve 38 is operated regardless of the operation position of the steering lever 43. While the left supply state is maintained, the operating pressure of the relief valve 41 is increased and the supply hydraulic pressure increases as the steering lever 43 approaches the second left operation position L2. Conversely, when the steering lever 43 is swung to the operation region extending from the first right operation position R1 to the second right operation position R2 on the right side thereof, the steering valve 38 is moved to the operation position of the steering lever 43. Regardless, the right supply state is maintained, while the operating pressure of the relief valve 41 is increased and the supply hydraulic pressure increases as the steering lever 43 approaches the second right operation position R2.
[0020]
With the above configuration, when the steering lever 43 is operated to the neutral position N, hydraulic oil is discharged from the oil chambers 27 of the side clutch 16, and the left and right shift members 23 are urged by the springs 24 and the input gear 21. Since the gears mesh with each other, non-decelerated power that is not decelerated by the turning mode switching mechanism 15 (power from the auxiliary transmission mechanism 14 that does not pass through the turning mode switching mechanism 15) is transmitted to the left and right crawler type traveling devices 1. Become so. That is, a straight traveling state in which the left and right crawler type traveling devices 1 are driven at a constant speed can be revealed.
[0021]
Further, when the steering lever 43 is operated from the neutral position N to the first left operation position L1, hydraulic oil is supplied to the left oil chamber 27 of the side clutch 16, and the left shift member 23 is biased by the spring 24. As a result, the sequence valve 39 and the relief valve 41 are opened due to the separation from the input gear 21 and the pressure that reaches the separation, thereby preventing the left shift member 23 from engaging the steering gear 22. For this reason, the crawler type traveling device 1 on the left side comes to idle. That is, the left idle turning state in which the left crawler type traveling device 1 is idled and only the right crawler type traveling device 1 is driven by the power from the subtransmission mechanism 14 can appear as the first left turning state. It has become.
[0022]
Further, when the steering lever 43 is operated from the first left operation position L1 toward the second left operation position L2, the operating pressure of the relief valve 41 is increased according to the operation position, whereby the left side of the side clutch 16 is increased. Is further supplied to the oil chamber 27, the left shift member 23 meshes with the steering gear 22 against the bias of the spring 24, and the multi-plate clutch 36 switches from the non-transmission state to the transmission state. Since it is operated, the decelerating power decelerated by the turning mode switching mechanism 15 (power from the auxiliary transmission mechanism 14 via the turning mode switching mechanism 15) is transmitted to the crawler type traveling device 1 on the left side. Become so. In other words, a second left turn state in which the left crawler traveling device 1 is forcibly decelerated with respect to the right crawler traveling device 1 can be displayed.
[0023]
Conversely, when the steering lever 43 is operated from the neutral position N to the first right operation position R1, hydraulic oil is supplied to the right oil chamber 27 of the side clutch 16, and the right shift member 23 biases the spring 24. As a result, the sequence valve 39 and the relief valve 41 are opened by the pressure increasing up to the separation from the input gear 21 to prevent the engagement of the right shift member 23 with the steering gear 22. Therefore, the crawler type traveling device 1 on the right side comes to idle. That is, the right idle turning state in which the right crawler type traveling device 1 is idled and only the left side crawler type traveling device 1 is driven by the power from the subtransmission mechanism 14 can appear as the first right turning state. It has become.
[0024]
Further, when the steering lever 43 is operated from the first right operation position R1 toward the second right operation position R2, the operating pressure of the relief valve 41 is increased in accordance with the operation position, whereby the right side of the side clutch 16 is increased. The hydraulic oil is further supplied to the oil chamber 27, the right shift member 23 meshes with the steering gear 22 against the bias of the spring 24, and the multi-plate clutch 36 switches from the non-transmission state to the transmission state. Since it is operated, the decelerating power decelerated by the turning mode switching mechanism 15 (power from the auxiliary transmission mechanism 14 via the turning mode switching mechanism 15) is transmitted to the crawler type traveling device 1 on the right side. Become so. That is, the second crawler traveling device 1 can be made to appear in the second right turning state in which the right crawler traveling device 1 is forcibly decelerated.
[0025]
In the second turning state on the left and right, the turning mode switching mechanism 15 that is connected to one of the crawler type traveling devices 1 is, as described above, the forward deceleration position, the reverse deceleration position of the shift member 30, Alternatively, since the transmission state is switched in accordance with the shift operation to the braking position, the steering lever 43 is moved from the first left operation position L1 to the first position with the shift member 30 positioned at the forward deceleration rotation position. 2 When operated toward the left operation position L2, the left crawler traveling device 1 can be caused to appear as the second left swivel state in which the left crawler traveling device 1 is driven to decelerate and forward rotate the left crawler traveling device 1. On the contrary, when the steering lever 43 is operated from the first right operation position R1 toward the second right operation position R2, the right crawler type traveling device 1 is decelerated forwardly with respect to the left crawler type traveling device 1. And it is capable to revealing the right soft turning state to dynamic as the second right-turning state.
[0026]
Further, when the steering lever 43 is operated from the first left operation position L1 to the second left operation position L2 in a state where the shift member 30 is positioned at the deceleration reverse rotation position, the right crawler type traveling device 1 is moved. The left spin turning state in which the left crawler type traveling device 1 is decelerated and reversely driven can be displayed as the second left turning state. Conversely, the steering lever 43 is moved from the first right operation position R1 to the second right operation position. When operated toward R2, the right spin turning state in which the right crawler type traveling device 1 is decelerated and reversely driven with respect to the left crawler type traveling device 1 can be made to appear as the second right turning state. ing.
[0027]
Further, when the steering lever 43 is operated from the first left operation position L1 toward the second left operation position L2 with the shift member 30 positioned at the braking position, only the left crawler type traveling device 1 is operated. The left braking turning state where the braking action is applied can appear as the second left turning state. Conversely, when the steering lever 43 is operated from the first right operation position R1 to the second right operation position R2, the right side The right braking turning state in which the braking action is applied only to the crawler type traveling device 1 can be made to appear as the second right turning state.
[0028]
In addition, in the left and right second turning states, the supply hydraulic pressure increases and the transmission rate of the multi-plate clutch 36 increases as the steering lever 43 is operated toward the left and right second operation positions L2 and R2. Therefore, the operation position of the steering lever 43 is changed to the operation region from the first left operation position L1 to the second left operation position L2, or the operation from the first right operation position R1 to the second right operation position R2. By changing in the region, the turning radius in the second turning state can be adjusted.
[0029]
That is, the turning mode switching mechanism 15 is configured to be meshed so that the transmission state for the side clutch 16 is switched between the deceleration normal rotation state, the deceleration reverse rotation state, and the braking state by a shift operation that changes the meshing state of the single shift member 30. In addition, the side clutch 16 is configured to be meshed so that the traveling state is switched between the straight traveling state, the first turning state, and the second turning state by a shift operation that changes the meshing state of the left and right shift members 30 and is turned. While having a simple configuration in which a single multi-plate clutch 36 capable of adjusting transmission is provided on the lower side of transmission of the mode switching mechanism 15, a straight traveling state, an idle turning state, a soft turning state, a spin turning state, and Each traveling state in the braking turning state can be suitably switched and displayed.
[0030]
[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) The side clutch 16 may be configured as a claw-engagement type in which the engagement of the left and right shift members 23 with the input gear 21 and the left and right steering gears 22 is performed by the engagement claws formed respectively. .
[Brief description of the drawings]
1 is an overall side view of a combine; FIG. 2 is a configuration diagram showing a traveling transmission structure; FIG. 3 is a longitudinal sectional view showing a turning mode switching mechanism; FIG. 4 is a configuration diagram showing a hydraulic operation system; Sectional view showing [signs]
DESCRIPTION OF SYMBOLS 1 Traveling device 14 Subtransmission 15 Turning mode switching mechanism 16 Side clutch 17a Engaging member 21 Input gear 30 Shift member 31 Second output gear 32 Brake gear 36 Hydraulic clutch A Transmission mechanism

Claims (2)

A first output gear and constantly occlusal inputting gear that outputs a normal rotation power provided, configured to enable bite leaving both provided with side clutch for transmitting power to the same shaft to the transmission system of the left and right traveling devices and the input gear Aside from the input gear, a transmission mechanism for transmitting the power on the transmission upper side to the left and right side clutches via a hydraulic clutch is provided,
A first state for supplying a driving force to the input gear and the side clutch directly traveling device by bite, switched to a second state for supplying a driving force to the driving device from the side clutch via the hydraulic clutch and the transmission mechanism Thus, the traveling transmission structure of the work vehicle is configured to be able to switch the left and right traveling device between a straight traveling state and a turning state,
A turning mode switching mechanism for obtaining a turning state by switching one of the left and right traveling devices to a deceleration normal rotation state, a deceleration reverse rotation state, and a braking state,
The turning mode switching mechanism selects a second output gear that outputs a reverse rotation output, a braking gear that displays a braking state, and any one of the second output gear, the braking gear, and the input gear. And an occlusable shift member,
While maintaining the state where the input gear and one side clutch are engaged, the shift member and the shift member are engaged with the other side clutch by engaging the other side clutch with the transmission mechanism. A forward deceleration state in which a forward deceleration output is transmitted through the input gear, the hydraulic clutch, and the transmission mechanism;
A deceleration reverse rotation state in which a deceleration reverse rotation output is transmitted to the other side clutch via the shift member, the hydraulic clutch, and the transmission mechanism by engaging the shift member with the second output gear ;
By engaging the shift member with the braking gear and bringing the hydraulic clutch into an engaged state, the braking gear is switched to a braking state that links the transmission mechanism and the other side clutch to brake the other traveling device. Freely configured traveling transmission structure for work vehicles. 2. The work vehicle according to claim 1, wherein an engagement member that engages with the brake gear from the fixed portion to prevent rotation is engaged with a portion of the brake gear other than the portion to be engaged with the shift member. Traveling transmission structure.

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