Mowing machine

Abstract

To provide a mowing machine capable of easily adjusting the cutting height of a cutting unit in accordance with the condition of grassland.SOLUTION: A mowing machine according to one embodiment of the present invention is a self-propelled mowing machine that cuts grass while traveling, and includes a cutting unit having a cutting blade. A rotational axis of the cutting blade extends in a direction perpendicular to a working surface. The cutting unit includes a roller and a roller support portion that rotatably supports the roller, and further includes a cutting height adjustment portion capable of adjusting a positional relationship between the working surface and the cutting blade.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a grass cutter. [Background technology]

[0002] Conventionally, mowing work has been carried out periodically using a mower to remove weeds and the like that have grown on the top surface or slopes of ridges. Patent Document 1 discloses a self-propelled mower that is remotely controlled via wireless communication and moves over the ridge to mow the top surface and slopes. The mower described in Patent Document 1 is equipped with a cutting blade unit that has a horizontal cutting blade and an inclined cutting blade at the front of the machine body, and while moving, it is able to remove weeds and the like that have grown on the top surface of the ridge using the horizontal cutting blade and to remove weeds and the like that have grown on the slopes of the ridge using the inclined cutting blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-176153 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional mowers described above, a bowl-shaped curved member is placed below the cutting blade to maintain a distance from the ground where the grass grows. However, because conventional mowers move forward with the bowl-shaped curved member in contact with the ground, there is a problem in that a large amount of power is required for forward movement due to the load caused by contact resistance.

[0005] One of the objectives of one embodiment of the present invention is to provide a mower that can easily adjust the mowing height of the mowing unit in accordance with the condition of the grassland (for example, the undulations of a slope, etc.) Another objective of one embodiment of the present invention is to provide a mower that can easily adjust the mowing height of the mowing unit while suppressing an increase in the power required for movement. [Means for solving the problem]

[0006] A grass mower according to one embodiment of the present invention is a self-propelled mower that cuts grass, and includes a cutting unit having a cutting blade, the rotation axis of which extends perpendicular to the work surface, and the cutting unit includes a roller and a roller support unit that rotatably supports the roller, as well as a cutting height adjustment unit that can adjust the positional relationship between the work surface and the cutting blade.

[0007] In the above-mentioned brush cutter, the cutting unit may include a casing that covers the blade unit from above. One end of the roller support unit may be rotatably connected to the upper surface of the casing, and the other end may support the roller. Here, the above-mentioned brush cutter may have two rollers as the rollers, and the other end of the roller support unit may support the two rollers between them. Furthermore, the rotation axis that is the center of rotation of the two rollers may be inclined so as to point rearward as it moves away from the connection part with the roller support unit. Also, the diameter of each of the two rollers may be smaller at the end farther from the connection part with the roller support unit than at the end closer to the connection part.

[0008] In the above-mentioned mower, the cutting unit may be attached so as to be tiltable relative to the machine body.

[0009] In the above-described brush cutter, the length of the roller may be shorter than the diameter of the rotation path of the cutting blade. [Effects of the Invention]

[0010] According to one embodiment of the present invention, it is possible to provide a mower that can easily adjust the mowing height of the mowing unit in accordance with the condition of the grassland (for example, the undulations of a slope, etc.). Also, according to one embodiment of the present invention, it is possible to provide a mower that can easily adjust the mowing height of the mowing unit while suppressing an increase in the power required for movement. Furthermore, according to one embodiment of the present invention, it is possible to provide a mower for ridges that has the above-mentioned functions. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a top view showing the configuration of a grass mower according to an embodiment of the present invention; [Figure 2] 1 is a left side view showing the configuration of a grass mower according to an embodiment of the present invention. [Figure 3] FIG. 1 is a rear view showing the configuration of a grass mower according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing the configuration of a cutting height adjustment unit provided in a slope cutting unit of a grass mower according to an embodiment of the present invention. FIG. [Figure 5] 1 is a rear view showing the configuration of a cutting height adjustment unit provided in a slope cutting unit of a grass mower according to an embodiment of the present invention. FIG. [Figure 6] 1 is a diagram showing the configuration of a cutting height adjustment unit provided in a slope cutting unit of a grass mower according to an embodiment of the present invention. FIG. [Figure 7] 1 is a diagram showing the configuration of a cutting height adjustment unit provided in a slope cutting unit of a grass mower according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes the brush mower of the present invention with reference to the drawings. However, the brush 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, identical parts or parts having similar functions are designated with the same reference numerals or the same reference numerals followed by an alphabet, and repeated description thereof will be omitted. Furthermore, when identical or similar parts are provided on the left and right sides of the direction of travel, the reference numerals of the parts are followed by L (left-side member) or R (right-side member). When there is no particular distinction between left and right members, the parts may be described using only the reference numerals, omitting L and R.

[0013] In the specification and claims of this application, "up" refers to the direction vertically away from the grass when the mower is moving forward while mowing a ridge or other grass area, and "down" refers to the opposite direction from "up." For ease of explanation, "front" refers to the direction in which the top cutting unit is positioned relative to the traveling unit, and "rear" refers to the opposite direction from "front." Furthermore, "left" and "right" refer to the left and right in a rear view of the mower as seen from the rear of the mower.

[0014] Furthermore, when the center line of the mower in a plan view (a line parallel to the direction of travel and passing through the center of the mower) is used as a reference, the side closer to the center line is called the "inside" and the side farther from the center line is called the "outside."

[0015] In the present specification, ridges, flat land and other grasslands where grass is cut by a mower are collectively referred to as grasslands.

[0016] First Embodiment [Configuration of the grass cutter 100] The mower 100 is a mower that performs mowing work while self-propelled. Specifically, the mower 100 is remotely controlled by a remote controller, and is a mower that performs mowing work while self-propelled on grass.

[0017] FIG. 1 is a top view showing the configuration of a mower 100 according to one embodiment of the present invention. FIG. 2 is a left side view showing the configuration of a mower 100 according to one embodiment of the present invention. Specifically, FIG. 2 shows a state in which, when the mower is traveling on a ridge, the slope mowing unit 80 (only the left slope mowing unit 80L is shown) described below is adjusted to a position parallel or approximately parallel to a horizontal plane 203 (see FIG. 3). FIG. 3 is a rear view showing the configuration of a mower 100 according to one embodiment of the present invention. Specifically, FIG. 3 shows a state in which, when the mower 100 is traveling on a ridge, the slope mowing unit 80 is adjusted to an oblique position in accordance with the inclination of the slope 202 of the ridge 200.

[0018] As shown in FIGS. 1 to 3, the mower 100 includes a machine body 10, a traveling unit 20, a mowing unit 120 including a top surface mowing unit 30 and a slope surface mowing unit 80, a position adjustment mechanism 90, an angle adjustment mechanism 130, an engine 60, an alternator 70, a battery 40, and an anti-tip mechanism 300. The drive of each unit is controlled by a control unit 50. The mower 100 is self-propelled by the traveling unit 20 and controls the drive of the mowing unit 120, so that it can mow the top surface 201 and slope surface 202 of a ridge 200 in a single run, as shown in FIG. 3. Note that in FIG. 3, for the sake of simplicity, parts other than the slope surface mowing unit 80, the position adjustment mechanism 90, and the angle adjustment mechanism 130 have been omitted or simplified.

[0019] 1 and 2, the machine body 10 includes a machine body 14, which is a frame forming the skeleton of the mower 100, and a support case 15 attached to the machine body 14 and extending forward. The support case 15 may be supported on the machine body 14 so as to be rotatable in the vertical direction. The support case 15 is provided with mounting members 11 facing downward for mounting the top surface cutting unit 30. A pair of left and right slope cutting units 80 are also provided at the rear of the machine body 14. As will be described in detail later, the slope cutting units 80 are supported by a position adjustment mechanism 90 and an angle adjustment mechanism 130 that adjust the position of the slope cutting units 80 in the vertical and horizontal directions. The machine body 10 can be made of a metal material (e.g., steel or aluminum), a fiber-reinforced plastic (FRP) material, or the like, but is not limited to these examples.

[0020] The travel unit 20 includes a pair of left and right travel units 20L and 20R, and functions as travel means for the mower 100. When viewed from behind, the travel unit 20L is the left travel unit when facing the direction of travel of the mower 100, and the travel unit 20R is the right travel unit. Note that the structure of the travel unit 20R is the same as that of the travel unit 20L, so the following description will focus on the travel unit 20L.

[0021] As shown in FIG. 2, the traveling unit 20L includes a crawler belt 21L, drive wheels 22L, driven wheels 23L, a crawler frame 24L, and a drive unit 54L. The crawler belt 21L is spanned between the drive wheels 22L and the driven wheels 23L and rotates in accordance with the rotation of the drive wheels 22L. The drive unit 54L is driven by power supplied from an alternator 70 or a battery 40. The drive wheels 22L rotate by power transmitted from the drive unit 54L. Power generated by the rotation of the drive wheels 22L is transmitted to the driven wheels 23L via the crawler belt 21L. The crawler frame 24L rotatably supports the drive wheels 22L and the driven wheels 23L. In this embodiment, the crawler belt 21L is made of an elastic member (specifically, rubber) and has a plurality of lugs (protrusions), and a motor is used as the drive unit 54L.

[0022] As described above, in FIG. 1 , the mowing unit 120 includes the top surface mowing unit 30 provided in front of the traveling unit 20 and the slope surface mowing unit 80 (specifically, a pair of left and right slope surface mowing units 80L and 80R) provided behind the traveling unit 20. As will be described in detail later, the top surface mowing unit 30 is provided in front of the machine body 10 and functions as a mowing unit that mows weeds and other grass that grow on the top surface (mowing work) when mowing ridges. The slope surface mowing unit 80 is provided behind the machine body 10 and functions as a mowing unit that mainly mows weeds and other grass that grow on slopes when mowing ridges. For example, when mowing the top surface of a ridge and the left and right slopes simultaneously, the top surface mowing unit 30 will be located between the left slope surface mowing unit 80L and the right slope surface mowing unit 80R in the left-right direction in a rear view. The positional relationship between the top surface reaping unit 30 and the slope surface reaping unit 80 is not limited to the example shown in FIGS. 1 to 3, and for example, the positions of the top surface reaping unit 30 and the slope surface reaping unit 80 may be reversed.

[0023] The work that can be performed by the slope mowing unit 80 is not limited to mowing on slopes, but it is also possible to perform mowing on grasslands other than slopes (for example, flat grasslands). For example, as shown in Figures 1 and 2, if the slope mowing unit 80 is adjusted to a position parallel or approximately parallel to the horizontal plane 203 (see Figure 3), it can perform mowing on a flat surface that is parallel or approximately parallel to the horizontal plane 203 (flat mowing).

[0024] The control unit 50 is provided, for example, above the machine body 10, and has the function of controlling the traveling unit 20, the cutting unit 120, the engine 60, the alternator 70, or the battery 40. The control unit 50 has, for example, an electronic circuit board equipped with a calculation unit, memory, a communication circuit, etc. In this case, a control program for controlling each part of the mower 100 is stored in the memory, and the calculation unit reads the control program from the memory and controls each part, such as the traveling unit 20, based on the control program.

[0025] As shown in Figures 1 to 3, the engine 60 is provided above the machine body 10. The engine 60 functions as a power source for the drive unit 33 that drives the top surface reaping unit 30, and as a power source for the alternator 70. The power generated by the engine 60 is transmitted to the drive unit 33 and the alternator 70 via power transmission means (not shown) formed of a belt or the like.

[0026] The alternator 70 is provided below the support case 15. The alternator 70 generates electric power by receiving power from the engine 60. The alternator 70 supplies the generated electric power to the battery 40 and also functions as a power source for the drive unit 83 that drives the slope reaping unit 80 and the drive unit 54 (see FIG. 2) that drives the traveling unit 20.

[0027] In this embodiment, an example has been shown in which the engine 60 is used as the power source for driving the top surface reaping unit 30, but the present invention is not limited to this example. For example, an alternator 70 can also be used as the power source for driving the top surface reaping unit 30. In other words, the top surface reaping unit 30, the slope reaping unit 80, and the traveling unit 20 can all be driven by power supplied from the alternator 70 or the battery 40.

[0028] The alternator 70 of this embodiment is equipped with a power generation control circuit (not shown) for controlling power generation. The mower 100 has a sensor that detects the battery voltage of the battery 40, and the power generation control circuit monitors the results detected by the sensor, allowing the alternator 70 to control its power generation state itself. The power generation control circuit controls the alternator 70 so that if the battery voltage of the battery 40 falls below a predetermined value, the alternator 70 generates power and enters a power supply state, and if the battery voltage of the battery 40 exceeds the predetermined value, the alternator 70 enters a power supply stopped state.

[0029] The battery 40 is provided at a position behind the control unit 50. The battery 40 stores the electric power generated by the alternator 70. The battery 40 may function as a power source that supplies the stored electric power to the drive unit 83 that drives the slope reaping unit 80 and the drive unit 54 that drives the traveling unit 20.

[0030] Although not shown in the drawings, the mower 100 may include a cover member that covers the battery 40, the control unit 50, and the engine 60 and serves to protect each part. The cover member may be configured to cover only a portion of the battery 40, the control unit 50, and the engine 60.

[0031] The tip-over prevention means 300L and 300R are arranged side by side on the left and right running sections 20L and 20R, respectively, so as to protrude to the sides (outside), and prevent the mower 100 from tipping over in the left-right direction during mowing work. The tip-over prevention means 300 includes a support frame 310, a main arm 320, and an auxiliary arm 330. The support frame 310 is attached to the side of the running section 20 by an attachment member 17 (see Figure 2; however, Figure 2 shows only attachment member 17L) that is connected to the machine body 14 and the crawler frame 24.

[0032] One end of the front side of the main arm 320 is rotatably connected to the support frame 310, and the main arm 320 is rotatably supported by the support frame 310. The auxiliary arm 330 is an extendable member that spans between the support frame 310 and the main arm 320 and is configured so that it can be fixed at a predetermined length. The main arm 320 can be rotated by extending or contracting the auxiliary arm 330. Specifically, when the auxiliary arm 330 is extended, the main arm 320 rotates downward and juts outward, and when the auxiliary arm 330 is retracted, the main arm 320 rotates upward and is held by the aircraft body. When mowing, the auxiliary arm 330 is extended, the main arm 320 is rotated downward, and the auxiliary arm 330 is fixed at a predetermined length. This allows the outward-hanging main arm 320 to come into contact with the field or grass and support the mower 100 when the mower 100 tilts. It is also possible to place a member that can ensure a large contact area at the part of the main arm 320 that comes into contact with the field. For example, if a plate-shaped member is attached to the rear end of the main arm 320, the plate-shaped member will function as a contact part with the field when the mower 100 tilts, making it possible to distribute the load (weight of the mower 100) on the main arm 320.

[0033] The configuration of the reaping unit 120 (specifically, the top surface reaping unit 30 and the slope surface reaping unit 80) will be described in detail below with reference to FIGS.

[0034] [Configuration of top surface reaping unit 30] The structure of the top surface reaping unit 30 will be described. As shown in FIG. 1, the top surface reaping unit 30 includes a casing 31, two blade units 32L and 32R arranged side by side, and drive units 33L and 33R corresponding to the blade units 32L and 32R, respectively. The drive units 33L and 33R are each connected to a mounting member 11. The casing 31 covers the top and sides of the blade unit 32 to prevent soil, pebbles, grass, and the like from scattering to the surrounding area. The casing 31 is sometimes referred to as a cover unit, and the side of the blade unit 32 not covered by the casing 31 faces the top surface 201 of the ridge 200. The structures of the blade unit 32R and drive unit 33R are the same as those of the blade unit 32L and drive unit 33L, respectively.

[0035] As shown in FIG. 2, the top surface cutting unit 30 is supported so as to be suspended from the support case 15 via the mounting member 11. The blade unit 32 is composed of multiple mowing blades. The blade unit 32 is connected to the rotation shaft of the drive unit 33, and rotation of the rotation shaft of the drive unit 33 rotates the blade unit 32, which includes multiple mowing blades. These rotating mowing blades perform the grass mowing work. The drive unit 33 uses the driving force of the engine 60 transmitted via a power transmission means (not shown) including a belt (not shown) as the driving force (rotational power) for the blade unit 32. The rotation shaft of the drive unit 33 extends in a direction perpendicular to the work surface (the ground on which the grass to be cut grows). However, in this specification, "perpendicular" does not only refer to a completely vertical state, but also refers to a state that can be considered substantially vertical. "When it can be considered substantially vertical" refers to, for example, when there is no functional difference in the object between when the object (here, the rotation axis of the drive unit 33) is completely vertical to the work surface and when it can be considered substantially vertical.

[0036] In this embodiment, the two blade sections 32L and 32R are provided symmetrically or approximately symmetrically with respect to the center line 110 of the machine body 10, and are arranged with a phase shift so that the mowing blades do not interfere with each other when the machine is stationary. The power transmission means is designed to transmit the driving force of the engine 60, transmitted via a belt, evenly or approximately evenly to both drive sections 33L and 33R. Therefore, the multiple mowing blades of blade section 32L and the multiple mowing blades of blade section 32R rotate at the same timing and the same speed.

[0037] In this embodiment, an example has been shown in which the engine 60 is used as the power source for rotating the blade section 32 of the top surface cutting section 30. However, when the alternator 70 is used as the power source for rotating the blade section 32, a motor can be used as the drive section 33. In this case, the control section 50 may be used to independently control the drive sections 33L and 33R, and independently drive the blade sections 32L and 32R. Furthermore, in this case, the power for driving the motor can be supplied from the alternator 70 or the battery 40.

[0038] [Configuration of the slope reaping unit 80] The structure of the slope reaping unit 80 will now be described. The slope reaping unit 80 includes a pair of left and right slope reaping units 80L and 80R. As shown in FIGS. 1 and 2, the slope reaping units 80L and 80R each include casings 81L and 81R, blade units 82L and 82R, drive units 83L and 83R corresponding to the blade units 82L and 82R, and grippers 140L and 140R. The casing 81, like the casing 31 of the top surface reaping unit 30, is sometimes referred to as a cover unit. It covers the top and sides of the blade units 82 and prevents soil, pebbles, grass, and the like from scattering into the surrounding area. The structure of the slope reaping unit 80R is the same as that of the slope reaping unit 80L.

[0039] As shown in FIG. 2, the blade unit 82 has multiple mowing blades. The blade unit 82 is connected to and rotates on the rotary shaft of the drive unit 83, which is driven by power from the alternator 70 or the battery 40. That is, the rotation of the rotary shaft of the drive unit 83 causes the blade unit 82, which includes multiple mowing blades, to rotate, and the blade unit 82 performs grass cutting work. Like the drive unit 33 of the top surface mowing unit 30, the rotary shaft of the drive unit 83 extends in a direction perpendicular to the work surface. For example, a motor can be used as the drive unit 83. The drive units 83L and 83R can be driven independently. That is, the mower 100 can perform grass cutting work by independently controlling the slope mowing unit 80L and the slope mowing unit 80R.

[0040] 1 and 3, the slope reaping units 80L and 80R are supported on the machine body 14 via position adjustment mechanisms 90L and 90R and angle adjustment mechanisms 130L and 130R, respectively. Because the position adjustment mechanism 90 is rotatably connected to the machine body 14, the slope reaping units 80 can also rotate relative to the machine body 14.

[0041] The position adjustment mechanism 90 is a mechanism for moving the slope mowing unit 80 to follow the shape of the slope when the slope mowing unit 80 mows the slope. It adjusts the left-right position of the slope mowing unit 80 to match the width of the ridge (ridge width) and the up-down position of the slope mowing unit 80 to match the undulations of the slope. The position adjustment mechanism 90 includes a parallel link structure for translating the slope mowing unit 80 in the vertical direction relative to the machine body 14, and a parallel link structure for translating the slope mowing unit 80 in the horizontal direction. These two parallel link structures allow the slope mowing unit 80 to translate up, down, left, and right without changing its posture. In other words, when the position adjustment mechanism 90 operates in response to changes in the ridge width or the undulations of the slope, the two parallel link structures translate the slope mowing unit 80 in the vertical and horizontal directions, preventing changes in posture relative to the slope and allowing for efficient mowing.

[0042] The angle adjustment mechanisms 130L and 130R are connected to the position adjustment mechanisms 90L and 90R and the slope mowing units 80L and 80R, respectively. The slope mowing unit 80 can change its inclination relative to the machine body 14 by operating the angle adjustment mechanism 130. Specifically, the angle adjustment mechanism 130 is configured to adjust the angle (angle α2) between the mowing surface 204 of the slope mowing unit 80 and the underside of the machine body 14 (the same plane as the plane 206 shown in FIG. 3) in accordance with the inclination angle (angle α) of the slope 202 of the ridge 200. In the following description, the "underside of the machine body 14" is synonymous with the plane 206 shown in FIG. 3. The "mowing surface 204" is the plane (indicated by the dashed line in FIG. 3) that includes the path of the blade 82 (see FIG. 2) of the slope mowing unit 80 when mowing the grass, and can also be referred to as the cut surface of the grass during mowing work.

[0043] 1 and 2, the slope mowing units 80L and 80R each include a mowing height adjustment unit 400L and 400R at their rear. The mowing height adjustment unit 400L includes a roller 410L and roller support units 420aL and 420bL that rotatably support the roller 410L. Similarly, the mowing height adjustment unit 400R includes a roller 410R and roller support units 420aR and 420bR that rotatably support the roller 410R.

[0044] The roller 410 is a cylindrical or rod-shaped rotating body that rotates in the direction of travel of the mower 100. The roller 410 of this embodiment has a rotation axis 411 (see FIG. 2 ; however, only the rotation axis 411L is shown in FIG. 2 ) that is parallel or substantially parallel to the mowing surface 204 of the slope mowing unit 80. As described above, the slope mowing unit 80 is configured to move in accordance with the shape of the slope through the operation of the position adjustment mechanism 90. As shown in FIG. 3 , the slope mowing unit 80 is configured so that the roller 410 comes into contact with the slope 202 of the ridge 200, thereby maintaining the positional relationship between the working surface (slope 202) and the blade unit 82, i.e., the distance from the mowing surface 204 to the slope 202 (corresponding to the mowing height), at a predetermined distance H1. In other words, the slope mowing unit 80 can maintain a constant mowing height of grass growing on the slope 202 in accordance with the undulations of the slope 202 of the ridge 200.

[0045] As described above, the mower 100 of this embodiment can translate the slope mowing unit 80 in the up, down, left, and right directions by operating the position adjustment mechanism 90, allowing mowing work to be performed without changing the posture of the slope mowing unit 80 in response to changes in ridge width and the undulations of the slope. Providing a cutting height adjustment unit 400 on the slope mowing unit 80 is extremely useful for effectively operating the position adjustment mechanism 90. The mower 100 can maintain a predetermined distance from the mowing surface 204 to the slope 202 using the cutting height adjustment unit 400, preventing the casing 81 of the slope mowing unit 80 from contacting the ridge 200 and enabling smooth translation of the slope mowing unit 80 by the position adjustment mechanism 90.

[0046] [Configuration of cutting height adjustment unit 400] The mowing height adjustment unit 400 of the slope mowing unit 80 will be described using Figure 4. Figure 4 is a perspective view showing the configuration of the mowing height adjustment unit 400R provided in the slope mowing unit 80R of the mower 100 according to one embodiment of the present invention. Specifically, Figure 4(A) is a view of the slope mowing unit 80R seen from the diagonally rear left, and Figure 4(B) is an enlarged view of the roller support unit 420bR when the slope mowing unit 80R is seen from the left side. Although Figure 4 illustrates the slope mowing unit 80R, the slope mowing unit 80L also has a similar configuration.

[0047] As shown in FIG. 4(A), the cutting height adjustment unit 400R includes a roller 410R and roller support units 420aR and 420bR. The cutting height adjustment unit 400R adjusts the distance (cutting height) between the cutting surface 204R and the slope 202 of the slope mowing unit 80R shown in FIG. 3. Specifically, the roller support units 420aR and 420bR are connected to (the side surface 81bR of) the casing 81R of the slope mowing unit 80R so as to be able to rotate up and down. The position of the roller 410R, which is supported at both ends by the roller support units 420aR and 420bR, is adjusted via the roller support units 420aR and 420bR to adjust the cutting height of the slope mowing unit 80R. The cutting height adjusting unit 400R has the function of keeping a predetermined distance between the cutting surface 204R and the slope 202 by bringing the roller 410R into contact with the ground (here, the slope 202).

[0048] The roller 410R is a cylindrical (e.g., cylindrical) or solid rod-shaped (e.g., columnar) rotating body. The roller 410R of this embodiment is a cylindrical rotating body, with a rotating shaft 411R inserted therein. The rotating shaft 411R is rotatably supported by roller support portions 420aR and 420bR. In other words, the roller 410R does not have a drive source for rotation, but is a driven roller (also called a self-rotating roller) that rotates by being pulled while in contact with the ground. In this way, the cutting height adjustment unit 400R comes into contact with the ground by the cylindrical roller 410R, so that the contact resistance with the ground during operation is very small, and the increase in power required to move the mower 100 can be suppressed compared to conventional techniques.

[0049] Furthermore, in this embodiment, a cylindrical rotating body with its longitudinal direction in the left-right direction is used as the roller 410R, so the surface that comes into contact with the ground is linear. Therefore, even if there is a localized depression in the ground (in this embodiment, the slope 202), there is little change in the position of the roller 410R due to such a depression, and the mower 100 of this embodiment is able to suppress fluctuations in the mowing height of the slope mowing section 80 during operation, allowing for stable mowing work.

[0050] The roller 410R can be made of a metal material or a plastic material. In this embodiment, a cylindrical rotating body is used as the roller 410R, so the vertical cross section is circular, but this is not limited to this example. For example, the vertical cross section may be polygonal or have a shape with multiple projections and recesses like a gear. In addition, the outer periphery of the roller 410R may be provided with a spiral step along the direction of the rotation axis 411R.

[0051] The roller support portions 420aR and 420bR function as bearings for the above-mentioned rotating shaft 411R and are bearing members that support the roller 410R at both ends. The roller support portions 420aR and 420bR are configured identically and are rotatably connected to the rear side of the side surface 81bR of the casing 81R so as to be bilaterally symmetrical. Specifically, as shown in FIG. 4(A), the roller support portion 420bR is connected to the side surface 81bR of the casing 81R by a connecting shaft 421bR that serves as a rotating shaft. Similarly to the roller support portion 420bR, the roller support portion 420aR is also connected to the side surface 81bR of the casing 81R by a connecting shaft (not shown) that serves as a rotating shaft. Therefore, roller 410R can rotate about a connecting shaft (not shown) provided on the right side surface of casing 81R and a connecting shaft 421bR provided on the left side surface of casing 81R, and as a result, its position can be adjusted in the vertical direction. Note that roller support portions 420aR and 420bR are bent to prevent deformation during operation. In this embodiment, both ends are bent outward to form a roughly U-shape (see FIG. 4(A)), but it is also possible to bend one end to form a roughly L-shape.

[0052] In addition, the casing 81R has a cover member 150R provided to cover the periphery (four sides) of the blade portion 82R (see FIG. 1) in a plan view, thereby reducing scattering of cut grass in all directions. Of the cover members 150R provided to cover the periphery (four sides) of the blade portion 82R, the cover members 150R arranged on the front, back, and left side (inside) of the blade portion 82R are made of a rubber material. By making the cover members 150R located on the front, back, and left side (inside) of the blade portion 82R out of a flexible material such as rubber, even if cut grass accumulates inside the casing 81R, the cover members 150R will turn over (deform) to allow the accumulated grass to be discharged. This reduces the load on the drive unit 83 (motor) and prevents problems such as grass getting stuck between the roller 410R and the roller support portions 420aR and 420bR and interfering with the rotation of the roller 410R. Furthermore, the cover member 150R on the rear side of the casing 81R is positioned so as not to overlap with the roller 410R in rear view, and consideration is given to preventing its lower end from interfering with the roller 410R during mowing work. However, the length of the cover member 150R on the rear side of the casing 81R can be set to any length as long as it does not interfere with the roller 410R during work. Furthermore, in this embodiment, multiple notches are provided on the underside of the cover member 150R located on the front, rear, and left side of the cutting section 82R, which is made of rubber (for example, in this embodiment, two notches are provided on the rear-side cover member 150R), making the cover member 150R more easily deformable and allowing grass inside the casing 81R to be smoothly discharged. Furthermore, in this embodiment, the cover member 150R is provided so as to leave a predetermined gap between the cover member 150R and the ground (work surface), but when viewed from the side, the roller 410R is positioned behind the blade portion 82R and the cover member 150R, so that grass that is scattered backward from the gap between the cover member 150R and the ground (work surface) can be stopped by the roller 410R without hitting the cover member 150R.In the mower 100 of this embodiment, the cover member 150R located on the right side (outside) of the casing 81R is made of an iron plate, and is designed to prevent cut grass from being discharged into the field. However, this is not limited to the example shown in Figure 4(A), and when constructing the casing 81R, it is possible to change as appropriate which side the cover member 150R is provided on and is arbitrary.

[0053] As shown in FIG. 4B, two through holes 422bR and 423bR are provided side by side in the roller support portion 420bR. In the example shown in FIG. 4B, two through holes 422bR and 423bR are provided in the roller support portion 420bR, but this is not limiting. For example, the number of through holes may be one, or three or more. On the other hand, although not shown, a plurality of through holes are also provided in a staggered pattern in the side surface 81bR of the casing 81R. The number of through holes provided in the side surface 81bR of the casing 81R is arbitrary, but it is desirable that the number be at least equal to or greater than the number of through holes provided in the roller support portion 420bR. In this embodiment, three through holes are provided in the side surface 81bR of the casing 81R.

[0054] In this embodiment, the position of the roller 410R can be adjusted by aligning the through holes 422bR and 423bR provided in the roller support portion 420bR with the through holes provided in the side surface 81bR of the casing 81R. Specifically, by aligning the position of one of the two through holes 422bR and 423bR provided in the roller support portion 420bR with one of the three through holes provided in the side surface 81bR of the casing 81R and inserting the fixing pin 424bR shown in Fig. 4(A) through both through holes, the relative positional relationship between the casing 81R and the roller support portion 420bR, i.e., the position of the roller 410R, can be fixed.

[0055] Two of the three through holes provided in the side surface 81bR of the casing 81R are arranged along the rotation locus of one of the two through holes 422bR and 423bR provided in the roller support portion 420bR, and the remaining one is arranged along the rotation locus of the other of the two through holes 422bR and 423bR. In other words, when the roller support portion 420bR rotates around the connecting shaft 421bR, one of the two through holes 422bR and 423bR sequentially overlaps one of the three through holes provided in the side surface 81bR of the casing 81R.

[0056] The reason for using two through-holes 422bR and 423bR is to enable precise position control of roller 410R. For example, if one through-hole is provided in roller support portion 420bR and three through-holes are provided in casing 81R along its rotation trajectory, the position of roller 410R can be adjusted in three stages. In this case, when arranging three through-holes in casing 81R side by side, if the spacing between the through-holes is too narrow, the strength around the through-hole may be insufficient. Therefore, it is desirable to ensure a certain amount of spacing between the through-holes. However, if the spacing between the through-holes is too wide, the adjustment range of the position of roller 410R may become too narrow.

[0057] Therefore, in this embodiment, of the three through holes provided in side surface 81bR of casing 81R, two through holes are provided along the rotation locus of through hole 423bR, and the remaining through hole is provided on the rotation locus of through hole 422bR. In this case, by arranging the three through holes provided in side surface 81bR of casing 81R in a staggered arrangement, for example, it is possible to solve the strength problem described above, while narrowing the adjustment range for the position of roller 410R, and enabling more precise position adjustment of roller 410R.

[0058] As described above, the slope mowing unit 80 of this embodiment is equipped with a mowing height adjustment unit 400 that can adjust the height at which the grass is mowed by adjusting the position of the roller 410. By providing the mowing height adjustment unit 400 at the rear of the slope mowing unit 80, the grass will not be toppled by the roller 410 before being mowed, allowing for stable mowing work. Furthermore, by providing the mowing height adjustment unit 400 in the slope mowing unit 80, the grass mower 100 can easily adjust the mowing height (the distance from the mowing surface 204 to the slope 202) of the mowing unit (in this embodiment, the slope mowing unit 80) in accordance with the condition of the grassland (for example, the undulations of the slope), and can maintain a predetermined distance from the mowing surface 204 of the mowing unit to the slope 202 even during work.

[0059] Furthermore, as described above, the mower 100 can prevent the casing 81 of the slope cutting unit 80 from coming into contact with the ridge 200 by using the cutting height adjustment unit 400, and the slope cutting unit 80 can be smoothly moved in parallel by using the position adjustment mechanism 90 described above.

[0060] (Variation) In this embodiment, an example is shown in which roller 410R is provided as a cylindrical rotating body provided over almost the entire area between roller support portion 420aR and roller support portion 420bR, but the shape of roller 410R is not limited to this example. Specifically, the length of roller 410R in the rotation axis direction can be changed as appropriate.

[0061] Fig. 5 is a rear view showing the configuration of cutting height adjustment units 400Ra and 400Rb provided on slope cutting units 80Ra and 80Rb of a mower 100 according to a modified embodiment of the present invention. Specifically, Fig. 5(A) shows the slope cutting unit 80Ra equipped with a cutting height adjustment unit 400Ra in which a roller 410Ra is disposed near the center of a rotation shaft 411Ra, and Fig. 5(B) shows the slope cutting unit 80Rb equipped with a cutting height adjustment unit 400Rb in which roller support units 420aR and 420bR each support a different rotation shaft 411Rb and a roller 410Rb is disposed on each rotation shaft 411Rb.

[0062] In the cutting height adjustment unit 400Ra shown in FIG. 5(A), the roller 410Ra is disposed only near the center of the rotation shaft 411Ra. That is, there is a predetermined distance between the right end of the roller 410Ra and the roller support portion 420aR, and between the left end of the roller 410Ra and the roller support portion 420bR. When there are gaps on the left and right sides of the roller 410Ra, grass cut by the blade portion 82 (see FIG. 1) is easily discharged rearward through the gaps, preventing excessive grass accumulation below the casing 81R. In particular, because the rotation axis of the blade portion 82R of the slope cutting unit 80R is perpendicular to the ground (work surface), grass cut and blown in the rotation direction by the blade portion 82R is likely to accumulate in the lower corners of the casing 81R. 4, when there is almost no gap between the roller 410R and the roller support portions 420aR and 420bR, grass also tends to accumulate between the casing 81R and the roller 410R (between the roller support portion 420aR and the roller support portion 420bR). Furthermore, even when there is a gap between the roller 410R and the roller support portions 420aR and 420bR, the roller support portion 420aR or the roller support portion 420bR blocks the discharge of grass cut and blown in the rotation direction by the blade portion 82R from between the roller 410R and the roller support portions 420aR and 420bR. This causes grass to easily accumulate near the surface of the roller support portion 420aR between the casing 81R and the roller 410R that faces the roller support portion 420bR, or near the surface of the roller support portion 420bR between the casing 81R and the roller 410R that faces the roller support portion 420aR. Therefore, it is desirable to have gaps on the left and right sides of the roller 410Ra in order to effectively prevent grass from accumulating near the lower corners of the casing 81R and between the casing 81R and the roller 410R. Here, there is no particular limitation on the above-mentioned "predetermined distance," but it is preferable that the left-right length of the roller 410Ra be 30% to 70% (preferably 40% to 60%) of the left-right length of the rotation shaft 411Ra. If it is too long, the effect of easily discharging grass rearward will be reduced, and if it is too short, it will be more susceptible to the influence of local depressions in the ground.

[0063] In this embodiment, an example is shown in which the rotation shaft 411Ra is inserted inside the roller 410Ra, but the present invention is not limited to this example. For example, the rotation shaft 411Ra disposed between the roller 410Ra and the roller support portion 420aR and the rotation shaft 411Ra disposed between the roller 410Ra and the roller support portion 420bR may be separate members.

[0064] Next, in the cutting height adjustment unit 400Rb shown in FIG. 5(B), the rollers 410Rb are arranged on the left and right sides of the rotary shaft 411Ra. That is, the left roller 410Rb and the right roller 410Rb are separated by a predetermined distance. In this case, too, the gap between the two rollers 410Rb makes it easier for grass cut by the blade section 82 (see FIG. 1) to be discharged rearward, preventing the problem of excessive grass accumulation below the casing 81R. In this case, for the same reasons as in the example shown in FIG. 5(A), it is preferable that the total length of the left and right rollers 410Rb in the left-right direction be 30% to 70% (preferably 40% to 60%) of the length of the rotary shaft 411Ra in the left-right direction.

[0065] In addition, in the example shown in FIG. 5(B), separate rotating shafts 411Rb are provided for the two rollers 410Rb, but this is not limited to this example, and one rotating shaft 411Rb can also be provided spanning the roller support portions 420aR and 420bR.

[0066] As described above, in this modified example, when viewed from the rear side, the length of roller 410 (the length along rotation shaft 411) is shorter than the diameter (maximum width) of the rotation path (shown by the dashed line in FIG. 1) of cutting blade 82R (see FIG. 1). In other words, an area can be formed in which grass scattered rearward as a result of being cut by rotating blade section 82 is not blocked by roller 410, making it easier to discharge grass cut by blade section 82 rearward of slope cutting section 80.

[0067] In the configurations shown in FIGS. 5(A) and 5(B), there is an area between the roller support portion 420aR and the roller support portion 420bR where the roller 410R is not present, and in this area, the roller 410R cannot block grass scattering rearward. In this case, for the area where the roller 410R is not present, the length (length perpendicular to the work surface) of the portion of the cover member 150R provided on the rear side of the casing 81R corresponding to the area can be extended, and the extended portion of the cover member 150R can prevent grass from scattering rearward. That is, in this modification, the length of the cover member 150R provided on the rear side of the casing 81R may be changed depending on the arrangement of the roller 410R. For example, in the case of FIG. 5(A), since the roller 410Ra is only arranged near the center of the rotation shaft 411Ra, the cover member 150R on the rear side of the casing 81R is longer in the areas on both sides where the roller 410Ra is not arranged and shorter in the central area where the roller 410Ra is arranged, when viewed from behind. 5(B), since the roller 410Rb is not disposed in the center of the rotation shaft 411Rb, the cover member 150R on the rear side of the casing 81R has a longer central region where the roller 410Rb is not disposed in rear view, and has shorter regions on both sides where the roller 410Rb is disposed. Note that, in order to prevent the cover member 150R from interfering with the roller 410 during mowing work, it is preferable that the end of the roller 410 and the end of the elongated cover member 150R located on the roller 410 side are spaced apart in rear view.

[0068] Second Embodiment In this embodiment, an example will be described in which the configuration of the slope reaping unit 80 is different from that of the first embodiment. In the description of the drawings of this embodiment, the basic configuration is the same as that of the slope reaping unit 80 of the first embodiment, but in this embodiment, a detailed description will be given focusing on the parts that are significantly different in structure. Also, in the first embodiment, the slope reaping unit 80R was described, but in this embodiment, the slope reaping unit 80L will be described as an example.

[0069] Figures 6 and 7 are diagrams showing the configuration of the mowing height adjuster 400Lc provided in the slope mowing unit 80Lc of the mower 100 according to one embodiment of the present invention. Specifically, Figure 6(A) is a diagram of the slope mowing unit 80Lc seen from diagonally above left, and Figure 6(B) is a diagram of the slope mowing unit 80Lc seen from above. Also, Figure 7(A) is a diagram of the slope mowing unit 80Lc seen from the back, and Figure 7(B) is a diagram of the slope mowing unit 80Lc seen from the left side.

[0070] As shown in Figures 6 and 7, the cutting height adjustment unit 400Lc includes two rollers 410Lc and a roller support unit 420Lc. A rotation shaft 411Lc is inserted into each roller 410Lc, and the rotation shaft 411Lc is rotatably supported by a support arm 425L of the roller support unit 420Lc. However, the rotation shaft 411Lc does not have to be inserted into each roller 410Lc. In other words, as long as each roller 410Lc is rotatably connected, the connection structure between each roller 410Lc and the rotation shaft 411Lc is not important.

[0071] Furthermore, the rotation axis 411Lc, which is the center of rotation of the roller 410Lc in this embodiment, is not perpendicular to the traveling direction of the slope mowing unit 80Lc during mowing work (i.e., the traveling direction of the mower 100), but extends in a direction that intersects it obliquely. Specifically, the rotation axis 411Lc is inclined so that it points rearward as it moves away from the connection part with the support arm 425, that is, so that it is positioned further rearward as it moves outward in a plan view. However, this is not a limitation, and the rotation axis 411Lc may be perpendicular to the traveling direction of the slope mowing unit 80Lc during mowing work.

[0072] Furthermore, the roller 410Lc of this embodiment has a truncated cone shape whose cross section narrows as it moves away from the connection portion with the support arm 425. In other words, each roller 410Lc is configured so that the diameter of the end farther (outer) from the connection portion with the roller support portion 420Lc is smaller than the diameter of the end closer (inner) to the connection portion, and so is configured to taper outward. As such, since the roller 410Lc of this embodiment has a shape that narrows as it moves away from the connection portion with the roller support portion 420Lc, even if grass discharged rearward by the blade portion 82L (see FIG. 1) becomes entangled in the roller 410Lc, as the roller 410Lc rotates, the grass gradually moves to the end farther from the connection portion with the roller support portion 420Lc and is released from that end. In other words, by having a configuration in which the roller 410Lc of this embodiment is tapered outward, it is possible to reduce tangling of grass discharged toward the rear of the slope mowing unit 80Lc and prevent problems such as the roller 410Lc stopping rotation due to grass tangling. In particular, in this embodiment, as described above, the rotation shaft 411Lc is inclined so that it is positioned rearward as it extends outward in a plan view, so that grass tangled in the roller 410Lc can be efficiently discharged outward and rearward.

[0073] 7(C), in this embodiment, the rotation shaft 411Lc, which is the center of rotation of each roller 410Lc, is inclined downward as it moves away from the connection portion with the roller support portion 420Lc. Specifically, the rotation shaft 411Lc is inclined so that the outer circumferential surface of each roller 410Lc makes linear contact with the ground (here, the slope 202). This allows the contact surface between each roller 410Lc and the ground to be linear. Therefore, even if there is a localized depression in the ground (in this embodiment, the slope 202), it is possible to prevent the position of the roller 410Lc from changing due to such a depression, and to minimize fluctuations in the mowing height.

[0074] The roller support part 420Lc includes a support arm 425L, a connecting bracket 426L, a connecting shaft 427L, a position adjustment plate 428L, and a fixing pin 429L. However, the configuration of the roller support part 420Lc shown in Figures 6 and 7 is merely an example, and is not limited to this configuration. Furthermore, although some are not shown, the support arm 425L is provided with three through holes 425aL, and the position adjustment plate 428L is provided with two through holes 428aL.

[0075] The support arm 425L serves to connect the casing 81Lc of the slope reaping unit 80Lc to the rollers 410Lc. Specifically, one end of the support arm 425L is pivotally supported by a connecting bracket 426L attached to the top surface of the casing 81Lc and rotates vertically around a connecting shaft 427L. The other end of the support arm 425L is connected to the two rollers 410Lc via a rotating shaft 411Lc. In other words, the rotation of the support arm 425L allows the rollers 410Lc to move (rotate) vertically.

[0076] A position adjustment plate 428L is attached to the upper surface of the casing 81Lc adjacent to the support arm 425L. The position adjustment plate 428L has a flat portion that protrudes away from the upper surface of the casing 81Lc, and the flat portion has two through holes 428aL. That is, in this embodiment, three through holes 425aL are provided in the support arm 425L, and two through holes 428aL are provided in the position adjustment plate 428L. The through holes 425aL provided in the support arm 425L and the through holes 428aL provided in the position adjustment plate 428L are aligned with each other, and a fixing pin 429L is inserted through both through holes to adjust the position of the roller 410Lc. The specific arrangement of the through holes 425aL and 428aL and the specific position adjustment method using them are the same as those in the first embodiment, so detailed description thereof will be omitted here.

[0077] In this embodiment, the two rollers 410Lc are supported by roller support parts 420Lc in a suspended manner from above, and each of the two rollers 410Lc is configured to easily release grass from its outer edge. Therefore, compared to the configuration in which the roller 410 is supported by both the left and right edges as in the first embodiment, the roller 410Lc of this embodiment has the advantage that cut grass is less likely to accumulate at the edges.

[0078] (Variation 1) In this embodiment, as shown in Fig. 5(A) in the modified example of the first embodiment, gaps may be provided behind the left and right ends of the slope mowing unit 80Lc. Specifically, in the rear view shown in Fig. 7(A), the length of each roller 410Lc in the left-right direction may be shortened, and a predetermined distance may be provided between the right end of the right roller 410Lc and the right end of the casing 81Lc, and between the left end of the left roller 410Lc and the left end of the casing 81Lc.

[0079] (Variation 2) In this embodiment, the roller support 420Lc supports two rollers 410Lc in a cantilevered manner. However, the present invention is not limited to this example. For example, a single roller as shown in the first embodiment can be supported at both ends by being suspended from above by the roller support. Specifically, a roller support having one end rotatably connected to the top surface of the casing and the other end branching into a first support portion and a second support portion (i.e., a bifurcated end) can be used as the roller support, with the roller axially supported between the first support portion and the second support portion. With this configuration, as in the second embodiment, a gap is formed between the casing and the roller, so that the roller support portion does not block the discharge of grass. This prevents problems such as grass accumulating between the casing and the roller or grass becoming entangled in the roller's rotation shaft.

[0080] Furthermore, this modified example 2 can be combined with the modified example of the first embodiment. Specifically, as explained in the modified example of the first embodiment, the length of the roller (length along the rotation axis) when viewed from the rear side may be shorter than the length of the rear end on the top surface of the casing (i.e., the width of the area where grass is discharged rearward). This allows a gap that is not blocked by the roller 410 to be formed behind the casing 81, making it easier to discharge grass cut by the blade section 82 rearward of the slope mowing section 80.

[0081] The brush cutter of the present invention has been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiments (including variations), and modifications can be made as appropriate without departing from the spirit of the present invention. For example, even if a person skilled in the art appropriately adds, deletes, or modifies components based on the embodiments, such modifications are included within the scope of the present invention as long as they incorporate the gist of the present invention. Furthermore, the configurations according to the above-described embodiments can be appropriately combined as long as they are not mutually inconsistent, and technical matters common to the embodiments are included in each configuration even if not explicitly stated.

[0082] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0083] 10...machine body, 11...mounting member, 14...machine body, 15...support case, 17...mounting member, 20...traveling unit, 20L...traveling unit, 20R...traveling unit, 21L...crawler belt, 22L...drive wheel, 23L...driven wheel, 24, 24L...crawler frame, 30...top surface cutting unit, 31...casing, 32, 32L, 32R...blade unit, 33, 33L, 33R...drive unit, 40...battery, 50...control unit, 54, 54L...drive part, 60...engine, 70...alternator, 80, 80L, 80R, 80Ra, 80Rb...slope mowing part, 81, 81L, 81R, 81Lc...casing, 81bR...side, 82, 82L, 82R...blade part, 83, 83L, 83R...drive part, 90, 90L...position adjustment mechanism, 100...grass mower, 110...center line, 120...mowing part, 130, 130L...angle adjustment mechanism, 140L...gripping part, 150R...casing Bar member, 200...ridge, 201...top surface, 202...sloping surface, 203...horizontal surface, 204, 204R...cutting surface, 206...flat surface, 300, 300L...anti-tip means, 310...support frame, 320...main arm, 330...auxiliary arm, 400, 400L, 400Lc, 400R, 400Ra, 400Rb...cutting height adjustment unit, 410, 410L, 410Lc, 410R, 410Ra, 410Rb...roller, 411 R, 411Ra, 411Rb, 411Lc...rotating shaft, 420aL, 420aR, 420bR, 420Lc, 420R...roller support portion, 421aR, 421bR...connecting shaft, 422bR, 423bR...through hole, 424bR...fixing pin, 425L...support arm, 425aL...through hole, 426L...connecting bracket, 427L...connecting shaft, 428aL...through hole, 428L...position adjustment plate, 429L...fixing pin

Claims

1. A self-propelled grass mower that cuts grass, a cutting unit having a cutting blade; The rotation axis of the cutting blade extends in a direction perpendicular to the work surface, The mower includes a roller and a roller support part that rotatably supports the roller, and also includes a mowing height adjustment part that can adjust the positional relationship between the work surface and the mowing blade.

2. The cutting unit includes a casing that covers the blade unit from above, The mower according to claim 1, wherein one end of the roller support portion is rotatably connected to the upper surface of the casing, and the other end axially supports the roller.

3. The rollers include two rollers, The mower according to claim 2 , wherein the other end of the roller support portion supports the two rollers between the two rollers.

4. The brush mower according to claim 3, wherein the rotation axis serving as the center of rotation of the two rollers is inclined rearward as it moves away from the connection portion with the roller support portion.

5. The mower according to claim 3, wherein each of the two rollers has a smaller diameter at an end farther from the connection with the roller support portion than at an end closer to the connection with the roller support portion.

6. The mower according to claim 1 or 2, wherein the cutting unit is attached to the machine body so as to be tiltable.

7. The grass mower according to claim 1 or 2, wherein the length of the roller is shorter than the diameter of a rotation path of the cutting blade.

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