Lawn mowing robot

Abstract

The present invention relates to a lawn mowing robot comprising: a lift motor; a lift shaft that rotates by receiving the rotational force of the lift motor; a lift cam that is coupled to the lift shaft by pin-slot coupling such that the rotation thereof is synchronized with the lift shaft and the height thereof is variable; a cam housing that accommodates the lift cam and includes housing threads protruding from the inner wall; a blade shaft that is coupled to the lift cam and moves in the vertical direction together with the lift cam when the height of the lift cam changes; a blade unit coupled to the lower end of the blade shaft; and a blade motor that provides rotational force to the blade shaft. The lift cam includes cam threads that engage with the housing threads, and the height of the lift cam varies according to the rotation direction of the lift shaft.

Description

lawn mowing robot

[0001] The present invention relates to a lawn mowing robot and a control method thereof, and more particularly, to a lawn mowing robot capable of performing continuous work by automatically adjusting the height of a blade.

[0002] A lawn mower robot is a device that moves autonomously and mows grass or lawns based on preset control information. Users can pre-enter control information related to the desired lawn mowing motion, time, and cycle. The lawn mower robot operates according to the input control information.

[0003] The environments where lawn mowing robots are used can be large areas, such as fields or gardens. Therefore, lawn mowing robots typically move along preset paths to mow grass and other grasses spread across large areas.

[0004] Additionally, the lawn mower robot divides the space into multiple smaller spaces and then moves along a preset path within each smaller space. This division allows the lawn mower robot to move densely within a large space. In other words, the lawn mower robot can pass through all spaces without missing any.

[0005] The above partition can be input through a control signal after the user sets up a virtual space. Alternatively, the partition can be performed by a physical method such as using a fence.

[0006] Lawn mowing robots can detect obstacles during their work and maneuver around them. However, for obstacles that protrude slightly above the ground, the blade height needs to be adjusted to protect it. Furthermore, if the desired grass length varies depending on the area, blade height adjustments are necessary.

[0007] In the past, blade height adjustments had to be made manually, but for fully automated lawn mowing robots, blade height adjustments also need to be performed automatically.

[0008] The purpose of the present invention is to provide a lawn mowing robot capable of performing continuous work by automatically adjusting the height of the blade.

[0009] A lawn mowing robot is provided, comprising: a main body housing including a driving part at the lower portion; and a driving assembly located inside the main body housing, wherein the driving assembly comprises: a lift motor; a lift shaft that rotates by receiving rotational force from the lift motor; a lift cam that is pin-slot coupled so that the rotation is synchronized with the lift shaft and the height is variable; a cam housing that receives the lift cam and includes a housing screw thread protruding from an inner wall; a blade shaft that is coupled to the lift cam and moves vertically together with the change in the height of the lift cam; a blade unit coupled to a lower end of the blade shaft; and a blade motor that provides rotational force to the blade shaft, wherein the lift cam includes a cam screw thread that engages with the housing screw thread, and the height of the lift cam is variable depending on the rotational direction of the lift shaft.

[0010] The lift cam may include a cylindrical shaft hole through which the lift shaft passes; and a vertical slot formed in the shaft hole, and the lift shaft may include a slot pin inserted into the vertical slot.

[0011] A lawn mowing robot characterized by including a power transmission gear that transmits the rotational power of the lift motor to the lift shaft.

[0012] The blade motor is coupled to the lower portion of the lift cam, and the cam housing may further include a vertical guide extending to the side of the blade motor and restricting rotation of the blade motor within the cam housing while allowing vertical movement.

[0013] The above vertical guide may include a guide slot formed in the cam housing; and a guide protrusion protruding from the blade motor and inserted into the guide slot.

[0014] The blade motor is coupled to the lower portion of the lift cam and further includes a motor spring that pulls the blade motor upward, and the motor spring can be coupled to the guide protrusion.

[0015] It may further include a drive shaft that rotates by receiving the rotational power of the blade motor and is pin-slot coupled with the blade shaft.

[0016] The above drive shaft can be arranged to pass through the above lift shaft.

[0017] A first power transmission gear that transmits the rotational force of the lift motor to the lift shaft; and a second power transmission gear that transmits the rotational force of the blade motor to the drive shaft, and may further include a first bearing positioned between the first power transmission gear or the lift shaft and the second power transmission gear or the drive shaft.

[0018] The second power transmission gear is positioned above the first power transmission gear, and the drive shaft can be inserted into the lift shaft through the first power transmission gear.

[0019] The blade shaft may penetrate a shaft hole formed in the center of the lift cam, and may include a second bearing positioned between the blade shaft and the lift cam.

[0020] A lawn mowing robot according to at least one embodiment of the present invention can automatically adjust its height and perform lawn mowing work unmanned.

[0021] In addition, the lawn mowing robot according to at least one embodiment of the present invention has the advantage of having a simple configuration of a height-adjusting drive unit, thereby reducing the weight and volume of the drive unit.

[0022] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0023] FIG. 1 is a perspective view showing the appearance of a lawn mowing robot according to an embodiment of the present invention.

[0024] FIG. 2 is a side view showing the appearance of one side of the lawn mowing robot of FIG. 1.

[0025] FIG. 3 is a perspective view illustrating one embodiment of a drive assembly of a lawn mowing robot of the present invention.

[0026] FIG. 4 is a cross-sectional view illustrating the operation of a blade motor according to one embodiment of a drive assembly of a lawn mowing robot of the present invention.

[0027] FIG. 5 is a cross-sectional view illustrating the operation of a lift motor according to one embodiment of a drive assembly of a lawn mowing robot of the present invention.

[0028] FIGS. 6 and 7 are cross-sectional views of another embodiment of a drive assembly of a lawn mowing robot of the present invention.

[0029] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0030] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0031] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0032] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0033] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0034] FIG. 1 is a perspective view showing the exterior of a lawn mowing robot (100) according to an embodiment of the present invention, and FIG. 2 is a side view showing the exterior of one side of the lawn mowing robot (100) of FIG. 1.

[0035] A lawn mowing robot (100) refers to a robot equipped with a lawn mowing device used for the purpose of tidying up a garden by cutting grass to a certain height. The lawn mowing robot (100) of the present invention refers to an autonomous robot that moves and mows grass automatically, rather than being held and moved by a worker.

[0036] A lawn mowing robot (100) according to an embodiment of the present invention may include a body (110), a driving unit (120), and a sensor unit (130). The body (110) may include a body (110) housing that forms an exterior for mounting components therein. The body (110) housing may include a lightweight and highly durable material, and for example, a synthetic resin such as reinforced plastic may be used.

[0037] A driving unit (120) may be positioned at the bottom of the body (110) housing, and may include various sensor units (130) for guiding the driving direction of the driving unit (120). The front may be aligned based on the driving direction.

[0038] The driving unit (120) may include a main wheel (121) that is connected to a driving motor to receive power and a sub wheel (122) for stable driving. As shown in FIGS. 1 and 2, a plurality of main wheels (121) may be provided, and in the present embodiment, they may be provided on the left and right sides, respectively.

[0039] A pair of main wheels (121) are independently driven and can change the driving direction by adjusting the rotation speed. The sub-wheel (122) can be rotated toward the direction steered by the main wheel (121).

[0040] The outer surface of the body (110) housing may include a sensor unit (130). It may include a camera (131) that collects image information to recognize the driving direction and detect obstacles in the driving direction, and a distance sensor (132) that detects the distance to the obstacle. The distance sensor is mainly positioned at the front based on the driving direction, and may be positioned at the left, right, or rear. The sensor unit (130) may include a location sensor that detects the location using GPS or the like in addition to optical information.

[0041] In addition to the sensor that assists driving, the robot may further include a height sensor to detect the distance from the ground and mow the lawn to a uniform height. The height sensor may measure the height from the ground or the top of the lawn. Multiple heights can be collected simultaneously, and the height of the mowing blade can be adjusted based on the height information with the lowest value.

[0042] A control unit (not shown) for controlling the driving unit (120) based on the input value of the sensor unit (130) may be mounted inside the body (110). The autonomous driving lawn mowing robot (100) may include a wireless communication unit for wireless communication with an external server or a user's terminal.

[0043] The lawn mowing robot (100) can store information such as distance information, image information, and location information acquired while driving, and can synthesize this information to form a map of the driving space and store it in a database.

[0044] A driving assembly (140) may be included within the body (110) housing. The driving assembly (140) includes a blade unit (144) that mows grass, and can mow grass by rotating the blade unit (144) using the rotational force of the blade motor. The height of the blade unit (144) can be adjusted based on the height from the ground acquired by the sensor unit (130) described above, so that the grass can be mowed to a desired length.

[0045] A battery may be included inside the body (110) housing for wireless operation. The battery may be connected to the control unit, sensor unit (130), driving unit (120), and driving assembly (140) to supply power.

[0046] Below, the configuration of the drive assembly (140) of the lawn mowing robot (100) will be described in detail with reference to the drawings.

[0047] FIG. 3 is a perspective view illustrating one embodiment of a drive assembly (140) of a lawn mowing robot (100) of the present invention.

[0048] The drive assembly (140) of the present invention may include a disc-shaped blade unit (144) in which a plurality of blades for mowing grass are combined. A blade shaft (1447) extending upward from the blade unit (144) rotates under the power of a blade motor (141) to mow grass. The blade motor (141) of the lawn mowing robot (100) of the present embodiment may be directly connected to the blade shaft (1447) as illustrated in FIG. 3 to rotate the blade unit (144).

[0049] The drive assembly (140) of the present invention may include a lift module for adjusting the height of the blade unit (144) from the floor surface that the drive unit (120) touches so that the grass can be mowed at various heights.

[0050] In the past, it was common to manually adjust the height of the drive assembly (140) in the up-and-down direction, but the drive assembly (140) of the present invention may include a lift module that operates automatically so that the height can be adjusted remotely or automatically in situations where it is difficult for a worker to directly access.

[0051] The lift module of the present invention may include a lift motor (145), a lift shaft (1457), a lift cam (146), and a cam housing (149) in which the lift cam (146) is accommodated.

[0052] The lift module of the present invention can adjust the position of the blade unit (144) in the up-and-down direction by moving the lift cam (146) up and down within the cam housing (149) using the rotational force of the lift motor (145). The lift cam (146) is a member that converts the rotational force of the lift motor (145) into an up-and-down force.

[0053] The lift cam (146) is a cylindrical member that rotates around a lift shaft and may include an inclined surface whose height varies vertically along the circumference. The lift cam (146) of the present embodiment may utilize a cylindrical member with a spiral formed on the outer surface.

[0054] The lift cam (146) can be housed in a cylindrical cam housing (149). The housing screw thread (1493) protruding from the inner surface of the cam housing (149) and the cam screw thread (1463) formed on the outer surface of the lift cam (146) can be configured to engage with each other. When the lift motor (145) rotates the lift cam (146), the lift cam (146) rotates within the cam housing (149), and the positions of the cam screw thread (1463) and the housing screw thread (1493) are changed, so that the lift cam can move vertically.

[0055] When the lift motor (145) is vertically placed on the upper side of the cam housing (149), there is a problem in that the height of the lawn mower robot (100) increases, thus increasing the size of the lawn mower robot (100).

[0056] As illustrated in FIG. 3, a lift motor (145) is placed on the side of the cam housing (149), and a first power transmission gear (1455, 1456) can be used to transmit the power of the lift motor (145) to the lift cam (146). The first power transmission gear (1455, 1456) can be configured such that a first gear (1455) connected to the rotational axis of the lift motor (145) and a second gear (1456) connected to the lift shaft (1457), which is the rotational axis of the lift cam (146), mesh with each other.

[0057] FIG. 4 is a cross-sectional view illustrating the operation of a blade motor (141) according to one embodiment of a drive assembly (140) of a lawn mower robot (100) of the present invention, and FIG. 5 is a cross-sectional view illustrating the operation of a lift motor (145) according to one embodiment of a drive assembly (140) of a lawn mower robot (100) of the present invention.

[0058] The lift shaft (1457) passes through the upper surface of the cam housing (149), and a lift bearing (1421) may be further included between the upper surface of the cam housing and the lift shaft (1457) so that the lift shaft (1457) rotates without friction with the cam housing (149).

[0059] Since the blade motor (141) is located lower than the lift cam (146), when the blade motor (141) is driven, only the blade shaft (1447) and the blade unit (144) can rotate as shown in Fig. 4. When the lift motor (145) is driven, the lift shaft (1457), which receives rotational force through the first power transmission gear (1455, 1456), rotates.

[0060] The lift cam (146) can be coupled with the lift shaft (1457) in a pin-slot manner so that the rotational force of the lift shaft (1457) is transmitted to the lift cam (146), but the vertical position relative to the lift shaft (1457) can be changed.

[0061] The lift cam (146) includes a shaft hole (1466) in the center into which a lift shaft (1457) is inserted, and a vertical slot (1468) may be formed in the shaft hole (1466). The lift shaft (1457) includes a slot pin (1458) inserted into the vertical slot (1468), and the slot pin (1458) may move vertically within the vertical slot (1468).

[0062] Accordingly, when the lift shaft (1457) rotates, the lift cam (146) also rotates, and the lift cam (146) can move up and down within the cam housing (149) depending on the direction of rotation. As illustrated in FIG. 4, the position of the slot pin (1458) within the vertical slot (1468) can vary depending on the position of the lift cam (146).

[0063] Unlike the embodiments illustrated in FIGS. 4 and 5, a pin-slot combination in which a vertical slot is formed in the lift shaft (1457) and a slot pin is protruded to be inserted into the vertical slot within the shaft hole (1466) of the lift cam (146) may also be included in the present invention.

[0064] The blade motor (141) is located at the bottom of the lift cam (146) and may include a motor spring (148) that connects the cam housing (149) to pull the blade motor (141) upward. The motor spring (148) pulls the blade motor (141) upward to prevent it from falling to the floor due to gravity.

[0065] The motor spring (148) of this embodiment provides an upward force so that the blade motor (141) is housed within the cam housing (149), and as shown in FIG. 3, the motor spring (148) can be brought into close contact with the lift cam (146) located on the upper side of the blade motor (141) due to the elasticity of the motor spring (148).

[0066] The motor spring (148) of this embodiment provides a compressive force, but conversely, a motor spring that provides a tensile force that pushes the blade motor (141) from the bottom to the top may also be used.

[0067] As shown in FIG. 4, the cam housing (149) may extend to the side of the blade motor (141) so that the blade motor (141) does not come off from the bottom of the lift cam (146). The blade motor (141) may further include a vertical guide (1418, 1498) that restricts the rotation of the blade motor (141) so that it does not rotate when the lift cam (146) rotates, since the motor spring (148) becomes twisted when the lift cam (146) rotates.

[0068] The vertical guide (1418, 1498) may include a guide slot (1498) formed in the cam housing (149) and a guide protrusion (1418) inserted into the guide slot (1498). The guide protrusion (1418) may extend laterally from the blade motor (141) and protrude outwardly from the cam housing (149). The upper end of the motor spring (148) may be fixed to the cam housing (149) and the lower end may be fixed to the guide protrusion (1418).

[0069] The vertical guide (1418, 1498) can move up and down while maintaining a state of close contact with the lower surface of the lift cam (146) within the cam housing (149) without rotating even when the lift cam (146) rotates. In order to reduce frictional force on the upper surface of the blade motor (141) when the lift cam (146) rotates, a low-friction surface treatment can be applied to the upper surface of the blade motor (141) or the lower surface of the lift cam (146).

[0070] However, since the load of the blade motor (141) is supported only by the elasticity of the motor spring (148), a lot of vibration may occur when the blade motor (141) rotates. The lift motor (145) must use a motor with a large output to drive while overcoming the load of the blade motor (141) and the elasticity of the motor spring (148), which causes the size of the drive assembly (140) to increase and the manufacturing cost to increase.

[0071] To solve the above problem, the arrangement of the blade motor (141) of the drive assembly (140) can be changed. FIGS. 6 and 7 are cross-sectional views according to another embodiment of the drive assembly (140) of the lawn mowing robot (100) of the present invention, wherein FIG. 6 illustrates a state in which the blade unit (144) is positioned at the upper side, and FIG. 7 illustrates a state in which the blade unit (144) is positioned at the lower side.

[0072] The lift module may include a lift motor (145), a lift shaft (1457), a lift cam (146), and a cam housing (149) as in the above-described embodiment. The blade motor (141) of the present embodiment is arranged parallel to the side of the cam housing (149) rather than below the lift cam (146), and the motor spring (148) is omitted. The blade motor (141) and the lift motor (145) may be arranged in a horizontal parallel manner.

[0073] In the above-described embodiment, the blade shaft (1447) is directly connected to the blade motor (141), but in the present embodiment, the rotational power of the blade motor (141) can be transmitted indirectly through the drive shaft (1417). The drive shaft (1417) of the blade motor (141) can be connected to the blade shaft (1447) by passing through the lift shaft (1457).

[0074] The drive shaft (1417) can rotate through the second power transmission gear (1415, 1416) for transmitting the rotational power of the blade motor (141), and the second power transmission gear (1415, 1416) can be located above the first power transmission gear (1455, 1456). The drive shaft (1417) can be located inside the lift shaft (1457) by passing through the first power transmission gear (1456) connected to the lift shaft (1457).

[0075] The drive assembly (140) of the present invention may include a first bearing (1422) positioned between the drive shaft (1417) or the second power transmission gear (1415, 1416) and the lift shaft (1457) or the first power transmission gear (1455, 1456).

[0076] The first bearing (1422) can separate the two components so that the blade motor (141) and the lift shaft (1457) rotate around the same axis but independently. When the blade motor (141) rotates, the lift shaft (1457) does not rotate and only the drive shaft (1417) can rotate, and when the lift motor (145) is driven, only the lift shaft (1457) can rotate.

[0077] In this embodiment, the first bearing (1422) is positioned between the first power transmission gear (1455, 1456) and the drive shaft (1417), but may also be positioned between the drive shaft (1417) and the lift shaft (1457). The drive shaft (1417) is fixed to the second power transmission gear (1415, 1416) and can rotate together with the second power transmission gear (1415, 1416).

[0078] The blade shaft (1447) can be connected within the shaft hole of the drive shaft (1417) and the lift cam (146). The blade shaft (1447) rotates together with the drive shaft (1417), but when the lift cam (146) moves, the blade shaft (1447) can move up and down in accordance with the vertical position of the lift cam (146).

[0079] The blade shaft (1447) and the drive shaft (1417) can only receive the rotational force of the drive shaft (1417) without being restricted in the vertical position through the pin-slot joint.

[0080] The pin-slot joint between the drive shaft (1417) and the blade shaft (1447) of the embodiment illustrated in FIGS. 6 and 7 illustrates a configuration in which a vertical slot (1418) is formed in the drive shaft (1417) located outside of the blade shaft (1447) and a slot pin (1448) is formed in the blade shaft (1447). Conversely, a vertical slot may be formed in the blade shaft and a slot pin may be formed in the drive shaft (1417).

[0081] Meanwhile, the blade shaft (1447) moves vertically together with the lift cam (146), but a second bearing (1423) may be provided between the lift cam (146) and the blade shaft (1447) to prevent the lift cam (146) from rotating when the blade shaft (1447) rotates.

[0082] The second bearing (1423) allows only the blade shaft (1447) to rotate when the blade motor (141) rotates, and allows only the lift cam (146) to rotate when the lift motor (145) rotates, so that the vertical positions of the lift cam (146) and the blade shaft (1447) can be synchronized.

[0083] As described above, the lawn mowing robot (100) according to at least one embodiment of the present invention can automatically adjust its height and perform lawn mowing work unmanned.

[0084] In addition, the lawn mowing robot (100) according to at least one embodiment of the present invention has the advantage of having a small weight and volume of the driving unit since the configuration of the driving unit for height adjustment is not complicated.

[0085] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are intended to be included within the scope of the present invention.

[0086] With respect to various embodiments for implementing the present invention, duplicate descriptions are omitted as they have been described above in the previous table of contents, Best Mode for Carrying Out the Invention.

[0087] The present invention is applicable to lawn mowing robots in various fields, and thus its industrial applicability is recognized.

Claims

1. A main body housing including a driving part at the bottom; and including a drive assembly located inside the main body housing, The above drive assembly lift motor; A lift shaft that rotates by receiving the rotational power of the above lift motor; A pin-slot coupled lift cam that is synchronized with the above lift shaft and rotates and has variable height; A cam housing in which the lift cam is housed and which includes housing threads protruding from the inner wall; A blade shaft coupled to the above lift cam and moving vertically together with the change in height of the lift cam; a blade unit coupled to the lower end of the blade shaft; and Includes a blade motor that provides rotational force to the blade shaft, The above lift cam Includes a cam thread that engages with the above housing thread. A lawn mowing robot in which the height of the lift cam is variable depending on the rotation direction of the lift shaft.

2. In paragraph 1, The above lift cam a cylindrical shaft hole through which the above lift shaft passes; and including a vertical slot formed in the above shaft hole, A lawn mowing robot, characterized in that the lift shaft includes a slot pin inserted into the vertical slot.

3. In paragraph 1, A lawn mowing robot characterized by including a first power transmission gear that transmits the rotational power of the lift motor to the lift shaft.

4. In paragraph 1, The above blade motor is coupled to the lower part of the above lift cam, The above cam housing extends to the side of the above blade motor; A lawn mowing robot characterized in that it further includes a vertical guide that restricts rotation of the blade motor within the cam housing and allows movement in a vertical direction.

5. In paragraph 4, The above vertical guide a guide slot formed in the cam housing; and A lawn mowing robot characterized by including a guide protrusion protruding from the blade motor and inserted into the guide slot.

6. In paragraph 5, The above blade motor is coupled to the lower part of the above lift cam, Further comprising a motor spring that pulls the blade motor upward, A lawn mowing robot characterized in that the above motor spring is coupled to the above guide protrusion.

7. In paragraph 1, A lawn mowing robot characterized in that it further includes a drive shaft that rotates by receiving the rotational power of the blade motor and is pin-slot coupled with the blade shaft.

8. In paragraph 7, A lawn mowing robot characterized in that the drive shaft is arranged to penetrate the lift shaft.

9. In paragraph 8, A first power transmission gear that transmits the rotational power of the lift motor to the lift shaft; and It includes a second power transmission gear that transmits the rotational power of the above blade motor to the above drive shaft, A lawn mowing robot further comprising a first bearing positioned between the first power transmission gear or the lift shaft and the second power transmission gear or the drive shaft.

10. In paragraph 9, The above second power transmission gear is located above the above first power transmission gear. A lawn mowing robot, characterized in that the drive shaft penetrates the first power transmission gear and is inserted into the inside of the lift shaft.

11. In paragraph 7, The above blade shaft passes through a shaft hole formed in the center of the above lift cam, A lawn mowing robot characterized by comprising a second bearing positioned between the blade shaft and the lift cam.

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