JP2005186832A - Crawler swing regulating device for work vehicle - Google Patents

Abstract

[PROBLEMS] To drive a crawler of a work vehicle that can drive a crawler without resistance even during turning or at high speed, has excellent running performance that does not roughen a running field or wear the crawler at an early stage, and can easily adjust the swing angle. To provide a dynamic regulation device.
SOLUTION: A traveling device 7 is lifted to the front or rear side of the rotational axis of the sprocket 2 of a pair of left and right crawler traveling devices 7 having a substantially triangular shape with a crawler driving sprocket 2 provided on a vehicle body as a vertex. A front stopper 30A and a rear stopper 30B are provided for restricting the swing angle of the traveling device 7 when the travel device 7 is lowered and when the front is lowered. The arm portion is connected to the portion of the traveling device 7 between the stoppers 30A and 30B. Is a crawler swing regulating device that supports a bell crank 30 that can freely swing back and forth to abut against the stoppers 30A and 30B.
[Selection] Figure 2

Description

  The present invention relates to configurations of agricultural work vehicles and construction work vehicles, and more particularly, to a crawler swing regulating device for a work vehicle having a crawler type traveling device.

  Conventionally, a pair of left and right drive shafts protrude from the side of the vehicle body, and a crawler drive sprocket is provided on the drive shaft, and a support member for supporting a driven wheel or a wheel is disposed below the drive shaft, and the crawler 2. Description of the Related Art A work vehicle is known that forms a substantially triangular crawler type traveling device by crawling a crawler between a driving sprocket and a driven wheel or a roller.

  For example, there is a semi-crawler type tractor that is provided with a pair of left and right wheel type front wheels and a pair of left and right crawler type rear traveling devices, and is configured such that a work machine can be connected up and down at the end of the vehicle body (actual (Kaihei 5-78682).

Further, a configuration is known in which stoppers are provided on the front and rear sides of the substantially triangular crawler driving sprocket for restricting the swing range of the crawler driving sprocket in the front-rear direction (Japanese Patent Laid-Open No. 2005-260707). 2000-255465).
Japanese Utility Model Publication No. 5-78682 JP 2000-255465 A

  However, since the conventional work vehicle described in Japanese Utility Model Laid-Open No. 5-78682 has a support member for supporting a wheel or a driven wheel fixed to the vehicle body, it is connected to the state of the running surface or connected. Regardless of the type and weight of the work implement, there are problems that the crawler is worn early or a large vibration occurs, which impairs the operability of the vehicle. In order to solve these problems, it is conceivable to provide means for changing the state of the support member so as to reduce the ground contact area of the crawler as much as possible. It is necessary to change the state of the support member so that the circumference of the crawler does not change as much as possible so as not to be disengaged from the guide portion on the inner surface side.

  The prior art described in Japanese Patent Application Laid-Open No. 2000-255465 can adjust the swing angle of the substantially triangular crawler drive sprocket. During the adjustment work, the work place is moved to a place other than the farm field. There is a problem that it is necessary and adjustment work is difficult.

  The problem of the present invention is that the crawler can be driven without resistance even when turning or traveling at high speed, and the traveling performance is excellent so as not to roughen the traveling field scene or cause the crawler to wear quickly, and the swing angle can be easily adjusted. It is providing the crawler rocking | fluctuation control apparatus of a working vehicle.

The above problem is solved by the following means.
According to the first aspect of the present invention, a pair of left and right crawler type traveling devices (7) having a substantially triangular shape having a pair of left and right front wheels (14) at the front part of the vehicle body and a crawler drive sprocket (2) at the rear part of the vehicle body. And a crawler swing regulating device for a working vehicle that supports the crawler travel device (7) so as to swing back and forth with respect to the vehicle body. The crawler travel device (7) is disposed in front of the vehicle body. The front side stopper (30A) that regulates the swing angle of the traveling device (7) when it rises and the crawler type traveling device (7) when the crawler traveling device (7) falls forward. A rear stopper (30B) for restricting the swing angle is provided on the front side or the rear side of the crawler drive sprocket (2), and the crawler type is provided between the stoppers (30A, 30B). A crawler swing regulating device for a work vehicle provided with a bell crank (30) freely swingable back and forth, which is connected to a predetermined part of the row device (7) and abuts the arm portion against each stopper (30A, 30B). is there.

  According to a second aspect of the present invention, the inclination angle of the abutted portion of the front and rear stoppers (30A, 30B) can be adjusted with respect to the abutting portion of the bell crank (30) swinging back and forth. It is a crawler rocking | fluctuation control apparatus of the described working vehicle.

  According to the first aspect of the present invention, the crawler type traveling device (7) regulates the swing angle of the front rising and the front falling by the bell crank (30) and the front and rear stoppers (30A, 30B). The crawler can be driven without resistance even during high-speed traveling, and can be run without ruining the traveling field scene or quickly wearing the crawler, and the crawler can be removed from the crawler rotation guide without changing the circumference of the crawler. The trouble can be solved.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, the front and rear stoppers (30A, 30B) are in contact with the contact portion of the bell crank (30) that swings back and forth. Since the inclination angle of the part can be adjusted, the stoppers (30A, 30B) can be brought into contact with a contact surface of the contact part of the bell crank (30) over a wide area. Vibration can be reduced and damage to these members can be prevented.

  An embodiment of the present invention will be described below with respect to a semi-crawler type agricultural tractor (hereinafter referred to as a tractor) which is an example of a work vehicle. FIG. 1 shows a side view of a tractor according to an embodiment of the present invention. The tractor 10 mounts an engine 12 inside a hood 11 at the front of the vehicle body, and a clutch housing (not shown), a transmission case 13 and the like are integrally connected to the engine 12 to form a main frame of the vehicle body. A pair of wheel-type front wheels 14 are provided on both the left and right sides of the bonnet 11 so as to be freely rotatable with respect to the center pivot 15 center. A steering post 16 is provided in the cabin 8 at the rear of the bonnet 11, and a steering handle 17 is provided above this. The front wheel 14 is steered by rotating the steering handle 17.

  The interior of the cabin 8 of the tractor 10 will be described. A traveling speed change lever 20 and a lifting operation lever 21 for lifting the work implement are provided on the side of the cockpit 19. A potentiometer (not shown) for detecting the operation angle is provided at the rotation base of the elevating operation lever 21 so that the lever operation angle coincides with a set angle of a lift arm 31 (see FIG. 1) described later. The height of the work machine R is changed.

  Further, a hand catcher 26A for getting on and off is directly attached to the cover fender 26, and as shown in FIG. 1, the attachment surface is lowered by one step (distance α in FIG. 1) behind the center pillar cover 27, and the cup holder 26B is attached. As described above, since the cup holder 26B is installed outside the center pillar, the inside of the cabin 8 can be easily maintained. In order to attach the cup holder 26B to the cover fender 26, a fixing means such as a stay (metal fitting) not shown may be fixed between the cup holder 26B and the cover fender 26. The stay attached to the cover fender 26 may also serve as a cup holder attaching stay. With such a configuration, it is possible to prevent the cover fender 26 from being shifted and lowered, and to maintain the appearance of the fender.

  The crawler type traveling device 7 of the tractor 10 is provided with a crawler frame 5 that supports the wheels 4a, 4b, 4c and the driven wheels 3F, 3R below the transmission case 13, and the wheels 4a, 4b, 4c and the driven wheels. The crawler 6 is stretched over 3F and 3R.

  Although not shown, the crawler frame 5 is a substantially “H” -shaped iron frame in a top view, and has a configuration in which left and right side portions have roller support portions 5 a provided in the front-rear direction. The front end of the roller support portion 5a has a cylindrical configuration so as to receive the support portion of the front driven wheel 3F.

  In addition, the front end of the said wheel support part 5a makes the support part of the front driven wheel 3F slide back and forth in a cylinder, and can adjust a front-back position. Between the front and rear driven wheels 3F and 3R, a first wheel 4a, a second wheel 4b, and a third wheel 4c are provided in this order from the front.

  The crawler drive sprocket 2 is provided at the tip of a pair of crawler drive sprocket shafts 1 projecting outward from left and right extending portions (not shown) of the rear portion of the transmission case 13, A large number of sprocket-shaped protrusions that mesh with a large number of engagement holes (not shown) of the crawler 6 are provided, and the crawler 6 is driven by these meshing.

  Next, the rear part of the mission case 13 of the tractor 10 will be described with reference to FIG. At the rear of the mission case 13, a lifting hydraulic cylinder 35A and an assist cylinder 35B are provided as actuators for lifting the work implement, and the lift arm 31 connected to the pistons of these cylinders (35A, 35B) is rotated up and down. The work machine R is lifted and lowered via the link mechanism 32. A lift arm angle sensor 33 is provided at the rotation base of the lift arm 31 so that the height of the work implement R can be indirectly detected.

  The control device (not shown) of the tractor 10 detects the output of the lift arm angle sensor 33 at regular intervals and measures the lift speed dθ / dt of the lift arm 31. When the ascending speed dθ / dt is equal to or less than a predetermined value, the control device determines that the work implement R is heavy and activates the assist cylinder 35B.

  When the work machine R is not attached, or when the light work machine R that does not require the assist cylinder 35B is attached, the assist cylinder 35B is not driven, so that the twist of the lift arm mounting portion due to the load is eliminated. , Improve durability.

  Specifically, the oil flow rate to the assist cylinder 35B is controlled by a flow rate control valve (not shown). When the work machine R is light (not attached), the cylinder case (not shown) of the lifting hydraulic cylinder 35A is omitted. Only the oil is fed, and the assist cylinder 35B is not operated, and the assist cylinder 35B is operated only when the work implement R is heavy.

Details of the crawler type traveling device 7 will be described with reference to FIG. 2 (side view), FIG. 3 (plan view), and FIG. 4 (partially enlarged side view).
The crawler type traveling device 7 of the tractor 10 is provided with a crawler frame 5 that supports the wheels 4a, 4b, 4c and the driven wheels 3F, 3R below the transmission case 13 (FIG. 1). The crawler 6 is stretched over the 4c and the driven wheels 3F, 3R.

  Although not shown, the crawler frame 5 is a substantially “H” -shaped iron frame in a top view, and has a configuration in which left and right side portions have roller support portions 5 a provided in the front-rear direction. The front end of the roller support portion 5a has a cylindrical configuration so as to receive the support portion of the front driven wheel 3F.

  In addition, the front end of the said wheel support part 5a makes the support part of the front driven wheel 3F slide back and forth in a cylinder, and can adjust a front-back position. Between the front and rear driven wheels 3F and 3R, a first wheel 4a, a second wheel 4b, and a third wheel 4c are provided in this order from the front.

  The crawler drive sprocket 2 is provided at the tip of a pair of crawler drive sprocket shafts 1 projecting toward the left and right outwards of the rear portion of the transmission case 13 (FIG. 3). The crawler 6 is driven by engaging with a large number of engagement holes. In addition, a concave portion that sandwiches central protrusions (not shown) provided in two left and right rows inside the crawler 6 at the left and right width center portions of the front and rear driven wheels 3F and 3R and the left and right width center portions of the rollers 4a, 4b, and 4c. (Not shown) is provided, and this concave portion regulates the lateral displacement of the crawler 6 and guides this rotational direction. Further, the front and rear driven wheels 3F and 3R are positioned slightly above the ground contact surface to guide the rotation of the crawler 6 when the first wheel 4a to the third wheel 4c are grounded. . Further, the crawler frame 5 has a structure in which a plate-like standing portion 5b is provided upward from the inner side of the wheel support portion 5a, and a drive shaft bearing portion 5c is connected to the upper portion.

  A feature of the present embodiment is that stoppers 30A and 30B for restricting the rotation of the bell crank 30 with respect to the bell crank 30 that can be rotated in conjunction with the swing of the crawler 6 of the pair of left and right crawler type traveling devices 7. Is provided so that the position can be easily adjusted.

  A pair of rotating shafts 1B projecting outward from the left and right extending portions 13b at the front portion of the transmission case 13 (FIG. 3) penetrates the stopper support frame 36, and at the tip of the rotating shaft 1B. The bell crank 30 is supported so as to be rotatable about the rotation shaft 1B. The stopper support frame 36 has a substantially L-shape bent forward from the crawler drive sprocket shaft 1 and is fixed to the crawler frame 5 so as to be rotatable about the crawler drive sprocket shaft 1. It is supported.

  Near the front end of the stopper support frame 36, a front stopper 30A is pivotally mounted so as to be capable of rotating by a predetermined angle about the fixed portion 30Ac and movable up and down along the slit 30As. Then, the user arbitrarily rotates or moves the stoppers 30A and 30B in accordance with the state of the field using the tractor 10 and arranges the stoppers 30A and 30B at a desired position, and then fixes the fixing portion 30Ac including a fixing means such as a nut. Can do.

  The fixing portion 30Ac is fixed to the stopper support frame 36 by an axis or the like passing through the gap between the longitudinal slits 30As formed at the approximate center of the front stopper 30A. Near the rear end of the stopper support frame 36, a second stopper support frame 37 that penetrates and holds the crawler drive sprocket shaft 1 is provided. Similarly, a rear stopper 30B that is paired with the front stopper 30A is pivotally attached to the second stopper support frame 37 so as to be rotatable and vertically movable at a predetermined angle.

  That is, near the rear end of the stopper support frame 37, the rear stopper 30B is pivotally mounted so as to be rotatable at a predetermined angle about the fixed portion 30Bc and vertically movable along the slit 30Bs.

  As shown in FIGS. 2A to 2C, the bell crank 30 of the present embodiment penetrates the rotating shaft 1 </ b> B in the vicinity of the bent portion and faces the front and rear direction below the stopper support frame 36. The crawler frame 5d is supported so as to be rotatable. On the other hand, an elongated hole 5G is provided near the front end of the bell crank 30, and a locking pin 1C extending from the crawler frame 5d is attached to the elongated hole 5G.

  The crawler frame 5d is rotatably supported around the rear axle housing. On the other hand, the stopper support frame 36 is a separate member from the crawler frame 5 and is fixed around the rear axle housing.

  When attaching the crawler 6 to the crawler frame 5 of the tractor 10 configured as described above, first, the crawler drive sprocket 2 is attached to one end of the crawler drive sprocket shaft 1, and the crawler frame 5 is placed below the transmission case 13. In this state, after the other end of the crawler driving sprocket shaft 1 is inserted into the bearing portion 5c of the crawler frame 5, the crawler driving sprocket shaft 1 is inserted into the bearing hole opened in the extending portion 13a of the transmission case 13. Attach the other end of. Next, the crawler 6 is stretched between the crawler driving sprocket 2 and the front and rear driven wheels 3F and 3R, and the rollers 4a, 4b and 4c.

Next, the rotating action of the crawler frame 5 will be described.
The crawler frame 5 rotates back and forth around the axis of the crawler drive sprocket shaft 1. When rotating forward, the locking plate 30C on the upper left surface of the bell crank 30 rotates upward from the state shown in FIG. 2B around the rotary shaft 1B and comes into contact with the front stopper 30A. It stops at the position (FIG. 2 (a)). In this state, the locking pin 1C is at a position in contact with the upper end of the long hole 5G (FIG. 2A). On the other hand, when rotating forward and downward from the state shown in FIG. 2B, the locking plate 30D on the upper right surface of the bell crank 30 rotates forward and downward about the rotation shaft 1B (FIG. 2B). ), And stops at a position where it abuts against the rear stopper 30B (FIG. 2C). In this state, the locking pin 1C is in a position in contact with the lower end of the range of the long hole 5G (FIG. 2 (c)).

  The stoppers 30A and 30B are fixed by inserting fastening bolts (30Ac and 30Bc) into slits 30As and 30Bs provided in the stopper support frame 36, respectively. Further, since the slits 30As and 30Bs are opened in the front-rear inclination direction, the positions where the stoppers 30A and 30B abut on the bell crank 30 can be adjusted.

  With such a configuration, the rotation range of the bell crank 30 can be limited to any predetermined range by the stoppers 30A and 30B, and the stoppers 30A and 30B for restricting the rotation of the bell crank 30 can be set according to the state of the field. By rotating or moving up and down arbitrarily and disposing at a desired position and fixing by the fixing portions 30Ac and 30Bc, the swing angle forward of the crawler 6 is eliminated in the towing work in a hard field or the like in the field, and the crawler 6 Can be prevented from completely swinging forward. Moreover, the trouble that the crawler 6 does not deviate from the guide for rotating the frame without changing the circumference of the crawler 6 can be solved, and stable traction work can be performed.

  In this way, in a heavy work machine in which the crawler 6 swings back and forth, the swamp can perform stable work according to the hardness of the field by the swing, but the swinging of the towing work in the field etc. It is possible to solve the conventional problem that the crawler part completely swings forward, the traction posture is greatly increased, and the traction force is reduced.

  As another embodiment of the stoppers 30A and 30B, the arrangement position of one or both of the stoppers 30A and 30B can be changed by driving the actuator, and the presence or absence of the swing angle of the crawler 6 can be automatically switched according to the hardness of the field. Good. Specifically, as shown in FIG. 5, the bottom surfaces of the stoppers 30A and 30B are automatically moved up and down by a variable cylinder 40 and the bottom surface is rotated by a predetermined angle by an angle adjusting actuator (not shown). You can do it.

  As a result, the swing angle of the crawler 6 before and after can be automatically adjusted, so that the swing of the crawler 6 can be varied between the field and the wet field, and stable work can be performed under any conditions.

  In addition, the system includes a plurality of slope sensors for detecting the inclination of the vehicle body and an actuator for swing control, and detects the inclination of the vehicle body by the slope sensor, and performs an appropriate swing according to the detected inclination of the vehicle body. May be.

Specifically, as shown in FIG. 6, a slope sensor 41A is provided on the front surface of the bonnet 11, a slope sensor 41B is provided around the center of gravity of the vehicle body, one end of the variable cylinder 42 is fixedly supported on the bell crank 30, and the like. The end is fixed near the front end of the stopper support frame 36. That is, the variable cylinder 42 is integrated with the bell crank 30 so that the stoppers 30A and 30B are unnecessary. The variable cylinder 42 controls the swing angle in accordance with the amount of slope detected from the slope sensors 41A and 41B.
Since the slope sensor 41A has a larger distance from the crawler 6 and a larger swing radius than the slope sensor 41B, the slope sensor 41A detects the slope more sensitively.

  With such a configuration, the posture of the vehicle body can be sensed by a plurality of slope sensors 41A and 41B, and the optimum swing angle can be set automatically by the variable cylinder 42, so that it can respond sharply to differences in fields such as wet fields and fields. Thus, for example, when the vehicle body posture is rearwardly raised, the forward swinging of the crawler 3 is suppressed, so that stable work can be performed and the crawler can be used efficiently.

  Further, the traveling hydraulic circuit L1 of the tractor 10 may have a configuration as shown in FIG. In the figure, the hydraulic pump P sucks up the oil in the transmission case 13 by driving the engine 12 and branches this pressure oil to the traveling system hydraulic circuit L1 and other various hydraulic circuits. The traveling hydraulic circuit L1 is connected to the pressure of the oil sucked up by the hydraulic pump P by being transmitted to the pressure reducing valve 51, the proportional pressure control valve 54 and the emergency valve 55, and the switching control valve in order from the upper side of the circuit. 52 and the filter 53A are connected to either the left or right hydraulic clutch 77.

Thus, pressure oil is sent to the hydraulic clutch 77 on the inner side of the turn by switching the switching control valve 52, and the amount of current supplied to the proportional pressure control valve 54 is changed to flow into the cylinder chamber of the hydraulic clutch 77 on the inner side of the turn. By controlling the oil amount to be gradually increased and decreased and operating the clutch piston, the rotation of the crawler 6 can be gradually decelerated from the normal rotation, and the speed can be switched to the reverse rotation through the stop state to increase the speed.
At this time, it is one of the features of this embodiment that the emergency valve 55 is connected to the upper side of the pressure reducing valve 51.

  When the pressure reducing valve 51 and the proportional pressure control valve 54 fail, oil may not flow to the hydraulic clutch 77. However, by providing the emergency valve 55 on the upper side of the pressure reducing valve 51 and opening the emergency valve 55, the oil is supplied. The pressure reducing valve 51 can be closed by flowing out to the pressure reducing valve 51 and increasing the internal pressure of the pressure reducing device. As a result, the pressure oil sucked up by the hydraulic pump P can be sent to the hydraulic clutch 77.

  By connecting the emergency valve 55 to the upper side of the pressure reducing valve 51 in this manner, even when the pressure control is abnormal, the pressure oil can be reliably sent to the hydraulic clutch 77, and the traveling is stopped. Can be avoided.

  In addition, it is possible to prevent the hydraulic oil sucked up by the hydraulic pump P from being directly applied to the hydraulic clutch 77 and stopping the hydraulic clutch 77 from sliding by the above configuration.

  Furthermore, by providing the filter 53B at the inlet of the traveling system hydraulic circuit L1, clogging of the various control valves included in the traveling system hydraulic circuit L1 with dust can be prevented in advance.

A state in which the emergency valve 55 is specifically controlled by the hydraulic control circuit 150 of the tractor 10 will be described with reference to FIG.
As shown in FIG. 8A, the hydraulic control circuit 150 of the tractor 10 detects the rotational speed of the engine, the controller 60, the hydraulic valve shift position sensor 61 that controls the pressure of the hydraulic clutch 77 with an electromagnetic valve, and the engine speed. The engine rotation sensor 62 for detecting the rotation speed of the hydraulic clutch 77, the emergency valve 55, and a display section 64 such as a liquid crystal display for displaying various messages and control modes. ing. Here, forward / reverse switching is performed by changing the connection state of the hydraulic clutch.
As shown in FIG. 8B, the controller 60 waits for detection signals from the hydraulic valve shift position sensor 61, the engine rotation sensor 62, and the clutch rotation sensor 63, and inputs the detection values of each sensor (step S101). . Then, the controller 60 calculates based on the detection value of each sensor and determines whether the hydraulic clutch 77 is operating normally (step S102). If it is operating normally, the process returns to step S101. On the other hand, if it is in an abnormal control state, the controller 60 proceeds to step S103 and automatically outputs a command to the emergency valve 55 to open the valve. In addition, data including characters indicating that the control state is abnormal is output and displayed on the display unit 64. Although the emergency valve 55 is automatically opened to switch to the hydraulic circuit that does not pass the proportional pressure control valve 54, this operation may be switched manually.

  With such a configuration, when the hydraulic clutch 77 is in an abnormal control state, the hydraulic circuit is automatically switched to a hydraulic circuit that does not pass the proportional pressure control valve 54, so that the clutch connected shock increases, but the traveling continues reliably. it can. In addition, since the abnormal control state can be displayed on the display unit 64, the operator is informed of the abnormality and given an opportunity for repair and improvement. From the trouble of the valve alone to the fatal trouble such as the wear of the hydraulic clutch. Can be prevented.

  In the conventional hydraulic control circuit that controls the pressure of the hydraulic clutch with the proportional pressure control valve, the performance of the proportional pressure control valve is greatly influenced by impurities such as dust contained in the hydraulic oil. The traveling can be reliably continued regardless of the state of the proportional pressure control valve.

  The present invention relates to a configuration of an agricultural work vehicle or a construction work vehicle, in addition to a semi-crawler type work vehicle in which a front wheel or a rear wheel is configured as a wheel type, a so-called traveling with only a pair of left and right crawlers without a wheel type wheel. The present invention can be applied to a full crawler type work vehicle and a work vehicle having four crawlers on the left and right and front and rear of the vehicle body.

It is a side view of the tractor of an embodiment of the invention. It is a side view of the crawler type traveling apparatus of FIG. It is a top view of the crawler type traveling device of FIG. It is a partial side surface enlarged view of the crawler type traveling apparatus of FIG. It is a side view of the crawler type traveling apparatus of FIG. It is a side view of the tractor of FIG. It is a block diagram which shows the structure of the traveling system hydraulic circuit of the tractor of FIG. FIG. 8 is a block diagram (FIG. 8A) showing a configuration of a hydraulic control circuit of the tractor of FIG. 1, and a flowchart showing a processing procedure of hydraulic control (FIG. 8B).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crawler drive sprocket shaft 1B Rotating shaft 1C Locking pin 2 Crawler drive sprocket 3F, 3R Front and rear driven wheels 4a, 4b, 4c Roller wheel 5 Crawler frame (support member) 5a Roller wheel support portion 5b Crawler frame standing portion 5c Crawler frame drive shaft bearing portion 5d Crawler frame 5G Long hole 6 Crawler 7 Crawler type traveling device 8 Cabin 10 Tractor 11 Bonnet 12 Engine 13 Mission case 13a Mission case (rear) extension 13b Mission case (front) extension 14 Front wheel 15 Center pivot 16 Steering post 17 Steering handle 19 Pilot seat 20 Traveling lever 21 Lifting lever 26 Cover fender 26A Hand catcher 26B Cup holder 27 Center pillar cover 30 bell Rank 30A Front stopper 30B Rear stopper 30C Left upper surface portion 30D Right upper surface portion 31 Lift arm 32 Link mechanism 33 Lift arm angle sensor 35A Lifting hydraulic cylinder 35B Assist cylinder 36, 37 Stopper support frame 40, 42 Variable cylinder 41A, 41B Slope sensor 51 Pressure Reduction Valve 52 Switching Control Valves 53A, 53B Filter 54 Proportional Pressure Control Valve 55 Emergency Valve 60 Controller 61 Hydraulic Valve Shift Position Sensor 62 Engine Rotation Sensor 63 Clutch Rotation Sensor 64 Display Unit 77 Hydraulic Clutch 150 Hydraulic Control Circuit L1 Traveling System Hydraulic Pressure Circuit P Hydraulic pump R Working machine α Distance

Claims (2)

A pair of left and right front wheels (14) are provided at the front of the vehicle body, and a pair of left and right crawler type traveling devices (7) having a crawler driving sprocket (2) at the apex are provided at the rear of the vehicle body. In a crawler swing regulating device for a work vehicle that supports the device (7) so as to swing back and forth with respect to the vehicle body,
The vehicle body is provided with a front stopper (30A) for restricting the swing angle of the traveling device (7) when the crawler traveling device (7) is lifted forward, and a crawler traveling device (7). A rear stopper (30B) for restricting the swing angle of the crawler type traveling device (7) when it is lowered is provided on the front side or the rear side of the rotation axis of the crawler drive sprocket (2), respectively. Between the stoppers (30A, 30B), it is connected to a predetermined part of the crawler type traveling device (7) so that the arm part comes into contact with the stoppers (30A, 30B). The crawler rocking | fluctuation control apparatus of the working vehicle characterized by the above-mentioned. 2. The operation according to claim 1, wherein an inclination angle of a contact portion of the front and rear stoppers (30A, 30B) is adjustable with respect to a contact portion of the bell crank (30) swinging back and forth. Vehicle crawler swing regulation device.

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