Mower

Abstract

To provide a mower that can transmit power by a compact structure.SOLUTION: A mower includes: an installation part which is provided with an input axis and connected to a travelling body; a work part which has an axis of rotation provided with a mower blade, which can be moved to a rear position of the travelling body and to a position offset to a side for an advancing direction of the travelling body, and which can be rotated upward or downward by making a rotation center with a rotation axis that is parallel to the advancing direction of the travelling body; a first power transmission part which transmits power to the side of the work part from the travelling body received by the input axis; and a second power transmission part which transmits the power from the first power transmission part to the work part. The rotation axis is superposed on a part of the second power transmission part in a back face view.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lawn mower. In particular, it relates to an offset type lawn mower that is mounted on the rear part of a traveling body and performs lawn mowing work on the side of the traveling body.

Background Art

[0002] Conventionally, a lawn mower is known as an agricultural working machine that performs lawn mowing work to remove weeds on farm roads and wastelands. Generally, the lawn mower advances the lawn mowing work by towing the working part with a traveling body such as a tractor. In recent years, an offset type lawn mower is known in which the working part for performing the lawn mowing work is movable to the side of the traveling body and the lawn mowing work is performed on the side of the traveling body (Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the lawn mowers described in Patent Documents 1 and 2, the power of the traveling body is transmitted to the working part by connecting the traveling body and the working part using a universal joint. The power transmitted to the working part is used for power for rotating the claw shaft of the working rotor and the like.

[0005] However, as also described in Patent Document 1, since there are limitations on the bending angle of the universal joint, various limitations also occur in the design of the working part accordingly. For example, regarding the universal joint, it is generally known that when the torque is constant, the life becomes shorter as the bending angle of the universal joint increases.

[0006] In order to ensure the offset amount of the working part while considering the service life of the universal joint, it is conceivable to increase the length of the universal joint. However, in that case, when working in a place close to the traveling body, there is a problem that the length of the universal joint becomes an obstacle and the work accessibility is impaired. Further, when the universal joint becomes longer, the overall center of gravity shifts rearward by the increased length. Therefore, especially after the work at the offset position is completed and the working part is moved to the rear of the traveling body and the traveling body is advanced, there is also a problem that the overall balance deteriorates and the traveling stability is impaired.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a lawn mower capable of transmitting power with a compact structure.

Means for Solving the Problems

[0008] A lawn mower according to an embodiment of the present invention includes a working part that receives power from a traveling body and performs a lawn mowing operation, an offset mechanism part that can move the working part to a position offset laterally with respect to the traveling direction of the traveling body, and a power transmission part that transmits the power to the working part. The power transmission part includes a roller chain wound between a pair of sprockets.

Effects of the Invention

[0009] The lawn mower according to the above-described embodiment of the present invention can transmit the power input from the traveling body to the working part with a compact structure.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the lawn mower of the present invention will be described with reference to the drawings. However, the lawn mower of the present invention can be implemented in many different modes and is not to be construed as limited to the description of the examples shown below. In the drawings referred to in the present embodiment, the same parts or parts having the same functions are denoted by the same reference numerals, and the repeated description thereof is omitted.

[0012] Also, for convenience of explanation, terms indicating directions such as upward, downward, forward, rearward, rightward, and leftward are used, but the direction in which gravity acts is downward and the opposite is upward. Also, the direction in which the traveling body advances is forward and the opposite is rearward. Further, toward the front, the right side is the rightward and the left side is the leftward.

[0013] 〈First Embodiment〉 [Configuration of Lawn Mower] Hereinafter, the schematic configuration of the lawn mower 100 in the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a plan view showing the configuration of the lawn mower 100 of the first embodiment. FIG. 2 is a side view showing the configuration of the lawn mower 100 of the first embodiment. FIG. 3 is a rear view showing the configuration of the lawn mower 100 of the first embodiment.

[0014] The lawn mower 100 in this embodiment includes a mounting portion 10, an offset mechanism portion 20, a power transmission portion 30, a working portion 40, and a rotation mechanism portion 50. Specifically, the lawn mower 100 is connected to a traveling body 200 such as a tractor by the mounting portion 10. The mounting portion 10 and the working portion 40 are connected via the offset mechanism portion 20 and the power transmission portion 30. Accordingly, as the traveling body 200 travels, the lawn mower 100 is towed, and the lawn mowing operation is performed by the working portion 40.

[0015] The mounting portion 10 is connected to a three-point link mechanism 220 (however, only the lower link is shown by a dotted line here) provided between two rear tires 210 of the traveling body 200 such as a tractor. The three-point link mechanism 220 is usually composed of a top link, a lift rod, and a lower link. Since the three-point link mechanism 220 is a known mechanism, the description thereof is omitted here.

[0016] The mounting portion 10 includes a hitch frame 11 extending in the left-right direction, which is the width direction of the traveling body 200, and the hitch frame 11 is configured to be connectable to the three-point link mechanism 220 provided at the rear portion of the traveling body 200. A gear box (not shown) is provided at the lower center of the hitch frame 11, and an input shaft (not shown) for receiving power from the traveling body 200 is provided in this gear box. The input shaft is configured such that power is transmitted from a PTO shaft 230 provided in the traveling body 200 via a universal joint (not shown).

[0017] The offset mechanism portion 20 is a mechanism for performing an offset movement of the working portion 40. Specifically, the offset mechanism portion 20 can move the working portion 40 to a position offset laterally with respect to the traveling direction of the traveling body 200. The offset mechanism portion 20 of this embodiment has an offset frame 21, a link rod 22, a support frame 23, and a telescopic member 24.

[0018] The offset frame 21 is a long frame composed of a hollow member and is disposed below the power transmission unit 30. One end of the offset frame 21 is pivotally connected to the hitch frame 11 on a horizontal plane, and the other end is connected to the support frame 23.

[0019] The link rod 22 is a long member composed of a cylindrical member and has a length comparable to that of the offset frame 21. One end of the link rod 22 is pivotally connected to the hitch frame 11 on a horizontal plane, and the other end is connected to the support frame 23. Note that the connection positions of the offset frame 21 and the link rod 22 on the hitch frame 11 are different.

[0020] The support frame 23 is a short member composed of a cylindrical member and is a member that interconnects the offset frame 21 and the link rod 22. The offset frame 21 and the link rod 22 are both pivotally connected to the support frame 23. Also, the support frame 23 is disposed substantially parallel to the hitch frame 11.

[0021] With the above configuration, the hitch frame 11, the offset frame 21, the link rod 22, and the support frame 23 constitute a link mechanism in the form of a parallelogram with each as a side. By this link mechanism, the offset mechanism unit 20 can offset-move the working unit 40.

[0022] The telescopic member 24 is a power source (actuator) of the offset mechanism unit 20 and is composed of, for example, a gas cylinder, a hydraulic cylinder, etc. One end of the telescopic member 24 is connected to the hitch frame 11, and the other end is connected to the rear side of the offset frame 21 (e.g., near the connection portion with the support frame 23). By the extension and contraction of the telescopic member 24, the offset mechanism unit 20 is driven, and the offset amount (the movement amount in the offset direction) of the working unit 40 can be controlled.

[0023] The power transmission unit 30 is a mechanism for transmitting the power from the traveling body 200 received by the input shaft (not shown) of the mounting unit 10 to the working unit 40 side. The lawn mower 100 of the present embodiment uses a chain drive mechanism as the power transmission unit 30 instead of a conventional universal joint. Specifically, the power transmission unit 30 includes at least a drive sprocket 31, a driven sprocket 32, and a roller chain 33. The roller chain 33 is configured to be wound around the drive sprocket 31 and the driven sprocket 32.

[0024] The drive sprocket 31 is a gear that rotates actively by the power received from the input shaft. The driven sprocket 32 is a gear that rotates passively by the rotational power transmitted from the drive sprocket 31 via the roller chain 33. The roller chain 33 is a mechanical element that transmits power and the like as tension. Details of the configuration of the power transmission unit 30 will be described later.

[0025] The working unit 40 is a part that actually performs the lawn mowing operation, and includes a working rotor 41, a rotor cover 42, two side plates 43, and a cutting blade drive unit 44. The working unit 40 performs the lawn mowing operation by the cutting blade drive unit 44 receiving the power transmitted from the power transmission unit 30 and driving the working rotor 41.

[0026] The working rotor 41 includes a rotating shaft 41a disposed between the side plates 43 and a plurality of cutting blades 41b radially provided on the rotating shaft 41a. The rotating shaft 41a is provided in a horizontal direction orthogonal to the traveling direction of the traveling body 200. The working rotor 41 rotates the rotating shaft 41a and cuts weeds and the like with the cutting blades 41b.

[0027] The rotor cover 42 is a cover member disposed to cover the working rotor 41. The rotor cover 42 prevents the scattering of weeds cut by the cutting blades 41b, soil adhering to the weeds, small stones falling on the working surface (ground surface), etc., and has the effect of returning the cut weeds to the cutting blades 41b again and finely crushing them.

[0028] The side plate 43 rotatably supports the rotating shaft 41a via a ball bearing or the like and supports the rotor cover 42. In the present embodiment, a cutting blade drive unit 44 is provided on the left side plate 43.

[0029] The cutting blade drive unit 44 transmits the rotational power transmitted from the traveling machine body 200 via the power transmission unit 30 to the rotating shaft 41a of the working rotor 41. As shown in FIG. 2, the cutting blade drive unit 44 of the present embodiment includes a drive pulley 44a, a driven pulley 44b, a belt 44c, and a tensioner 44d. The belt 44c is wound between the drive pulley 44a and the driven pulley 44b. The tensioner 44d is disposed on the side where the belt 44c is pushed out from the drive pulley 44a toward the driven pulley 44b, and applies tension from the inside to the outside of the belt 44c.

[0030] In the cutting blade drive unit 44 having the above-described structure, the drive pulley 44a rotates by the rotational power transmitted from the power transmission unit 30, and transmits the rotational power to the driven pulley 44b via the belt 44c. The driven pulley 44b transmits the rotational power given from the drive pulley 44a to the rotating shaft 41a, and drives the working rotor 41.

[0031] The pivoting mechanism unit 50 is a mechanism for pivoting the working unit 40 about an axis when the traveling direction of the traveling machine body 200 is taken as the axis. The power output from the power transmission unit 30 is transmitted to the cutting blade drive unit 44 via the first transmission shaft 51, the pivoting mechanism unit 50, and the second transmission shaft 52. The pivoting of the working unit 40 will be described later.

[0032] (Configuration of the power transmission unit) The configuration of the power transmission unit 30 used in the lawn mower 100 of the present embodiment will be described with reference to FIG. 4. FIG. 4 is a plan view showing the configuration of the power transmission unit 30 provided in the lawn mower 100 of the first embodiment.

[0033] In FIG. 4, a roller chain 33 is wound around between a drive sprocket 31 and a driven sprocket 32. Note that a part of the roller chain 33 is omitted by a dotted line. Here, among the roller chain 33, the portion moving from the drive sprocket 31 toward the driven sprocket 32 is the portion pushed by the drive sprocket 31. For convenience of explanation, in this specification, this portion is referred to as the slack side 33a. Further, among the roller chain 33, the portion moving from the driven sprocket 32 toward the drive sprocket 31 is the portion pulled by the drive sprocket 31. In this specification, this portion is referred to as the tension side 33b.

[0034] The power transmission unit 30 of the present embodiment further includes a tensioner 34a disposed outside the slack side 33a of the roller chain 33 and a tensioner 34b disposed inside the slack side 33a of the roller chain 33. Here, the outside referred to herein is the outside of the annular roller chain 33 (the region not surrounded by the roller chain 33), and the inside is the inside of the roller chain 33.

[0035] The tensioner 34a is pulled by the elastic force of the elastic member 35 and applies a tension to the roller chain 33 from the outside toward the inside. In the present embodiment, a tension coil spring is used as the elastic member 35, but other spring members may be used.

[0036] The tensioner 34b is disposed on the upstream side (that is, the side closer to the drive sprocket 31) than the tensioner 34a. The position of the tensioner 34b is fixed and functions as a guide member for fixing the trajectory of the roller chain 33. Therefore, when the tensioner 34a applies a tension to the roller chain 33 from the outside toward the inside, relatively, the tensioner 34b applies a tension to the roller chain 33 from the inside toward the outside.

[0037] Thus, in this embodiment, by applying tension to the roller chain 33 using the tensioners 34a and 34b, slack of the roller chain 33 during power transmission can be prevented, and rotational power can be efficiently transmitted. Note that the tensioners 34a and 34b are not essential components and can be omitted, or a configuration with only the tensioner 34a provided may also be used.

[0038] The drive sprocket 31, driven sprocket 32, roller chain 33, tensioner 34a, tensioner 34b, and elastic member 35 described above are housed inside the chain case 36 and covered on the outside by the chain cover 37. The power transmission unit 30 is disposed on a support member (not shown) mounted on the upper portion of the offset frame 21 and moves together with the offset frame 21. That is, in this embodiment, it can also be said that the power transmission unit 30 constitutes a part of the offset mechanism unit 20.

[0039] As shown in FIG. 4, the lawn mower 100 of this embodiment transmits the power input from the traveling body 200 to the working unit 40 using the power transmission unit 30 that operates in a chain drive system. That is, unlike conventional lawn mowers, it is not necessary to connect the mounting unit 10 and the working unit 40 with a universal joint. Therefore, the offset amount of the working unit 40 can be freely controlled without being limited by the folding angle of the universal joint.

[0040] In addition, as an advantage of not using a universal joint as the power transmission unit, there is no drawback such that the life of the power transmission unit is shortened depending on the offset amount of the working unit, so it is possible to realize a highly durable lawn mower.

[0041] Furthermore, since the power transmission unit 30 of the present embodiment can freely set the distance between the drive sprocket 31 and the driven sprocket 32, there are no drawbacks such as the length of the joint becoming an obstacle. Therefore, there is no drawback that the work accessibility deteriorates when working in a place close to the traveling body 200, and when the working unit 40 is moved to the rear of the traveling body 200 and the traveling body 200 is advanced after the work at an offset position, there is no drawback that the overall balance deteriorates and the traveling stability is impaired.

[0042] In addition, when the chain drive method is adopted as the power transmission unit 30 as in the present embodiment, there is also an advantage that the rotational speed of the working rotor 41 can be easily changed by changing the diameter of the sprocket. That is, the rotational speed or torque of the working rotor 41 can be improved only by a simple operation of exchanging the sprocket.

[0043] As described above, the lawn mower 100 in the present embodiment can transmit the power input from the traveling body 200 to the working unit 40 with a compact structure.

[0044] (Operation of the lawn mower) The state in which the working unit 40 of the lawn mower 100 in the first embodiment is offset and moved will be described. FIG. 5 is a plan view showing the normal working state of the lawn mower 100 in the first embodiment. FIG. 6 is a rear view showing the configuration of the normal working state of the lawn mower 100 in the first embodiment.

[0045] Here, "normal time" refers to a state in which the working unit 40 remains offset and moved from the non-working state toward the working state. That is, it refers to a state in which the working unit 40 is offset and moved laterally with respect to the traveling direction of the traveling body 200 and is in a position substantially parallel to the horizontal plane. For example, the state of performing lawn mowing work on the field where the traveling body 200 travels corresponds to the normal working state.

[0046] As shown in FIGS. 5 and 6, during the mowing operation, the working unit 40 is offset and moved to the right with respect to the traveling direction of the traveling body 200 by driving the offset mechanism unit 20. Thereby, it is possible to perform the mowing operation at a position offset to the side with respect to the traveling direction of the traveling body 200.

[0047] At this time, the mower 100 of the present embodiment can offset and move the working unit 40 to such an extent that the power transmission unit 30 and the working unit 40 are substantially in a straight line. That is, as shown in FIGS. 5 and 6, it is possible to perform the mowing operation in a state where the working unit 40 is offset significantly to the right of the rear tire 210 of the traveling body 200. This is because, as described above, a chain drive mechanism is adopted as the power transmission unit 30, so it is not subject to the limitation due to the bending angle of the universal joint as in the conventional case.

[0048] Furthermore, the mower 100 of the present embodiment rotates in a state where the working unit 40 is offset and moved. FIG. 7 is a rear view showing a state where the working unit 40 of the mower 100 in the first embodiment is in a position rotated downward. FIG. 8 is a rear view showing a state where the working unit 40 of the mower 100 in the first embodiment is in a position rotated upward.

[0049] The mower 100 shown in FIG. 7 has the working unit 40 rotated downward (here, clockwise) by the rotation mechanism unit 50 in an offset state. As described above, the rotation mechanism unit 50 is a mechanism for rotating the working unit 40 about its axis when the traveling direction of the traveling body 200 is taken as the axis. The state shown in FIG. 7 is a state where the working unit 40 performs the mowing operation on an inclined surface (normal surface) located below the traveling body 200.

[0050] The mower 100 of the present embodiment can increase the offset amount while maintaining durability by adopting a chain drive method for the power transmission unit 30, so it is possible to efficiently work on the normal surface located below.

[0051] In the lawn mower 100 shown in FIG. 8, the working unit 40 is rotating upward (counterclockwise in this case) in an offset state. The state shown in FIG. 8 is a state in which the working unit 40 performs lawn mowing work on an inclined surface (normal surface) located above the traveling body 200. Even in this case, the lawn mower 100 of the present embodiment can efficiently perform work on the inclined surface (normal surface) located above.

[0052] 〈Second Embodiment〉 In the lawn mower of the second embodiment, the configuration of the power transmission unit is different from that of the first embodiment. Specifically, the lawn mower of the present embodiment is characterized in that the power transmission unit 30a is composed of a drive pulley 31a, a driven pulley 32a, and a belt 33A. In the present embodiment, the description will be made focusing on the differences in configuration from the lawn mower 100 of the first embodiment, and the same components may be denoted by the same reference numerals and the description may be omitted.

[0053] FIG. 9 is a plan view showing the configuration of the power transmission unit 30a provided in the lawn mower of the second embodiment. While the first embodiment adopted a chain drive system, the present embodiment adopts a belt drive system. Even in this case, the power transmission unit 30a can be configured without using a universal joint as in the prior art.

[0054] According to the present embodiment, since there is no worry about rusting like a chain, a lawn mower that is easy to maintain can be realized. Also, since the operating noise is smaller than that of the chain drive system, a lawn mower with improved quietness can be configured.

[0055] As described above, the present invention has been described with reference to the drawings, but the present invention is not limited to the above embodiments, and can be appropriately changed without departing from the spirit of the present invention.

Description of Reference Numerals

[0056] 10... Mounting part, 11... Hitch frame, 20... Offset mechanism part, 21... Offset frame, 22... Link rod, 23... Support frame, 24... Telescopic member, 30, 30a... Power transmission part, 31... Driving sprocket, 31a... Driving pulley, 32... Driven sprocket, 32a... Driven pulley, 33... Roller chain, 33A... Belt, 34a, 34b... Tensioner, 35... Elastic member, 36... Chain case, 37... Chain cover, 40... Working part, 41... Working rotor, 41a... Rotating shaft, 41b... Cutting blade, 42... Rotor cover, 43... Side plate, 44... Cutting blade drive part, 44a... Driving pulley, 44b... Driven pulley, 44c... Belt, 44d... Tensioner, 50... Rotating mechanism part, 51... First transmission shaft, 52... Second transmission shaft, 200... Traveling body, 210... Rear tire, 220... Three-point link mechanism, 230... PTO shaft

Claims

【Claim 1】 a mounting portion provided with an input shaft and connected to the traveling body; a working portion having a rotating shaft provided with a cutting blade, capable of being moved to a rear position of the traveling body and a position offset laterally with respect to the traveling direction of the traveling body, and capable of rotating upward or downward about a rotation axis parallel to the traveling direction of the traveling body; a first power transmission portion that transmits the power from the traveling body received by the input shaft to the working portion side; a second power transmission portion that transmits the power from the first power transmission portion to the working portion; comprising; a lawn mower, wherein the rotation axis overlaps a part of the second power transmission portion in a rear view.

Images