JP2016137776A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle that is mounted with tires which can absorb vibration from the ground to improve riding comfort and can be reduced in weight.SOLUTION: In a work vehicle having a spraying device 11 mounted on a vehicle body 2 comprising front wheels 3 and rear wheels 4, the front wheels 3 and the rear wheels 4 comprise vehicle shafts 50 and 60, flanges 62, a plurality of spokes 64, rims 66 and tires 68. The tires 68 have: inner rubber filled layers 80 that contact the rims 66 and have rubber filled thereinto; an outer rubber filled layers 82 that are positioned outside in a radial direction of the inner rubber filled layers 80 integrally with the inner rubber filled layers 80 and have rubber filled thereinto; and air layers 84 provided between the inner rubber filled layers 80 and the outer rubber filled layers 82. The air layers 84 are provided consecutively or intermittently in an outer periphery direction of the rims 66. The air layers 84 between the inner rubber filled layers 80 and the outer rubber filled layers 82 can reduce vibration from the ground so as to improve riding comfort. Further the provision of the air layers 84 allows the tires 68 to be reduced in weight.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a tire for a work vehicle including a working device such as a tillage device or a spraying device.

  2. Description of the Related Art Conventionally, a work vehicle having a configuration (4WS) in which both front wheels and rear wheels are steerable is known as a work vehicle including a drug spraying device that sprays drugs, fertilizers, and the like on a farm field. By actively giving steering angles to all four wheels, the vehicle stability in a high speed range is improved, and the turning ability in a very low speed range is improved.

  According to the work vehicle described in Patent Document 1, steering cylinders are provided on the front wheel side and the rear wheel side, respectively, and when turning, the front wheel and the rear wheel are turned in the opposite phase or the same phase so that the turning radius is as large as possible. It is a structure that moves forward while preventing damage to culm and crops.

  In addition, a backup function is provided that raises the work equipment when operated backward by the forward / reverse switching lever. Regardless of whether this backup function is used or not, the rear wheel steering mode is set when the shift position is set to the back. In addition, a control device is provided in which the four-wheel steering mode or the front-wheel steering mode is set depending on the position of the work implement when the shift position is set to a position 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.

  Further, a tire having a solid structure (solid tire) is used in a work vehicle that does not travel at high speed. Solid tires are solid tires that are filled with rubber instead of air. They are able to withstand large loads even when they are small, and do not puncture. Solid tires are also called no-puncture tires because they do not puncture. Unlike a normal pneumatic tire having a hollow structure, a no-puncture tire is a total rubber tire, and therefore has a large weight and lacks elasticity.

  In Patent Document 2, a tire tube is provided between an annular rim and an annular tire base attached to the rim for the purpose of reducing the weight of the no-punk tire, and the tire tube is made of a single-foam rubber material that can be elastically deformed. And is constituted by an annular hollow body including an annular inner space in which 1 atmosphere of air is sealed. When the atmosphere of 1 atmosphere is sealed, the annular hollow body forms a circular cross-sectional shape and the air is exhausted. In this case, a non-puncture tire is disclosed in which a flat cross-sectional shape is formed and the cross-sectional shape is restored to a circular shape by a hollow tool in a state where air is exhausted.

JP 2004-187502 A JP 2012-254785 A

  Since no puncture tires are poor in elasticity, they cannot absorb vibration from the ground as compared with pneumatic tires, and the operator (operator) feels that the ride comfort is hard and the ride comfort becomes worse. Therefore, even if 4WS is mounted as in the configuration described in Patent Document 1 to improve the controllability of the wheels, it is difficult to control if the ride comfort is poor, which is a burden on the operator who drives the vehicle. Moreover, since the weight of the tire is increased, the weight of the entire vehicle is increased and the fuel consumption is also deteriorated.

According to the configuration described in Patent Document 2, by providing an annular hollow body such as a floating ring inside the tire base body, the weight of the tire is reduced and vibration is absorbed.
However, since the tire base outside the annular hollow body is a solid tire, the operator feels sensitively the vibration transmitted from the tire base closer to the cockpit than the annular hollow body. Moreover, since it is fundamentally a solid tire, it cannot be said that it is very effective about weight reduction of a tire. Further, Patent Document 2 targets a road-only tire such as an automobile, and the automobile-specific tire is originally pneumatic and is intended to improve the pneumatic tire. And it has a complicated structure in which the tire tube is provided inside the tire, and when the hole is formed, the adhesive on the inner peripheral surface of the tube closes the hole.

  In the case of a work vehicle, particularly in a vehicle for wet field driving, the height of the lug formed on the tire surface is high and the ground contact surface is narrow. Therefore, when traveling on a road such as asphalt, vibrations are concentrated.

  An object of the present invention is to provide a work vehicle equipped with a tire that absorbs vibration from the ground to improve riding comfort and can be reduced in weight.

The above-described problems of the present invention are solved by the following solution means.
According to the first aspect of the present invention, in the work vehicle in which the working device (11) is mounted on the traveling vehicle body (2) having the traveling wheels (3, 4), the traveling wheels (3, 4) are provided on the axle (50). , 60), flange portions (61, 62) fixed to the outer periphery of the axle (50, 60), a plurality of spokes (64) extending radially from the flange portions (61, 62), and the plurality of spokes A rim (66) to which the tip of (64) is connected, and a tire (68) attached to the outer periphery of the rim (66), the tire (68) being in contact with the outer periphery of the rim (66) An inner rubber filled layer (80) filled with rubber, and an outer rubber filled layer (80) integrated with the inner rubber filled layer (80) and positioned radially outside the inner rubber filled layer (80) and filled with rubber inside ( 82) and between the inner rubber filled layer (80) and the outer rubber filled layer (82) An air layer (84) provided, the air layer (84) being continuous over the entire circumference of the tire (68) and wider than the rim width. is there.

  According to a second aspect of the present invention, in the working vehicle in which the working device (11) is mounted on the traveling vehicle body (2) having the traveling wheels (3, 4), the traveling wheels (3, 4) are provided on the axle (50). , 60), flange portions (61, 62) fixed to the outer periphery of the axle (50, 60), a plurality of spokes (64) extending radially from the flange portions (61, 62), and the plurality of spokes A rim (66) to which the tip of (64) is connected, and a tire (68) attached to the outer periphery of the rim (66), the tire (68) being in contact with the outer periphery of the rim (66) An inner rubber filled layer (80) filled with rubber, and an outer rubber filled layer (80) integrated with the inner rubber filled layer (80) and positioned radially outside the inner rubber filled layer (80) and filled with rubber inside ( 82) and between the inner rubber filled layer (80) and the outer rubber filled layer (82) An air layer (84) provided, and the air layer (84) is intermittent over the entire circumference of the tire (68) and wider than the rim width. is there.

  The invention according to claim 3 is the work vehicle according to claim 2, wherein the air layer (84) is not provided on an extension line of the plurality of spokes (64).

  According to the first aspect of the present invention, by providing a continuous air layer (84) on the tire (68), the cushioning property of the solid tire is enhanced, and vibrations from the ground are reduced, so that the operator who drives the vehicle Ride comfort is improved. Further, since the air layer (84) is partly provided as compared with the conventional solid tire, the weight of the tire (68) can be reduced.

  Further, since the tire (68) is easily dented by the impact from the ground due to the air layer (84), the ground contact area of the tire (68) is increased, so that the grip force (friction force) of the tire (68) is improved. To do. Therefore, the running property in a wet field such as a wet field becomes good.

  Furthermore, the elasticity of the air layer (84) is enhanced by providing the air layer (84) so as to be overhanging wider than the width of the rim (66) that receives impact from the ground. For example, when traveling on hard ground such as asphalt, the performance of absorbing impact from the ground is increased, so that the ride comfort is further improved.

  Also, in working vehicles that run in wet fields such as wet fields, the height of the lugs formed on the tire surface is high and the ground contact surface is narrow, so in the wet fields the action of the rug part entering the soil and scratching the ground Appear. Furthermore, by having the air layer (84), the tire (68) is likely to be subtly deformed, whereby the surface shape of the tire (68) is in close contact with the uneven shape of the soil, thereby scratching the ground. The action is improved. Therefore, slip does not easily occur and the running property is excellent.

  According to the invention described in claim 2, by providing the tire (68) with the air layer (84) intermittently, the cushioning property of the solid tire is increased, and vibrations from the ground are reduced, thereby driving the vehicle. The ride comfort is improved. Further, since the air layer (84) is partly provided as compared with the conventional solid tire, the weight of the tire (68) can be reduced.

  Further, since the tire (68) is easily dented by the impact from the ground due to the air layer (84), the ground contact area of the tire (68) is increased, so that the grip force of the tire (68) is improved. Therefore, the traveling property in a wet field such as a wet paddy field is improved.

  In addition, if there is an air layer (84), it is considered that twisting occurs between the inner rubber filled layer (80) and the outer rubber filled layer (82). However, by providing the air layer (84) intermittently, that is, discontinuously, the air layer (84) is less than when the air layer (84) is continuously provided, and therefore the tire (68) is less likely to twist. Therefore, it is possible to suppress the torsion of the tire (68), which is likely to occur when turning on the headland in the field, the uneven wear or the like that the tire (68) wears only on one side, and the rigidity of the tire (68) can be increased.

  Furthermore, the elasticity of the air layer (84) is enhanced by providing the air layer (84) so as to be overhanging wider than the width of the rim (66) that receives impact from the ground. For example, when traveling on hard ground such as asphalt, the performance of absorbing impact from the ground is increased, so that the ride comfort is further improved.

  Also, in working vehicles that run in wet fields such as wet fields, the height of the lugs formed on the tire surface is high and the ground contact surface is narrow, so in the wet fields the action of the rug part entering the soil and scratching the ground Appear. Furthermore, by having the air layer (84), the tire (68) is likely to be subtly deformed, whereby the surface shape of the tire (68) is in close contact with the uneven shape of the soil, thereby scratching the ground. The action is improved. Therefore, slip does not easily occur and the running property is excellent.

  When the spoke (64) is in a vertical position with respect to the ground when traveling on a hard ground such as on the road, a large load (on the rubber part between the spoke (64) and the ground contact surface) Load). Therefore, if there is an air layer (84) on the extension line of the spoke (64), the air layer (84) receives this load, and the tire (68) is likely to be twisted.

  However, according to the third aspect of the present invention, in addition to the effect of the second aspect of the invention, the air vehicle (84) is not disposed on the extension line of the spoke (64), so that the work vehicle is on a hard ground. Even when traveling, the tire (68) is not twisted, and the swaying of the fuselage is reduced, resulting in stable traveling.

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 rear view of the self-propelled 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. FIG. 9A is a side view of the rear wheel of the self-propelled control machine of FIG. 1, and FIG. 9B is a view taken along line S1-S1 of FIG. 9A. FIG. 10 is an enlarged view of the tire portion of FIG. It is a development view (a part) of the tire surface. FIG. 10 is another example (side view) of the rear wheel of FIG. 9.

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 having a control spraying device for spraying chemicals and fertilizers on a field as an example of a work vehicle, and FIGS. 1 shows a front view, a rear view, and a plan view of a self-propelled control machine 1. FIG. 5 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 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 which are traveling wheels on a body frame 2a. A control spraying device 11 is attached to the front side of the traveling vehicle body 2. In the present embodiment, a self-propelled control machine provided with a control spraying device as a work device is shown, but other work vehicles include a tractor provided with a tillage device, a lawn mower provided with a lawn mower device, and the like. There is also.

  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 a pair of left and right front wheels 3 (3L, 3R) and a pair of left and right rear wheels 4 (4L, 4R), and a handle 7 is provided in front of the pilot seat 6.

  When the steering wheel 7 is steered left and right, the front wheel 3 only (FWS), the rear wheel 4 only (RWS), and the front wheel 3 and rear wheel 4 steer (4WS) can be selected. The 4WS is used when 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 so that the front wheel 3 and the rear wheel 4 are steered in opposite phases to reduce the turning radius. It has a four-wheel steering configuration that can travel.

  Although the configuration of this four-wheel steering is not described in detail, as described in Japanese Patent Application Laid-Open No. 2004-187502, steering cylinders are provided on the front wheel side and the rear wheel side, respectively, and the turning direction and rotation of the handle 7 are adjusted. A configuration may be adopted in which oil is supplied to each cylinder by operating a switching valve provided in the hydraulic circuit according to the moving angle. Alternatively, a configuration in which the handle 7 and the traveling wheels 3 and 4 are connected by a mechanical mechanism such as a gear or a shaft may be employed.

  Further, a chemical tank 9 is detachably provided so as to surround the cockpit 6, and a control pump 10 (FIG. 7) 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. 4, 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 and 11R provided on both left and right sides of the center spraying boom 11C.

  Then, the control spraying device 11 is moved up and down by the lifting cylinder 15 (see FIG. 1), and the open / close levers 17L and 17R (see FIG. 4) are operated back and forth, so that the left and right side spraying booms 11L and 11R are independently left and right. It is configured so as to be housed in a projecting state (see FIG. 5) that protrudes and in a state along both sides of the traveling vehicle body 2 (see FIGS. 1 to 4).

  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, 5).

  Next, a speed change transmission mechanism that receives power from 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 case 21 side transmission input shaft 22. 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. A shift input shaft 22 and a coaxial PTO shaft 24 are supported on the rear wall portion of the rear case portion 21r, and a bearing is provided on a boss-like portion 24a at the front end to support the rear end of the shift input shaft 22. .

  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 mainly accommodated in the rear case portion 21r of the transmission case 21 is provided with three auxiliary transmission gears 28a, 28b, and 28c fixed to the transmission input shaft 22 and having different gear diameters. A sub-transmission sliding gear 29 for selecting the sub-transmission gears 28a to 28c is provided on the counter shaft 25 side, 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 formed integrally 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 with the internal gear part 30a of the counter gear 30 always meshed. 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 of the transmission case 21 accommodated in the front case portion 21f. 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 of 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 rear transmission shaft (not shown). The spline shaft 44b on the front side drives the front wheel differential mechanism via the front transmission shaft (not shown) to drive the front wheels 3L and 3R.

  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 a front-rear guide guide. The right side of the cockpit 6 is provided with a PTO lever 49 for switching 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 at 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 at 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 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.

  Brake means 45 is provided on a metal portion 21m that is detachably fastened and fixed to the rear wall of the transmission case 21 on the rear side of the traveling 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 allows the PTO clutch mechanism 48 to be interlocked with turning on and off, 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.

  By providing a transmission input shaft 22 and a first counter shaft 25 in parallel with the transmission input shaft 22 and selecting a transmission gear group provided between the first counter shaft 25 and the input transmission shaft 22, a sub-transmission device 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 and the front wheels 3 and Since the rear wheels 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. 6 and 8, 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. 8 and the like, the transmission case 21 is mounted on the traveling vehicle body 2 in such a manner that base members 2B and 2B are integrally provided on a pair of left and right traveling frames 2aL and 2aR. 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.

  FIG. 9A shows a side view (detailed view) of the rear wheel 4 of the self-propelled pest control machine of FIG. 1 (the front wheel 3 has the same configuration), and FIG. The S1-S1 arrow directional view (partial sectional view) of A) is shown. FIG. 9A shows a state in which some tires 68 are removed for easy viewing. The same applies to FIG. 12 described later. A round frame X shows a partially enlarged view of the tire 68.

  10 shows an enlarged view of the tire 68 portion of FIG. 9B, and FIG. 11A shows a surface development view (part) of the tire 68 portion. 11B is a cross-sectional shape taken along line S3-S3 in FIG. 11A, and FIG. 11C is a cross-sectional shape taken along line S4-S4 in FIG. 10 shows a cross section taken along line S2-S2 in FIG. 9A and a cross section taken along line S2-S2 in FIG.

  The front wheel 3 and the rear wheel 4 of the self-propelled control machine in FIG. 1 are connected to the flange 61 of the front axle 50 and the rear axle 60 and fixed with bolts 70. A plurality of spokes 64 extending radially from the wheel-side flange 62, a pipe-shaped rim 66 having a circular cross-section to which the tips of the plurality of spokes 64 are connected, and a tire 68 mounted on the outer periphery of the rim 66.

  A flange 61 is integrally attached to the front axle 50 and the rear axle 60. The axle-side flange 61 and the wheel-side flange 62 are connected by a bolt 70. On the other hand, six spokes 64 in the illustrated example are attached to the flanges 62 of the wheels (front wheel 3 and rear wheel 4) by welding. The inner periphery of the rim 66 is fixed to the tip of the spoke 64 by welding.

  Rubber, which is a constituent member of the tire 68, is baked on the outer periphery of the rim 66 having a hollow cross section. In the self-propelled pest control machine 1 of the present embodiment, the rubber portion includes an inner rubber filling layer 80 in contact with the rim 66, an outer rubber filling layer 82 formed integrally with the outer side, and an inner rubber filling layer. And an air layer 84 provided between the outer rubber filling layer 82 and the outer rubber filling layer 82. The air layer 84 is preferably provided continuously over the entire circumference of the tire 68.

  In addition, since the inner rubber filling layer 80 and the outer rubber filling layer 82 are integrated, it is not always necessary to clearly distinguish them. In this specification, the rubber on the radially inner side (center side) of the air layer 84 is used. For the sake of convenience, the portion is referred to as the inner rubber filling layer 80, and the radially outer rubber portion of the air layer 84 is referred to as the outer rubber filling layer 82.

  The tires 68 of the front wheel 3 and the rear wheel 4 of the self-propelled control machine 1 are solid tires in which the entire cross section of the inner rubber filling layer 80 and the outer rubber filling layer 82 is rubber (no air), By providing the air layer 84 between the rubber-filled layer 80 and the outer rubber-filled layer 82, the cushioning property of the solid tire is enhanced, vibration from the ground is reduced, the ride comfort is softened, and the self-propelled control machine 1 The ride comfort of the operator who drives is improved. Further, since the air layer 84 is partly provided as compared with the conventional solid tire, the weight of the tire can be reduced. Hard rubber of solid tires is considerably harder than rubber for automobile tires, etc., and there is no problem even if there is a hole in the air layer 84. Also, because of the hard rubber, the air layer 84 is provided to reduce vibration. Become.

  Further, the air layer 84 makes the tire 68 easily dent due to an impact from the ground, so that the tire width is wide at the portion in contact with the farm scene, that is, the ground contact area is increased, so that the grip force of the tire 68 is improved. Therefore, the running property in a wet field such as a wet field becomes good.

  In wet fields, the height of the lugs (projections 90) formed on the tire surface is high and the ground contact surface is narrow. Therefore, in the wet fields, the rug portion enters the soil and scratches the ground. Furthermore, by having the air layer 84, the tire 68 is likely to be subtly deformed, so that the surface shape of the tire 68 closely adheres to the uneven shape of the soil so that the action of scratching the ground is improved. Therefore, slip is less likely to occur and the running performance is excellent. The case where the air layer 84 is continuously provided along the outer peripheral direction of the rim 66 (the air layer 84 is present on the entire cross section of the tire 68) is particularly remarkable.

  Further, as shown in FIG. 10, the width W1 of the air layer 84 is preferably made larger than the width W2 of the rim 66, that is, the rim 66 may be formed so as to fit in the air layer 84 in plan view. Even if an impact from the ground received by the rim 66 is transmitted to the tire 68, the elasticity of the tire 68 is increased by forming the air layer 84 by overhanging the rim 66. For example, when traveling on hard ground such as asphalt, the performance of absorbing impact from the ground is increased, so that the ride comfort is further improved. Further, in a wet field such as a wet field, the amount of deformation of the rubber portion is increased, so that the rubber part is more closely attached to the unevenness of the field, so that slip does not easily occur and excellent traveling performance is achieved.

The cross-sectional shape of the air layer 84 may be an arc shape or a flat plate shape along the cross-sectional shape (circular shape) of the rim 66. The air layer 84 is formed by the following method.
A method (1) of setting a bag containing air in a tire mold, a method of injecting air during molding (2), a method of applying plastic blow molding (hollow molding) to a tire (3), The inner rubber filling layer 80 and the outer rubber filling layer 82 are independently molded and bonded after molding (with a recess on the inner side on the outer peripheral side and a concave portion on the outer side on the inner peripheral side) (4). In the case of the method (4), the joint portion between the inner rubber-filled layer 80 and the outer rubber-filled layer 82 becomes the boundary between these layers.

  Further, the inner rubber filling layer 80 and the outer rubber filling layer 82 may be formed of different materials without being limited to the method (4). For example, the inner rubber filling layer 80 serving as a base is made of rubber having high strength, and the outer rubber filling layer 82 in contact with the ground is selected from rubber that is resistant to friction. The inner rubber filling layer 80 and the outer rubber filling layer 82 may each have a multilayer structure (for example, rubbers having different hardnesses are used). The rubber material may be those used for ordinary tires, and includes natural rubber, synthetic rubber such as butadiene rubber, styrene butadiene rubber, and isoprene rubber.

The rim 66, the spoke 64, and the center flange 62 are integrally formed by welding, and the tire portion 68 is crimped around the rim 66. The tire part is also crimped to the spoke part.
In order to form the air layer 84, there are a blow molding method, a method using a die, a method of dividing the left and right sides in the circumferential direction, molding the die with a die, and matching the left and right with an adhesive. In this example, there is a parting line P (FIG. 11) at the center in the circumferential direction of the tire 68, and the rim 66, the spoke 64, and the center flange 62 are integrally formed by welding, and the components of this integrated structure are set in a mold Then, the rubber is poured to manufacture.

FIG. 12 shows another example of the rear wheel 4 of FIG. The front wheel 3 has the same configuration.
The air layer 84 may be provided intermittently along the outer circumferential direction of the rim 66 as shown in FIG. The cross-sectional view of the tire in the air layer 84 is the same as FIG. 9B and FIG.

  If the air layer 84 is continuously formed along the outer peripheral direction of the rim 66, it is also conceivable that twisting occurs between the inner rubber filled layer 80 and the outer rubber filled layer 82. However, if the air layer 84 is intermittent, that is, discontinuous, the air layer 84 is less than when the air layer 84 is continuous, and the tire 68 is less likely to twist. Therefore, it is possible to suppress the twist of the tire 68 that is likely to occur when turning on the headland in the field, and to increase the rigidity of the tire 68.

  As shown in FIG. 2 and FIG. 3, the self-propelled pest controller 1 of the present embodiment has a front surface so that the distance between the left and right front wheels 3L and 3R and the distance between the left and right rear wheels 4L and 4R increases as the distance increases. The front wheels 3L and 3R and the rear wheels 4L and 4R are attached in a reverse C shape when viewed and viewed back. Therefore, as compared with the case where the distance between the left and right front wheels 3L and 3R and the distance between the left and right rear wheels 4L and 4R are the same in the upper and lower directions, the tire 68 is grounded from an oblique direction. It is easy to generate.

However, since the tire 68 is difficult to twist, the occurrence of such uneven wear can be reduced.
In the case where the air layer 84 is provided intermittently, a left and right divided formwork may be used.
When the spoke 64 is in a vertical position with respect to the ground when traveling on hard ground such as on the road, a large load (load) is generated in the rubber portion between the spoke 64 and the ground contact surface. To do. Therefore, if there is an air layer 84 on the extension line of the spoke 64, the tire 68 may be easily twisted by the air layer 84 receiving this load.

  Therefore, if the air layer 84 is designed not to be disposed on the extension line of the spoke 64, even when the self-propelled pest control machine 1 travels on a hard ground, the tire 68 does not twist and the body sways. Reduced and stable running.

  Further, as shown in FIG. 11, a lug-shaped tread pattern (projection) 90 is provided on the outer peripheral surface of the tire 68 (the outer peripheral surface of the outer rubber-filled layer 82). For easy understanding, the protrusion 90 is indicated by a bold line.

The lug-shaped protrusion 90 is excellent in driving force and braking force even on uneven fields and roads that are not paved, and can ensure stable running performance.
In particular, when working in wet locations such as paddy fields, it has the effect of preventing mud adhesion and the effect of improving gripping power. That is, when the traveling wheels 3 and 4 rotate and the protrusion 90 comes out from the water surface, the mud adhering to the protrusion 90 naturally falls.

Since the tire 68 and the ground contact portion of the ground are easily dented, the surface pressure of the contact surface is reduced, and the presence of the protrusion 90 prevents slipping and improves the propulsive force of the tire 68.
As shown in FIG. 11, the protrusion 90 has a T-shaped pattern including a head portion 90a having a longitudinal direction in the front-rear direction and a foot portion 90b having a longitudinal direction in the left-right direction. The head portion 90a is provided so as to protrude gently from the upper surface 91 of the outer rubber filling layer 82, and the head portions 90a and the upper surface 91 are alternately formed in the front-rear direction.

The conventional lug pattern has protrusions symmetrically with respect to the circumferential center line (P), the interval between the protrusions is short, and the mud adhesion reduction effect between the lugs is small.
However, such a left-right alternating (shifted in the front-rear direction) T-shaped pattern greatly improves the running performance in work running such as paddy fields.

  Also, the foot portion 90b of the T-shaped pattern is not provided along the left-right direction of the tire 68 (perpendicular to the head portion 90a), but is provided obliquely rearward from the left-right center, thereby preventing mud adhesion. The prevention effect and the improvement effect of grip power are further increased. In FIG. 11 (plan view), when the foot portion 90b comes into contact with the ground, there is an effect of pushing mud sideways with the rotation of the tire 68 at an angle of 75 degrees. Since the convex portions 90d around the triangular concave portions 90c are present at the side angle of 30 ° and 20 °, traveling thrust can be obtained when the tire 68 sinks.

  In particular, when the T-shaped protrusion 90 is used for the tire 68 in which the air layer 84 shown in FIG. 12 is discontinuous, the tire 68 is also less likely to be twisted. Even if it is a simple travel path, stable travel is possible.

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 shift lever 47 auxiliary shift lever 48 PTO clutch mechanism 49 PTO lever 50 front axle 60 rear axle 61, 62 flanges 64 spokes 66 the rim 68 tire 70 volts 80 inner rubber filler layer 82 outer rubber filler layer 84 air layer 90 protruding E engine

Claims (3)

In a working vehicle in which a working device (11) is mounted on a traveling vehicle body (2) having traveling wheels (3, 4),
The traveling wheels (3, 4)
Axle (50, 60),
Flange portions (61, 62) fixed to the outer periphery of the axle (50, 60);
A plurality of spokes (64) extending radially from the flange portions (61, 62);
A rim (66) to which tips of the plurality of spokes (64) are connected;
A tire (68) mounted on the outer periphery of the rim (66),
The tire (68) includes an inner rubber filling layer (80) in contact with the outer periphery of the rim (66) and filled with rubber, and an inner rubber filling layer (80) integrated with the inner rubber filling layer (80). There is an outer rubber filling layer (82) located radially outside and filled with rubber, and an air layer (84) provided between the inner rubber filling layer (80) and the outer rubber filling layer (82). And
The work vehicle characterized in that the air layer (84) is continuous over the entire circumference of the tire (68) and is wider than the rim width. In a working vehicle in which a working device (11) is mounted on a traveling vehicle body (2) having traveling wheels (3, 4),
The traveling wheels (3, 4)
Axle (50, 60),
Flange portions (61, 62) fixed to the outer periphery of the axle (50, 60);
A plurality of spokes (64) extending radially from the flange portions (61, 62);
A rim (66) to which tips of the plurality of spokes (64) are connected;
A tire (68) mounted on the outer periphery of the rim (66),
The tire (68) includes an inner rubber filling layer (80) in contact with the outer periphery of the rim (66) and filled with rubber, and an inner rubber filling layer (80) integrated with the inner rubber filling layer (80). There is an outer rubber filling layer (82) located radially outside and filled with rubber, and an air layer (84) provided between the inner rubber filling layer (80) and the outer rubber filling layer (82). And
The work vehicle characterized in that the air layer (84) is provided intermittently over the entire circumference of the tire (68) and wider than the rim width.   The work vehicle according to claim 2, wherein the air layer (84) is not provided on an extension line of the plurality of spokes (64).

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