JP2017118838A - Lawn mower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a lawn mower capable of suppressing float-up of front wheels during a work is required.SOLUTION: Right and left front wheels 14 are rotatable independently around a common front wheel shaft 14A, and the structure thereof is bilaterally symmetrical. Further, an outer peripheral surface of each front wheel 14 has a cylindrical shape using the front wheel shaft 14A as a center axis. In this case, each front wheel 14 includes a front wheel body 141 constituted by including the outer peripheral surface (ground plane) having the cylindrical shape, and a weight part 142 constituted of a material different from the front wheel body 141.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structure of a lawn mower that performs lawn mowing while traveling on the ground.

  Lawn mowers that are operated by an operator so as to travel on the ground and perform lawn mowing during traveling are widely used. The structure of such a lawn mower is described in Patent Document 1, for example.

  In a lawn mower, a blade that is rotationally driven is provided in a lower part of a main body that contains a power source (motor) and a power source (battery or the like). A front wheel and a rear wheel are respectively provided before and after the blade in the main body. For this reason, it is possible to mow the lawn with the rotating blade while running the main body by rolling the front wheel and the rear wheel in a grounded state. In addition, a handle is provided that extends obliquely upward and rearward from the main body. For this reason, the operator located behind the main body can grip the handle and freely move the main body (lawn mower) back and forth, and can also bend the traveling direction left and right. The handle is also provided with a switch for controlling on / off of rotation of the blade.

  As a result, the operator can freely run the lawn mower, and the lawn mowing work over a large area can be easily performed. At this time, as the blade rotates, an air flow is generated toward the rear, and the cut grass is guided into the grass collection bag attached to the rear of the main body by the air flow. At the end of the work, the grass bag can be removed and the turf inside can be discarded.

Japanese Patent Laying-Open No. 2015-8669

  In the above lawn mower, the operator is positioned behind the lawn mower (main body) and grips the handle during the operation, so that the load on the front wheel is reduced particularly by the force applied to the handle of the operator, and the front wheel I sometimes lifted off the ground. As a result, it may be difficult for the operator to control the travel of the lawn mower by operating the handle.

  In particular, as the lawn mowing operation continues, the amount of turf accommodated in the grass collection bag attached to the rear of the main body increases. For this reason, in the lawn mower, the weight of the rear part increases as the lawn mowing operation continues. In particular, when mowing turf with a high water content, the specific gravity of the turf increases, and this increase in weight becomes significant.

  In this case, as the lawn mowing work proceeded, the center of gravity of the lawn mower gradually moved backward, and the load on the front wheels provided in front of the main body gradually decreased. For this reason, as the lawn mowing work progressed, the lifting of the front wheels from the ground became particularly noticeable.

  For this reason, a lawn mower that suppresses lifting of the front wheels during work has been desired.

  The present invention has been made in view of such problems, and an object thereof is to provide an invention that solves the above problems.

In order to solve the above problems, the present invention has the following configurations.
The lawn mower according to the present invention is attached to the main body so as to cut the lawn when driven, a main body provided with front wheels and rear wheels on the front and rear, respectively, and extending rearward from the main body. A lawn mower capable of traveling by rolling with the front wheel and the rear wheel in contact with the ground, wherein the front wheel has a substantially cylindrical outer periphery that contacts the ground during traveling. A front wheel body having a surface and a weight portion made of a material different from the material constituting the front wheel body are combined.
In the lawn mower of the present invention, the front wheel body is made of a resin material, and the weight portion is made of metal.
In the lawn mower according to the present invention, the front wheel is formed by integrally molding the front wheel main body and the weight portion.
In the lawn mower according to the present invention, the weight portion is detachable from the front wheel body.
In the lawn mower according to the present invention, the weight portion has an annular shape.
The lawn mower according to the present invention is characterized in that the weight portion is attached by being screwed to the front wheel body.
The lawn mower according to the present invention is characterized in that the weight part is attached to the front wheel body using a fastening member that fixes the weight part to the front wheel body.
In the lawn mower according to the present invention, the weight portion is attached to the front wheel main body by being locked to a locking portion provided in the front wheel main body.
In the lawn mower according to the present invention, the front wheel main body includes a plurality of rib portions formed radially extending from a rotation shaft of the front wheel, and the plurality of weight portions mounted between the adjacent rib portions. Is used.
The lawn mower according to the present invention is characterized in that a plurality of the weight portions are detachable.
In the lawn mower according to the present invention, the front wheel main body is provided with a cavity capable of containing a liquid, and the weight portion is configured by the liquid contained in the cavity.
The lawn mower according to the present invention is characterized in that a grass collection bag for housing the cut grass is mounted behind the rear wheel in the main body.

  Since the present invention is configured as described above, it is possible to obtain a lawn mower that prevents the front wheel from being lifted during work.

It is a perspective view from the side of a lawn mower which becomes an embodiment of the invention. It is sectional drawing perpendicular | vertical to the front-back direction in the part with the front wheel of the lawn mower which becomes embodiment of this invention. It is sectional drawing of the front wheel in the lawn mower which becomes embodiment of this invention. It is sectional drawing of the 1st modification (a) of the front wheel in the lawn mower which becomes embodiment of this invention, and a 2nd modification (b). It is sectional drawing of the 3rd modification (a) of the front wheel in the lawn mower which becomes embodiment of this invention, and a 4th modification (b). It is sectional drawing of the 5th modification (a), the 6th modification (b), and the 7th modification (c) of the front wheel in the lawn mower according to the embodiment of the present invention. It is sectional drawing of the 8th modification (a), 9th modification (b), and 10th modification (c) of the front wheel in the lawn mower according to the embodiment of the present invention. It is sectional drawing of the 11th modification (a) of the front wheel in the lawn mower which becomes embodiment of this invention, and a 12th modification (b). It is sectional drawing (a) and the side view (b) of the 13th modification of the front wheel in the lawn mower which becomes embodiment of this invention. It is sectional drawing (a) and the side view (b) of the 14th modification of the front wheel in the lawn mower which becomes embodiment of this invention.

  The configuration of the lawn mower according to the embodiment of the present invention will be described. FIG. 1 is a perspective view from the side showing the configuration of the lawn mower 1. In FIG. 1, a state in which the lawn mower 1 is placed on the ground G is shown. FIG. 2 is a cross-sectional view in the AA direction in FIG. In the main body 10, a motor 11 having a rotating shaft in the vertical direction is mounted, and a blade (cutting blade) 12 driven by the rotating shaft is provided in a lower portion of the main body 10. At this time, by operating (turning) the height adjustment lever 13 shown in FIGS. 1 and 2, the relative position between the front wheel 14 and the main body 10 changes, and the height of the blade 12 from the ground is adjusted. Is possible. As a result, the height of the lawn after trimming can be adjusted.

  The main body 10 is supported on the ground G by the front wheels 14 and the rear wheels 15. The front wheel 14 and the rear wheel 15 are rotatable around a front wheel shaft 14A and a rear wheel shaft 15A, which are rotation axes perpendicular to the paper surface in FIG. Further, as shown in FIG. 2, the front wheel 14 is actually provided with the front wheel shaft 14A as a common rotation axis independently on the front side and the back side in FIG. On the other hand, the rear wheel 15 is elongated in the direction perpendicular to the paper surface in FIG. 1 and has a single cylindrical shape whose central axis coincides with the rotation axis 15A. For this reason, the main body 10 can be run on the ground G by rolling with the two front wheels 14 and the rear wheels 15 in contact with the ground G. At this time, since the two front wheels 14 can be independently rolled, the traveling direction can be bent left and right.

  The main body 10 is provided with a handle 16 that extends upward and rearward from the upper side in the rear part. For this reason, the operator can be positioned behind the main body 10 and can grip the handle 16 to move the main body 10 in the horizontal direction. During this movement, the lawn in contact with the blade 12 is cut off. A switch 16A for controlling on / off of the drive of the blade 12 is provided near a portion of the handle 16 that is held by the operator.

  A fan (not shown) that generates an airflow is fixed to the rotating shaft of the motor 11, and the air cut by the blade 12 is set to flow backward and upward by this airflow. The turf is guided by the airflow to the grass collection bag 17 attached to the rear of the main body 10 and is accommodated in the grass collection bag 17. The grass collection bag 17 can be attached to and detached from the main body 10, and the grass collection bag 17 containing a sufficient amount of turf inside is removed from the main body 10, and the collected grass is discarded and then collected again. The bag 17 is attached to the main body 10 and the lawn mowing work is performed. For this reason, at the time of lawn mowing work, the grass collection bag 17 is attached to the main body 10, and the amount of turf accommodated in the grass collection bag 17 increases as the work proceeds. For this reason, the weight of the grass collection bag 17 containing the accommodated turf increases as work progresses.

  In FIG. 1, in a state where the operator grips the handle 16 at the rear, the front wheel 14 is positioned at the foremost part of the configuration including the worker and the lawn mower 1, while the rear wheel 15 is positioned at substantially the center thereof. To position. For this reason, the lawn mower 1 does not easily rotate in the vertical plane with the front wheel 14 as an axis, but it is easy to rotate the lawn mower 1 with the rear wheel 15 as an axis. For example, when the operator pushes the handle 16 downward or the weight of the turf accommodated in the grass collection bag 17 increases, the center of gravity of the lawn mower 1 moves backward. The lawn mower 1 is easy to turn counterclockwise (tilt backward) about 15 as an axis. In this case, since the front wheel 14 is lifted from the ground G, it is difficult for the operator to properly drive the lawn mower 1.

  In order to suppress such lifting of the front wheel 14, the lawn mower 1 is configured such that the front wheel 14 is particularly heavy without impairing its rotational operation. As shown in FIG. 2, the left and right front wheels 14 are independently rotatable around a common front wheel shaft 14 </ b> A, and the structure thereof is bilaterally symmetric. The outer peripheral surface of the front wheel 14 has a cylindrical shape with the front wheel shaft 14A as its central axis.

  Here, each front wheel 14 includes a front wheel main body 141 configured to include this cylindrical outer peripheral surface (grounding surface), and a weight portion 142 formed of a material different from that of the front wheel main body 141. Further, the left and right front wheels 14 in FIG. 2 have the same structure and are provided symmetrically.

  FIG. 3 is a cross-sectional view along the center of the front wheel shaft 14A showing the structure of the front wheel 14 in detail. The front wheel main body 141 is formed of a lightweight resin material by integrating an outer peripheral portion 141A having a cylindrical grounding surface and a shaft portion 141B that is rotatably supported by the front wheel shaft 14A. In FIG. 3, the outer peripheral portion 141A and the shaft portion 141B are integrated by being connected in the left (outside) region of the shaft portion 141B.

  On the other hand, the weight part 142 is fixed between the shaft part 141B and the outer peripheral part 141A, and is made of a metal (steel material or the like). As shown in the figure, the weight portion 142 has a substantially annular shape that can be fitted to the front wheel main body 141 from the inner side (right side), and its outer diameter corresponds to the inner diameter of the outer peripheral portion 141A. This corresponds to the outer diameter of the portion 141B. For this reason, the weight part 142 and the front wheel main body 141 are integrated by making the outer diameter of the weight part 142 substantially equal to the inner diameter of the outer peripheral part 141A and fitting the outer peripheral surface of the weight part 142 with the outer peripheral part 141A. Can do. Alternatively, the weight portion 142 and the front wheel main body 141 are integrated by making the inner diameter of the weight portion 142 substantially equal to the outer diameter of the shaft portion 141B and fitting the inner peripheral surface of the weight portion 142 with the outer peripheral surface of the shaft portion 141B. It can also be made. At this time, if the weight portion 142 is attached to the main body 141 from the inner side (the side where the main body 10 is present) when the front wheel 14 is attached, the weight portion 142 is difficult to drop off after attachment.

  By making the front wheel 14 have such a structure and increasing its weight by the weight portion 142, the front wheel 14 can be prevented from rising. Further, the weight 142 reinforces the mechanical strength of the front wheel 14. Here, there are many types of lawn mowers to be produced, and the ease with which the front wheel 14 is lifted varies depending on the configuration, weight, etc. of the lawn mower. On the other hand, in order to make it easy for an operator to handle, the entire lawn mower is preferably lightweight. For this reason, it is preferable that the front wheel is lightweight in a model in which the front wheel is unlikely to lift. When producing such a large number of models of lawn mowers, if the front wheels can be made common to each model, the production cost can be reduced. Therefore, it is preferable to make the front wheels common to each model.

  When the front wheel 14 is constituted by the front wheel body 141 and the weight part 142 as described above, a plurality of kinds of weight parts 142 having the same outer diameter and inner diameter and different weights are provided, and these are combined with the single kind of front wheel body 141. Thus, the front wheels 14 having different weights can be easily obtained. Or it can also be used as a front wheel in the state of only the front wheel main body 141 in which the weight part 142 is not mounted. Thereby, the front wheel 14 according to the lawn mower model can be manufactured at low cost, and the production cost of the lawn mower can be reduced.

  The lawn mower 1 travels on the ground G where the lawn grows while rotating the blade 12 during the lawn mowing work. However, the blade 12 (the motor 11) is also used during the movement other than the lawn mowing work. ) May be stopped, for example, on a paved road, a concrete road surface, a building floor, or the like. When the lawnmower 1 travels on the ground G on which the grass grows, the noise generated from the front and rear wheels during traveling is small, or this noise does not pose a problem when the blade 12 is driven. When moving as described above, noise generated from the front and rear wheels becomes a problem. This noise is particularly great when the grounding surfaces of the front and rear wheels are made of metal. Or when this grounding surface is comprised with high intensity | strength metals (steel materials etc.), there exists a possibility of damaging the floor of a building at the time of movement.

  For this reason, it is particularly preferable that the ground plane is made of a resin material. In the above configuration, the front wheel main body 141 including the ground contact surface is made of a lightweight resin material, and the weight portion 142 made of a metal material is combined with this to make the front wheel 14 heavy and away from the front wheel 14 when traveling. Noise generated can be reduced. For this reason, it is particularly preferable to provide an elastomer on the ground contact surface.

  In the same manner as described above, as a structure in which the front wheel main body and the weight portion are combined, other structures are possible in addition to the structure in which these are fitted as described above. 4 (a) and 4 (b) are cross-sectional views showing two examples (first modification and second modification) of such a configuration.

  In the first modification (FIG. 4A), the weight 142 is formed integrally with the front wheel main body 141 made of a resin material, and is embedded in the front wheel main body 141. Thereby, the weight part 142 can be particularly firmly fixed to the front wheel main body 141. At this time, since the outer shape of the front wheel main body 141 (front wheel 14) can be made common, a common shape is used as a mold for molding the resin material, and the weight 142 has a different shape, size, The thing of a weight can be used.

  In the second modified example (FIG. 4B), the front wheel main body 141 provided with a cavity 141C and a small liquid supply port 141D for communicating the cavity 141C with the outside is provided in advance as shown in the upper stage. Manufactured. Thereafter, as shown in the lower stage, the liquid 200 (water or the like) is injected from the liquid supply port 141D into the cavity 141C, and the liquid supply port 141D is closed by the stopper 143, whereby the liquid 200 in the cavity 141C is exchanged with the weight part 142. can do. While the front wheel main body 141 is common, the weight of the weight portion 142 can be adjusted by the injection amount of the liquid 200 and its type (specific gravity). In this case, once the liquid is supplied to form the weight part 142, the weight of the weight part 142 can be changed by extracting or adding the liquid from the liquid supply port 141D.

  In order to make it possible to easily change the weight of the weight portion 142, a plurality of weight portions 142 having different weights may be prepared so that the weight portion 142 can be easily attached to and detached from the front wheel main body 141. For this purpose, the third modification (FIG. 5A) and the fourth modification (FIG. 5B) are fixed by screwing an annular weight 142 to the front wheel body 141. This is an example of a configuration. In FIG. 5A, a threaded portion S is formed which is connected by a screw between the outer peripheral surface of the weight portion 141 and the inner peripheral surface of the outer peripheral portion 141A of the front wheel main body 141. In FIG. A threaded portion S is formed between the inner peripheral surface of the weight portion 141 and the outer peripheral surface of the shaft portion 141B of the front wheel main body 141 by a screw. In either case, the weight 142 can be fixed to the front wheel main body 141 by rotating and tightening the weight 142 from the right side in FIG. 5 and can be easily removed. In order to prevent the screwed portion S from loosening during traveling, it is preferable that the direction of the screw (left screw, right screw) in the screwed portion S is reversed between the left and right front wheels 14.

  The weight of the weight portion 142 is adjusted by adjusting the shape of the weight portion 142 other than the outer peripheral surface and the inner peripheral surface. For example, a plurality of through holes that penetrate the weight portion 142 in the direction of the front wheel shaft 14A are provided. Can be adjusted by changing. The weight can also be adjusted by changing the thickness of the weight portion 142 in the direction of the front wheel shaft 14 </ b> A and changing the material of the weight portion 142.

  In the fifth modification (FIG. 6A), the sixth modification (FIG. 6B), and the seventh modification (FIG. 6C), the weight 142 is locked to the front wheel main body 141. By providing a locking portion to be held and locking the weight portion 142 to this locking portion, the weight portion 142 can be attached to the front wheel main body 141. At this time, the weight 142 has a substantially annular shape as in the structure of FIG. 3, but unlike the case where the weight 142 is fitted to the front wheel main body 141 as shown in FIG. Between the outer peripheral surface of the outer peripheral portion and the inner peripheral surface of the outer peripheral portion 141A, and between the inner peripheral surface of the weight portion 142 and the outer peripheral surface of the shaft portion 141B. It becomes easy.

  In the fifth modification (FIG. 6A), a locking portion 141E that protrudes toward the front wheel shaft 14A is provided on the outer peripheral portion 141A of the front wheel main body 141. In FIG. 6A, one section of the front wheel 14 is shown, but in actuality, the locking portion 141E is provided separately at a plurality of locations in the circumferential direction. At this time, if a concave portion that engages with the locking portion 141E is provided at a position corresponding to the locking portion 141E of the weight portion 142, the weight portion 142 is prevented from rotating with respect to the front wheel body 141 after mounting. . In the sixth modification (FIG. 6B), the locking portion 141F is provided so as to protrude from the shaft portion 141B to the side opposite to the front wheel shaft 14A. Also with this structure, the weight 142 can be attached to the front wheel main body 141 as in FIG. In particular, when the front wheel main body 141 is made of a resin material, the locking portions 141E and 141F formed as a part of the front wheel main body 141 can be elastically deformed to be small, so that the weight 142 can be easily attached and detached. is there.

  In the seventh modification (FIG. 6C), the weight portion 142 is provided with a plurality of through-holes 142A that are small-diameter through-holes penetrating the weight portion 142 in the direction of the front wheel shaft 14A. On the other hand, between the outer peripheral portion 141A and the shaft portion 141B of the front wheel main body 141, a locking portion 141G that extends parallel to the front wheel shaft 14A and has a tip bent to the opposite side to the front wheel shaft 14A passes through the through hole 142A. A plurality are provided. The bent portion at the tip of the locking portion 141G locks the weight portion 142 on the side farther from the front wheel shaft 14A than the through hole 142A, whereby the weight portion 142 is mounted on the front wheel main body 141. The locking portion 141G may be formed of a resin material integrated with the front wheel main body 141, or may be formed of an elastic metal material and fixed to the front wheel main body 141.

  Also in the configuration of FIG. 6, a plurality of weight portions 142 having different weights can be used as in the configuration of FIG. 5. In this case, the weight of the weight part 142 can be changed by changing the thickness of a part other than the part in contact with the locking part in the weight part 142. In addition, since the shape of the weight portion 142 other than the portion in contact with the locking portion can be changed, the weight of the weight portion 142 can be adjusted also by this shape.

  Contrary to each configuration of FIG. 6, the engaging portion may be provided on the weight portion side, and the weight portion may be similarly attached to the front wheel body. However, when the front wheel body is made of a resin material and the weight part is made of metal, the locking part can be formed of a resin material that can be elastically deformed small. It is particularly preferred to form.

  Further, the weight portion 142 can be attached to the front wheel main body 141 by using a member (fastening member) different from the front wheel main body 141 and the weight portion 142. FIG. 7 is a cross-sectional view showing an eighth modified example (FIG. 7A), a ninth modified example (FIG. 7B), and a tenth modified example (FIG. 7C) as examples. It is.

  In the eighth modification (FIG. 7A), a fixing screw (fastening member) 144 that penetrates the front wheel main body 141 in the direction of the front wheel shaft 14A is provided on the weight portion 142, and the inner peripheral surface is threaded. The weight portion 142 is fixed by screwing into the through-hole 142 </ b> A and using the through-hole 142 </ b> A as the screw-in portion S. The numbers of the fixing screws 144 and the engaging portion through holes 142A are set as appropriate.

  In the ninth modification (FIG. 7B), the weight support section is attached to the front wheel main body 141 with the weight 142 having a larger margin from the front wheel main body 141 than in the configuration of FIG. (Fastening member) 145 is further mounted. The weight support portion 145 is threaded on the outer peripheral surface in the same manner as the weight portion 142 in FIG. 5 (a), and is similarly threaded on the inner peripheral surface in the same manner as the front wheel body 141 in FIG. 5 (a). The outer peripheral portion 141A (front wheel main body 141) is screwed. For this reason, the weight part 142 is attached to the front wheel main body 141 by using the weight part support part 145 and the inner peripheral surface of the outer peripheral part 141A (the outer peripheral surface of the weight part support part 145) being the threaded portion S. Can do. Similarly, in the tenth modification (FIG. 7C), as in the configuration of FIG. 5B, the inner peripheral surface of the weight support portion (fastening member) 146 and the outer peripheral surface of the shaft portion 141B are By using the threaded portion S, the weight portion 142 can be attached to the front wheel main body 141 using the weight portion support portion 146.

  In the eighth to tenth modified examples, the weight 142 is fixed to the front wheel main body 141 by screwing and fastening the fastening member, whereas the eleventh modified example (FIG. 8A). In the twelfth modification (FIG. 8B), a metal retaining ring is used as the fastening member. In the eleventh modification (FIG. 8A), a locking groove 141AA is formed over the entire inner peripheral surface of the outer peripheral portion 141A of the front wheel main body 141, and the locking groove 141AA is engaged with the locking groove 141AA on the outside. A ring (fastening member) 147 is used. The retaining ring 147 has a substantially annular shape centered on the front wheel shaft 14A, and has a configuration in which one circumferential direction is divided. The outer diameter of the retaining ring 147 is set so that the retaining ring 147 can be attached to the front wheel body 141 in a state where the outer end of the retaining ring 147 is engaged with the retaining groove 141AA. For this reason, as shown in FIG. 8A, the retaining ring 147 and the weight 142 are attached to the front wheel main body 141 by further engaging the retaining ring 147 with the retaining groove 141AA with the weight 142 attached. Can be installed. By elastically deforming the retaining ring 147, the retaining ring 147 can be easily attached and detached. Similarly, in the twelfth modified example (FIG. 8B), a retaining ring (fastening member) 148 that engages with an engaging groove 141BA formed over the entire outer periphery of the shaft portion 141B is used. It is done.

  In the eighth to twelfth modifications, a fastening member is required as a component other than the front wheel main body 141 and the weight portion 142, but the weight portion 142 is used as long as the weight portion 142 can be attached to the front wheel main body 141 using the fastening member. For example, the clearance between the outer peripheral surface of the weight portion 142 and the inner peripheral surface of the outer peripheral portion 141A, and the gap between the inner peripheral surface of the weight portion 142 and the outer peripheral surface of the shaft portion 141B may be set large. it can. For this reason, the weight of the weight part 142 can be set widely, and various kinds of weight parts 142 having a wide range of weight setting can be easily attached to the front wheel main body 141.

  The shape of the weight portion can be set according to the configuration of the front wheel body. FIG. 9 is a sectional view (a) and a side view (b) of a thirteenth modified example in which the strength of the front wheel body is particularly increased and a weight portion corresponding to this is provided. The cross-sectional view (FIG. 9A) corresponds to FIG. 3 and the like, and the side view (FIG. 9B) corresponds to the case of FIG. 1 viewed from the back side of the page (viewed from the inside to the outside).

  As with the front wheel 14, the front wheel body 241 of the front wheel 24 is formed of a resin material by integrating the outer peripheral portion 241A and the shaft portion 241B. However, in the front wheel 24, as shown in FIG. 9B, a plurality of plate-like rib portions 241C are formed radially from the shaft portion 241B toward the outer peripheral portion 241A side. Due to the rib portion 241C, the mechanical strength of the front wheel 24 is higher than that of the front wheel 14. The weight portion 242 provided with a plurality of grooves corresponding to the plurality of rib portions 241C is fitted and attached to the front wheel body 241 from the inside to the outside in FIG. However, in this case, the mechanical strength is sufficiently high even in the state of the front wheel main body 241 to which the weight portion 242 is not attached, so that the range of weight setting of the front wheel 24 is particularly wide.

  In this case, the rib portion 241C prevents the weight portion 242 from rotating with respect to the front wheel body 241. Further, in this front wheel 24, as a method of mounting the weight part 242 to the front wheel main body 241, the method in the above-described modification other than the third and fourth modifications (FIG. 5) in which the weight part 142 itself is screwed is used. be able to. In this case, if the groove in the weight portion 242 and the rib portion 241C are fitted, the outer peripheral surface of the weight portion 242 and the inner peripheral surface of the outer peripheral portion 241A, the inner peripheral surface of the weight portion 242 and the shaft portion. Even if the gap between the outer peripheral surface of 241B is increased, the weight portion 242 can be fitted and attached to the front wheel main body 241. For this reason, the weight of the weight part 242 can also be adjusted by adjusting the gap between them.

  FIG. 10 shows a configuration of a front wheel 34 as a fourteenth modified example in which the configuration of FIG. 9 is further modified, corresponding to FIG. The front wheel main body 241 used here is the same as that in FIG. In the configuration of FIG. 9, a single weight portion 242 is used. In this configuration, 242A to 242H corresponding to the case where the weight portion 242 is divided into eight by seven rib portions 241C are used. It has been. Each of the weight portions 242A to 242H can be detached between the rib portions 241C. For this reason, the weight of the whole weight part can be adjusted by selecting a part or all of the weight parts 242A to 242H and mounting it on the front wheel main body 241. At this time, in order to make the rotation of the front wheel 24 smooth, it is preferable to select the weight portions 242A to 242H so as to be symmetrical around the shaft portion 241B (front wheel shaft).

  In addition, as long as the shape of the front-wheel main body in said structure can rotate around the front-wheel axis | shaft and can roll on the ground, the thing of a structure different from the above can be used. Accordingly, the shape of the weight portion can be set according to the shape of the front wheel body. Depending on the shape of the front wheel main body and the weight portion, the structure and position of the locking portion and the fastening portion can also be set.

1 Lawn mower 10 Main body 11 Motor 12 Blade (cutting blade)
13 Height adjusting levers 14, 24 Front wheel 14A Front wheel shaft 15 Rear wheel 15A Rear wheel shaft 16 Handle 16A Switch 17 Grass bag 141, 241 Front wheel main body 141A, 241A Outer portion 141AA, 141BA Locking groove 141B, 241B Shaft portion 141C Cavity 141D Liquid supply ports 141E, 141F, 141G Locking portions 142, 242, 242A to 242H Weight portion 142A Through hole 143 Plug 144 Fixing screw (fastening member)
145, 146 Weight support (fastening member)
147, 148 Retaining ring (fastening member)
200 Liquid 241C Rib G G Ground S Threaded part

Claims (12)

A cutting blade that cuts grass by being driven, and a main body provided with front and rear wheels on the front and rear sides,
A handle attached to the main body so as to extend rearward from the main body;
A lawn mower capable of traveling by rolling in a state where the front wheel and the rear wheel are grounded,
The front wheel is configured by combining a front wheel main body having a substantially cylindrical outer peripheral surface that comes into contact with the ground during traveling and a weight portion made of a material different from the material constituting the front wheel main body. Lawn mower.   The lawn mower according to claim 1, wherein the front wheel main body is made of a resin material, and the weight portion is made of metal.   The lawn mower according to claim 1 or 2, wherein the front wheel is configured by integrally molding the front wheel main body and the weight portion.   The lawn mower according to claim 1 or 2, wherein the weight part is detachable from the front wheel body.   The lawn mower according to claim 4, wherein the weight portion has an annular shape.   The lawn mower according to claim 5, wherein the weight portion is screwed onto the front wheel body.   The lawn mower according to claim 4, wherein the weight part is attached to the front wheel body using a fastening member that fixes the weight part to the front wheel body.   The lawn mower according to claim 4, wherein the weight portion is attached to the front wheel main body by being locked to a locking portion provided in the front wheel main body. The front wheel body includes a plurality of rib portions formed radially extending from the rotation axis of the front wheel,
The lawn mower according to claim 7 or 8, wherein a plurality of the weight parts mounted between the adjacent rib parts are used.   The lawn mower according to claim 9, wherein the plurality of weight parts are detachable. The front wheel body is provided with a cavity capable of containing liquid,
The lawn mower according to claim 1, wherein the weight portion is composed of the liquid contained in the cavity.   The lawn mower according to any one of claims 1 to 11, wherein a grass collection bag for storing the cut grass is mounted behind the rear wheel in the main body.

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