CN113906897A

CN113906897A - Grass cutter

Info

Publication number: CN113906897A
Application number: CN202010660982.2A
Authority: CN
Inventors: 彭士璇; 王彭生; 赵作秀
Original assignee: Makita Corp
Current assignee: Makita Corp
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2022-01-11
Also published as: DE202021002152U1

Abstract

The invention provides a technology capable of mounting a battery unit with a large rated capacity on a mower without damaging the operability of the mower. The present specification discloses a lawn mower. The lawn mower may include: a cutter for mowing; a motor connected to the cutter; a housing accommodating the motor; front and rear wheels supporting the housing; and a battery unit disposed outside the case and configured to supply electric power to the motor. The rated capacity of the battery cell may be 300Wh or more. The center of gravity of the battery unit may be disposed in a range from a front end of the motor to a rear end of the rear wheel in a front-rear direction.

Description

Grass cutter

Technical Field

The technology disclosed in this specification relates to a lawn mower.

Background

Chinese patent publication No. 106686971 discloses a lawn mower. The lawn mower comprises: a cutter for mowing; a motor connected to the cutter; a housing accommodating the motor; front and rear wheels supporting the housing; and a battery unit disposed outside the case and configured to supply electric power to the motor.

Disclosure of Invention

Problems to be solved by the invention

When a battery cell having a large rated capacity is used as the battery cell, the weight of the battery cell also increases. In the lawnmower disclosed in chinese patent application publication No. 106686971, the center of gravity of the battery unit is disposed forward of the front end of the motor in the front-rear direction. Therefore, when a battery unit having a large rated capacity is mounted, the load applied to the front wheels becomes large due to the large weight of the battery unit, and the operability when changing the traveling direction of the lawnmower is deteriorated. The present specification provides a technique that enables a battery unit having a large rated capacity to be mounted on a lawnmower without impairing the operability of the lawnmower.

Means for solving the problems

The present specification discloses a lawn mower. The lawn mower may include: a cutter for mowing; a motor connected to the cutter; a housing accommodating the motor; front and rear wheels supporting the housing; and a battery unit disposed outside the case and configured to supply electric power to the motor. The rated capacity of the battery cell may be 300Wh or more. The center of gravity of the battery unit may be disposed in a range from a front end of the motor to a rear end of the rear wheel in a front-rear direction.

With the above configuration, the center of gravity of the battery unit is disposed rearward of the front end of the motor in the front-rear direction. Therefore, even if the weight of the battery unit becomes large, the load applied to the front wheels can be suppressed from becoming excessive. With the above configuration, the battery unit having a large rated capacity can be mounted on the lawnmower without impairing the operability of the lawnmower.

Drawings

Fig. 1 is a perspective view of a lawnmower 2 according to embodiment 1.

Fig. 2 is a side view of the lawn mower 2 of embodiment 1.

Fig. 3 is a longitudinal sectional view of the lawnmower 2 according to embodiment 1.

Fig. 4 is a perspective view of the vicinity of the support base 50 with the battery unit 52 removed from the lawnmower 2 according to example 1.

Fig. 5 is a perspective view of the battery unit 52 of the lawnmower 2 according to example 1, as viewed from above.

Fig. 6 is a perspective view of the battery unit 52 of the lawnmower 2 according to example 1, as viewed from below.

Fig. 7 is a perspective view of the battery unit 52 of the lawnmower 2 according to example 1, viewed from above, in a state where the upper housing 64 is opened.

Fig. 8 is a side view of the lawn mower 102 of embodiment 2.

Fig. 9 is a perspective view of the vicinity of the support base 104 of the lawnmower 102 according to example 2.

Fig. 10 is a longitudinal sectional view of the mower 102 according to embodiment 2.

Fig. 11 is a perspective view showing an external appearance of a battery unit 202 according to a modification.

Fig. 12 is a perspective view showing the internal structure of a battery unit 202 according to a modification.

Description of the reference numerals

2. A mower; 4. a main body portion; 6. a handle portion; 7. a front wheel; 8. a rear wheel; 10. a grass collecting basket; 12. a base; 14. a cover; 14a, a battery pack mounting portion; 16. a drive shaft; 18. cutting; 20. an air supply fan; 22. a motor; 22a, a motor housing; 24. an ECU; 26. a battery pack; 28. a cover; 29. a housing; 30. a lower frame; 30a, a right support bar; 30b, a left support bar; 32. an upper frame; 34. a handle; 36. a switch lever; 38. a right holding portion; 40. a left holding portion; 42. a control cable; 50. a support table; 52. a battery cell; 53. a support plate; 54. an abutting portion; 56. a clamping claw; 57. a clamping claw; 58. a clamping sheet; 60. a locking member; 62. a lower housing; 62a, a battery pack mounting portion; 64. an upper housing; 64a, a battery pack mounting portion; 66. a clamping sheet; 68. a locking socket; 70. a power line; 72. a unit handle; 74. a battery pack; 102. a mower; 104. a support table; 106. a support plate; 108. a support column; 110. a support leg; 202. a battery cell; 204. a lower housing; 206. an upper housing; 208. a battery cell assembly; 210. a control circuit substrate; 212. a power line; 214. a unit handle.

Detailed Description

Representative, non-limiting examples of the present invention are described in detail below with reference to the accompanying drawings. The detailed description is intended to show the skilled person the details of preferred examples for implementing the invention, without limiting the scope of the invention. In addition, additional features and inventions disclosed below can be used separately or in conjunction with other features, inventions to provide further improved mowers, methods of making and methods of using the same.

In addition, combinations of features and steps disclosed in the following detailed description are not essential to practice of the present invention in the broadest sense, and are described in order to particularly describe representative specific examples of the present invention. Furthermore, the various features of the representative specific examples described above and below, as well as those described in the independent and dependent claims, do not necessarily have to be combined in the specific examples described herein or in the order listed in order to provide additional and useful embodiments of the present invention.

All of the features described in the present specification and/or claims are intended to be disclosed independently of the structure of the features described in the embodiments and/or claims, as limitations on the disclosure of the original application and specific matters described in the claims, individually and independently of each other. Further, the description of all the numerical ranges and groups or groups is intended to disclose the intermediate structures thereof as limitations to the specific matters described in the disclosure of the original application and the claims.

In the 1 or more embodiments, the lawnmower may include: a cutter for mowing; a motor connected to the cutter; a housing accommodating the motor; front and rear wheels supporting the housing; and a battery unit disposed outside the case and configured to supply electric power to the motor. The rated capacity of the battery cell may be 300Wh or more. The center of gravity of the battery unit may be disposed in a range from a front end of the motor to a rear end of the rear wheel in a front-rear direction.

In the 1 or more embodiments, the center of gravity of the battery unit may be disposed in a range from a front end of the rear wheel to the rear end of the rear wheel in a front-rear direction.

With the above configuration, even if the weight of the battery unit becomes large, the influence on the load applied to the front wheel can be reduced. The operability of the lawnmower can be further improved.

In the 1 or more embodiments, the lawnmower may further include a handle for a user to move the lawnmower when pushing the lawnmower. The handle may include a 1 st support rod and a 2 nd support rod arranged in a left-right array. The battery unit may be disposed between the 1 st support rod and the 2 nd support rod.

With the above configuration, since the battery unit is disposed so as to be separated from the case, it is possible to suppress deterioration of the appearance of the case due to mounting of the battery unit.

In the 1 or more embodiments, the lawnmower may further include a support base to which the battery unit is detachably attached.

With the above configuration, in a state where the battery unit is detached from the lawnmower, the battery unit can be charged and discharged with respect to another device.

In the 1 or more embodiments, the support base may be fixed to the 1 st support rod and the 2 nd support rod.

With the above configuration, the rigidity of the handle can be further improved, and the operability of the lawnmower can be further improved.

In the 1 or more embodiments, the center of gravity of the battery unit may be disposed in a range from the front end of the motor to a front end of the rear wheel in a front-rear direction.

Generally, grass cut by a mower is conveyed to a grass collecting basket connected to the rear of the housing. Since the grass collecting basket protrudes rearward relative to the rear wheel of the lawnmower, when a large amount of grass is collected in the grass collecting basket, the lawnmower may fall rearward and float the front wheel due to the weight of the grass collecting basket, which may deteriorate the operability. With the above configuration, the center of gravity of the battery unit is disposed forward of the front end of the rear wheel in the front-rear direction, and therefore the weight of the battery unit acts in a direction in which the lawnmower is prevented from falling backward. Even in the case where a lot of grass is collected in the grass collecting basket, it is possible to suppress the deterioration of the operability of the lawnmower.

In the 1 or more embodiments, the support base may be fixed to the housing.

With the above configuration, the battery unit can be stably supported.

(example 1)

The mower 2 of the present embodiment is explained with reference to the drawings. As shown in fig. 1, the lawnmower 2 includes a main body 4 and a handle 6. The main body portion 4 includes: two front wheels 7, the two front wheels 7 contacting the ground on the front left side and the front right side; and two rear wheels 8, the two rear wheels 8 being in contact with the ground at the rear left side and the rear right side. A grass collecting basket 10 is detachably mounted to the rear of the main body 4. The handle portion 6 is connected to the rear upper portion of the body portion 4. When a user stands behind the lawnmower 2 and grips the upper portion of the grip portion 6 with both hands and pushes it forward, the front wheel 7 and the rear wheel 8 rotate and the main body portion 4 moves forward along the ground. Further, the outer diameter of the rear wheel 8 is larger than the outer diameter of the front wheel 7.

As shown in fig. 2, the main body 4 includes: a base 12 that rotatably supports an axle (not shown) of the front wheel 7 and an axle (not shown) of the rear wheel 8; and a cover 14 attached to a central upper portion of the base 12. As shown in fig. 3, the lower surface side of the base 12 is open toward the ground. A drive shaft 16, a cutter blade 18, and an air blowing fan 20 are disposed in a space inside the base 12. The drive shaft 16, the cutter blades 18, and the air blowing fan 20 are all disposed rearward of the front wheels 7 and forward of the rear wheels 8 in the front-rear direction of the lawnmower 2. The drive shaft 16 is disposed along a substantially vertical direction. The cutter blade 18 is fixed to the lower end of the drive shaft 16 and extends from the drive shaft 16 in a substantially horizontal direction. The blower fan 20 is fixed to the drive shaft 16 at a position above the cutter blade 18. The base 12 has a shape in which a space inside the base 12 is enlarged upward as it approaches the rear end. A grass collecting basket 10 is mounted to the rear end of the base 12. The space inside the base 12 communicates with the space inside the grass collecting basket 10 at the rear end of the base 12. When the drive shaft 16 rotates, the cutter 18 rotates to cut grass on the ground. When the drive shaft 16 rotates, the air blowing fan 20 rotates to generate an air flow in the space inside the base 12 from the opening in the lower surface of the base 12 toward the grass basket 10 behind the base 12. Therefore, the grass cut by the cutter blades 18 is sucked up by the air-sending fan 20 and collected in the grass collecting basket 10.

The motor 22 and the ECU24 are mounted on the upper surface side of the base 12. The motor 22 is, for example, a brushless motor including a stator (not shown) and a rotor (not shown). The motor 22 rotates the drive shaft 16. The motor 22 is accommodated in a motor housing 22 a. The ECU24 includes, for example, an inverter circuit (not shown) including a plurality of switching elements, and a control circuit (not shown) that controls each of the plurality of switching elements. In the front-rear direction of the lawnmower 2, the motor 22 and the ECU24 are both disposed behind the front wheels 7 and in front of the rear wheels 8. The ECU24 controls the electric power supplied to the motor 22 to control the operation of the motor 22. The cover 14 is attached to the upper surface side of the base 12 so as to cover the motor 22 and the ECU 24.

A battery pack mounting portion 14a is provided on the upper surface side of the cover 14. A battery pack 26 is detachably mounted to the battery pack mounting portion 14 a. The battery pack 26 incorporates a plurality of secondary battery cells (e.g., lithium ion battery cells). The battery pack mounting portion 14a is provided with a main body side terminal (not shown) that is electrically connected to a battery side terminal (not shown) of the battery pack 26 when the battery pack 26 is mounted. The body side terminal is connected to the ECU 24. The lawnmower 2 of the present embodiment includes, for example, two battery pack attachment portions 14a, and can attach, for example, two battery packs 26. For each battery pack 26, for example, the rated voltage is 18V and the rated capacity is 108 Wh. A cover (japanese: カウルカバー)28 is attached to the upper surface side of the cover 14 so as to cover the battery pack mounting portion 14a and the battery pack 26. The cover 28 is opened and closed by rotating relative to the cover 14. In a state where the cover 28 is opened with respect to the cover 14, the battery pack 26 is detachably attached to be slidable with respect to the battery pack attachment portion 14 a. In the following description, the base 12, the cover 14, and the cover 28 of the main body 4 will be collectively referred to as a case 29. In the lawnmower 2, the motor 22, the ECU24, the battery pack attachment portion 14a, and the battery pack 26 are housed inside the housing 29.

As shown in fig. 1, the handle portion 6 includes: a substantially U-shaped lower frame 30 connected to the rear upper portion of the base 12 and extending rearward and upward; and a substantially U-shaped upper frame 32 connected to a rear upper portion of the lower frame 30, extending rearward and upward, and then bent forward and upward. The lower frame 30 includes a right support rod 30a and a left support rod 30 b. The right and left

support bars

30a, 30b are arranged in a left-right array and extend rearward and upward from the base 12. The upper frame 32 includes: a handle 34 to be held by a user; a switch lever 36 disposed on the front side of the handle 34; a right holding portion 38 disposed on the right front side of the handle 34; and a left holding portion 40 disposed at a position further to the left front than the handle 34. A control cable 42 extending from the main body 4 is connected to the right holding portion 38.

The switch lever 36 is supported by the right-side holding portion 38 and the left-side holding portion 40 so as to be rotatable about a rotation shaft extending in the left-right direction. The switch lever 36 is biased in a direction away from the handle 34 by a spring (not shown) housed in the right holding portion 38. The user can pull the switch lever 36 with the fingers gripping the handle 34 while gripping the handle 34. An unlock button (not shown) is provided on the right holding portion 38. When the user presses the unlock button and pulls the switch lever 36, a pulling force acts on the control cable 42. If the user does not press the unlock button and the switch lever 36 is pulled, the pulling force does not act on the control cable 42.

Inside the cover 14 of the main body 4 and on the upper surface side of the base 12, there are provided: a brake mechanism (not shown) that brakes rotation of the drive shaft 16; a link mechanism (not shown) that couples the control cable 42 and the brake mechanism together; and a drive switch (not shown) that detects the operation of the link mechanism. The brake mechanism brakes rotation of the drive shaft 16 when a tensile force is not applied to the control cable 42, and releases braking of rotation of the drive shaft 16 when a tensile force is applied to the control cable 42. The drive switch is turned off when a pulling force is not applied to the control cable 42, and is turned on when a pulling force is applied to the control cable 42. The drive switch is electrically connected to the ECU 24. When the drive switch is on, the ECU24 drives the motor 22, and when the drive switch is off, the ECU24 stops the motor 22.

A support base 50 is provided in the vicinity of the connection portion between the body portion 4 and the handle portion 6. A battery unit 52 is detachably mounted on the support base 50. As shown in fig. 4, the support table 50 includes: a substantially flat plate-shaped support plate 53; an abutting portion 54 that abuts against the upper surface of the base 12 of the main body portion 4 at the front end of the support plate 53; an engaging claw 56 that engages with the right support rod 30a of the handle 6 at the right end of the support plate 53; an engaging claw 57 that engages with the left support rod 30b of the handle 6 at the left end of the support plate 53; an engaging piece 58 that engages with the battery cell 52 on the upper surface of the support plate 53; and locking pieces 60 provided at front and rear ends of the support plate 53. As shown in fig. 2 and 3, the support base 50 is attached to the body 4 and the handle 6 such that the inclination angle of the support plate 53 with respect to the body 4 is substantially the same as the inclination angle of the handle 6 with respect to the body 4.

As shown in fig. 5 and 6, the battery unit 52 includes a lower case 62 and an upper case 64. The upper case 64 is attached to the lower case 62 so as to be rotatable with respect to the lower case 62. As shown in fig. 6, an engagement piece 66 corresponding to the engagement piece 58 of the support base 50 is formed on the lower surface of the lower case 62. Further, lock receivers 68 corresponding to the lock members 60 of the support base 50 are formed at both front and rear ends of the lower case 62. The battery unit 52 is attached to the support base 50 by engaging the lock receiver 68 with the lock member 60 of the support base 50 in a state where the engagement piece 66 is engaged with the engagement piece 58 of the support base 50.

As shown in fig. 7, a battery pack mounting portion 62a is provided on the upper surface side of the lower case 62. The battery pack 74 is detachably mounted to the battery pack mounting portion 62 a. The battery pack 74 incorporates a plurality of secondary battery cells (e.g., lithium ion battery cells). The battery pack mounting portion 62a is provided with a unit side terminal (not shown) that is electrically connected to a battery side terminal (not shown) of the battery pack 74 when the battery pack 74 is mounted. The unit side terminals are connected to a control circuit board (not shown) built in the lower case 62. The control circuit board of the lower case 62 is electrically connected to the ECU24 of the main body 4 via the power line 70 (see fig. 1 to 3). The battery unit 52 of the present embodiment includes, for example, 4 battery pack attachment portions 64a, and is capable of attaching, for example, 4 battery packs 74. For each battery pack 74, for example, the rated voltage is 18V and the rated capacity is 108 Wh. In the state where 4 battery packs 74 are mounted, the rated voltage of the battery unit 52 is 18V or 36V, and the rated capacity is 436 Wh. The weight of each battery pack 74 is, for example, 0.6kg, and the weight of the battery unit 52 is, for example, 7kg or more in a state where 4 battery packs 74 are mounted.

As shown in fig. 7, the battery pack 74 can be attached to and detached from the battery pack attachment portion 62a in a state where the upper case 64 is opened with respect to the lower case 62. As shown in fig. 5 and 6, when the upper case 64 is closed with respect to the lower case 62, the battery pack 74 is covered with the upper case 64 and the lower case 62. A unit handle 72 is provided on the lower case 62, and a user can carry the battery unit 52 by holding the unit handle 72.

In the lawnmower 2 of the present embodiment, the ECU24 drives the motor 22 with the electric power supplied from the battery pack 26 mounted on the battery pack mounting portion 14a of the cover 14 and/or the electric power supplied from the battery pack 74 mounted on the battery pack mounting portion 62a of the battery unit 52. The lawnmower 2 may not include the battery pack attachment portion 14a of the cover 14, or may not include the battery pack 26. In this case, the ECU24 drives the motor 22 with electric power supplied from the battery pack 74 mounted on the battery pack mounting portion 62a of the battery unit 52.

As shown in fig. 2, the center of gravity G of the battery unit 52 is located forward of the rear end of the rear wheel 8, more specifically, forward of the axle of the rear wheel 8, in the front-rear direction of the lawnmower 2. As shown in fig. 3, the center of gravity G of the battery unit 52 is located rearward of the front end of the motor 22, that is, the front end of the motor housing 22a, more specifically, the drive shaft 16 connected to the cutter blades 18, and even more specifically, the front end of the rear wheel 8 in the front-rear direction of the lawnmower 2.

As described above, the lawnmower 2 of the present embodiment includes: a cutter for mowing 18; a motor 22 connected to the cutter blade 18; a housing 29 that houses the motor 22; front wheels 7 and rear wheels 8, the front wheels 7 and rear wheels 8 supporting a housing 29; and a battery unit 52 disposed outside the case 29 and configured to supply electric power to the motor 22. The rated capacity of the battery cell 52 is 300Wh or more. The center of gravity G of the battery unit 52 is disposed in the range from the front end of the motor 22 to the rear end of the rear wheel 8 in the front-rear direction.

With the above configuration, the center of gravity G of the battery unit 52 is disposed rearward of the front end of the motor 22 in the front-rear direction. Therefore, even if the weight of the battery unit 52 becomes large, the load applied to the front wheels 7 can be suppressed from becoming excessive. With the above configuration, the battery unit 52 having a large rated capacity can be mounted on the lawnmower 2 without impairing the operability of the lawnmower 2.

In the lawnmower 2 of the present embodiment, the center of gravity G of the battery unit 52 is disposed in the range from the front end of the rear wheel 8 to the rear end of the rear wheel 8 in the front-rear direction.

With the above configuration, even if the weight of the battery unit 52 becomes large, the influence on the load applied to the front wheels 7 can be reduced. The operability of the mower 2 can be further improved.

The lawnmower 2 according to the present embodiment further includes a handle portion 6 (an example of a handle) for allowing a user to move the lawnmower 2 when the user pushes the lawnmower 2. The handle portion 6 includes a right support rod 30a (an example of a 1 st support rod) and a left support rod 30b (an example of a 2 nd support rod) arranged in a left-right direction. The battery unit 52 is disposed between the right support rod 30a and the left support rod 30 b.

With the above configuration, since the battery unit 52 is disposed so as to be separated from the case 29, it is possible to suppress the deterioration of the appearance of the case 29 due to the mounting of the battery unit 52.

The lawnmower 2 of the present embodiment further includes a support base 50 to which the battery unit 52 is detachably attached.

With the above configuration, in a state where the battery unit 52 is detached from the lawnmower 2, the battery unit 52 can be charged and the battery unit 52 can be discharged to other devices.

In the mower 2 of the present embodiment, the support base 50 is fixed to the right support rod 30a and the left support rod 30 b.

With the above configuration, the rigidity of the handle portion 6 can be further improved, and the operability of the lawnmower 2 can be further improved.

(example 2)

As shown in fig. 8, the lawnmower 102 of the present embodiment has substantially the same configuration as the lawnmower 2 of embodiment 1. The following description deals with differences of the lawnmower 102 of the present embodiment from the lawnmower 2 of embodiment 1.

The mower 102 of the present embodiment includes a support base 104 instead of the support base 50. In the lawnmower 102 of the present embodiment, the battery unit 52 is detachably attached to the support base 104. As shown in fig. 9, the support base 104 includes: a substantially flat plate-shaped support plate 106; a support column 108 extending downward at the rear end of the support plate 106; a support leg 110 extending downward in the vicinity of the center of the support plate 106 in the front-rear direction; and an engaging portion (not shown) that engages with the engaging piece 66 of the battery cell 52 on the upper surface of the support plate 106. The lower end of the support column 108 abuts on the upper surface of the base 12 of the body 4. The support legs 110 penetrate the cover 14 of the main body 4 and are fixed to a support portion (not shown) provided on the base 12 of the main body 4. As shown in fig. 8 and 10, the support base 104 is attached to the main body 4 such that the support plate 106 is substantially parallel to the ground.

As shown in fig. 8, the center of gravity G of the battery unit 52 is disposed forward of the rear end of the rear wheel 8, more specifically, forward of the axle of the rear wheel 8, and even more specifically, forward of the front end of the rear wheel 8 in the front-rear direction of the lawnmower 102. As shown in fig. 10, the center of gravity G of the battery unit 52 is located rearward of the front end of the motor 22, that is, the front end of the motor housing 22a, more specifically, the drive shaft 16 connected to the cutter blades 18, and even more specifically, the rear end of the motor 22, that is, the rear end of the motor housing 22a, in the front-rear direction of the lawnmower 102.

As described above, the lawnmower 102 of the present embodiment includes: a cutter for mowing 18; a motor 22 connected to the cutter blade 18; a housing 29 that houses the motor 22; front wheels 7 and rear wheels 8, the front wheels 7 and rear wheels 8 supporting a housing 29; and a battery unit 52 disposed outside the case 29 and configured to supply electric power to the motor 22. The rated capacity of the battery cell 52 is 300Wh or more. The center of gravity G of the battery unit 52 is disposed in the range from the front end of the motor 22 to the rear end of the rear wheel 8 in the front-rear direction.

With the above configuration, the center of gravity G of the battery unit 52 is disposed rearward of the front end of the motor 22 in the front-rear direction. Therefore, even if the weight of the battery unit 52 becomes large, the load applied to the front wheels 7 can be suppressed from becoming excessive. With the above configuration, the battery unit 52 having a large rated capacity can be mounted on the mower 102 without impairing the operability of the mower 102.

In the lawnmower 102 of the present embodiment, the center of gravity G of the battery unit 52 is disposed in the range from the front end of the motor 22 to the front end of the rear wheel 8 in the front-rear direction.

The grass cut by the mower 102 is conveyed to the grass collecting basket 10 connected to the rear of the housing 29. Since the grass collecting basket 10 protrudes rearward with respect to the rear wheel 8 of the mower 102, when a large amount of grass is collected in the grass collecting basket 10, the mower 102 may fall rearward and float the front wheel 7 due to the weight of the grass collecting basket 10, which may deteriorate the operability. With the above configuration, the center of gravity G of the battery unit 52 is disposed forward of the front end of the rear wheel 8 in the front-rear direction, and therefore the weight of the battery unit 52 acts in a direction in which the lawnmower 102 is restrained from falling backward. Even in the case where a lot of grass is collected in the grass collecting basket 10, it is possible to suppress the deterioration of the operability of the mower 102.

The lawnmower 102 of the present embodiment further includes a support base 104 to which the battery unit 52 is detachably attached.

With the above configuration, in a state where the battery unit 52 is detached from the lawnmower 102, the battery unit 52 can be charged and the battery unit 52 can be discharged to other devices.

In the mower 102 of the present embodiment, the support base 104 is fixed to the housing 29.

With the above configuration, battery unit 52 can be stably supported.

(modification example)

In the above embodiment, the description has been given of the structure in which the motor 22 is a brushless motor, but the motor 22 may be another type of motor such as a brush motor, unlike the above.

In the above-described embodiment, the configuration in which the battery unit 52 to which the plurality of battery packs 74 can be attached and detached is mounted on the

lawnmowers

2 and 102 has been described, but other types of battery units, for example, the battery unit 202 shown in fig. 11 and 12 may be mounted on the

lawnmowers

2 and 102. As shown in fig. 11, the battery unit 202 includes a lower case 204 and an upper case 206. As shown in fig. 12, a battery cell assembly 208 and a control circuit board 210 electrically connected to the battery cell assembly 208 are accommodated in a space inside the lower case 204 and the upper case 206. The battery cell assembly 208 includes a plurality of secondary battery cells (for example, lithium ion battery cells). The control circuit board 210 is electrically connected to the ECU24 of the main body 4 of the

lawnmowers

2 and 102 via an electric power line 212. The battery cell 202 has a rated voltage of 18V or more and a rated capacity of 300Wh or more, for example. The weight of the battery unit 202 is, for example, 5kg or more. A unit handle 214 is provided on the lower case 204, and a user can carry the battery unit 202 by holding the unit handle 214.

In the above embodiment, the support bases 50 and 104 may be configured to include a 1 st support base (not shown) to which the battery unit 52 is detachably attached and a 2 nd support base (not shown) which is fixed to the body portion 4 and the handle portion 6 and to which the 1 st support base is detachably attached. In the case of such a configuration, by preparing the 1 st support base provided with the corresponding engagement piece and lock piece for the battery unit 52 having different positions and shapes of the engagement piece 66 and the lock receiver 68, the battery unit 52 can be mounted on the

lawnmower

2 or 102 without replacing the 2 nd support base.

Claims

1. A lawn mower, wherein,

the lawn mower comprises:

a cutter for mowing;

a motor connected to the cutter;

a housing accommodating the motor;

front and rear wheels supporting the housing; and

a battery unit disposed outside the case to supply electric power to the motor,

the rated capacity of the battery unit is more than 300Wh,

the center of gravity of the battery unit is disposed in a range from a front end of the motor to a rear end of the rear wheel in a front-rear direction.

2. The mower of claim 1 wherein,

the center of gravity of the battery unit is disposed in a range from a front end of the rear wheel to the rear end of the rear wheel in a front-rear direction.

3. The mower of claim 2 wherein,

the mower further comprises a handle for moving the mower when a user pushes the mower,

the handle is provided with a 1 st supporting rod and a 2 nd supporting rod which are arranged in a left-right arrangement,

the battery unit is disposed between the 1 st support rod and the 2 nd support rod.

4. The mower of claim 3 wherein,

the lawn mower further comprises a support base to which the battery unit is detachably attached.

5. The mower of claim 4 wherein,

the support table is fixed to the 1 st support rod and the 2 nd support rod.

6. The mower of claim 1 wherein,

the center of gravity of the battery unit is disposed in a range from the front end of the motor to a front end of the rear wheel in a front-rear direction.

7. The mower of claim 6 wherein,

8. The mower of claim 7 wherein,

the support table is fixed to the housing.