JP2015208237A - Self-propelled pest control machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-propelled pest control machine which includes a simple steering constitution enabling four-wheel steering and suppresses a weight of the whole vehicle and a manufacturing cost.SOLUTION: The self-propelled pest control machine comprises a right/left pair of front/rear wheels 3 and 4, a four-wheel steering constitution and a chemical tank 9. The four-wheel steering constitution includes: a steering cylinder 70 including piston rods 71 actuated right/left in front of a front wheel axle case 51; arms 64 and 65 steering the front wheels 3 in linkage with the actuation of the piston rod 71; a tie rod 82 connecting front/rear the front wheel side arms 64 and 65 and a rear wheel side arm 81 steering the rear wheel 4; and the like. A ball joint 84 connecting the tie rod 82 and the rear wheel side arm 81 is disposed between a bottom part of the tank 9 and a rear wheel axle case 88. The tie rod 82 is arranged over on a lower side of the bottom part of the tank 9. The steering cylinder 70 provided on the front wheel 3 side enables four-wheel steering and a simple steering constitution. Thereby, interference of a steering mechanism with the bottom part of the tank 9 is not caused.

Description

  The present invention relates to a self-propelled control machine that sprays drugs, fertilizers, and the like on a field.

2. Description of the Related Art Conventionally, a work vehicle having a configuration in which both front wheels and rear wheels can be steered is known as a work vehicle (self-propelled control machine) provided with a drug spraying device that sprays drugs, fertilizers, and the like onto a farm field. .
According to the work vehicle described in Patent Document 1, a backup function is provided in which the work implement rises when operated backward by a forward / reverse switching lever. Regardless of the use or non-use of this backup function, the shift position A control device is provided that is in the rear-wheel steering mode when the vehicle is in the back, and in the four-wheel steering mode or the front-wheel steering mode depending on the position of the work machine when the shift position is other than the back. Regardless of whether the backup function is used or not, the automatic switching operation of the steering mode is constant, improving maneuverability and workability.

  Steering of the front and rear wheels in these steering modes is performed by hydraulically operating a front wheel steering cylinder provided on the front wheel side drag arm and a rear wheel steering cylinder provided on the rear wheel side drag arm.

JP 2004-187502 A

  However, in the work vehicle shown in Patent Document 1, since the steering cylinders are provided on the front wheel side and the rear wheel side, respectively, the structure of the steering mechanism for the front wheels and the rear wheels becomes complicated, and the weight of the entire vehicle also increases. Also, the manufacturing cost is increased.

  An object of the present invention is to provide a self-propelled pest control machine that is capable of four-wheel steering, has a simple steering configuration, and suppresses the weight and manufacturing cost of the entire vehicle.

The above-described problems of the present invention are solved by the following solution means.
The invention according to claim 1 includes a traveling vehicle body (2) having a pair of left and right front wheels (3L, 3R) and a pair of left and right rear wheels (4L, 4R) and having a four-wheel steering configuration by a steering member (7). In the self-propelled pest control machine provided with a chemical tank (9) for storing a chemical solution to be sprayed on the field, a front wheel axle housing an axle (50) for transmitting driving force to the front wheels (3L, 3R) A case (51) and a rear wheel axle case (88) that houses an axle (92) for transmitting driving force to the rear wheels (4L, 4R) are provided, and the four-wheel steering configuration includes the front wheel axle. A steering cylinder (70) provided in front of the case (51) and having a piston rod (71) that operates in the left-right direction toward the forward direction of the traveling vehicle body (2) in response to an operation of the steering member (7); Piston rod (71) of the steering cylinder (70) A pair of left and right front wheel steering arms (64L, 64R, 65L, 65R) that are pivotally connected to the left and right ends and pivotally steer the left and right front wheels (3L, 3R) by operating the piston rod (71); A pair of left and right rear wheel steering arms (81L, 81R) for rotating and steering the rear wheels (4L, 4R) and one end connected to a pair of left and right front wheel steering arms (64L, 64R, 65L, 65R) and the other end Are coupled to the pair of left and right rear wheel steering arms (81L, 81R), and the pair of left and right rear wheel steering arms (81L, 81R) are interlocked with the rotation of the front wheel steering arms (64L, 64R, 65L, 65R). A pair of left and right tie rods (82L, 82R) to be operated, and connecting portions (84L, 84R) between the pair of left and right tie rods (82L, 82R) and the pair of left and right rear wheel steering arms (81L, 81R); A self-propelled type provided between the bottom of the liquid tank (9) and the rear axle case (88), and the tie rods (82L, 82R) are provided below the bottom of the chemical liquid tank (9). It is a control machine.

  The vehicle body frame (2a) of the traveling vehicle body (2) includes a pair of left and right traveling frames (2aL, 2aR), and the pair of left and right traveling frames (2aL, 2aR) and a rear axle case. The self-propelled type according to claim 1, wherein a pair of left and right lift brackets (106L, 106R) fixed to (88) are provided, and the chemical liquid tank (9) is supported from below by the lift brackets (106L, 106R). It is a control machine.

  According to a third aspect of the present invention, the chemical liquid tank (9) and the four-wheel steering components (81L, 81R, etc.) are located on the inner side of the left and right sides of the plan view position of the upper ends of the left and right rear wheels (4L, 4R). It is the self-propelled type | formula control machine of Claim 1 or Claim 2 provided.

  According to the first aspect of the invention, since the four-wheel steering can be performed by the steering cylinder (70) provided on the front wheel (3L, 3R) side, the steering cylinder is provided on both the front wheel side and the rear wheel side. Compared to the case, the steering structure is simple, and the weight and manufacturing cost of the entire vehicle can be suppressed.

  In addition, the connecting portions (84L, 84R) between the steering arms (81L, 81R) on the rear wheel (4L, 4R) side and the tie rods (82L, 82R) serve as the bottom of the chemical tank (9) and the rear axle case (88). Further, since the tie rods (82L, 82R) are arranged so as to pass below the bottom of the chemical liquid tank (9), the steering mechanism does not interfere with the bottom of the chemical liquid tank (9).

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, a pair of left and right lift brackets fixed to the pair of left and right traveling frames (2aL, 2aR) and the rear wheel axle case (88) ( 106L, 106R) can secure a space between the left and right traveling frames (2aL, 2aR) and the chemical tank (9). And the space which arrange | positions a tie rod (82L, 82R) can be formed by lifting a chemical | medical solution tank (9) by a lift bracket (106L, 106R) in this way.

  Further, since the lift brackets (106L, 106R) are fixed to the left and right traveling frames (2aL, 2aR) and the rear wheel axle case (88), they integrally support the chemical tank (9). It becomes a stable support structure.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the liquid chemical tank (9) is located on the inner side in the left and right directions of the upper end of the left and right rear wheels (4, 4) in plan view. By arranging four-wheel steering components such as the rear wheel steering arms (81L, 81R) and the like, the structure of the steering mechanism on the rear wheel (4) side that accompanies mud splashing in work in a wet place such as paddy fields Since the occurrence of dirt and wear of the object can be prevented, the shortening of the life of the structure can be suppressed.

It is a whole side view of the self-propelled control machine of this embodiment. It is a front view of the self-propelled pest control machine of FIG. It is a top view of the self-propelled pest control machine of FIG. It is a front view of the self-propelled control machine which shows a spraying work state. It is a sectional side view of the transmission mechanism part of the self-propelled pest control machine of FIG. It is a top view of the transmission mechanism part periphery of the self-propelled pest control machine of FIG. It is a front view of the transmission mechanism part periphery of the self-propelled control machine of FIG. It is the top view which carried out the partial cross section of the front axle and steering cylinder mechanism of the self-propelled pest control machine of FIG. It is AA sectional drawing of FIG. It is the top view of the partial cross section which decomposed | disassembled the front axle right and left. FIG. 11A is a front view showing a non-swinging state of the front axle housing, and FIG. 11B is a front view showing a swinging state. FIG. 12A is a back cross-sectional view of the left front wheel transmission unit, and FIG. 12B is a rear view of the final case. 13A is a plan sectional view of the steering shaft case, and FIG. 13B is a partially enlarged side view of the connecting member. It is a front view of a front axle and a steering cylinder mechanism. It is a schematic back view which shows the fixed state of the left front wheel side tie rod and a ball joint. FIG. 16A is a schematic plan view showing the movement of the pair of left and right knuckle arms, and FIG. 16B is a diagram showing the structure of the steering cylinder mechanism. It is a top view which shows the steering and interlocking | linkage state of a front-and-back wheel. It is a side view which shows the steering and interlocking state of a front-and-rear wheel. It is a back sectional view of a left rear-wheel transmission part. It is the top view which showed the positional relationship of the chemical | medical solution tank and steering mechanism of the self-propelled control machine of this embodiment. It is the top view which showed the positional relationship of the chemical | medical solution tank and steering mechanism of the self-propelled control machine of another embodiment. It is the rear view which showed the positional relationship of the chemical | medical solution tank and steering mechanism of the self-propelled control machine of FIG. It is a top view at the time of omitting the chemical | medical solution tank of the self-propelled control machine of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a side view of a self-propelled control machine in which a control spraying device for spraying chemicals and fertilizers on a field is attached to the front, and FIGS. 2 to 3 respectively show the self-propelled control of FIG. A front view and a plan view of the machine are shown. FIG. 4 shows a front view of a state in which a chemical solution is sprayed. In this specification, the left and right directions in the forward direction of the self-propelled control machine are referred to as left and right, respectively. When there is a pair of left and right components, the symbol L represents the left side and the symbol R represents the right side. Further, in the present specification, the “medicine” refers to a liquid material that may contain a solid material that needs to be applied to a crop such as a nutrient or an agricultural chemical.

  As shown in FIGS. 1 and 2, the traveling vehicle body 2 of the self-propelled pest control machine 1 is provided with a pair of left and right front wheels 3L and 3R and a pair of left and right rear wheels 4L and 4R on a vehicle body frame 2a. A control spraying device 11 is attached to the front side portion of 2.

  As shown in FIG. 2, in the self-propelled pest control machine 1 of the present embodiment, the minimum ground height H from the farm scene to the vehicle body frame 2a is relatively high, and the inter-wheel distance (tread) W is relatively wide. It is configured. In a conventional tractor or the like, the position of the axis of the wheel is close to the body frame, but the axis of the wheel of the self-propelled control machine of the present embodiment is below the body frame.

  An engine E covered with a bonnet 5 is mounted above the pair of left and right front wheels 3L, 3R of the traveling vehicle body 2. A pilot seat 6 is provided above the pair of left and right front wheels 3L, 3R and the pair of left and right rear wheels 4L, 4R, and a handle (steering member) 7 is provided in front of the pilot seat 6.

  When the steering wheel 7 is steered left and right, as will be described later, the pair of left and right front wheels 3L and 3R and the pair of left and right rear wheels 4L and 4R are simultaneously interlocked and steered in the opposite phase, so that a four-wheel steering configuration is possible. . Further, a chemical tank 9 is detachably provided so as to surround the cockpit 6, and a control pump 10 (FIG. 6) for feeding liquid from the chemical tank 9 to the control spraying device 11 is provided below the cockpit 6. It has been.

  Further, as shown in FIG. 3, the control spraying device 11 includes a center spraying boom 11C located in front of the machine body and left and right side spraying booms 11L, 11R provided on both the left and right sides of the center spraying boom 11C.

  Then, the control spraying device 11 is moved up and down by a lifting cylinder 15 (see FIG. 1), and the left and right side spraying booms 11L and 11R protrude left and right independently by operating the open / close levers 17L and 17R (see FIG. 3). The spraying operation state (see FIG. 4) and the state along the both sides of the traveling vehicle body 2 are accommodated (see FIGS. 1 to 3).

  And the chemical | medical solution of the chemical | medical solution tank 9 is sent to the control spraying apparatus 11 by the control pump 10, and a chemical | medical solution is sprayed from the spray nozzle 14 provided in multiple numbers by the center spraying boom 11C and the left and right side spraying booms 11L and 11R (FIG. 1 and 4).

  Next, a speed change transmission mechanism that receives the power of the engine E and transmits the speed change power to each part will be described with reference to FIGS. A main clutch 23 is interposed between the output shaft 20 supported coaxially with a crankshaft (not shown) of the engine E and the transmission input shaft 22 on the transmission case 21 side. The main clutch 23 has a known configuration in the form of a multi-plate clutch, and is configured such that the power in the normally connected state is interlocked with each other by stepping on the clutch pedal 23 a disposed in the step portion below the cockpit 6.

  The power passing through the main clutch 23 is linked to the transmission mechanism in the transmission case 21 via the speed change input shaft 22, and this transmission case 21 is configured to join the front and rear case portions 21f and 21r. The structure is such that various transmission shafts and the like are supported on the bearing wall portions around 21.

  The transmission input shaft 22 extends rearward and is supported in the transmission case 21 to form a transmission transmission shaft, and is provided with a plurality of transmission gears. The PTO shaft 24 coaxial with the transmission input shaft 22 is supported on the rear wall portion of the rear second case portion 21r, and a bearing is provided on the boss-shaped portion 24a at the front end to support the rear end of the transmission input shaft 22. It is a configuration.

  A first counter shaft 25 is provided in parallel with the speed change input shaft 22. Then, by selecting a transmission gear group provided between the first counter shaft 25 and the input transmission shaft 22, a three-stage auxiliary transmission 26 serving as a first transmission is configured, and a second transmission is performed. A main transmission 27 that can select a forward-side high / low-second speed and a back-first speed is configured as a device. Then, after the power from the transmission input shaft 22 passes through the gear stage shifted by the first transmission device 26 (hereinafter referred to as the sub-transmission device 26), the second transmission device 27 (hereinafter referred to as the main transmission device 27). The front wheels 3 and the rear wheels 4 are driven through either the forward or lower two speeds or the first back speed.

  That is, the auxiliary transmission 26 that is mainly housed in the second case portion 21r of the transmission case 21 is provided with three auxiliary transmission gears 28a, 28b, and 28c that are fixed to the transmission input shaft 22 and have different gear diameters. The first countershaft 25 side is provided with a sub-transmission sliding gear 29 for selecting the sub-transmission gears 28a to 28c, and a large-diameter gear 29b of the two-stage gears of the sliding gear 29 meshes with the sub-transmission gear 28b. The small-diameter gear 29c meshes with the auxiliary transmission gear 28c, and the minimum-diameter gear 29a integrally formed with the boss portion 29d of the sliding gear 29 is rotatably supported by the first counter shaft 25, and the auxiliary transmission gear 28a. It is the structure which meshes | engages with the internal gear part 30a of the counter gear 30 always meshed with. Since it is configured in this manner, the auxiliary transmission first speed (low speed) is obtained by sliding the auxiliary transmission sliding gear 29 and meshing the minimum diameter gear 29a with the internal gear portion 30a of the counter gear 30. The second speed (medium speed) is obtained by meshing the large-diameter gear 29b of the two-stage gear with the sub-transmission gear 28b, and the sub-gear 29c is meshed with the sub-transmission gear 28c. A third speed (high speed) is obtained.

  The boss portion 29d and the two-stage gear of the auxiliary transmission sliding gear 29 are separately formed, and the pawl clutch portion 29e is assembled in a constantly meshing state so as to be slidably fitted to a spline formed on the first counter shaft 25. I am letting.

  A main transmission device 27 is provided in a portion accommodated in the first case portion 21 f in front of the transmission case 21. The driving force shifted by the auxiliary transmission 26 of the first countershaft 25 is transmitted to the second countershaft 35 by selecting the main shift high / low 2nd speed and reverse speed.

  In other words, the back speed intermediate gear 36 is loosely fitted to the front end portion of the first counter shaft 25, and the low speed intermediate gear 37 is loosely fitted to the front side of the counter gear 30 on the auxiliary transmission 26 side. The main transmission sliding gear 38 that is slidable by being fitted to the spline portion of the second counter shaft 35 includes an internal gear 38b for the back speed and an intermediate internal gear 38c for the low speed centered on the high speed intermediate gear 38a. Formed back and forth. Further, a forward counter gear 39 is pivotally supported on the speed change input shaft 22 so as to be able to rotate independently of the rotation of the speed change input shaft 22. The counter counter gear 39 for normal rotation is formed with a counter gear 39a for low speed and a counter gear 39b for high speed having different diameters.

  The forward counter gear 39c formed integrally with the boss portion of the forward counter gear 39 is always meshed with the forward transmission gear 40 of the second counter shaft 35, and the back speed intermediate gear 36 is also a second gear. This is a configuration that always meshes with the transmission gear 41 for the back speed of the counter shaft 35.

  When the low-speed intermediate internal gear 38c of the main transmission sliding gear 38 is fitted to the low-speed intermediate gear 37, the rotational power changed by the auxiliary transmission 26 of the first countershaft 25 is converted to the low-speed intermediate gear 37, The forward rotation transmission gear 40 is driven via the low speed counter gear 39a and the forward rotation counter gear 39c to transmit low speed forward rotation power to the second counter shaft 35. When the high-speed intermediate gear 38a of the main shift sliding gear 38 is engaged with the high-speed counter gear 39b, the power of the first counter shaft 25 passes through the high-speed intermediate gear 38a, the high-speed counter gear 39b, and the forward counter gear 39c. Then, the normal transmission gear 40 is driven to transmit high-speed normal rotation power to the second counter shaft 35.

  Further, when the back speed internal gear 38b of the main transmission sliding gear 38 is fitted to the back speed intermediate gear 36, the main-shifted rotational power of the first counter shaft 25 becomes the back speed intermediate gear 36, The speed transmission gear 41 is driven to transmit the reverse speed power to the second counter shaft 35.

  The driving force of the main shift and the sub shift of the second counter shaft 35 is transmitted to the travel transmission shaft 44 through the deceleration intermediate transmission gear groups 42 and 43. The traveling transmission shaft 44 projects forward and backward from the transmission case 21, and the rear spline shaft portion 44a drives the rear wheels 4L and 4R via the rear axle by interlocking with the rear wheel differential mechanism via the long transmission shaft 44r (FIG. 17). The front spline shaft 44b drives a front wheel differential mechanism 53 (FIG. 8), which will be described later, via the short transmission shaft 44f (FIG. 17) to drive the front wheels 3 and 3.

  The main transmission lever 46 of the main transmission device 27 and the auxiliary transmission lever 47 of the auxiliary transmission device 26 are provided on the left side of the cockpit 6 and can be shifted along the front-rear direction guide. A PTO lever 49 is provided on the right side of the cockpit 6 to switch a PTO clutch mechanism 48 disposed on the PTO shaft 24 between on and off.

  That is, the PTO clutch mechanism 48 is a clutch supported by an internal gear clutch 24b formed on the inner periphery of the front end of the boss-like portion 24a at the front end of the PTO shaft 24 and a spline portion formed on the rear portion of the transmission input shaft 22. A body 48a is provided, and the clutch body 48a is configured to engage and disengage the clutch body 48a with the internal gear clutch 24b as the shifter 48b moves back and forth.

  The shifter 48 b is configured to interlock with the PTO lever 49. The shifter stay 48c, to which the shifter 48b is fixed, is supported by the transmission case 21 so as to be reciprocally slidable in parallel with the transmission input shaft 22, and an interlocking link 48d (on the rear end side protruding from the transmission case 21 of the shifter stay 48c ( It is linked with the proximal end portion of the PTO lever 49 via FIG.

  The base end side 49a of the PTO lever 49 is rotatably attached to one side of the pair of left and right traveling frames 2aL and 2aR constituting the body frame 2a of the traveling vehicle body 2 (right traveling frame 2aR side in the illustrated example) A bending portion 49b to be bent is provided so as to be swingable back and forth with the mounting base side 49a as an axis, and the meshing clutch mechanism 48 is entered by swinging forward and swinging backward. The engagement clutch mechanism 48 is cut off.

  Also, a brake means 45 is provided on a metal portion 21m that is detachably fastened to the rear wall of the transmission case 21 on the rear side of the travel transmission shaft 44. The brake unit 45 is configured to brake the travel transmission shaft 44 by pressing a multi-plate brake shoe against the wall surface of the metal portion 21m. As a result, the front, rear, left and right four wheels are braked at once.

  As described above, by providing the PTO shaft 24 coaxially with the main clutch 23, the PTO shaft 24 is arranged behind the transmission case 21, and the pulley 31 at the rear end of the shaft protruding rearward from the rear wall of the transmission case 21 is In this configuration, the pump 10 is driven by belt transmission to the pulley 12 of the control pump 10 approaching the side. The control pump 10 has a size extending between the pair of travel frames 2aL and 2aR, and the body portion 10a is fixed by brackets 32 and 32 standing on the left travel frame 2aL.

  By providing the PTO clutch mechanism 48 between the speed change input shaft 22 that receives engine power via the main clutch 23 and the PTO shaft 24, the control pump 10 can be operated even if the main clutch 23 is engaged. The operation of 49 can be interlocked with the on / off of the PTO clutch mechanism 48, and the operator can arbitrarily select and set the drive state and non-drive state of the pump.

  The PTO clutch mechanism 48 is supported by an internal gear clutch 24b formed on the inner periphery of the front end of the boss-like portion 24a at the front end of the PTO shaft 24 provided coaxially with the speed change input shaft 22, and a spline portion formed at the rear portion of the speed change input shaft 22. The clutch body 48a is engaged and disengaged with the forward and backward movement of the shifter 48b. Since the boss-like portion 24a originally supports the rear end of the transmission input shaft 22, the transmission case 21 does not require a special support structure, and the structure can be simplified and the cost can be reduced.

  A sub-transmission device is provided by selecting a transmission input shaft 22 and a first counter shaft 25 parallel to the transmission input shaft 22 and selecting a transmission gear group provided between the first counter shaft 25 and the input transmission shaft 22. 26 and the main transmission device 27, the power of the transmission input shaft 22 passes through the gear stage shifted by the auxiliary transmission device 26, and then passes through the forward high / low speed or reverse speed gear stage by the main transmission device 27. 3 and the rear wheel 4 are driven, the shift output does not affect the rotation of the shift output shaft 22 and the PTO shaft 24.

  As shown in FIGS. 5 and 7, a clutch housing 34 that covers the main clutch 23 is provided. The clutch housing 34 is formed in a U shape when viewed from the front, and bases 34a and 34a are detachably attached to the front wall of the transmission case 21, and a bearing 34b is formed on the wall formed on the front side. The main clutch 23 body appears on the upper and lower surfaces, but the upper surface is covered with a thin plate member (not shown). The bearing portion 34b supports the output shaft 20 that is linked to the crankshaft of the engine E. If comprised in this way, the support structure of the output shaft 20 will become integral with the transmission case 21, and when the main clutch 23 is assembled | attached, the improvement of the precision can be aimed at.

  As shown in FIG. 7 and the like, the transmission case 21 is mounted on the traveling vehicle body 2 by integrally providing base members 2B and 2B to a pair of left and right traveling frames 2aL and 2aR, and the base members 2B and 2B. The transmission case 21 is fastened from the side.

  The pump mounting space varies widely with the change in size of the control pump 10, but if the mounting position of the transmission case 21 can be changed in the front-rear direction with respect to the traveling frames 2aL and 2aR, the mounting space is reduced. It can be secured.

Next, the front wheel transmission mechanism and the steering mechanism will be described with reference to FIGS.
FIG. 8 shows a schematic plan view of a partial cross section of the front axle housing (front wheel axle case) 51, and FIG. 9 shows a schematic view of the AA cross section of FIG.

A front axle housing 51 that houses a front axle 50 (FIG. 12) for transmitting driving force to the pair of left and right front wheels 3, 3 is disposed below the front side of the traveling vehicle body 2.
A cylindrical boss portion 51A (FIG. 9) that supports a front wheel input shaft 52 that is linked to the traveling transmission shaft 44 via a short transmission shaft 44f (FIG. 17) is formed at the center rear portion of the front axle housing 51. The bevel gear 52a of the front wheel input shaft 52 is interlocked with a front wheel differential mechanism 53 disposed at the center of the axle housing 51. A front axle 50 extending left and right from the front wheel differential mechanism 53 is connected to a steering shaft 55 of a front wheel steering shaft case 54 (FIG. 12) connected to left and right ends of the axle housing 51 by bevel gears 56 and 57. Here, the bevel gear 56 is provided at the end of the front axle 50, and the bevel gear 57 is a driven bevel gear of the bevel gear 56 and is supported on the upper portion of the steering shaft 55.

The front axle housing 51 will be described in detail.
FIG. 10 is an exploded plan view of the front axle housing 51 of FIG. 8, and the front axle housing 51 is divided into left and right parts. Of these, the front and rear cylindrical bosses 51A and 51B are integrally formed in the left split half 51L, and the front wheel input shaft 52 directly supported by the cylindrical boss 51A and the front wheel input The large-diameter bevel gear 100 that meshes with the pinion of the shaft 52 is supported by bearings, and the front wheel differential mechanism 53 is accommodated, and substantially the entire front axle 50L on the left side and a part of the front axle 50R on the right side are accommodated. It is made possible. On the other hand, the right divided half 51R is formed so as to be able to accommodate the intermediate portion of the right front axle 50R and the differential lock mechanism 101.

  In the bearing portion 102 of the large-diameter bevel gear 100 of the left split half 51L, the right split half 51R is flange-joined and detachable by a bolt 103, and the traveling direction axis X at the time of joining is the left-right center of the entire front axle housing 51 It is a line. Therefore, the front axle housing 51 can swing around the axis X with a good left / right balance. Furthermore, since the split surface of the axle housing 51 is the bearing portion 102 of the large-diameter bevel gear 100, the strength of the split surface can be ensured.

  The left split half 51L of the front axle housing 51 is integrally formed with a frame fixing joint base 51aL on the upper surface of the intermediate part, and the right split half 51R has a similar joint fixing base 51aR (FIGS. 8 and 10). ).

  These fixing bases 51aL and 51aR also have a function as a rocking stopper by a rocking motion around the front and rear axis X. That is, the fixing pedestal 51aL or 51aR can swing upward until it contacts the traveling frame 2aL or 2aR (FIG. 11B), and these fixing pedestals 51aL and 51aR serve as stoppers. The stopper configuration is not required.

  Also, flanges 51Lb and 51Rb (FIG. 12) for detachably joining a cylindrical upper portion 54a (to be described later) of the front wheel steering shaft case 54 are integrally formed on the end sides of the left and right divided halves 51L and 51R, respectively. ing.

  Further, an operation interlocking portion 105 (FIG. 10) of the differential lock mechanism 101 is provided in the right split half 51R of the front axle housing 51. An operating pin 105c that is eccentrically arranged is provided on the rotating body 105b that is fitted to the boss portion 105a and rotates, and the operating pin 105c moves left and right as the rotating body 105c rotates. Can be switched to the differential lock state or the non-diff lock state. Since the differential lock mechanism 101 is configured on the open side of the left split half 51L, it is easy to assemble. The rotating body 105b can be rotated by an external operation via the operating arm 105d and can be differentially locked. The operating arm 105 is normally biased by a spring in the direction of releasing the differential lock.

  As described above, by forming the front axle housing 51 in the left and right divided halves 51L and 51R, the configuration of the front and rear cylindrical bosses 51A and 51B formed in the left divided half 51L is arranged on the axis X. Therefore, high-precision coaxiality processing is required, but it is easy to ensure the above-mentioned accuracy in machining because it is formed integrally with the divided left half 51L both front and back, and it is divided and easy to handle. .

  Since the input shaft 52, the large-diameter bevel gear 100, the differential mechanism 53, and the left and right axles 50L and 50R are arranged in the divided left half 51L, the input / output is in a state before the right divided half 51R is connected and joined. The rotation operation of the shaft can be confirmed.

  As shown in FIG. 12, the front wheel steering shaft case 54 includes an outer fitting portion to the terminal side of the axle housing 51 and a cylindrical upper portion 54 a that is connected to the axle housing 51 via a flange of the axle housing 51 and protrudes upward. A conical portion 54b formed so as to gradually decrease in diameter toward the lower portion, and a cylindrical lower portion 54c that includes a bearing 58 (FIG. 12) and rotatably supports the final case 59 around the steering shaft 55. Bevel gears 56 and 57 from the end of the front axle 50 to the steering shaft 55 are provided. The final case 59 includes a bevel gear 60 at the lower end of the steering shaft 55 and a driven bevel gear 61 that meshes with the front wheel shaft 66 that supports the right front wheel 3. The final case 59 includes a fitting portion 59a for fitting the lower portion of the front wheel steering shaft case 54 to the outside and a side surface portion 59b for connecting the driven bevel gear 61 to the outside surface of the fitting portion 59a.

  The steering shaft 55 of the front wheel steering shaft case 54 is inclined with respect to the vertical line so that the lower end side faces the left and right outwards of the vehicle body, and the final case 59, the power transmission mechanism such as an internal bevel gear, and the front wheel 3 are It is provided so as to be rotatable around an inclined steering shaft 55.

  A boss portion 54d is formed at the top of the cylindrical upper portion 54a of the front wheel steering shaft case 54, and a rotating member 62 and a final case 59 that are rotatably fitted to the boss portion 54d via a sleeve. Are detachably connected by a connecting member 63 in a suspended manner along the front wheel steering shaft case 54. An annular portion 63a is formed in the middle of the connecting member 63 in the vertical direction, and is externally fitted to the conical portion 54b of the front wheel steering shaft case 54. In other words, the flange-like annular portion 63a is rotatably fitted to the outside of the conical portion 54b via a sleeve. A knuckle arm 64 for rotating and steering the final case 59 in conjunction with a steering cylinder mechanism 70 described later is attached to the upper surface of the annular portion 63a.

  The upper and lower positions of the annular portion 63a of the connecting member 63 are directly below the portion where the thickness is increased due to the shaft support of the driven bevel gear 57 attached to the upper portion of the steering shaft 55, and the front wheel steering shaft case 54 It is fitted to a relatively strong part. For this reason, the steering force from the steering cylinder mechanism 70 transmitted through the knuckle arm 64 is received in a concentrated manner, but the connecting member 63 forms an annular portion 63a and is fitted to the front wheel steering shaft case 54. The steering load transmitted to the knuckle arm 64 is received by being shared by the front wheel steering shaft case 54, thereby preventing deformation and distortion of the connecting member 63.

  Furthermore, the position of the annular portion 63a is arranged in the vicinity of a portion (Z1 <Z2 in FIG. 12) formed thick for the bearing portion that supports the steering shaft 55 and the bevel gear 57 of the front wheel steering shaft case 54. Thus, since the reinforcing structure for receiving the steering load is exhibited, the conical portion 54b that does not directly receive the steering load can be formed as thin as possible. That is, the Z2 portion of Z1 <Z2 is strong in strength, and the support strength is increased by arranging the annular portion 63a in the Z2 portion.

  Further, the front side surface 63af (FIG. 13) of the annular portion 63a has an inclined surface shape that is inclined by a predetermined angle β toward the left front wheel 3L side with respect to the traveling direction F of the traveling vehicle body 2. Further, the knuckle arm 64 fixed to the upper surface of the annular portion 63a is fixed with an inclination of a predetermined angle γ toward the left front wheel 3L side in the same manner as the front side surface 63af of the annular portion 63a with respect to the traveling direction F. (FIG. 13A).

  For self-propelled control machines that need to raise the minimum ground height H from the farm scene to the body frame 2a as much as possible due to the work form straddling the straw and crops, it is possible to prevent damage to the crops. Although it is necessary to have a structure that does not only become an obstacle, the above-described inclined configuration allows the crop to smoothly flow through the lower part of the traveling vehicle body 2, so that the crop is hardly damaged.

  On the other hand, the knuckle arm is conventionally attached with an offset from the final case. However, the knuckle arm is either a rotatable rotating member provided on the upper part of the steering shaft case or a connecting member. When the height H is high, there is a problem in that the structure of each part for rotating the final case is subjected to strong bending stress and is easily damaged.

  On the other hand, according to the above configuration of the present embodiment, the upper side of the front wheel steering shaft case 54 has a height at which the knuckle arm 64 is disposed, and the annular portion 63a is not provided near this height. Further, unnecessary bending stress can be prevented from being applied to the connecting member 63 for rotating the final case 59. Further, the front wheel steering shaft case 54 has a substantially conical shape whose diameter decreases from the cylindrical upper portion 54a downward, so that the annular portion 63a and the lower cylindrical portion 54c can be configured with a small number of parts at low cost. Further, since the connecting member 63 and the annular portion 63a are integrated, this structure can be configured with a small number of parts and at a low cost.

Next, the configuration of the steering cylinder mechanism 70 that steers the left and right front wheels 3 and the rear wheels 4 in conjunction with each other will be described.
A steering cylinder mechanism 70 for steering the pair of left and right front wheels 3L, 3R is disposed in front of the traveling vehicle body 2 and in front of the front axle housing 51.

  The steering cylinder mechanism 70 includes a double-acting double-sided rod cylinder portion 70a (FIG. 9). The piston rod 71 of the steering cylinder mechanism 70 is connected to the knuckle arms 64L and 64R via tie rods 72L and 72R, respectively. It is connected. The knuckle arm 64 and a later-described interlocking arm 65 function as a steering arm for steering the front wheels 3.

  A hydraulic distributor (not shown) is provided at the rotation base of the handle 7 (the amount of oil flowing and the flow direction change according to the amount of rotation of the handle (the left chamber 70L side or the right chamber 70R side in FIG. 16B)). Oil is sent to the cylinder part 70a.

  When pressure oil is supplied to one of the steering cylinder mechanisms 70 (the right chamber 70R), the piston 69 operates, the piston rod 71 extends to the left side, the knuckle arm 64L rotates to the left via the tie rod 72L, and the left front wheel 3L moves to the left. (Solid arrows G and I in FIG. 8). At this time, as the piston rod 71 moves, the right tie rod 72R is pulled to pull the knuckle arm 64R and the right front wheel 3R is also turned to the left (dotted line arrows J and K). The tie rods 72L and 72R are connected to the left and right ends of the piston rod 71 by ball joints 73L and 73R, respectively. The knuckle arms 64L and 64R are rotatably connected to a pair of left and right tie rods 72L and 72R by a pair of left and right ball joints 74L and 74R.

  FIG. 13B shows a configuration for attaching the knuckle arm 64 to the annular portion 63a. A vertical mounting portion 64 a is added to the base of the knuckle arm 64 by means such as integral molding or welding, and is fixed to the base of the knuckle arm 64 with vertical bolts 67 and horizontal bolts 68. With this configuration, the knuckle arm 64 can be firmly attached to the connecting member 63 without loosening of the bolt.

  In FIG. 9, a cylinder portion 70a of the steering cylinder mechanism 70 is a sheet metal member bent in a channel shape, and a cylinder housing 75 in which about half of the outer peripheral surface of the cylindrical body of the cylinder portion 70a is accommodated and fixed in a concave portion thereof. Is provided.

  Further, in the center of the cylinder housing 75, a cylindrical fitting portion 76 extending rearward, that is, toward the front axle housing 51 is integrally provided by a welding structure in the illustrated example. The inside of the cylindrical fitting portion 76 is formed in a cylindrical internal space. On the other hand, in the center of the front axle housing 51, a cylindrical fitting portion 76 provided in the cylinder housing 75 is provided at a symmetrical position on the front side with respect to the cylindrical boss portion 51A on the rear side that supports the front wheel input shaft 52. A front cylindrical boss portion 51B to be fitted is integrally formed. And after the said cylindrical fitting part 76 is inserted in the front side cylindrical boss | hub part 51B, the fixing pin 77 which is a fastening member for prevention of a removal and rotation prevention is penetrated and fixed to the connection part. .

  As described above, the front axle housing 51 has a pair of front and rear support metals that are provided with a cylindrical boss portion 51B on the front side thereof and a cylindrical boss portion 51A on the rear side thereof so as to be rotatable about the axis X. (Pivot metal) 78A and 78B are firmly attached by bolts and nuts, respectively. The end surfaces of the support metals 78A and 78B on the side away from the front axle housing 51 are small diameter portions, and the regulation end surfaces 78a and 78b formed by the small diameter portions are the cylindrical boss portion 51A and the cylindrical boss portion 51B. By facing the rear end surface and the front end surface, the front axle housing 51 can be prevented from shifting in the front-rear direction.

  The shape of the support metals 78A and 78B is such that the outer shape of the cylindrical boss portions 51A and 51B formed on the front and rear sides of the front axle housing 51 is the same, so that the support metals 78A and 78B are common to the front and rear. The number of parts can be reduced.

  Further, in order to control the amount of movement of the piston rod 71 of the steering cylinder mechanism 70, hydraulic oil is applied to the left chamber 70L or the right chamber 70R (FIG. 16B), which is a space arranged on the left and right sides with the piston 69 interposed therebetween. Are connected to the cylinder portion 70a of the steering cylinder mechanism 70 via the left and right sides of the front support metal 78B.

  In the self-propelled pest control machine according to this embodiment, the front wheel 3 and the rear wheel 4 are steered in opposite phases by operating the piston rod 71 of the steering cylinder mechanism 70 in conjunction with the operation of the handle 7. In addition, a four-wheel steering configuration that allows a small turn is provided. When the steering cylinders are provided on the front wheel side and the rear wheel side, the structure is complicated, the weight of the entire vehicle is increased, and the manufacturing cost is increased. However, with this configuration, the four-wheel steering can be performed by one cylinder portion 70a and a simple steering configuration is provided, so that the weight and manufacturing cost of the entire vehicle can be suppressed.

  Note that the hydraulic cylinder mechanism 70 is configured such that the lower end edge of the hydraulic cylinder mechanism 70 does not fall below the height of the front axle housing 51 on the front side of the front axle housing 51 as shown in FIG. That is, when viewed from the front, the front cylindrical boss portion 51B is formed at the vertical center position of the front axle housing 51, and the lower edge of the steering cylinder mechanism 70 configured to be shorter than the vertical length of the front axle housing 51 is always the front axle. It is configured to be higher than the lower edge of the housing 51. Therefore, the steering cylinder mechanism 70 does not hinder the improvement of the ground height. Further, in this arrangement state, even if the front axle housing 51 swings around the axis X, the relationship between the two does not change. Therefore, regardless of the presence or absence of the swing and the size, the front wheel turning angle is constant and the steering performance is improved. Can be improved.

  As shown in FIG. 14, a V-shaped configuration is formed in a front view by an angle θ formed by the central axis B of the steering shaft 55 and the rotation surface V including the ground contact point of the front wheel 3. The extension line of the central axis B of the steering shaft 55 is provided so as to intersect substantially in the vicinity of the grounding portion (indicated by the position C). In this way, the steering resistance from the ground is reduced, and a large and large capacity steering cylinder is not required. In addition, while ensuring the minimum ground height H, the outer peripheral surface of the axle housing 51 and the outer peripheral surface of the front wheel steering shaft case 54 have no relatively large convex portions, and are configured so as not to damage the crop.

The above-described configuration centered on the pair of left and right front wheels 3L and 3R is basically applied in the same manner to the pair of left and right rear wheels 4L and 4R.
Thus, when the axle housing 51 as a whole swings left and right around the support metals 78A and 78B, the steering cylinder mechanism 70 can also easily swing around the same axis X and receive the vehicle weight. 78B can be configured without being separated from the axle housing 51, and there is no need to separately provide a long and strong holder for receiving the steering cylinder mechanism 70.

Therefore, according to the present embodiment, the axle housing 51 and the steering cylinder mechanism 70 can be connected with a simple configuration and can be strongly connected in terms of strength.
Next, a connection structure between the pair of left and right knuckle arms 64L and 64R and the pair of left and right tie rods 72L and 72R will be further described with reference to FIGS.

FIG. 15 is a schematic rear view for explaining a fixed state between the tie rod 72L connected to the left front wheel 3L side and the ball joint 74L.
As shown in FIG. 12A, the central axis B of the steering shaft 55 is inclined inward by an angle α with respect to the vertical line D. On the other hand, the steering cylinder mechanism 70 and the tie rods 72L and 72R In this embodiment, the ball joints 74L and 74R used for connecting the tie rods 72L and 72R and the knuckle arms 64L and 64R are inclined by an angle α as shown in FIG. The tie rods 72L and 72R are fixed to the distal ends. This inclination angle α is the same as the angle formed by the central axis B of the steering shaft 55 shown in FIG. With this configuration, the movement of the steering cylinder mechanism 70 is smoothly transmitted to the left and right front wheels 3L and 3R via the tie rods 72L and 72R, the ball joints 74L and 74R, the knuckle arms 64L and 64R, and the like.

  By the way, in the conventional configuration, the ball joint that is straightly fixed to the tie rod and disposed horizontally is disposed perpendicular to the originally inclined rotation shaft (corresponding to the steering shaft 55 in FIG. 12). In order to connect the knuckle arms, it is necessary to make a part of the shape of the knuckle arm itself in an oblique shape in accordance with the connection surface with the ball joint. Therefore, conventionally, the left and right knuckle arms have different shapes.

  However, according to the configuration described above, the ball joints 74L and 74R themselves are inclined by the angle α as shown in FIG. 12, and therefore the knuckle arms 64L and 64R can be formed in the same shape on the left and right. The number of mold points and the types of parts can be reduced.

In the above-described configuration described with reference to FIGS. 12 and 15, the description has been made centering on the left front wheel 3 </ b> L side, but since the configuration is the same on the right front wheel 3 </ b> R side, description thereof is omitted.
The above-described configuration centered on the pair of left and right front wheels 3L and 3R is basically applied in the same manner to the pair of left and right rear wheels 4L and 4R. As shown in FIG. 19, a rear wheel steering shaft case 86 is attached to the left and right of a rear axle housing (rear wheel axle case) 88 that houses the rear axle 92, and the steering shaft 87 is pivotally supported in an inclined position therein. A final case 93 is rotatably supported around the steering shaft 87 at the lower portion of the rear wheel steering shaft case 86. At the top of the rear-wheel steering shaft case 86 is provided a rotating member 80 that can rotate around the steering shaft 87 axis, and the rotating member 80 and the final case 93 are connected by a connecting member 89. Like the connecting member 63 of the front wheel 3, the connecting member 89 is provided with an annular portion 89 a that fits the rear wheel steering shaft case 86 in the middle of the connecting member 89 in the same configuration as the connecting member 63 and the annular portion 63 a on the front wheel 3 side. ing.

  The driving force from the rear axle 92 reaches the rear wheel 4 through the steering shaft 87 and the rear wheel shaft 94 in the final case 93 in combination with the transmission by the bevel gear mechanism. Specifically, it is transmitted to the rear wheel 4 via bevel gears 95 and 96 between the rear axle 92 and the steering shaft 87 and bevel gears 97 and 98 between the steering shaft 87 and the rear wheel shaft 94.

Next, based on FIG. 17 and FIG. 18, an interlocking configuration by steering the front wheels 3 and the rear wheels 4 will be described.
An interlocking arm 65 of front and rear tie rods 82L and 82R, which will be described later, is formed by extending the lid-like rotating member 62 to interlock the steering of the front and rear wheels. At this time, in the front wheels 3L and 3R, the interlocking arms 65L and 65R are formed so as to extend inward (left and right inside) of the traveling vehicle body 2 as shown in FIG. On the other hand, the interlocking arms (rear wheel steering arms) 81L and 81R extending to the lid-like rotating members 80L and 80R of the rear wheels 4L and 4R are both outward (right and left outer sides) of the traveling vehicle body 2 as shown in FIG. ) To extend.

  The interlocking arm 65L of the left front wheel 3L and the interlocking arm 81L of the left rear wheel 4L are connected by the front and rear tie rods 82L, and the interlocking arm 65R of the right front wheel 3R and the interlocking arm 81R of the right rear wheel 4R are connected by the front and rear tie rods 82R. . With this configuration, when the left and right front wheels 3L and 3R are steered leftward (arrow L), the left and right rear wheels 4L and 4R are steered rightward (arrow M) via the front and rear tie rods 82L and 82R. Then, the vehicle can turn counterclockwise in the four-wheel steering state (indicated by a solid line arrow in FIG. 17). Conversely, when the left and right front wheels 3L, 3R are steered to the right (arrow N), the left and right rear wheels 4L, 4R are steered to the left (arrow O), and can turn slightly clockwise (dotted arrow in the figure). ).

  The front and rear tie rods 82 </ b> L and 82 </ b> R extend rearward and outward from the front axle housing 51, pass through the lower front side of the chemical tank 9, and reach the rear axle housing 88. Of these, the left front and rear tie rods 82L extend back and forth via the support portion of the left and right lifting step 85 of the traveling vehicle body 2.

  Each connection of the front and rear tie rods 82L and 82R to the interlocking arms 65 and 81 is performed by a ball joint. That is, the interlocking arms 65L and 65R of the front wheels 3L and 3R project the connecting part side such as the arms of the ball joints 83L and 83R on the upper ends of the arms 65L and 65R, and the interlocking arms on the rear wheels 4L and 4R side. 81L and 81R project the connecting parts such as the arms of the ball joints 84L and 84R below the distal ends of the arms 81L and 81R.

  Therefore, the front end sides of the front and rear tie rods 82L and 82R are connected to the upper surface side of the interlocking arms 65L and 65R, while the rear end sides are connected to the lower surface side of the interlocking arms 81L and 81R. As shown in FIG. 12, the center axis B of the steering shaft 55 of the front wheel steering shaft case 54 is provided in a state where the lower end side is inclined with respect to the vertical line D by an angle α so The rear wheel steering shaft case 86 in the wheel 4 is also configured such that the central axis of the interior steering shaft 87 is inclined (FIG. 19).

  Accordingly, the interlocking arms 65L, 65R on the front wheels 3L, 3R side extend inward of the traveling vehicle body 2, so that the interlocking arms 81L, 81R on the rear wheels 4L, 4L side face outward of the traveling vehicle body 2. Since it is extended, it becomes high, and the arrangement of the ball joint as described above makes the front and rear tie rods 82L, 82R substantially horizontal (FIG. 18), which is advantageous for securing the high position of the minimum ground clearance, The structure which avoids interference with the structural members which comprise the traveling vehicle body 2, such as the chemical | medical solution tank 9 and the raising / lowering step 85, can be simplified. Thereby, the trouble by the said interference can be prevented beforehand.

  By the way, the rotating member 62 and the interlocking arm 65 on the front wheel 3 side are integrally formed, but the same shape as the integrally formed product of the rotating member 80 and the interlocking arm 81 on the rear wheel 4 side is used to reduce the production cost. Can be achieved. That is, the bolt insertion hole 63b for connecting the connecting member 63 on the front wheel 3 side is required at a symmetrical position with respect to the rotation axis of the interlocking arm 65 of the rotation member 62 (FIG. 12A). On the other hand, the bolt insertion hole 89b of the rear wheel side connecting member 89 is necessary at the base of the interlocking arm 81 (FIG. 19), but the integrally formed product of the rotating member and the interlocking arm has the same shape on both the front wheel 3 side and the rear wheel 4 side. The bolt insertion hole 63b or 89b is drilled according to each mounting position. The bolt insertion holes 63b and 89b can be processed together in advance. In this case, the man-hour for managing the number of parts can be reduced.

  The front axle housing 51 swings about the traveling direction axis X with respect to the traveling vehicle body 2, but one rear axle housing 88 is mounted integrally with the vehicle body frame 2 a of the traveling vehicle body 2. However, the left and right errors can be absorbed by the connection by the ball joints 83L, 83R, 84L, 84R.

  The rear wheel steering shaft cases 86L and 86R connected to the left and right sides of the rear axle housing 88 have the same configuration as the front wheel steering shaft cases 54L and 54R connected to the front axle housing 51, so that parts can be shared. This is effective for cost reduction and assembly man-hour reduction.

  The interlocking arm 65 on the front wheel 3 side and the interlocking arm 81 on the rear wheel 4 side are substantially located in the projection planes of the front axle housing 51 and the rear axle housing 88, respectively, in plan view when the handle 7 is in a straight traveling state. Is formed. When the vehicle body is inspected and maintained, the vehicle body is lifted by a crane. At that time, a band or rope lifting band 90 is wound around the front axle housing 51 or the rear axle housing 88. In this case, since it is configured as described above, when the handle 7 is set to go straight and the lifting band 90 (FIG. 8) is wound, the interlocking arms 65 and 81 are held in the straight movement state by the lifting band 90. Thus, when the crane is lifted, the wheels 3 and 4 become free and turn around the steering axis under their own weight, which is prevented, and the front wheel 3 and the rear wheel 4 can be maintained in a substantially straight state. Inspection work can be performed safely without causing an uneven load state due to the rotation of the rear wheels 3 and 4.

  FIG. 20 is a plan view showing the positional relationship between the chemical tank 9 and the steering mechanism of the self-propelled control machine of FIG. Moreover, in FIG.21 and FIG.22, another example of the self-propelled type | mold control machine of FIG. 1 is shown. 21 and 22 are a plan view and a rear view showing the positional relationship between the chemical tank 9 and the steering mechanism. FIG. 23 shows a plan view when the chemical tank 9 of the self-propelled control machine of FIG. 21 is omitted.

FIG. 20 shows a view when the chemical tank 9 is arranged in the plan view of FIG. Although there are some differences in the shape of each part, the basic configuration is the same.
The above-described self-propelled control machine is a standard type control machine with a tread of 1500 mm.

  On the other hand, the self-propelled control machine shown in FIGS. 21 and 22 is a tread of 1200 mm and is a small control machine. The overall shape of the small control machine and the standard control machine is almost the same. However, in a small control machine with a narrow tread, it is necessary to suppress the width in the left-right direction, so the front axle housing 51 shown in FIG. The rear axle housing 88 is formed with a small length (horizontal width). Moreover, although the positions of the short transmission shaft 44f and the long transmission shaft 44r and the positions of the first case portion 21f and the second case portion 21r are reversed in the front-rear direction, the other points are almost the same as those of the self-propelled control device described above. Since it is the same structure, detailed description is abbreviate | omitted. Moreover, the same code | symbol is attached | subjected to the corresponding member.

  In the self-propelled control machine of this embodiment and another embodiment, the positions of the ball joints 84L, 84R that connect the interlocking arms 81L, 81R on the rear wheels 4L, 4R side and the front and rear tie rods 82L, 82R are the chemical tank 9 Between the bottom and the rear axle housing 88, the front and rear tie rods 82L, 82R are arranged to pass below the bottom of the chemical tank 9.

  According to this configuration, the front and rear tie rods 82L, 82R that connect the interlocking arms 65L, 65R of the front wheels 3L, 3R and the interlocking arms 81L, 81R on the rear wheels 4L, 4R side are located below the bottom of the chemical liquid tank 9, There is no interference with the chemical tank 9.

  Specifically, lift brackets 106L and 106R fixed to the rear axle housing 88 are respectively joined to the left and right traveling frames 2aL and 2aR of the traveling vehicle body 2 and fastened with bolts. That is, left and right lift brackets 106L and 106R extending in the vertical direction from the left split half 88L and the right split half 88R of the rear axle housing 88 are respectively provided, and the left and right inner sides of the lift brackets 106L and 106R are respectively provided on the left and right traveling frames 2aL and 2aR. The structure is fixed. And the bottom part of the chemical | medical solution tank 9 is supported by the upper surface of the left and right lift brackets 106L and 106R.

  In the structure of the conventional control machine (for example, FIG. 1 of Patent Document 1), the chemical tank is directly mounted on the upper surface of the vehicle body frame, but by providing the lift brackets 106L and 106R, the left and right traveling frames 2aL and 2aR A space between the chemical tanks 9 can be secured. And the space which arrange | positions the front-and-rear tie rods 82L and 82R can be formed by lifting the chemical | medical solution tank 9 by the lift brackets 106L and 106R in this way. Further, since the lift brackets 106L and 106R are fixed to the left and right traveling frames 2aL and 2aR and the rear axle housing 88, the lift brackets 106L and 106R integrally support the chemical liquid tank 9, thereby providing a stable support structure.

  If the tread width is changed by changing the left and right split half portions 88L and 88R of the rear axle housing 88 in the left-right direction, the rear axle housing 88 can be used as a small size control machine and a standard type control machine. it can. In the illustrated example, the left divided half 88L is shorter than the right divided half 88R, but the reverse is also possible. The same applies to the left split half 51L and the right split half 51R of the front axle housing 51.

  In the case of a standard type control machine, the left split half part 88L and the right split half part 88R are both of the same length on the left and right, and in the case of a small control machine, the left split half part 88L (or Assembly can be performed simply by changing the right split half 88R) to one having a short left and right width. Therefore, since it is only necessary to assemble parts having the same number of parts and different lengths, it is possible to prevent erroneous assembly or complicated work, and the quality of manufacturing is stabilized.

  Further, as shown in FIGS. 12 and 19, with respect to the connecting portion by the ball joints 83L and 83R between the front and rear tie rods 82L and 82R and the front and rear interlocking arms 65 and 81, the front connecting portion is the front wheel steering shaft case of the front wheel 3. 54 is provided on the left and right inner sides of the body with respect to the steering shaft 55, and a connecting portion by the rear ball joints 84 </ b> L and 84 </ b> R is provided on the left and right outside of the body with respect to the steering shaft 87 of the rear wheel steering shaft case 86.

  Accordingly, as shown in FIGS. 17, 20, and 21, the front and rear tie rods 82L and 82R have a C-shape that expands rearward in a plan view, and has a structure that does not catch a crop in a turning operation on a headland in a field. That is, since one end of the front and rear tie rods 82L and 82R is on the inner side, the probability of contact with the crop is reduced, so that damage to the crop can be prevented.

  Further, a connecting portion by ball joints 84L, 84R between the front and rear tie rods 82L, 82R and the interlocking arms 81L, 81R on the rear wheels 4L, 4R side is provided at a high position at the left and right outer ends of the interlocking arms 81L, 81R (FIG. 19). And FIG. 22), if it is as close to the bottom of the chemical tank 9 as possible, it can be placed at a high position from the farm scene.

  As described above, when the front and rear tie rods 82L and 82R are shaped like a letter C that extends rearward in a plan view, the rear position of the front and rear tie rods 82L and 82R is made as high as possible, so that it is possible to cope with a variety having a high plant height. It becomes difficult to abut only on the rear side of the aircraft.

  In the small control machine, the interlocking arm 65 of the front wheel 3 is attached to the uppermost part of the front wheel steering shaft case 54, and the interlocking arm 81 of the rear wheel 4 is attached to the uppermost part of the rear wheel steering shaft case 86. . That is, by attaching the interlocking arms 65 and 81 to the uppermost parts of the left and right steering shaft cases 54 and 86, it is possible to assemble steering-related parts when an operator stands and works on a mass production line at the production site. There is a merit that it is easy to do.

In addition, when the attachment portions of the interlocking arms 65 and 81 are in a low position, dirt is likely to be caused by mud splashing during traveling, but mud splashing and the like can be prevented by being provided at a high position.
Also, the airframe is located above the upper ends of the rear wheels 4L and 4R so that the chemical tank 9 and the interlocking arms 81L and 81R of the rear wheels 4L and 4R are not positioned on the tire width Y (FIG. 22) of the rear wheel 4 in plan view. The chemical tank 9, the interlocking arms 81L and 81R, the front and rear tie rods 82L and 82R, and the like are disposed on the left and right inner sides.

  When working in a wet place such as a paddy field, the attachment portion of the interlocking arm 81 becomes dirty due to mud splashing during traveling, or wear due to mud occurs, so that the interlocking arm 81 and its surrounding rotating member 80 are removed. This causes the life of the structure of the steering mechanism on the rear wheel 4 side such as (FIG. 19) to be shortened. However, by disposing these structures on the inner side of the tire width Y, it is possible to prevent the occurrence of dirt and wear due to mud splashing, so that the shortening of the life of the structure can be suppressed.

  Further, similarly to the front wheels 3L and 3R shown in the front view of FIG. 14, the rear wheels 4L and 4R also depend on the angle formed by the center axis of the steering shaft 87 and the line connecting the lower end and the upper end of the rear wheel 4 in the rear view. V-shaped configuration. Then, the front wheels 3L, 3R and the rear wheels 4L, in a reverse letter C shape in front view and rear view so that the distance between the left and right front wheels 3L, 3R and the left and right rear wheels 4L, 4R increases upward. 4R is attached.

  Even if the mud splashes on the left and right outer sides of the front wheels 3L and 3R and the rear wheels 4L and 4R due to mud splashes when the self-propelled control machine 1 travels, these wheels 3 and 4 are inclined toward the left and right outer sides as they move upward. By doing so, since mud falls on the inclined surface, mud can be prevented from entering the left and right inner sides of the front wheels 3L, 3R and the rear wheels 4L, 4R.

  Since the structure of the steering mechanism is arranged on the left and right inner sides of these wheels 3 and 4, this configuration allows control in paddy fields where there is a lot of moisture regardless of the type of control machine such as standard type or small size. It is possible to reduce damages such as dirt and wear on the structure due to lifting of mud during work.

DESCRIPTION OF SYMBOLS 1 Self-propelled control machine 2 Traveling vehicle body 2a Body frame 2aL, 2aR A pair of left and right traveling frames 3 Front wheel 4 Rear wheel 5 Bonnet 6 Pilot seat 7 Handle 9 Chemical liquid tank 10 Control pump 11 Control spraying device 12 Pulley 14 Spray nozzle 15 Lifting cylinder 17 Opening / closing lever 20 Output shaft 21 Transmission case 22 Shift input shaft 23 Main clutch 24 PTO shaft 25 First counter shaft 26 Sub transmission 27 Main transmission 28 Sub transmission gear 29 Sub transmission gear 30 Counter gear 31 Pulley 32 Bracket 34 Clutch housing 35 Second countershaft 36 Back speed intermediate gear 37 Low speed intermediate gear 38 Main transmission sliding gear 39 Forward rotation counter gear 40 Forward rotation transmission gear 41 Back speed transmission gears 42, 43 Reduction intermediate transmission gear group 44 Traveling drive shaft 45 Brake means 4 Main transmission lever 47 Sub transmission lever 48 PTO clutch mechanism 49 PTO lever 50 Front axle 51 Axle housing 51A, 51B Cylindrical boss portion 52 Front wheel input shaft 53 Front wheel differential mechanism 54 Front wheel steering shaft case 55 Front wheel steering shaft 56, 57 Bevel gear 58 Bearing 59 Front wheel final case 60, 61 Bevel gear 62 Rotating member 63 Connecting member 64 Knuckle arm 65 Interlocking arm 66 Front wheel shaft 67, 68 Bolt 69 Piston 70 Steering cylinder mechanism 71 Piston rod 72 Tie rod 73, 74 Ball joint 75 Cylinder housing 76 Cylindrical fitting portion 77 Fixing pin 78 Support metal 79L, 79R A pair of left and right hydraulic hoses 80 Rotating member 81 Interlocking arm 82 Tie rod 83, 84 Ball joint 85 Lifting step 86 Rear wheel steering shaft Case 87 Rear wheel steering shaft 88 Rear axle housing 89 Connecting member 90 Lifting band 92 Rear axle 93 Rear wheel final case 94 Rear wheel shaft 95, 96, 97, 98, 100 Bevel gear 101 Differential lock mechanism 102 Bearing portion 103 Bolt 105 Operation interlocking portion 106 Lift bracket E Engine

Claims (3)

A chemical solution to be applied to a farm field on a traveling vehicle body (2) having a pair of left and right front wheels (3L, 3R) and a pair of left and right rear wheels (4L, 4R) and having a four-wheel steering configuration by a steering member (7). In the self-propelled control machine provided with the chemical tank (9) for storing
A front wheel axle case (51) housing an axle (50) for transmitting driving force to the front wheels (3L, 3R) and an axle (92) for transmitting driving force to the rear wheels (4L, 4R) A rear wheel axle case (88) containing
The four-wheel steering configuration is:
A steering cylinder (70) provided in front of the front wheel axle case (51) and having a piston rod (71) that operates in the left-right direction toward the forward direction of the traveling vehicle body (2) in accordance with the operation of the steering member (7). )When,
A pair of left and right front wheels that are pivotally connected to the left and right ends of the piston rod (71) of the steering cylinder (70) and turn the left and right front wheels (3L, 3R) by the operation of the piston rod (71). Arms (64L, 64R, 65L, 65R);
A pair of left and right rear wheel steering arms (81L, 81R) for turning the left and right rear wheels (4L, 4R);
One end is connected to a pair of left and right front wheel steering arms (64L, 64R, 65L, 65R), and the other end is connected to a pair of left and right rear wheel steering arms (81L, 81R), and the front wheel steering arms (64L, 64R, 65L) are connected. , 65R) and a pair of left and right tie rods (82L, 82R) that operate the pair of left and right rear wheel steering arms (81L, 81R) in conjunction with the rotation of the left and right wheels,
A connecting portion (84L, 84R) between the pair of left and right tie rods (82L, 82R) and the pair of left and right rear wheel steering arms (81L, 81R) is formed at the bottom of the chemical tank (9) and the rear wheel axle case (88). And a tie rod (82L, 82R) is provided over the bottom of the bottom of the chemical tank (9). The vehicle body frame (2a) of the traveling vehicle body (2) includes a pair of left and right traveling frames (2aL, 2aR),
A pair of left and right lift brackets (106L, 106R) fixed to the pair of left and right traveling frames (2aL, 2aR) and the rear axle case (88);
The self-propelled pest control machine according to claim 1, wherein the chemical liquid tank (9) is supported from below by the lift bracket (106L, 106R).   The liquid chemical tank (9) and the four-wheel steering components (81L, 81R, etc.) are provided on the inner side of the left and right sides of the top view position of the upper ends of the left and right rear wheels (4L, 4R). The self-propelled pest control machine according to claim 1 or 2.

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