JP2008195271A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tractor capable of easily performing the elevating/lowering, speed change and drive stopping operations of a working device connected thereto while a driver is in a seated condition, and of easily performing a normal elevating/lowering operation. <P>SOLUTION: The tractor comprises a connection device for connecting a working device in a freely elevating/lowering manner, a power take-out shaft for transmitting the power to the working device, and a work speed change device for changing the driving speed of the power take-out shaft. A work speed change lever 91 for changing the work speed change device to a high-speed transmission state, a neutral state and a low-speed transmission state is arranged along a straight speed change operation path 94 in the longitudinal direction of a vehicle body aside a driving seat 5 in a freely rocking manner. An elevating/lowering lever 92 for operating the connection device is arranged along a straight direction path 95 in the longitudinal direction of the vehicle body arranged forward of the vehicle body from the speed change operation path 94 on the same side where the work speed change lever 91 of the driving seat 5 is located in a freely rocking manner. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a coupling device that couples work devices so as to be movable up and down, a power take-out shaft that transmits power to the work device, a work transmission device that changes a drive speed of the power take-out shaft, and a driver seat. Regarding tractors.

Conventionally, there has been a tractor disclosed in, for example, Patent Document 1.
The tractor shown in Patent Document 1 is a seat as a driver's seat, a lever guide provided on a fender located on the left side of the seat, a PTO shift lever provided on the lever guide, and a lever guide provided on a fender located on the right side of the seat. A position control lever for raising and lowering the work implement provided in the lever guide is provided.

Japanese Patent No. 3472965 (paragraphs [0007], [0009], FIG. 2)

  In the tractor having the above-described coupling device, work transmission device, and driver's seat, a lifting lever for operating the coupling device so that the connected work device can be lifted, shifted, driven and stopped with a seating posture. Even if the above-described conventional technique is used to provide the work speed change lever for switching the work speed change device, there is still room for improvement.

  In other words, the speed change of the working device and the switching between driving and stopping are generally performed in a state where the working device is raised to the non-working state so that no work load is applied to the working device. Then, when changing the speed of the working device or turning while stopping the working device, the connecting device is operated by operating the lifting lever on the left or right side of the driver seat. As a result, when the working device is raised to the non-working state, the working transmission device is operated by operating the working transmission lever on the lateral side of the driver seat opposite to the side where the lifting lever is located. When the speed of the work equipment changes or when the work equipment is returned to the driving state after turning, the side of the driver seat on the side opposite to the side where the work speed change lever is located is set so that the work equipment is returned to the lowered working state. The connecting device is operated by operating the lifting lever. That is, the posture to operate the lever on one side of the driver seat and the driving to perform the operation for raising and lowering the working device and the operation for shifting, driving and stopping the working device. There was an annoyance that had to move the upper body greatly to switch the posture to operate the lever on the other side of the seat.

  An object of the present invention is to provide a tractor that can easily perform a lifting operation, a shifting operation, a driving and a stopping operation of a working device with a seating posture, and that can easily perform a normal lifting operation such as turning.

According to the first aspect of the present invention, there is provided a coupling device that couples work devices so as to be movable up and down, a power take-off shaft that transmits power to the work device, a work transmission device that changes a drive speed of the power take-off shaft, and a driver seat In the provided tractor,
A work speed change lever for switching the work speed change device between a high speed transmission state, a neutral state and a low speed transmission state is swung along a linear speed change operation path facing the front and rear of the vehicle body on a lateral side of the driver seat. Arrange it freely,
A lifting lever for operating the connecting device is arranged in the same lateral side as the side on which the work speed change lever of the driver seat is located, on the front side of the vehicle with respect to the speed change operation path. It is arranged so as to be swingable along the operation path.

According to the configuration of the first aspect of the present invention, if the elevating lever is swung in the longitudinal direction of the vehicle body along the linear elevating operation path on the lateral side of the driver's seat, the connecting device can be operated and the working device can be moved up and down. . If the work speed change lever is swung in the longitudinal direction of the vehicle along the linear speed change operation path on the same lateral side as the side where the lift lever of the driver seat is located, the work speed change device can be operated at high speed or low speed. The operation device can be switched to a state or to a neutral state, and the work device can shift or stop.
According to the configuration of the first aspect of the invention, since the lifting operation path is located on the front side of the vehicle body with respect to the speed change operation path, both levers approach each other when operating either the lifting lever or the work speed changing lever. Even if the operation target lever is located closer to the front or rear of the vehicle than the non-operation target lever, the non-operation target lever is less likely to become an obstacle to the grip support of the operation target lever, and the operation target lever can be operated easily. . In addition, the lifting lever is positioned on the front side of the vehicle body relative to the work speed change lever, so that the frequently used lifting lever can be operated more easily.

  Therefore, not only can the lift lever and work speed change lever be operated with the seating posture, but it is not necessary to move the upper body largely by operating only on one side of the driver's seat. In any case, it is easy to operate without being disturbed by the lever on the non-operation target side, and the frequently used lifting lever can be operated more easily than the work shift lever, and the working device can be lifted and lowered. Therefore, gear shifting, driving and stopping operations can be performed easily and quickly, and work can be performed efficiently.

  According to a second aspect of the present invention, in the configuration of the first aspect of the invention, the grip portion side portion of the work speed change lever is inclined toward the front side of the vehicle body as viewed along the work speed change lever swing axis with respect to the base side portion. A bent portion is provided.

  Since the speed change operation path is located on the rear side of the vehicle with respect to the lifting / lowering operation path, when the work speed change lever is operated to the rear end side of the speed change operation path, the grip portion side portion is inclined toward the rear of the car body. Then, it becomes difficult to handle the work speed change lever. However, according to the configuration of the second aspect of the present invention, the grip portion side portion is in a vertical position or a posture close to it, so that the work speed change lever can be handled easily regardless of the operation position of the work speed change lever. .

  Therefore, although the speed change operation path is located on the rear side of the vehicle body with respect to the ascending / descending operation path, the work speed change lever can be easily handled, and the speed change and drive stop of the work device can be performed easily and accurately.

  According to a third aspect of the present invention, in the configuration of the first or second aspect of the invention, the lifting / lowering operation path is located on the lateral outer side of the vehicle body with respect to the speed change operation path.

  According to the configuration of the third aspect of the invention, when operating the elevating lever, the hand is extended from the body to the front side while being moved slightly laterally outward, so that it can be operated with a relatively easy posture. When operating the work speed change lever, it is operated by pulling it toward the rear side with the hand slightly closer to the body, and can be operated with a relatively easy posture.

  Therefore, while the elevating operation path is located on the front side of the vehicle body with respect to the speed change operation path, the elevating lever and the work speed changing lever are operated with a comfortable posture, and the elevating, shifting, driving and stopping operations of the work device are easily and accurately performed. Can be done.

  According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects of the invention, the work speed change lever and the elevating lever are located on the right lateral side of the driver seat.

  According to the configuration of the fourth aspect of the invention, both the work speed change lever and the lift lever are operated with the right hand.

  Therefore, the steering device is lifted, stopped, lowered and driven accurately with the right hand while turning the steering device, such as when turning, so that the lifting height of the working device and the positioning to the work start location are properly adjusted. You can go and work efficiently.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of a tractor according to an embodiment of the present invention. FIG. 2 is a plan view of the tractor according to the embodiment of the present invention. As shown in these figures, the tractor according to the present embodiment is self-propelled by a pair of left and right steering operations and front wheels 1 and 1 that can be driven and a pair of left and right rear wheels 2 and 2 that can be driven, and A driving part having an engine 3 provided at the front of the vehicle body, a steering wheel 4 located near the rear side of the driving part, and a driving seat 5 located behind the steering wheel 4. A self-propelled vehicle body, a connecting device 10 having lift arms 11 provided on both sides of the rear portion of the body frame 7 of the self-propelled vehicle body, and a rear end portion of the vehicle body frame 7 provided in the vehicle body rearward direction. A power take-out shaft 8 is provided.

  This tractor forms various riding-type work machines by connecting various working devices to the rear part of the vehicle body so as to be lifted and driven freely. For example, a rotary tiller device (not shown) is connected by the connecting device 10 so as to be movable up and down, and the output of the engine 3 is transmitted to the rotary tiller device by the power take-off shaft 8. Configure.

  The self-propelled vehicle body frame 7 includes the engine 3, a clutch housing 7a connected to the rear portion of the engine 3, a transmission case 7b connected to the rear portion of the clutch housing 7a, And a front wheel support frame 7c extending to the front. The transmission case 7b supports the pair of left and right rear wheels 2 and 2 so as to be able to drive, and supports the pair of left and right lift arms 11 and 11 so as to swing up and down.

  As shown in FIGS. 1 and 2, the coupling device 10 includes the pair of left and right lift arms 11, 11, and a pair of left and right lower links 12 that are supported by the lower part of the mission case 7 b so as to be swingable up and down. 12, a lift rod 13 that connects the left lift arm 11 and the left lower link 12, and a lift rod 13 that connects the right lift arm 11 and the right lower link 12. And a hydraulic lifting cylinder 15 provided inside the transmission case 7b.

  The pair of left and right lower links 12 and 12 are rotatably connected to a frame of a work device to be connected using connection holes provided in the free end portions thereof. The elevating cylinder 15 is interlocked inside the mission case 7b with a rotating shaft 16 (see FIG. 5) that rotatably connects the bases of the pair of left and right lift arms 11, 11 to the mission case 7b.

  That is, the connecting device 10 swings the pair of left and right lift arms 11 and 11 up and down with the lift cylinder 15, and the left lift link 11 with the left lift arm 11 connects the left lower link 12 with the right lift arm. 11, the lower link 12 on the right side is swinged up and down via the lift rod 13, thereby moving the working device up and down relative to the vehicle body.

  FIG. 3 is a diagram of a travel transmission device that transmits the output of the engine 3 to the front wheels 1 and the rear wheels 2. As shown in this figure, the travel transmission device includes a main clutch 21 mounted on the output shaft 20 of the engine 3, and an input shaft 31 connected to the output shaft 22 of the main clutch 21 via a gear 23 and a gear 24. A traveling main transmission 30 that is interlocked, and a forward / reverse switching type traveling auxiliary transmission 40 that is coupled to an output shaft 32 of the traveling main transmission 30 via a gear 25 and a gear 26. The input gear 61 is connected to the rear wheel differential mechanism 51 in which the input gear 50 is integrally formed with the output shaft 42 of the traveling auxiliary transmission 40, and the output shaft gear 43 with which the output shaft 42 is integrally rotatable. The drive switching device 60 is engaged with each other, and the front wheel differential mechanism 53 is linked to the output shaft 62 of the drive switching device 60 via a rotary shaft 52. The traveling main transmission 30, the traveling auxiliary transmission 40, the drive switching device 60, and the rear wheel differential mechanism 51 are accommodated in the transmission case 7b.

  As shown in FIG. 3, the travel main transmission 30 includes the input shaft 31 and the output shaft 32, a low-speed shift gear 33 that is rotatably supported by the output shaft 32, and the output shaft 32. A high-speed shift gear 34 disposed on the front side of the vehicle body with respect to the low-speed shift gear 33 and supported so as to be integrally rotatable is provided for a shift operation. The low-speed shift gear 33 is shifted along the output shaft 32 from the neutral position to the rear end side of the output shaft, and the teeth 33a of the low-speed shift gear 33 and the transmission gear 35 supported on the output shaft 32 so as to be relatively rotatable. When the tooth portion 35a meshes, the traveling main transmission 30 enters the first speed state. Then, the traveling main transmission 30 transmits the driving force of the input shaft 31 to the output shaft 32 through the input shaft gear 36, the transmission gear 35, and the low speed shift gear 33, and the driving force of the output shaft 32 is transmitted to the traveling auxiliary gear. This is transmitted to the transmission 40.

  When the low-speed shift gear 33 is shifted from the neutral position to the front end side of the output shaft and the tooth portion located on the outer peripheral side of the low-speed shift gear 33 and the input shaft gear 37 integrally formed with the input shaft 31 are engaged, The transmission 30 is in the second speed state. Then, the traveling main transmission 30 transmits the driving force of the input shaft 31 to the output shaft 32 via the input shaft gear 37 and the low speed shift gear 33, and transmits the driving force of the output shaft 32 to the traveling auxiliary transmission 40. . When the high speed shift gear 34 is shifted from the neutral position to the rear end of the output shaft along the output shaft 32, the tooth portion 34a of the high speed shift gear 34 and the input shaft gear 38 integrally formed with the input shaft 31 are engaged with each other. The traveling main transmission 30 is in the third speed state. Then, the traveling main transmission 30 transmits the driving force of the input shaft 31 to the output shaft 32 via the input shaft gear 38 and the high speed shift gear 34, and transmits the driving force of the output shaft 32 to the traveling auxiliary transmission 40. .

  When the high-speed shift gear 34 is shifted from the neutral position to the output shaft front end side and the tooth portion 34b of the high-speed shift gear 34 and the input shaft gear 39 formed integrally with the input shaft 31 mesh with each other, the traveling main transmission 30 is The fourth speed state is entered. Then, the traveling main transmission 30 transmits the driving force of the input shaft 31 to the output shaft 32 via the input shaft gear 39 and the high speed shift gear 34, and transmits the driving force of the output shaft 32 to the traveling auxiliary transmission 40. .

  As shown in FIG. 3, the traveling auxiliary transmission 40 includes the input shaft 41 and the output shaft 42, an input shaft shift gear 44 that is rotatably supported by a holder portion of the input shaft 41, and the output An output shaft shift gear 45 supported by the shaft 42 so as to be integrally rotatable is provided for shift operation. The input shaft shift gear 44 is shifted from the neutral position to the front end side of the input shaft along the holder portion, and the tooth portion 46a of the input shaft shift gear 44 and the transmission gear 46 supported on the input shaft 41 so as to be relatively rotatable. And the traveling auxiliary transmission 40 is in a forward low speed state. Then, the traveling auxiliary transmission 40 is configured so that the driving force of the input shaft 41 is input shaft shift gear 44, the transmission gear 46, and the output shaft gear supported by the output shaft 42 so as to be integrally rotatable with the transmission gear 46 in mesh. 47, the forward drive force of the output shaft 42 is transmitted to the rear wheel differential mechanism 51 and the drive switching device 60.

  When the output shaft shift gear 45 is shifted from the neutral position to the front end side of the output shaft, and the output shaft shift gear 45 and the input shaft gear 48 supported by the input shaft 41 so as to be integrally rotatable are engaged, the traveling auxiliary transmission 40 Becomes a forward high speed state. Then, the traveling auxiliary transmission 40 transmits the driving force of the input shaft 41 to the output shaft 42 via the input shaft gear 48 and the output shaft shift gear 45, and the forward driving force of the output shaft 42 is transmitted to the rear wheel differential mechanism 51. To the drive switching device 60.

  When the input shaft shift gear 44 is shifted from the neutral position to the rear end side of the input shaft, the input shaft shift gear 44 and the toothed portion 49a of the transmission gear 49 supported relative to the input shaft 41 are engaged with each other. The auxiliary transmission 40 is in the reverse drive state. Then, the traveling auxiliary transmission 40 outputs the driving force of the input shaft 41 with the input shaft shift gear 44, the transmission gear 49, the reverse gear 56 meshed with the transmission gear 49, and the output shaft while meshed with the reverse gear 56. Is transmitted to the output shaft 42 via a transmission gear 57 that is rotatably supported by the unit 42, and the reverse drive force of the output shaft 42 is transmitted to the rear wheel differential mechanism 51 and the drive switching device 60.

  As shown in FIG. 3, the drive switching device 60 includes not only the input gear 61 and the output shaft 62 but also a switching gear 63 that is supported by the output shaft 62 so as to be integrally rotatable so as to be capable of shifting operation. When the switching gear 63 is shifted to the second drive position, the meshing between the switching gear 63 and the transmission gear 64 integrally formed with the input gear 61 is released. Then, the drive switching device 60 enters the front wheel stop state, interrupts transmission from the input gear 61 to the output shaft 62, and stops transmission to the front wheel differential mechanism 53. That is, the drive switching device 60 puts the self-propelled vehicle into a two-wheel drive state in which the pair of left and right front wheels 1 and 1 are idle wheels and the pair of left and right rear wheels 2 and 2 are drive wheels.

  When the switching gear 63 is shifted to the four-wheel drive position, the switching gear 63 and the transmission gear 64 are engaged with each other. Then, the drive switching device 60 enters the front wheel drive state, transmits the driving force of the input gear 61 to the output shaft 62 via the transmission gear 64 and the switching gear 63, and transmits the driving force of the output shaft 62 to the front wheel differential mechanism. 53. That is, the drive switching device 60 puts the self-propelled vehicle into a four-wheel drive state in which the pair of left and right front wheels 1 and 1 and the pair of left and right rear wheels 2 and 2 are drive wheels.

  FIG. 3 is a diagram of a work transmission device that transmits the output of the engine 3 to the power take-out shaft 8. As shown in this figure, the work transmission device includes the main clutch 21, the input shaft 31, a transmission shaft 71 interlocked with the input shaft gear 38 via a transmission gear 70, and the transmission shaft 71. A work transmission device 80 with which an input shaft 81 is interlocked is provided, and an output shaft 82 of the work transmission device 80 is interlocked with the power take-out shaft 8 via a transmission shaft 72. The transmission shaft 72 supports the reverse gear 56 of the traveling sub-transmission device 40 and the input gear 61 and the transmission gear 64 of the drive switching device 60 in a relatively rotatable manner.

  As shown in FIG. 3, the work speed change device 80 includes the input shaft 81 and the output shaft 82, and also includes a shift gear 83 that is rotatably supported by a holder portion of the output shaft 82. When the shift gear 83 is shifted along the holder portion to the neutral position, the shift gear 83 is supported on the output shaft 82 so as to be relatively rotatable on the front side of the shift gear 83, and a claw portion 84a of the output shaft gear 84; The output shaft 82 is disengaged from the claw portion 85a of the output shaft gear 85 supported on the rear side of the shift gear 83 so as to be relatively rotatable. Then, the work transmission device 80 is in a neutral state so as to cut off the transmission from the input shaft 81 to the output shaft 82 and stops the power take-off shaft 8.

  When the shift gear 83 is shifted from the neutral position to the output shaft rear end side to the low speed position, the shift gear 83 engages with the holder portion of the output shaft 82 and the claw portion 85 a of the output shaft gear 85. Then, the work speed change device 80 transmits the driving force of the input shaft 81 to the output shaft 82 through the input shaft gear 86 integrally formed with the input shaft 81, the output shaft gear 85, and the shift gear 83. The power transmission shaft 8 is driven at low speed by the output shaft 82 via the transmission shaft 72.

  When the shift gear 83 is shifted from the neutral position to the output shaft front end side to reach the high speed position, the shift gear 83 engages with the holder portion of the output shaft 82 and the claw portion 84a of the output shaft gear 84. Then, the work transmission device 80 transmits the driving force of the input shaft 81 to the output shaft 82 through the input shaft gear 87 integrally formed with the input shaft 81, the output shaft gear 84, and the shift gear 83. The power transmission shaft 8 is driven at high speed by the output shaft 82 via the transmission shaft 72.

  FIG. 5 is a side view of an operation unit provided in the operation unit 6 so as to operate the coupling device 10 and the work transmission device 80. FIG. 6 is a plan view of the operation unit. FIG. 7 is a front view of the operation unit. As shown in these drawings, the operation portion includes a work speed change lever 91, an elevating lever 92, and a lever guide 93 disposed between the driver seat 5 and the rear wheel fender 90 on the right side of the vehicle body.

  The lever guide 93 is provided with a pair of long holes 94, 95 spaced apart in the vehicle longitudinal direction and the vehicle lateral direction. The lever guide 93 forms a speed change operation path 94, which is a linear path facing the front and rear of the vehicle body, on the right side of the driver seat 5 by one of the pair of long holes 94. The lever guide 93 has an elevating operation path 95 that is a linear path facing the front and rear of the vehicle body through the other elongate hole 95 of the pair of elongate holes 94, 95. It is formed on the vehicle front side and on the vehicle body lateral outer side.

  As shown in FIG. 5, the work speed change lever 91 includes a mounting cylinder portion 91 a provided at the base portion thereof. The mounting cylinder portion 91a is connected to the right side of the transmission case 7b via a support shaft 96 on which the mounting cylinder portion 91a is fitted so as to be relatively rotatable and a bracket 97 to which the support shaft 96 is fixed. Supported by the department. The bracket 97 is fastened and fixed to the mission case 7b by a connecting bolt that fastens and connects the mission case main body and the rear axle case portion of the mission case 7b.

  The work speed change lever 91 includes a swing arm 100 that is connected to the attachment cylinder portion 91a so as to be integrally rotatable. The swing arm 100 is linked via a linkage rod 102 to a shift arm 101 that is supported on the front side of the vehicle body from a portion where the work shift lever 91 is connected to the right side of the transmission case 7b. Yes. When the shift arm 101 is swung, the shifter operating shaft 103 is rotated, and the shift gear is connected via a shift fork (not shown) connected to the shifter operating shaft 103 inside the transmission case 7b. 83 is shifted.

  In other words, the work speed change lever 91 swings in the longitudinal direction of the vehicle body along the speed change operation path 94 around the lateral axis X of the vehicle body of the support shaft 96. When the work shift lever 91 is swung in this way, the shift arm 101 is swung through the swing arm 100 and the interlocking rod 102, the shifter operating shaft 103 is rotated, and the shift gear 83 is moved. Shift operation.

  As shown in FIG. 5, the work speed change lever 91 includes a bent portion 98 provided in the middle of the lever 91 and disposed slightly below the vehicle body from the lever guide 93. The bend portion 98 is such that the grip portion side portion 91c provided with the grip portion 91b of the work shift lever 91 is a work lever swinging shaft core with respect to the base portion side portion 91d provided with the mounting tube portion 91a. The vehicle body is tilted forward of the vehicle body as viewed in the direction along the lateral axis X.

  As shown in FIG. 5, the base portion of the elevating lever 92 is connected to an operation arm 111 of a position control valve device 110 (hereinafter abbreviated as a valve device 110) provided on the upper portion of the mission case 7b. That is, the elevating lever 92 is swung in the longitudinal direction of the vehicle body along the elevating operation path 95 around the vehicle body lateral axis Y of the rotation support shaft 112 of the operation arm 111. When the elevating lever 92 is swung in this way, the operating arm 111 is swung to operate the valve device 110.

  FIG. 4 is a hydraulic circuit diagram for operating the elevating cylinder 15. As shown in this figure, the valve device 110 includes the operation arm 111, a balance link 113, a feedback link 114, a main spool 115 interlocked with the balance link 113, and an interlocking member with the balance link 113. A lowering valve 117, a relief valve 118, and an unloading valve 119, which are connected to an operation shaft 117 a via 116, are provided. The main spool 115, the lowering valve 117, the relief valve 118, and the unload valve 119 are accommodated in one valve block 120.

  The main spool 115 and the lowering valve 117 are connected to the elevating cylinder 15 via a drop adjustment valve 121. One end side of the balance link 113 is locked to the command link 122. The command link 122 is connected to the rotation support shaft 112 of the operation arm 111 so as to be integrally rotatable. The other end side of the balance link 113 is locked to the feedback link 114. The rotation support shaft 123 of the feedback link 114 is linked to the lift arm 11 via a feedback linkage mechanism 124.

  In other words, the valve device 110 operates the lifting / lowering cylinder 15 to the lifting / lowering side when the lifting / lowering lever 92 is swung to the lifting / lowering side. When raising or lowering the connection height corresponding to the operation stroke of the lever 92, the elevating cylinder 15 is automatically stopped.

  That is, when the lifting lever 110 is swung upward, the operation arm 111 is swung upward. Then, the command link 122 is swung to the ascending side around the axis of the rotary support shaft 112, and the balance link 113 is swung to the ascending side with the support point by the feedback link 114 as the swinging fulcrum. Is operated to move the main spool 115 in the upward direction U and switch to the upward operation state. At this time, the lowering valve 117 is not operated by the relative movement between the interlocking member 116 and the valve operating shaft 117a, and maintains the closed state. As a result, the main spool 115 supplies pressure oil from the hydraulic pump 125 to the lifting cylinder 15, and the lifting cylinder 15 raises the lift arm 11. Accordingly, the feedback interlocking mechanism 124 swings the feedback link 114 around the axis of the rotary support shaft 123, and the feedback link 114 brings the balance link 113 into a state where the support point by the command link 122 becomes the swing support point. To swing. When the lift stroke of the lift arm 11 becomes a stroke corresponding to the operation stroke of the elevating lever 92, the main spool 115 is operated to return to the neutral state and the oil supply to the elevating cylinder 15 is stopped. At this time, the lowering valve 117 is in a closed state, and the elevating cylinder 15 stops the lift arm 11 at the swing position corresponding to the operating position of the elevating lever 92.

  When the elevating lever 92 is swung downward, the operation arm 111 is swung downward. Then, the command link 122 is swung to the lower side around the axis of the rotary support shaft 112, and the balance link 113 is swung to the lower side with the support point by the feedback link 114 as the swing fulcrum. Moves the interlocking member 116 and the valve operating shaft 117a together, and switches the lowering valve 117 to the open state. At this time, the main spool 115 is slid in the descending direction D and switched to the oil drained state. As a result, the lowering valve 117 drains oil from the hydraulic cylinder 15, and the lifting cylinder 15 lowers the lift arm 11. Accordingly, the feedback interlocking mechanism 124 swings the feedback link 114 around the axis of the rotary support shaft 123, and the balance link 113 swings about the support point by the command link 122 as the swinging support point. 116 and the main spool 115 are operated. When the lowering stroke of the lift arm 11 becomes a stroke corresponding to the operation stroke of the elevating lever 92, the lowering valve 117 is returned to the closed state by its restoring force, and the main spool 115 is returned to the neutral state to supply oil to the elevating cylinder 15. To stop. As a result, the lift cylinder 15 stops the lift arm 11 at the swing position corresponding to the operation position of the lift lever 92.

  As shown in FIG. 6, the lever guide 93 includes a lever stopper 130 disposed on the rear end side of the lifting operation path 95. FIG. 9 is a perspective view of the lever stopper 130. As shown in this figure, the lever stopper 130 is formed of a bar material that is bent so as to include a stopper portion 130a, a mounting shaft portion 130b, and a lever portion 130c. The lever stopper 130 is rotatably supported on the holder 131 provided on the lever guide 93 by the mounting shaft portion 130b.

  FIG. 8A is a front view of the lever stopper 130 in the operating state. As shown in this figure, the lever stopper 130 is rotated around the axis of the mounting shaft portion 130b, and the stopper portion 130a is laid down so that it is mounted across the lifting operation path 95. Then, the lever stopper 130 is in an operating state, and the stopper portion 130a holds the elevating lever 92 so as not to move to the highest position A (see FIG. 6).

  FIG. 8B is a front view of the lever stopper 130 in a released state. As shown in this figure, the lever stopper 130 is rotated around the axis of the mounting portion 130b, so that the stopper portion 130a is retracted to the laterally outer side of the lifting operation path 95. Then, the lever stopper 130 is in a released state, and the position holding of the elevating lever 92 by the stopper portion 130a is released.

  As shown in FIG. 8 (a), when the lever stopper 130 is switched to the operating state, the lever portion 13c is inclined and can be used as a lever for switching the lever stopper 130 to the released state. As shown in FIG. 8B, when the lever stopper 130 is switched to the released state, the lever portion 130c falls down and becomes difficult to use. At this time, the stopper portion 130a is inclined and can be used as a lever for switching the lever stopper 130 to the operating state.

  The positioning body 133 shown in FIGS. 6, 7, and 9 positions the lifting / lowering lever 92 at the highest lift position A while preventing the lever guide 93 from being deformed or damaged due to the hitting of the lifting / lowering lever 92.

When the work device is connected, the work device is operated to change speed with the work speed change lever 91, or is switched between driving and stopping, and is moved up and down with the elevating lever 92.
That is, the work speed change lever 91 is swung in the longitudinal direction of the vehicle body along the speed change operation path 94 to a neutral position N (see FIG. 6) disposed at an intermediate portion of the speed change operation path 94 in the longitudinal direction of the vehicle body. Then, the operation arm 100 operates the speed change arm 101 to the neutral posture via the interlocking rod 102. As a result, the work transmission device 80 is switched to the neutral state, the power take-off shaft 8 is stopped, and the work device is stopped.

  When the work speed change lever 91 is operated to the first speed position P1 (see FIG. 6) arranged at the front end of the speed change operation path 94, the operation arm 100 operates the speed change arm 101 to the low speed posture via the interlocking rod 102. As a result, the work transmission device 80 is switched to the low-speed transmission state to drive the power take-off shaft 8 at a low speed, and the work device is driven at a low speed.

  When the work speed change lever 91 is operated to the second speed position P2 (see FIG. 6) arranged at the rear end portion of the speed change operation path 94, the operation arm 100 operates the speed change arm 101 to a high speed posture via the interlocking rod 102. As a result, the work transmission device 80 is switched to the high-speed transmission state to drive the power take-off shaft 8 at a high speed, and the work device is driven at a high speed. At this time, the base side portion 91 d of the work speed change lever 91 extends from the support shaft 96 toward the rear of the vehicle body. However, the bent portion 98 of the work speed change lever 91 makes the grip portion side portion 91c close to a vertical posture so that the grip portion 91b can be easily supported and handled when the work speed change lever 91 is moved from the second speed position P2. To.

  When the elevating lever 92 is swung to the front side of the vehicle body along the elevating operation path 95, the operating arm 111 is swung downward by the lever operating force, and the valve device 110 is switched to the lowered state. Thereby, the raising / lowering cylinder 15 drains oil, the coupling device 10 swings downward, and the working device descends. As the working device is lowered, the lift arm 11 operates the feedback link 114 via the feedback interlock mechanism 124. As a result, when the working device is lowered by the lowering amount corresponding to the operation stroke of the lifting lever 92, the valve device 110 is switched to the neutral state, the lifting cylinder 15 is stopped, and the lowering of the connecting device 10 is stopped. The connection height corresponds to the operation position of the lift lever 92.

  When the elevating lever 92 is swung to the rear side of the vehicle body along the elevating operation path 95, the operating arm 111 is swung upward by this lever operating force, and the valve device 110 is switched to the raised state. Thereby, the raising / lowering cylinder 15 is refueled, the connection apparatus 10 raises and rocks, and a working apparatus raises. As the working device is raised, the lift arm 11 operates the feedback link 114 via the feedback interlocking mechanism 124. As a result, when the working device increases the lift amount corresponding to the operation stroke of the lifting lever 92, the valve device 110 is switched to the neutral state, the lifting cylinder 15 is stopped, the lifting of the connecting device 10 is stopped, and the working device is The connection height corresponds to the operation position of the lift lever 92.

  When the elevating lever 92 is operated to the highest position A, the lever stopper 130 is switched to the operating state. Then, the lever stopper 130 prevents the lifting / lowering lever 130 from moving due to traveling vibration or the like by the stopper portion 130a, and prevents the working device from descending.

Side view of tractor Top view of tractor Diagram of travel gear and work gear Hydraulic circuit diagram Side view of the operation unit Top view of the operation unit Front view of the operation unit (A) is a front view of the lever stopper in the operating state, and (B) is a front view of the lever stopper in the released state. Perspective view of lever stopper

Explanation of symbols

5 Driver's seat 8 Power take-off shaft 10 Connecting device 80 Work transmission device 91 Work transmission lever 91c Grip side portion 91d Base side portion 92 Lifting lever 94 Shifting operation path 95 Lifting operation path 98 Bending portion

Claims (4)

A tractor comprising: a coupling device that couples the work device so as to be movable up and down; a power take-out shaft that transmits power to the work device; a work transmission device that changes a drive speed of the power take-out shaft; and a driver seat. ,
A work speed change lever for switching the work speed change device between a high speed transmission state, a neutral state and a low speed transmission state is swung along a linear speed change operation path facing the front and rear of the vehicle body on a lateral side of the driver seat. Arrange it freely,
A lifting lever for operating the connecting device is arranged in the same lateral side as the side on which the work speed change lever of the driver seat is located, on the front side of the vehicle with respect to the speed change operation path. A tractor that can be swung freely along the operation path.   The tractor according to claim 1, wherein the work shift lever includes a bent portion in which the grip portion side portion is bent with respect to the base side portion so as to incline toward the front side of the vehicle body as viewed along the work shift lever swing axis. .   The tractor according to claim 1 or 2, wherein the elevating operation path is located on a lateral outer side of the vehicle body with respect to the speed change operation path.   The tractor according to any one of claims 1 to 3, wherein the work speed change lever and the elevating lever are located on a right lateral side of the driver seat.

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