Grass trimmer

Abstract

To provide a mower capable of transmitting power with a compact structure. The mower includes a working unit that receives power from a traveling machine body to perform mowing work, an offset mechanism that can move the working unit to a position offset laterally with respect to the traveling direction of the traveling machine body, and a power transmission unit that transmits the power to the working unit, the power transmission unit including a roller chain wound between a pair of sprockets. The power transmission unit may also include a tensioner that applies tension from the outside to the inside of the roller chain.

Description

[Technical field]

[0001] The present invention relates to a grass mower, and more particularly to an offset type grass mower that is attached to the rear of a traveling body and performs grass cutting work to the side of the traveling body. [Background technology]

[0002] Conventionally, mowers are known as agricultural machines that perform mowing work to remove weeds from farm roads and wastelands. Generally, mowers perform mowing work by pulling a working unit with a traveling machine body such as a tractor. In recent years, offset-type mowers have become known in which the working unit that performs mowing work can be moved to the side of the traveling machine body, and the mowing work is performed to the side of the traveling machine body (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-39941 A [Patent Document 2] JP 2012-191864 A Summary of the Invention [Problem to be solved by the invention]

[0004] In both of the mowers described in Patent Documents 1 and 2, the traveling body and the working unit are connected with a universal joint to transmit the power of the traveling body to the working unit. The power transmitted to the working unit is used to rotate the claw shaft of the working rotor, etc.

[0005] However, as described in Patent Document 1, the bending angle of a universal joint is limited, which in turn imposes various limitations on the design of the working part. For example, it is generally known that, with respect to a universal joint, if the torque is constant, the lifespan of the universal joint becomes shorter as the bending angle of the universal joint becomes larger.

[0006] In order to ensure the offset amount of the working part while considering the life of the universal joint, it is possible to lengthen the universal joint, but in that case, when working in a place close to the traveling body, the length of the universal joint gets in the way and the accessibility of the work is impaired. Also, if the universal joint is longer, the center of gravity of the whole body shifts backward by the same amount, so there is a problem that the whole balance is worsened and the traveling stability is impaired when the working part is moved to the rear of the traveling body and the traveling body is advanced, especially after the work at the offset position is completed.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide a grass mower capable of transmitting power with a compact structure. [Means for solving the problem]

[0008] In one embodiment of the present invention, the grass mower comprises a working unit that receives power from a running body to perform grass cutting work, an offset mechanism that can move the working unit to a position offset laterally in the direction of travel of the running body, and a power transmission unit that transmits the power to the working unit, and the power transmission unit includes a roller chain wound between a pair of sprockets. Effect of the Invention

[0009] The grass mower according to the embodiment of the present invention described above converts the power input from the traveling body into a power converter. It is possible to transmit the force to the working part in a compact structure. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view showing a configuration of a grass mower in a first embodiment. [Diagram 2] FIG. 1 is a side view showing a configuration of a grass mower in a first embodiment. [Diagram 3]FIG. 2 is a rear view showing the configuration of the grass mower in the first embodiment. [Figure 4] FIG. 2 is a plan view showing the configuration of a power transmission unit of the grass mower in the first embodiment. [Diagram 5] FIG. 2 is a plan view showing the configuration of the grass mower in the first embodiment during operation. [Figure 6] FIG. 2 is a rear view showing the configuration of the grass mower in the first embodiment during operation. [Figure 7] FIG. 2 is a rear view showing a state in which the working unit of the mower in the first embodiment has been rotated downward (clockwise). [Figure 8] FIG. 2 is a rear view showing a state in which the working unit of the mower in the first embodiment has been rotated upward (counterclockwise). [Figure 9] FIG. 11 is a plan view showing the configuration of a power transmission unit of a grass mower in a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the mower of the present invention will be described with reference to the drawings. However, the mower of the present invention can be implemented in many different forms, and should not be construed as being limited to the description of the examples shown below. In the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same reference numerals, and repeated explanations thereof will be omitted.

[0012] For the sake of convenience, terms indicating directions such as up, down, forward, backward, right, and left are used, but the direction in which gravity acts is downward, and the opposite is upward. The direction in which the traveling body moves is forward, and the opposite is backward. Furthermore, when facing forward, the right side is the right side, and the left side is the left side.

[0013] First embodiment [Grass cutter configuration] The general configuration of the mower 100 in the first embodiment will be described below with reference to Figures 1 to 3. Figure 1 is a plan view showing the configuration of the mower 100 in the first embodiment. Figure 2 is a side view showing the configuration of the mower 100 in the first embodiment. Figure 3 is a rear view showing the configuration of the mower 100 in the first embodiment.

[0014] The mower 100 in this embodiment includes a mounting unit 10, an offset mechanism unit 20, a power transmission unit 30, a working unit 40, and a rotating mechanism unit 50. Specifically, the mower 100 is connected to a traveling machine body 200 such as a tractor by the mounting unit 10. The mounting unit 10 and the working unit 40 are connected via the offset mechanism unit 20 and the power transmission unit 30. As a result, the mower 100 is pulled as the traveling machine body 200 travels, and grass cutting work is performed by the working unit 40.

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

[0016] The mounting section 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 a three-point link mechanism 220 provided at the rear 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) that receives power from the traveling body 200 is connected to the gear box. The input shaft is configured to receive power from a PTO shaft 230 provided on the traveling machine body 200 via a universal joint (not shown).

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

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

[0019] The link rod 22 is a long member formed of a cylindrical member, and has approximately the same length as the offset frame 21. One end of the link rod 22 is connected to the hitch frame 11 so as to be rotatable 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 formed of a cylindrical member, and is a member that connects the offset frame 21 and the link rod 22 to each other. The offset frame 21 and the link rod 22 are both rotatably connected to the support frame 23. In addition, the support frame 23 is disposed approximately 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 form a link mechanism of a parallelogram with each of the sides being the respective sides. With this link mechanism, the offset mechanism unit 20 can move the working unit 40 in an offset manner.

[0022] The expandable 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 expandable member 24 is connected to the hitch frame 11, and the other end is connected to the rear side of the offset frame 21 (for example, near the connection part with the support frame 23). The expansion and contraction of the expandable member 24 drives the offset mechanism unit 20, and the offset amount (amount of movement 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 an input shaft (not shown) of the mounting unit 10 to the working unit 40. In the grass mower 100 of this embodiment, the power transmission unit 30 is a chain drive mechanism rather than a conventional universal joint. Specifically, the power transmission unit 30 has at least a driving sprocket 31, a driven sprocket 32, and a roller chain 33. The roller chain 33 is configured to be wound around the driving sprocket 31 and the driven sprocket 32.

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

[0025] The working section 40 is the section where the actual mowing work is performed, and includes a working rotor 41, a rotor cover, The working unit 40 has a blade 42, two side plates 43, and a blade drive unit 44. The working unit 40 performs grass cutting work by the blade drive unit 44 receiving power transmitted from the power transmission unit 30 and driving the working rotor 41.

[0026] The work 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 perpendicular to the traveling direction of the traveling machine body 200. The work rotor 41 rotates the rotating shaft 41a to cut weeds and the like with the cutting blades 41b.

[0027] The rotor cover 42 is a cover member disposed to cover the work rotor 41. The rotor cover 42 has the effect of preventing the scattering of weeds cut by the cutting blade 41b, soil adhering to the weeds, and pebbles that have fallen to the work surface (ground surface), and also of returning the cut weeds to the cutting blade 41b again to finely crush them.

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

[0029] The blade drive unit 44 transmits the rotational power transmitted from the traveling machine body 200 via the power transmission unit 30 to the rotation shaft 41a of the work rotor 41. As shown in Fig. 2, the blade drive unit 44 of this 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 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 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 provided from the drive pulley 44a to the rotary shaft 41a, thereby driving the work rotor 41.

[0031] The turning mechanism 50 is a mechanism for turning the working unit 40 around an axis that corresponds to the traveling direction of the traveling body 200. The power output from the power transmission unit 30 is transmitted to the blade driving unit 44 via a first transmission shaft 51, the turning mechanism 50, and a second transmission shaft 52. The turning of the working unit 40 will be described later.

[0032] (Power transmission section configuration) The configuration of the power transmission unit 30 used in the grass mower 100 of this 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 grass mower 100 of the first embodiment.

[0033] In FIG. 4, roller chain 33 is wound between driving sprocket 31 and driven sprocket 32. Note that part of roller chain 33 is omitted by dotted lines. Here, the part of roller chain 33 that moves from driving sprocket 31 toward driven sprocket 32 ​​is the part that is pushed by driving sprocket 31. For ease of explanation, this specification refers to this part as slack side 33a. Also, the part of roller chain 33 that moves from driven sprocket 32 ​​toward driving sprocket 31 is the part that is pulled by driving sprocket 31. In this specification, this part is referred to as tight side 33b.

[0034] The power transmission unit 30 of this embodiment further includes a tensioner 34a disposed on the outside of the slack side 33a of the roller chain 33, and a tensioner 34b disposed on the inside of the slack side 33a of the roller chain 33. Note that the "outside" here refers to the outside of the annular roller chain 33 (the area not surrounded by the roller chain 33), and the "inside" here refers to the inside of the roller chain 33.

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

[0036] Tensioner 34b is disposed upstream of tensioner 34a (i.e., closer to drive sprocket 31). Tensioner 34b is in a fixed position and functions as a guide member that fixes the track of roller chain 33. Therefore, tensioner 34a applies tension to roller chain 33 from the outside to the inside, and thus tensioner 34b applies tension to roller chain 33 from the inside to the outside in comparison.

[0037] In this manner, in this embodiment, tension is applied to the roller chain 33 using the tensioners 34a and 34b, thereby preventing slack in the roller chain 33 during power transmission and enabling efficient transmission of rotational power. Note that the tensioners 34a and 34b are not essential components and may be omitted, or a configuration may be provided with only the tensioner 34a.

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

[0039] As shown in Fig. 4, the mower 100 of this embodiment transmits power input from the traveling body 200 to the working unit 40 using the power transmission unit 30 that operates by a chain drive system. In other words, unlike conventional mowers, there is no need to connect the mounting unit 10 and the working unit 40 with a universal joint. Therefore, it is possible to freely control the offset amount of the working unit 40 without being restricted by the bending angle of the universal joint.

[0040] Another advantage of not using a universal joint as the power transmission section is that there is no drawback such as the lifespan of the power transmission section being shortened depending on the offset amount of the working section, making it possible to realize a highly durable grass mower.

[0041] Furthermore, in the power transmission unit 30 of this embodiment, the distance between the drive sprocket 31 and the driven sprocket 32 ​​can be freely set, so there is no drawback such as the length of the joint getting in the way. Therefore, there is no drawback in that the accessibility of the work is reduced when working in a place close to the traveling body 200, and there is no drawback in that the overall balance is poor and the traveling stability is impaired when the working unit 40 is moved to the rear of the traveling body 200 to move the traveling body 200 forward after the work at the offset position is completed.

[0042] In addition, when a chain drive system is adopted as the power transmission unit 30 as in this embodiment, there is an advantage that the rotation speed of the work rotor 41 can be easily changed by changing the diameter of the sprocket. It is possible to improve the rotation speed and torque of the rotor 41.

[0043] As described above, the mower 100 in this embodiment is capable of transmitting the power input from the traveling body 200 to the working unit 40 with a compact structure.

[0044] (Lawn mower in motion) A state in which the working unit 40 of the mower 100 in the first embodiment has been moved to an offset state will be described. Fig. 5 is a plan view showing the normal working state of the mower 100 in the first embodiment. Fig. 6 is a rear view showing the configuration of the mower 100 in the normal working state in the first embodiment.

[0045] Here, "normal" refers to a state in which the working unit 40 remains offset from a non-working state toward a working state. In other words, it refers to a state in which the working unit 40 has offset to the side relative to the traveling direction of the traveling body 200 and is in a position approximately parallel to the horizontal plane. For example, a state in which the traveling body 200 is traveling and performing grass cutting work in a field scene corresponds to the normal working state.

[0046] 5 and 6, during grass cutting work, the offset mechanism 20 is driven to offset the working unit 40 to the right relative to the traveling direction of the traveling body 200. This makes it possible to perform grass cutting work at a position offset to the side relative to the traveling direction of the traveling body 200.

[0047] At this time, the mower 100 of this embodiment can offset the working unit 40 to the extent that the power transmission unit 30 and the working unit 40 are connected in a substantially straight line. In other words, as shown in Figures 5 and 6, it is possible to perform mowing work in a state where the working unit 40 is offset significantly to the right from the rear tire 210 of the traveling body 200. This is because, as described above, a chain drive mechanism is used as the power transmission unit 30, and therefore there is no restriction due to the bending angle of the universal joint as in the past.

[0048] Furthermore, the mower 100 of this embodiment rotates with the working unit 40 in an offset state. Fig. 7 is a rear view showing the working unit 40 of the mower 100 in the first embodiment in a position where it has been rotated downward. Fig. 8 is a rear view showing the working unit 40 of the mower 100 in the first embodiment in a position where it has been rotated upward.

[0049] In the mower 100 shown in Fig. 7, the working unit 40 is rotated downward (here, clockwise) by the rotation mechanism 50 in an offset state. As described above, the rotation mechanism 50 is a mechanism for rotating the working unit 40 about an axis that corresponds to the traveling direction of the traveling body 200. The state shown in Fig. 7 is a state in which the working unit 40 is performing mowing work on an inclined surface (slope) located below the traveling body 200.

[0050] The grass mower 100 of this embodiment employs a chain drive system for the power transmission unit 30, which allows the offset amount to be increased while maintaining durability, making it possible to work efficiently on slopes located below.

[0051] The mower 100 shown in Fig. 8 rotates upward (counterclockwise in this case) with the working unit 40 in an offset state. The state shown in Fig. 8 is a state in which the working unit 40 performs mowing work on an inclined surface (slope) located above the traveling body 200. Even in this case, the mower 100 of this embodiment can efficiently work on an inclined surface (slope) located above.

[0052] Second Embodiment In the grass mower of the second embodiment, the configuration of the power transmission unit is different from that of the first embodiment. Specifically, in the grass mower of this embodiment, the power transmission unit 30a is composed of a drive pulley 31a, a driven pulley 32a, and a belt 33A. Note that in this embodiment, the explanation will be given focusing on the differences in configuration from the grass mower 100 of the first embodiment, and the same components will be given the same reference numerals and explanations may be omitted.

[0053] Fig. 9 is a plan view showing the configuration of the power transmission unit 30a provided in the grass mower of the second embodiment. While the first embodiment uses a chain drive system, this embodiment uses a belt drive system. Even in this case, the power transmission unit 30a can be configured without using a universal joint as in the conventional case.

[0054] According to this embodiment, it is possible to realize a grass mower that is easy to maintain because there is no need to worry about rust as with a chain. In addition, since the operating noise is smaller than that of a chain drive system, it is possible to configure a grass mower that is quieter.

[0055] The present invention has been described above with reference to the drawings, but the present invention is not limited to the above-described embodiment and can be modified as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0056] 10...mounting portion, 11...hitch frame, 20...offset mechanism portion, 21...offset frame, 22...link rod, 23...support frame, 24...expandable member, 30, 30a...power transmission portion, 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...drive 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 linkage mechanism, 230...PTO shaft

Claims

1. A working unit that receives power from the traveling machine body and performs grass cutting work; an offset mechanism that is rotatably connected to a frame that is connected to the traveling body and that can move the working unit to a position that is offset laterally with respect to the traveling direction of the traveling body; Equipped with the power transmission unit includes a chain drive mechanism including a roller chain wound around a pair of sprockets, or a belt drive mechanism including a belt wound around a pair of pulleys, The working unit is rotatable about a rotation axis in the traveling direction of the traveling body, the rotation shaft overlaps with a part of a power transmission path that transmits power from the power transmission unit to the working unit in a rear view, A grass mower in which, as a result of the offset mechanism rotating, the chain drive mechanism or the belt drive mechanism rotates relative to the frame and the working unit moves to the offset position.

2. A working unit that receives power from the traveling machine body and performs grass cutting work; An offset mechanism unit that is rotatably connected to a frame connected to the traveling body and can move the working unit to a position offset laterally with respect to the traveling direction of the traveling body; a power transmission unit that transmits the power; a rotation mechanism that transmits the power output from the power transmission unit to the working unit; Equipped with the power transmission unit includes a chain drive mechanism including a roller chain wound around a pair of sprockets, or a belt drive mechanism including a belt wound around a pair of pulleys, The working unit is rotatable about a rotation axis in the traveling direction of the traveling body, The rotation shaft overlaps with a part of the rotation mechanism in a rear view, A grass mower in which, as a result of the offset mechanism rotating, the chain drive mechanism or the belt drive mechanism rotates relative to the frame and the working unit moves to the offset position.

3. 3. The method according to claim 1, wherein the offset mechanism and the power transmission unit overlap each other in a plan view.

2. The grass mower according to claim 1 .

4. The grass mower according to claim 1 , wherein the working section includes a work rotor having a plurality of cutting blades attached to a rotary shaft that rotates by receiving the power.

5. The grass mower according to claim 1 , wherein the working unit includes a blade drive unit configured as a wrap-around transmission device to which the power is input.

Images