JP2002356174A - Crawler car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assembling workability and reduce the weight of an entire mechanism when a control mechanism controlling a hydraulic mechanism for steering according to rotating operation manipulation of a steering wheel and a reduction mechanism transmitting the rotation of the steering wheel to the control mechanism are provided. SOLUTION: In a combine 1 provided with a continuously variable transmission mechanism for steering 20 for differential operation of right and left crawlers, a control mechanism 30 for controlling the continuously variable transmission mechanism for steering 20 according to a rotating operation of the steering wheel 26, and a reduction mechanism 29 for reducing the rotation of the steering wheel 26 and conveying it to the control mechanism 30, a panel frame 27 for supporting the steering wheel 26, a bracket 31 for supporting the control mechanism 30 and a reduction case 32 into which the reduction mechanism 29 is incorporated are constituted separately, the reduction case 32 to which the bracket 31 is assembled in advance is mounted on a car body frame 34, and the panel frame 27 is mounted above it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a crawler traveling vehicle such as a combine which steers an airframe by rotating a steering handle.

[0002]

2. Description of the Related Art In recent years, there has been proposed a crawler traveling vehicle such as a combine vehicle in which the body can be steered according to a rotation operation of a steering wheel. The steering system includes a traveling hydraulic continuously variable transmission mechanism that synchronously drives the left and right crawlers at variable speeds, and a steering hydraulic continuously variable transmission mechanism that differentially drives the left and right crawlers. In some systems, the speed change mechanism is controlled in accordance with the operation of turning the steering wheel and the operation of the travel speed change lever. In this method, various turning patterns can be exhibited while ensuring good straight running performance.

[0003]

However, in the prior art described above, the control mechanism for controlling the steering hydraulic mechanism in accordance with the rotation operation of the steering handle, and the control mechanism for reducing the rotation of the steering handle, In order to provide a speed reduction mechanism that transmits power to the steering wheel, these mechanisms are integrally formed with a panel frame or the like that supports the steering handle. In addition, there is a disadvantage that the above-mentioned mechanism is dedicated to each model and causes an increase in cost.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve these problems in view of the above situation, and has a steering hydraulic mechanism for differentially moving left and right crawlers. A crawler traveling vehicle comprising: a control mechanism that controls a steering hydraulic mechanism in accordance with a rotation operation of a steering handle; and a reduction mechanism that reduces the rotation of the steering handle and transmits the rotation to the control mechanism. A frame that supports the steering wheel, a bracket that supports the control mechanism, and a speed reduction case in which the speed reduction mechanism is incorporated are separately configured, and the speed reduction case in which the bracket is pre-assembled is attached to the body frame. And mounting the panel frame above the panel frame. In other words, since each mechanism can be configured individually, it is not permissible to improve the assemblability, and it is possible to reduce the weight of the entire mechanism, and to partially share the mechanism between different models. it can. The control mechanism includes a rotating body that rotates in accordance with an operation of a steering handle, a sliding body that slides in accordance with an operation of a shift lever, and an engaging body that engages with the rotating body and the sliding body. The engaging body is connected to a steering hydraulic mechanism for differentially moving the left and right crawlers, and a traveling hydraulic mechanism for synchronously driving the left and right crawlers to change the speed. . That is, by displacing the engaging body connected to the traveling hydraulic mechanism and the steering hydraulic mechanism in accordance with the traveling shift lever operation and the steering handle operation, the traveling hydraulic mechanism and the steering hydraulic mechanism are combined. Therefore, functions such as an automatic deceleration function at the time of turning and a direction reversal prevention function at the time of forward / reverse switching can be easily added based on the setting of the shape of the engaging portion of the rotating body or the sliding body. Further, a neutral return spring for returning the steering handle to a neutral position is attached to the rotating body. That is, even when the traveling speed change lever is in the neutral state, the steering handle can be automatically returned to the neutral position, and the steering operation load can be arbitrarily changed by adjusting or replacing the neutral return spring. . Further, a stopper for regulating a rotation range of the rotating body is attached to the bracket so as to be adjustable in position. In other words, the handle rotation angle can be arbitrarily changed based on the stopper position adjustment. As a result, the handle rotation angle cannot be adjusted according to the operator's preference, and the control mechanism cannot be used for other models. It will be easier. Further, in providing a link fulcrum of a link mechanism linked to the engagement body, or a link fulcrum of a link mechanism linked to the slide body below the step of forming the operation unit floor surface, It is characterized in that the link fulcrum is provided in any of the steps. That is,
The step can also be used as a link fulcrum mounting member,
In addition, by removing the other divided step, a space where a hand can be reached is secured, so that the assemblability of the link mechanism with respect to the step can be improved.

[0005]

Next, one embodiment of the present invention will be described with reference to the drawings. In the drawings, 1 is a combine, the combine 1 is a pre-processing unit 2 for cutting stem culms, a threshing unit 3 for threshing cut stems and selecting threshed grains, A grain tank 4 for storing grains, a post-processing section 5 for post-processing threshed culms, an operating section 7 provided with a driver's seat 6 and various operating tools, and a pair of left and right provided at the lower part of the machine body Crawler traveling device 8L,
8R.

A traveling transmission 9 is provided on a traveling body of the combine 1. The traveling transmission 9 converts the power supplied from the engine 10 into a mechanical auxiliary transmission mechanism 11 and a main transmission power combining mechanism 12.
And the power of the power distribution shaft 13 is transmitted to the pair of left and right differential power combining mechanisms 14.
Left and right crawler traveling devices 8L, 8R via L, 14R
It is configured to be transmitted to.

Each of the power combining mechanisms 12, 14L, and 14R is constituted by using a planetary gear mechanism. Among them, the main gear power combining mechanism 12 receives the power input from the auxiliary transmission mechanism 11 and the input power from the ring gear 12a. The combined power is output to the output shaft 12b, and the differential power combining mechanism 14
L and 14R combine the power input from the power distribution shaft 13 and the power input from the ring gear 14a to output the output shaft 1
4b.

Reference numeral 15 denotes a traveling continuously variable transmission mechanism constituted by a hydraulic continuously variable transmission mechanism. The traveling continuously variable transmission mechanism 15 includes a variable displacement hydraulic pump 16 driven to discharge by engine power, It is configured by combining a hydraulic motor 17 (in this embodiment, a pair of variable displacement motors is used) driven by the discharge oil of the hydraulic pump 16. Hydraulic pump 16
Performs forward / reverse rotation control and rotation speed control of the hydraulic motor 17 based on swash plate angle adjustment and the like, and the hydraulic motor 17 outputs the motor output to the ring gear 1
2a is input via the gear transmission mechanism 18. This makes it possible to change the running power steplessly.
The swash plate of the hydraulic pump 16 is connected to a travel control shaft 19, and forward and reverse rotation control and rotation speed control of the hydraulic motor 17 are performed based on a rotation operation of the travel control shaft 19.

Reference numeral 20 denotes a steering stepless speed change mechanism constituted by a hydraulic stepless speed change mechanism. The steering stepless speed change mechanism 20 is a variable displacement type hydraulic pump 21 driven to discharge by engine power. And a hydraulic motor 22 driven by the discharge oil of the hydraulic pump 21. The hydraulic pump 21 performs forward / reverse rotation control and rotation speed control of the hydraulic motor 22 based on swash plate angle adjustment and the like.
The motor output is input to the ring gears 14a of the differential power combining mechanisms 14L and 14R via the gear transmission mechanism 23. The gear transmission mechanism 23 includes one of the differential power combining mechanisms 1.
The motor output is directly input to 4L, and the motor output is input to the other differential power combining mechanism 14R via the reverse gear shaft 23b. Thereby, it becomes possible to make the left and right crawler traveling devices 8L, 8R differential in a stepless manner. A swash plate of the hydraulic pump 21 is connected to a steering control shaft 24, and forward / reverse rotation control and rotation speed control of the hydraulic motor 22 are performed based on a rotation operation of the steering control shaft 24. .

That is, when the steering control shaft 24 is set to the neutral position and the traveling control shaft 19 is rotated forward, the left and right crawler traveling devices 8L and 8R travel at the same speed in the forward direction to advance the body. On the other hand, when the traveling control shaft 19 is rotated backward, the crawler traveling devices 8L on the left and right sides are moved.
8R travels in the reverse direction at the same speed to make the aircraft move backward (straight), and the traveling speed at that time changes steplessly in accordance with the operation amount of the traveling control shaft 19. When the steering control shaft 24 is rotated leftward or rightward while the body is moving forward or backward based on the rotation operation of the traveling control shaft 19, one of the crawler traveling devices is operated. 8
L and 8R are accelerated, while the other crawler traveling device 8
L and 8R are decelerated and the aircraft turns. The turning angle (turning radius) at that time changes steplessly according to the operation amount of the steering control shaft 24.

Reference numeral 25 denotes a traveling speed change lever provided on one side of the driver's seat 6. In the operation region of the traveling speed change lever 25, a forward speed change operation region and a reverse speed change operation region are continuously provided via a neutral region. Is secured. On the other hand, driver's seat 6
Is provided with a round steering handle 26. The steering handle 26 is attached to an upper end of a handle shaft 28 rotatably supported in the panel frame 27, and the operation rotation is transmitted to a reduction mechanism 29 described later via the handle shaft 28.

A speed reduction mechanism 29 and a control mechanism 30 are provided below the panel frame 27. Reduction mechanism 2
9 is a control mechanism 30 that reduces the rotation of the steering handle 26
It is configured to be transmitted to. The control mechanism 30 controls the rotation angle of the traveling control shaft 19 according to the lever operation of the traveling transmission lever 25 and controls the rotation angle of the steering control shaft 24 according to the rotation operation of the steering handle 26. It is configured as follows. The panel frame 27 that supports the steering handle 26, the bracket 31 that supports the control mechanism 30, and the reduction case 32 in which the reduction mechanism 29 is incorporated are configured separately. After assembling to the deceleration case 32, the deceleration case 32
Is attached to the body frame 34 via the attachment member 33,
After that, the panel frame 27 is attached to the reduction case 32. This makes it possible to configure each of the mechanisms 29 and 30 individually, so that it is not permissible to improve the assemblability, and it is possible to reduce the weight of the entire mechanism. Further, the bracket 31 of the present embodiment is formed integrally by, for example, casting. For this reason, it is not possible to reduce the dimensional error as much as possible and to ensure the assembling to the speed reduction case 32.
1 can be increased in strength.

The speed reduction mechanism 29 includes an input gear 35 integrally connected to a lower end of the handle shaft 28,
A first counter gear 36a meshing with the second counter gear 36a, a counter gear shaft 37 supporting the first counter gear 36a and the second counter gear 36b so as to be rotatable integrally, and an output gear 38 meshing with the second counter gear 36b. Output gear 38
And a rotatable output gear shaft 39 that is integrally connected to the motor. The input position and the output position of the speed reduction mechanism 29 are set in consideration of the layout of the panel frame 27 and the control mechanism 30, and by interposing the speed reduction mechanism 29 between the panel frame 27 and the control mechanism 30, The layout of the panel frame 27 and the control mechanism 30 is optimized. In the present embodiment, the input position and the output position of the speed reduction mechanism 29 are set on a straight line extending in the front-rear direction in plan view. As a result, the shapes of the panel frame 27 and the bracket 31 can be made symmetrical. Will be possible. The speed reduction mechanism 29 of the present embodiment has a fixed reduction ratio. However, the speed reduction ratio may be freely switched by incorporating a speed change mechanism. In this case, the steering is performed based on the speed change operation of the speed reduction mechanism 29. The handle rotation angle of the handle 26 can be arbitrarily changed. Further, the reduction mechanism 29 is not limited to the gear transmission, and may employ a transmission method such as a chain transmission.

The control mechanism 30 includes a rotating body 40 integrally connected to an output gear shaft 39 of the reduction mechanism 29, and a sliding body 4 provided on the bracket 31 so as to be slidable back and forth.
1 and an engagement body 42 that engages with the rotating body 40 and the slide body 41. The rotating body 40 is a hollow box-shaped member that rotates in accordance with the rotating operation of the steering handle 26, and the bottom surface thereof overlaps the slide body 41 at a predetermined interval. The slide body 41 has a connecting projection 4 at the rear.
1a, wherein the connecting projection 41a is
By being linked to the travel speed change lever 25 via the speed change connection link mechanism 43, it slides back and forth according to the operation of the travel speed change lever 25. The engagement body 42 is a shaft member that faces in the up-down direction, and is formed in the rotating body 40 so as to face in the front-rear direction, and has a long hole-shaped steering engagement hole 40a, and is formed in the slide body 41 in the left-right direction. Through the long hole-shaped traveling engagement hole 41b. Further, the upper end of the engaging body 41 is connected to the steering control shaft 24 via a steering connecting link mechanism 44, while the lower end of the engaging body 41 is connected via a running connecting link mechanism 45. It is connected to the travel control shaft 19. Thereby, the engaging body 42 moves in a complex manner in accordance with the rotation of the rotating body 40 and the sliding of the sliding body 41, and the traveling control shaft 1 in accordance with the movement of the engaging body 42.
9 and the steering control shaft 24 are rotated.

The steering engagement hole 40a is formed as an arc-shaped long hole centered on the link connection point A of the steering connection link mechanism 44. Therefore, when the rotating body 40 is in the neutral state, even if the sliding body 41 slides back and forth,
The link connection point A of the steering connection link mechanism 44 is not displaced, and the steering control shaft 24 is held at the neutral position. On the other hand, the traveling engagement hole 41b is also basically formed as an arc-shaped long hole centered on the link connection point B of the traveling connection link mechanism 45. Of the side edges, the rear edge to which the engaging body 42 engages during the forward operation (during forward sliding) is set in an arc shape so that the left and right ends approach the link connection point B, while the reverse operation is performed. The front edge with which the engaging body 42 engages at the time (at the time of backward sliding) is formed in an arc shape so that the left and right ends are further away from the link connection point B. Accordingly, when the engaging body 42 is displaced left and right in response to the rotation operation of the steering handle 26, the traveling control shaft 19 is returned to the neutral side, and the traveling speed is automatically reduced.

Next, the operation of the control mechanism 30 will be described. When the traveling speed change lever 25 and the steering handle 26 are in the neutral state, the engaging body 42 is located at the center point of the steering engaging hole 40a and the traveling engaging hole 41b.
9 and the steering control shaft 24 maintain the neutral state, and the aircraft stops. In this state, even if the steering handle 26 is rotated, the engagement body 42 is not displaced, so that the aircraft maintains the stopped state.

In the above state, the traveling speed change lever 25
Is operated forward, the engaging body 42 is displaced forward in accordance with the sliding of the slide body 41, and the travel control shaft 19 is accordingly rotated forward. As a result, the aircraft advances at a speed corresponding to the operation position of the traveling shift lever 25. At this time, since the engagement body 42 is displaced along the arc of the steering engagement hole 40a, the steering control shaft 24 does not rotate, and the body advances straight.

In the above state, when the steering handle 26 is rotated left or right, the engaging body 42 is displaced in the left-right direction in accordance with the rotation of the rotating body 40, and the steering control shaft 24 rotates accordingly. I do. Accordingly, the aircraft turns at a turning angle corresponding to the operation amount of the steering handle 26. In addition, the rear edge of the traveling engagement hole 41b that guides the displacement of the engagement body 42 returns the traveling control shaft 19 slightly to the neutral side by bringing the engagement body 42 closer to the link connection point B, thereby turning the traveling speed. Automatically decelerate.

In the above state, the traveling speed change lever 25
Is returned to the neutral position, the engagement body 42 returns to the traveling neutral position in accordance with the sliding of the slide body 41, so that the traveling control shaft 1
9 returns to the neutral position and the aircraft stops. At this time, since the engagement body 42 returns to the steering neutral position by receiving the inclination guide action of the steering engagement hole 40a, the steering control shaft 24 also returns to the neutral position, and the aircraft turns on the spot. Is avoided.

Next, the components of the control mechanism 30, the transmission link mechanism 43, the steering link mechanism 44, and the traveling link mechanism 45 will be described in detail. The engagement body 42 provided in the control mechanism 30 includes an engagement shaft 46 pointing in the up-down direction.
A pair of upper and lower ball joints 47 penetratingly connected to both ends of the engagement shaft 46, a retaining nut 48 screwed to a lower end of the engagement shaft 46, The ball bush 49 is provided at an intermediate portion, and a pair of upper and lower collars 50 is provided between the ball bush 49 and the ball joint 47. The ball bush 49 reduces sliding resistance between the rotating body 40 and the slide body 41, and promotes a smooth operation of the engaging body 42. Further, the ball bush 49 is formed to be longer than the thickness of the slide body 41 and is a member that suppresses the fall of the engagement body 42 by engaging with the traveling engagement hole 41b with a slight gap. Also works. The collar 50 is for holding the ball joint 47 at a predetermined position, and it is necessary to form a step on the ball joint holding surface of the collar 50 to avoid interference with the ball joint 47. Usually, when a step is formed, two collars having different diameters are used in combination in a superposed manner. In the present embodiment, the collar 50 having the step 50a is integrally formed and the upper and lower sliding surfaces are smoothed. Finished. As a result, the play is not allowed to be reduced as compared with the case where two collars are combined, and the smoothness of the engagement body 42 is enabled by improving the sliding surface degree.

A rotating body 40 is provided on the right side of the bracket 31.
A stopper 51 is provided for restricting the rotation range of the contact. The stopper 51 includes a left rotation stopper 51L that restricts the left rotation range of the rotating body 40 and a right rotation stopper 51R that restricts the right rotation range of the rotating body 40. Each of the stoppers 51L and 51R is attached to the bracket 31 via a bolt 52 penetrating the elongated hole 51a.
Position adjustment along a becomes possible. And the stopper 5
When the position of 1L and 51R is adjusted, the rotation angle of the steering handle 26 is changed in accordance with the change of the rotation range of the rotating body 40, so that the handle rotation angle can be set according to the operator's preference and the model. become.

A neutral return spring 53 is interposed between the front end of the rotating body 40 and the body-side fixed portion. The neutral return spring 53 returns the steering handle 26 to neutral by urging the rotating body 40 toward the neutral side. Thus, even when the traveling speed change lever 25 is in the neutral state, the steering handle 26 can be automatically returned to the neutral position, and the steering operation load can be arbitrarily changed by adjusting or replacing the neutral return spring 53. In addition, since the mounting position of the neutral return spring 53 is at the front of the body, adjustment and replacement can be easily performed. Further, the front end side of the neutral return spring 53 is fixed to the fuselage side fixing portion via an L-shaped plate 54. The L-shaped plate 54 has a neutral return spring 53
Is a member provided with a pin 54a for hooking the front end side of the body, but is attached to the machine body via a bolt 55 penetrating the long hole 54b. By loosening the bolt 55, the mounting position in the left-right direction can be adjusted. When the position of the L-shaped plate 54 is adjusted right and left, the neutral position of the rotating body 40 is changed, and accordingly, the steering handle 2
6 becomes possible to adjust the neutral position. In the present embodiment, the rear end side of the neutral return spring 53 is
Although it is hooked on the hole of the plate portion projecting forward from the rotating body 40, it may be hooked on a pin protruding from the rotating body 40. In this case, the movement of the neutral return spring 53 with respect to the rotating body 40 Becomes smooth, and it becomes possible to improve the position accuracy and the like in the neutral return.

The speed change connecting link mechanism 43 is rotatable back and forth with a link support shaft 56 as a fulcrum, and has a speed change connecting link 57 whose leading end is connected to the connecting projection 41a of the slide body 41; The transmission coupling shaft 58 is configured to rotate in response to the operation of the lever 25, and the transmission coupling rod 59 is configured to convert the rotation of the transmission coupling shaft 58 into the forward and backward rotation of the transmission coupling link 57. You. Further, the steering connection link mechanism 44 is rotatable left and right with the link support shaft 60 as a fulcrum, and one end is connected to the engagement body 42 via the first connection rod 61 for steering. Connecting link 62 and steering control arm 24a that rotates integrally with steering control shaft 24
And a second steering connection rod 63 that connects the other end of the steering connection link 62. The traveling connecting link mechanism 45 is rotatable back and forth about the link support shaft 64, and has one end connected to the traveling first connecting rod 65.
Connecting link 66 connected to the engaging body 42 through the
And a traveling second connecting rod 67 that connects the traveling control arm 19 a that rotates integrally with the traveling control shaft 19 to the other end of the traveling connecting link 66.

A step 68 is provided on the floor of the operation unit 7. Step 68 is divided into left and right,
It is individually attached to the floor of the operation unit 7. Of the left and right divided steps 68a and 68b, the left step 68a
The link support shafts 56 and 64 are integrally protruded from the lower surface of. That is, the link support shaft 64 of the traveling connection link mechanism 45 connected to the engagement body 42 and the slide body 41
Link support shaft 5 of the transmission link mechanism 43 linked to the
6 is provided below the step 68 for forming the floor of the operation section, the step 68 is divided into left and right, and the link supports 56 and 64 are provided on the left step 68a. In addition, by removing the divided right side step 68b, a space where a hand can be accessed is secured.
This makes it possible to improve the assemblability of the link mechanisms 43 and 45 with respect to a. By the way, the link support shafts 56 and 64
Are the same length, and the link support 5
The bosses 57a, 66a of the links 57, 66, which are pivotally supported by the links 6, 64, are also formed to the same length. As a result, it is not allowed to improve the assemblability and reduce the cost by sharing parts, but it is possible to suppress the collapse of the link by making the boss portions 57a and 66a as long as possible.

In the structure constructed as described above, the combine 1 is steered in response to a rotation operation of a steering wheel 26 and a continuously variable steering mechanism 20 for differentially moving the left and right crawler traveling devices 8L and 8R. A control mechanism 30 for controlling the continuously variable transmission mechanism 20 for use, and a reduction mechanism 29 for reducing the rotation of the steering handle 26 and transmitting the rotation to the control mechanism 30.
Panel frame 27 supporting the steering handle 26
And a bracket 31 that supports the control mechanism 30 and a speed reduction case 32 in which the speed reduction mechanism 29 is incorporated are configured separately, and the speed reduction case 32 in which the bracket 31 is assembled in advance is attached to the body frame 34. The panel frame 27 is mounted above the panel frame. That is, since each of the mechanisms 29 and 30 can be individually configured, the assemblability cannot be improved, the weight of the entire mechanism can be reduced, and the mechanism is partially shared between different models. can do.

The control mechanism 30 includes a rotating body 40 that rotates in accordance with the operation of the steering handle 26 and a slide body 41 that slides in accordance with the operation of the traveling speed change lever 25.
And an engagement body 42 that engages with the rotating body 40 and the slide body 41, and the steering continuously variable transmission mechanism 20 that causes the left and right crawler traveling devices 8 </ b> L and 8 </ b> R to be different from each other. The left and right crawler traveling devices 8L and 8R are configured to be linked to a traveling continuously variable transmission mechanism 15 that synchronously drives the speed change. That is, the control mechanism 30 displaces the engaging body 42 linked to the continuously variable transmission mechanism 15 for steering and the continuously variable transmission mechanism 20 for steering in accordance with the operation of the traveling speed change lever and the operation of the steering handle. Automatic deceleration function at the time of turning based on the setting of the shape of the engaging portion of the rotating body 40 and the slide body 41, forward / reverse switching It is possible to easily add a function such as a direction reversal prevention function at the time.

Further, since the neutral return spring 53 for returning the steering handle 26 to the neutral position is attached to the rotating body 40, the steering handle 26 is automatically moved even when the traveling speed change lever 25 is in the neutral state. The steering operation load can be arbitrarily changed by adjusting or replacing the spring force of the neutral return spring 53.

Further, since the stopper 51 for regulating the rotation range of the rotating body 40 is attached to the bracket 31 so as to be adjustable in position, the handle rotation angle can be arbitrarily changed based on the position adjustment of the stopper 51. As a result, the steering wheel rotation angle cannot be adjusted according to the operator's preference, and the control mechanism 30 can be easily used for other models.

The link support shaft 64 of the traveling connection link mechanism 45 connected to the engaging body 42 or the link support shaft 56 of the speed change connection link mechanism 43 connected to the slide body 41 is connected to the operating section. Step 68 of forming a floor surface
When providing the link support shaft 56, the step 68 is divided into right and left parts.
64, the step 68a can also be used as a link fulcrum mounting member. Further, by removing the other divided step 68b, a space for a hand can be secured.
The assemblability of 3, 46 can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a combine.

FIG. 2 is a transmission circuit diagram of a traveling transmission.

FIG. 3 is a right side view of a main part of an operation unit.

FIG. 4 is a front view of a main part of the same.

FIG. 5 is a plan view of a main part of the same.

FIG. 6 is a side sectional view of a speed reduction mechanism and a control mechanism.

FIG. 7 is a front sectional view of the same.

FIG. 8 is a plan view of a control mechanism.

FIG. 9 is a plan view of a speed reduction case.

[Explanation of symbols]

 Reference Signs List 1 combine 8L crawler traveling device 8R crawler traveling device 9 traveling transmission 15 traveling continuously variable transmission mechanism 19 traveling control shaft 20 steering continuously variable transmission mechanism 24 steering control shaft 25 traveling transmission lever 26 steering handle 27 panel frame 28 Handle shaft 29 Reduction mechanism 30 Control mechanism 31 Bracket 32 Reduction case 40 Rotating body 40a Steering engagement hole 41 Slide body 41b Traveling engagement hole 42 Engagement body 43 Speed change link mechanism 44 Steering link mechanism 45 Run Link mechanism 51 Stopper 53 Neutral return spring 56 Link support shaft 64 Link support shaft 68 Step

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinjiro Nowaki 667 Iya-cho, Oji-machi, Higashi-Izumo-cho, Yatsuka-gun, Shimane 1 F-term in Mitsubishi Agricultural Machinery Co., Ltd. 3D052 AA19 DD04 EE01 FF02 GG03 HH01 JJ10

Claims (5)

[Claims] A steering hydraulic mechanism for differentially moving the left and right crawlers; a control mechanism for controlling the steering hydraulic mechanism in accordance with a rotation operation of the steering handle; and a rotation mechanism for reducing the rotation of the steering handle. In a crawler traveling vehicle including a speed reduction mechanism that transmits to the control mechanism, a panel frame that supports the steering handle, a bracket that supports the control mechanism,
A crawler running, wherein a speed reduction case in which the speed reduction mechanism is incorporated is formed separately, and the speed reduction case in which the bracket is previously mounted is mounted on a body frame, and the panel frame is mounted thereon. car. 2. The control device according to claim 1, wherein the control mechanism includes a rotating body that rotates in response to an operation of a steering handle, a sliding body that slides in accordance with an operation of a shift lever, and the rotating body and the sliding body. And a driving hydraulic mechanism that drives the left and right crawlers synchronously to change the speed of the left and right crawlers. A crawler traveling vehicle characterized by that: 3. The crawler traveling vehicle according to claim 1, wherein a neutral return spring that returns the steering handle to a neutral position is attached to the rotating body. 4. The crawler traveling vehicle according to claim 1, wherein a stopper that regulates a rotation range of the rotating body is attached to the bracket so as to be adjustable in position. 5. The method according to claim 1, wherein a link fulcrum of a link mechanism linked to the engaging body or a link fulcrum of a link mechanism linked to the slide body forms an operation unit floor surface. A crawler traveling vehicle characterized in that the step is divided into a plurality of steps, and the link fulcrum is provided in any of the steps.