JPWO2017051663A1 - Self-propelled mower - Google Patents

Abstract

Provided is a self-propelled mower configured such that when an external force is applied to a cutting blade held by an elevating mechanism, a drive mechanism including the cutting blade can be retracted upward. The cutting blade motor 30 that is held so that the rotating shaft 30c faces in the vertical direction, the rotary cutting blade 35 that is attached to the tip of the rotating shaft and rotates on a surface substantially parallel to the ground, and the motor is moved in the vertical direction In the self-propelled mower that adjusts the cutting height by the cutting blade, when the force to lift the cutting blade 35 is applied, the motor cylinder 70 is moved so that the motor and the cutting blade can be moved upward. . For this reason, the steel ball 68b is arranged in the hemispherical depression 64b formed on the outer peripheral surface of the dial cylinder part 60, and the motor cylinder part is suspended by the lifting guide ribs 73 formed on the motor cylinder part side. The blade can be moved upward.

Description

The present invention relates to a self-propelled mower that uses an electric motor as a drive source and autonomously runs in a mowing area to cut grass.

As a mower for mowing lawns and weeds that grow on the ground, it is a self-propelled type (self-propelled type or robot type) that automatically runs in the mowing area partitioned by wires etc. and mows the grass. Mowers have become popular. In self-propelled mowers, a wheel motor for driving the wheels and a motor for the cutting blades for driving the mowing blades for mowing are provided, and a secondary battery that supplies power to these motors is installed and controlled. Autonomous driving is controlled by the device.

When the rechargeable battery's charging capacity decreases during mowing work in a self-propelled type, the mower automatically returns to the charging station (charging base) where the power transmission device is installed. Charging is performed automatically. After the secondary battery has been charged, the work in the designated mowing area is automatically resumed. Such a mower does not require the operator to guide the mower to the charging station every time charging is necessary, and can mowing for a long time without the operator. Here, an example of use of a conventional self-propelled mower will be described with reference to FIG. A lawn (not shown) is planted in a garden 210 adjacent to the house 200, and this is a mowing area 290 that is a target for mowing. In the mowing area 290, a self-propelled mower 301 is disposed on the lawn. A charging station 270 for charging the mower 301 is disposed in the mowing area 290. Charging station 270 is installed in the corner of the lawn mowing area, and is connected to AC adapter 250 by cable 260. The AC adapter 250 is connected to an outlet (not shown) such as a commercial AC power source, and converts an AC voltage (for example, 230 V) supplied from the outlet into a DC voltage (for example, 21 V). The charging station 270 has a DC output terminal (positive electrode, negative electrode). When the mower 301 reaches the charging position of the charging station 270, the power receiving terminal (not shown) of the mower 301 is connected to the DC output terminal of the charging station 270 ( The power is supplied from the charging station 270 side to the mower 301 side, and the mower 301 charges the mounted secondary battery.

The mower 301 is provided with a plurality of wheels (for example, four), and some of the wheels are driven by a wheel motor (not shown). In addition, a rotary type cutting blade (not shown) that rotates on a surface substantially parallel to the ground is provided between the front wheel and the rear wheel as viewed in the front-rear direction of the mower 301. Is rotated by an independent cutting blade motor (not shown).

In order to help the mower 301 autonomously travel, boundary notification means using a boundary cable, a fence, radio, light, or the like is arranged in advance at the boundary portion between the grass cutting area 290 and other areas in the garden 210. The In FIG. 12, a guide wire (guide wire) 280 formed in a loop shape is disposed (for example, embedded) as a boundary notification means. The arrangement of the guide wire 280 is performed in advance by the user of the mower 301 before mowing, and the self-propelled mower 301 performs the mowing work in an inner region having the guide wire 280 as an outer edge. An induction signal generator (not shown) in the charging station 270 is connected to the guide wire 280, and a pulsed current flows at a predetermined interval. The mower 301 detects a magnetic field generated by the current flowing through the guide wire 280 to determine whether it is inside or outside the guide wire 280, and performs mowing work while traveling automatically and autonomously.

Japanese Patent Laid-Open No. 2015-15922

A conventional self-propelled mower as described in Patent Document 1 is configured so that the cutting height can be adjusted by changing the height of the cutting blade from the ground. Adjustment in 10 mm intervals is possible within a range of ˜60 mm. However, in a self-propelled mower, work is performed in the absence of an operator, so that force from the lower side of the cutting blade is applied by undulations of the ground or small obstacles, and excessive force is applied to the cutting blade. The cutting blade may ride on the protrusions and the mowing machine may become difficult to travel.

An object of the present invention is made in view of the above background, and is configured such that when an external force is applied to the cutting blade held by the lifting mechanism, the drive mechanism including the cutting blade can be retracted upward. Is to provide a self-propelled mower. Another object of the present invention is to provide a self-propelled grass mower with improved reliability by avoiding grass and soil from entering a lifting mechanism that houses a motor for a cutting blade and hindering operation. There is.

The characteristics of representative ones of the inventions disclosed in the present application will be described as follows. According to one aspect of the present invention, a main body chassis that can be driven by driving wheels and driven wheels, a motor that is held by the main body chassis, and a tip of a rotary shaft that is driven by the motor, In a self-propelled mower having a cutting blade that rotates on a parallel surface, a cutting height adjustment mechanism that adjusts the cutting height by the cutting blade, and a main body cover that covers the upper side of the main body chassis, the cutting height adjustment mechanism is: The cutting blade can be moved upward when a force for lifting the cutting blade is applied. In addition, the trimming height adjustment mechanism includes a locking portion having a plurality of height positions and a protruding portion that engages with the locking portion in the chassis portion, and the other in the holding portion of the cutting blade, The cutting blade holding part was held so as to be suspended from the chassis part. Furthermore, the trimming height adjustment mechanism is capable of moving both the motor and the cutting blade.

According to another aspect of the present invention, the trimming height adjusting mechanism includes a cup-shaped dial tube portion that is held by the main body chassis and has an opening on the lower side, and a cup shape that has an opening on the upper side and holds the cutting blade. The cylinder portions are arranged so that the diameters of the dial tube portion and the motor tube portion are different from each other. Also, a protrusion is provided on one surface side of the overlapping portion of the dial tube portion and the motor tube portion, a locking portion is provided on the other surface side, and the motor tube portion is turned into the dial tube portion by engagement of the protrusion portion and the lock portion. It is held so that it hangs. The motor cylinder portion accommodates the motor inside, and is arranged so that the rotation shaft of the motor penetrates the bottom surface of the motor cylinder portion and extends downward. Further, the engaging portion is formed obliquely, for example, in a rib shape so that the height position changes in the circumferential direction, and the engaging position between the engaging portion and the protruding portion is changed by rotating the dial tube portion. A space in which the protrusion can move is formed on the lower side.

According to still another feature of the present invention, the protrusion is formed by a hemispherical depression formed on the outer peripheral surface of the dial cylinder part and a steel ball disposed in the depression, and the locking part is a motor cylinder part It is a guide rib which protrudes radially inward in the inner peripheral surface. Further, three recesses and three steel balls are arranged at equal intervals in the circumferential direction, and three guide ribs are arranged at equal intervals in the circumferential direction, and are formed to extend obliquely toward the circumferential direction of the inner wall side surface. . In addition, a click mechanism that holds the rotational position of the dial cylinder in the circumferential direction is provided at several locations in the circumferential direction of the dial cylinder and the motor cylinder, and the guide rib is moved downward by the steel ball at the held rotational position. It was comprised so that the load of might be received.

According to still another feature of the present invention, a stopper for limiting the range of movement of the motor cylinder portion in the upward direction is provided on the dial cylinder portion or the main body chassis side. Further, a rotation preventing means is provided so that the motor cylinder portion does not rotate in the circumferential direction with respect to the main body chassis. Further, the trimming height adjustment mechanism enables the cutting blade to be set at a position lower than the height of the front lower end of the main body chassis, and when a force for lifting the cutting blade is applied, the cutting blade is set to the height of the front lower end of the main body chassis. It was configured to be movable to almost the same position.

According to the present invention, when a force for lifting the cutting blade is applied, the motor and the cutting blade move upward together (withdrawal), so that an excessive load is applied to the motor rotation mechanism and the cutting blade. Can be prevented, and stable mowing work can be performed. In addition, the trimming height adjustment mechanism allows the cup-shaped dial tube portion having an opening on the lower side and the cup-shaped motor tube portion having an opening on the upper side to overlap with each other, and the motor tube portion is positioned on the outer diameter side. Since there is no route through which dust enters directly from the lower side, grass or dust that has been cut into the motor portion is less likely to enter. Furthermore, since the motor cylinder is held by being suspended by the weight of the motor or cutting blade, there is no need to provide a biasing means such as a compression spring between the dial cylinder and the motor cylinder, and the trimming height adjustment mechanism The structure can be simplified.

1 is a perspective view of a mower 1 according to an embodiment of the present invention. It is a top view of the state which removed the main body cover 2 of the mower 1 which concerns on the Example of this invention. It is the figure which looked at the right direction from the cross section of the AA part of FIG. It is a block diagram which shows the various functional components with which the main body chassis 10 of the mower 1 which concerns on the Example of this invention is equipped. FIG. 4 is a partially enlarged view showing a lifting mechanism of a cutting blade motor 30 in FIG. 3. It is a perspective view of the dial cylinder part 60 single-piece | unit of FIG. It is a perspective view which shows the cylindrical part 71 which forms the motor cylinder part 70 of FIG. It is the expanded view which expand | deployed the inner wall face of the cylindrical part 71 of FIG. 4 is a diagram showing a state in which the cutting blade motor 30 of FIG. 3 is set at the uppermost position, (1) is a partial top view in the vicinity of the dial tube portion 60, and (2) is a longitudinal section of a lifting mechanism of the cutting blade motor 30. FIG. It is a figure which shows the state which set the cutting blade motor 30 of FIG. 3 to the lowest position, (1) is a partial top view of dial cylinder part 60 vicinity, (2) is a vertical section of the raising / lowering mechanism of the cutting blade motor 30 FIG. It is a figure which shows operation | movement when the force thrusted up from a cutting blade is received by the raising / lowering mechanism of the cutting blade motor 30, (1) is sectional drawing of the normal state which does not receive external force, (2) is the upper side which received external force. It is sectional drawing of the state which moved to. It is a figure for demonstrating the outline | summary of operation | movement of the self-propelled mower 301 in a prior art.

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. Further, in this specification, description will be made assuming that the front, rear, left, right, and up and down directions are directions shown in the drawing.

FIG. 1 is a perspective view of a self-propelled mower 1 according to an embodiment of the present invention. The mower 1 has small-diameter front wheels 12a and 12b (12a is not visible in FIG. 1) provided so as to be able to rotate or swing along the traveling direction, and large-diameter rear wheels 13a and 13b (FIG. 1). 13a is not visible), and the mower 1 is entirely covered with the body cover 2. The power source of the mower 1 is a detachable battery pack (described later in FIG. 2), and the driving of a wheel motor (not shown) is controlled by a microcomputer (hereinafter referred to as “microcomputer”) included in the control device. Mowing the grass while traveling autonomously. The front lower end 2c of the main body cover 2 is configured to have a gap of a predetermined distance H between the main body cover 2 and the grass that has entered the main body cover 2 through this gap is disposed below the main body chassis 10. Mowing with a cutting blade (described later). On the upper side of the main body cover 2, an opening / closing cover 3 that can be opened / closed about a rotation shaft on the front side is provided. The opening / closing cover 3 is made of, for example, a transparent resin member. By opening the opening / closing cover 3, the dial knob 61, the keyboard 24, and the display 25, which will be described later with reference to FIG. A substantially rectangular opening 5 is provided in front of the main body cover 2 when viewed from the front, and the power transmission terminal of the charging station 270 can contact the power receiving terminal 41 via the opening 5 during charging. The front end portion of the main body chassis 10 is located inside the opening 5, and a power receiving terminal 41 is provided on the left side surface and the right side surface thereof. Fenders 2a and 2b for covering the upper portions of the front wheels 12a (see FIG. 2) and 12b are formed on the left and right sides of the opening 5 of the main body cover 2, respectively. A stop switch 4 for manual stop is provided on the upper rear side of the main body cover 2.

FIG. 2 is a top view of the mower 1 according to the embodiment of the present invention with the main body cover 2 removed. The main body chassis 10 has a convex tip and is narrowed down to a triangle when viewed from above, and mounting arms 11a and 11b extend from the slope to the left and right sides. Front wheels 12a and 12b are pivotally supported on the mounting arms 11a and 11b, and are respectively held so that the directions of the wheels can follow freely according to the moving direction of the mower 1. Rear wheels 13 a and 13 b are provided on the rear side of the main body chassis 10. Here, large wheels are used for the rear wheels 13a and 13b, and they are driven by independent wheel motors for driving (right wheel motor 16a and left wheel motor 16b). The two wheel motors can be steered by a microcomputer (not shown) mounted on the main board 26 by being driven synchronously or asynchronously. The rotation shaft of the wheel motor rotates the rear wheels 13a and 13b after being decelerated at a predetermined reduction ratio by a reduction mechanism (not shown). For example, the mower 1 moves forward or backward by driving the rear wheels 13a and 13b synchronously, and rotates the mower 1 in a predetermined direction by driving the rear wheels 13a and 13b to generate a rotational difference. be able to. As the wheel motor, for example, a brushless DC motor is used, and is driven via an inverter circuit (not shown).

Two power receiving terminals 41 (a positive terminal 41 a and a negative terminal 41 b) are provided on the slopes on both the left and right sides in the vicinity of the front end of the main chassis 10. On the upper side of the horizontal portion of the mounting arms 11a and 11b, in order to support the main body cover 2, the end of a leaf spring portion (not shown) provided on the inner wall portion of the main body cover 2 is movable within a predetermined range. Receiving recesses 17a and 17b are provided. Near the rear end of the main body chassis 10, a recess 18 a (in the vicinity of the left end) that accommodates an end of a leaf spring (not shown) provided on the inner wall of the main body cover 2 movably within a predetermined range. A recess is not shown).

In the vicinity of the center of the main body chassis 10, there is provided a trimming height adjusting mechanism for adjusting the height H1 of the cutting blade from the ground, that is, the trimming height, by moving the motor for the cutting blade (not shown) in the vertical direction. . The dial knob 61 can be rotated by an operator. The dial knob 61 can be rotated by a base portion 21 in which distances (cutting height) between a cutting blade and the ground described later are engraved as “20”, “30”, “40”, “50”, “60”. To be held. By adjusting the mark on the dial knob 61 to any numerical value, a cutting blade and a cutting blade motor, which will be described later, correspondingly move upward or downward. In front of the dial knob 61, the mower 1 is in contact with a lift sensor 47 that detects a collision with an obstacle, a lifted state, a tilted state, etc. of the main body cover 2 based on the relative movement amount of the main body chassis 10 and the main body cover 2. A sensor 48 is provided. Magnets 19 a and 19 b are provided on the inner wall side of the main body cover 2 at positions corresponding to the lift sensor 47 and the contact sensor 48. The lift sensor 47 and the contact sensor 48 are configured to include a substrate having a hall sensor, for example.

A container portion 22 that houses a battery pack (described later in FIG. 3) is provided on the rear side of the main body chassis 10, and the opening portion of the container portion 22 is covered with a lid portion 23 that can be opened and closed. A display 25 such as a liquid crystal display panel, a keyboard 24 and a main switch 42 are provided on the upper surface of the lid 23. The operator can set the mowing schedule by operating the keyboard 24. The main board on which the microcomputer is mounted is provided between the container portion 22 of the main body chassis 10 and the motor housing 80.

Although not shown in FIG. 2, the cutting blade 35 (see FIG. 3) that rotates at a predetermined distance parallel to the ground rotates coaxially with the rotation center of the dial knob 61, and the cutting blade motor 30 (see FIG. 2). 3 is provided between the front wheels 12a and 12b and the rear wheels 13a and 13b when viewed in the front-rear direction of the main body chassis 10. The outer edge position of the cutting blade 35 is arranged so as to be within the range of a virtual rectangle connecting the center positions of the front wheels 12a and 12b and the rear wheels 13a and 13b. Further, the outer edge position of the main body cover 2 indicated by the dotted line is set so as to be located sufficiently outside the outer edge position of the cutting blade 35, and a sufficient clearance between the cutting blade 35 and the main body cover 2 is ensured.

FIG. 3 is a diagram (a vertical sectional view passing through the left and right center position of the mower 1) as viewed from the cross section of the AA portion of FIG. The main body cover 2 has a shape that covers almost the entire body chassis 10 except for the ground side, and is held in a floating state with respect to the main body chassis 10 by a spring or the like, so that the main body cover 2 moves slightly in the front-rear, left-right, and vertical directions. Is possible. The main body cover 2 may collide with obstacles such as rocks, protrusions, walls, etc., and a relative position change of the main body cover 2 at that time is detected by a lift sensor, a contact sensor, etc., which will be described later. Detects a collision or the like of the mower 1.

A drive device (cutting blade motor 30) for rotating the plurality of blades 35b and a motor cylinder portion 70 for housing the drive device are provided on the lower side near the center of the main body chassis 10. The motor cylinder 70 rotates the dial cylinder 60 to move the vertical position of the motor with respect to the main body chassis 10, so that the cutting blade holder is configured to be relatively movable in the vertical direction of the cutting blade 35. Part. FIG. 3 shows a state where the motor cylinder portion 70 is at the lowest position (cutting blade height H ₁ = 20 mm) with respect to the rotary shaft of the cutting blade motor 30.

The cutting blade motor 30 is accommodated inside a cup-shaped motor cylinder portion 70 having an opening upward. The rotating shaft 30c (see FIG. 5) of the cutting blade motor 30 is arranged to extend in the vertical direction, and the cutting blade 35 is attached to the lower end of the rotating shaft 30c. The cutting blade 35 is provided with movable metal blades 35b at several places, for example, four places on the outer peripheral side of a disc portion 35a made of synthetic resin formed in a disk shape, and is a horizontal plane substantially parallel to the ground. Rotate within.

The cutting blade motor 30 is a brushless DC motor, and a rotor core (not shown) having a permanent magnet rotates inside a stator (not shown) around which an exciting coil is wound. A circular inverter circuit board (not shown) is provided on the upper end side of the cutting blade motor 30, and there are a plurality of Hall ICs (not shown) and a plurality of switching elements (for example, FET (Field Effect Transistor) and IGBT). (Insulated gate bipolar transistor)).

A substantially rectangular parallelepiped container portion 22 for accommodating a battery pack (not shown) is provided on the rear side of the cutting blade motor 30. The container part 22 is manufactured by integral molding with the plate-like base part 21 using a synthetic resin such as plastic. The container part 22 has an opening on the upper side, is provided with a hinge 23 a for opening and closing the lid part 23, and the opening is closed by the lid part 23. The battery pack 28 accommodated in the container part 22 is detachable, and a plurality of secondary battery cells (not shown) are accommodated therein. In the vicinity of the upper rear end of the container part 22, there is provided a lid operation part 37 made of a screw or the like for fixing the opening and closing of the lid part 23 on the opposite side of the hinge 23 a. The lid portion 23 is provided with the keyboard 24 and the display 25 shown in FIG.

A guide wire sensor 45 is provided near the front end of the main chassis 10. The guide wire sensor 45 converts a change in the surrounding magnetic field into a change in current by a coil. Here, the mounting direction of the guide wire sensor 45 is set so that the axial direction of the coil (not shown) (magnetic field detection direction) is the vertical direction (vertical direction). Although not shown in FIG. 3, a second guide wire sensor is provided near the rear end of the main body chassis 10. The rear guide wire sensor is provided at a position where the vertical center position thereof substantially coincides with the height of the rotation shaft of the rear wheel drive motors 16a and 16b (see FIG. 2).

FIG. 4 is a block diagram showing various functional components provided in the main body chassis 10 of the mower 1. A control device that controls the operation of the mower 1, a power supply circuit (not shown), and the like are mounted on the main board 26. The control device includes a microcomputer not shown (hereinafter referred to as “microcomputer”), a storage device, and other electronic elements. The main board 26 has a power receiving terminal 41 (positive terminal 41a, negative terminal 41b) that can be connected to two power transmitting terminals (positive electrode and negative electrode) of the charging station 270, and a terminal (not shown) of a battery pack attached to the battery mounting portion. A battery terminal 29 that is detachably connected to the output voltage terminal and the identification terminal. The main switch 42 is inserted into the connection line between the battery terminal 29 and the main board 26, and is a power supply switch to the main board 26 and the motor of the mower 1. The main board 26 is connected to the cutting blade motor 30, the right wheel motor 16a, and the left wheel motor 16b, and the driving power is supplied from the main board 26 via the motor driving circuits 27a to 27c, whereby the cutting blade 35 is provided. The rear wheels 13a and 13b are driven independently. The motor drive circuits 27a to 27c include inverter circuits, and generate a three-phase alternating current excitation current from a direct current power source in accordance with a PWM control signal controlled by a microcomputer to produce a cutting blade motor 30, a right wheel motor 16a, and a left wheel motor. Rotate 16b. The microcomputer rotates the cutting blade motor 30 to rotate the cutting blade 35 directly connected to the rotary shaft 30c of the cutting blade motor 30 without a speed reduction mechanism. Further, the microcomputer rotates the rear wheels 13a and 13b by rotating the right wheel motor 16a and the left wheel motor 16b in conjunction with each other or in an unlinked manner.

A keyboard 24, a display 25, and a stop switch 4 are connected to the main board 26, and a first (front side) guide wire sensor 45, a second (rear side) guide wire sensor 46, a lift sensor 47, and a contact sensor. 48 and various sensors such as an inclination sensor 49 are connected. Signals detected by the coils of the first and second guide wire sensors 45 and 46 are output to the main board 26, and the boundary of the mowing area is recognized by a microcomputer mounted on the main board 26. In accordance with the recognition result, the microcomputer drives the mower 1 forward, backward, and turns by independently driving the left wheel motor 16b and the right wheel motor 16a for controlling the direction of the mower 1 and the like. The lift sensor 47 detects this when the main chassis 10 of the mower 1 is lifted or when the mower 1 is tilted more than a predetermined angle with respect to the ground. The wheel motor 16a, the left wheel motor 16b, and the cutting blade motor 30 are stopped. The contact sensor 48 detects an impact when the mower 1 contacts something. The inclination sensor 49 detects this when the mower 1 is inclined at a predetermined angle or more with respect to the ground, and prevents the mower 1 from entering the inclined surface.

The stop switch 4 is a manual stop means and is provided at an easily operable position on the rear end side upper part of the main body cover 2, and the user can stop the mower 1 during automatic traveling or mowing by manual operation. A keyboard 24 and a display 25 mounted thereon are input / output devices for information on mowing, and are arranged so that an operator can access them by opening the opening / closing cover 3 provided on the main body cover 2, and an operation start instruction, Set timer settings, work areas, etc. Although the keyboard 24 is provided here, a touch-type liquid crystal display may be used as the display 25 to integrally form them.

In the above-described configuration of the mower 1, when the battery pack 28 is attached to the battery mounting portion of the main body chassis 10 and the main body chassis 10 is positioned at the charging station 270, the control device on the charging station 270 side determines the connection of the mower 1. Then, a DC voltage for charging is supplied to the main body chassis 10 from a power transmission circuit (not shown). The charging circuit charges the battery pack 28 at the rated output voltage. After the charging is completed, the microcomputer controls the relay (not shown) to switch the battery pack 28 from the load side (the power supply side to the motor or the like) to the side connected to the motors 16a, 16b, 30. Thereafter, the mower 1 leaves the charging station 270 and performs a mowing operation according to a predetermined automatic traveling program by a microcomputer on the main board 26. The mower 1 returns to the charging station 270 when the requested mowing operation is completed or when the remaining battery pack 28 is low.

Next, the raising / lowering mechanism of the cutting blade motor 30 is demonstrated using FIG. The figure is a partially enlarged view showing the lifting mechanism of the cutting blade motor 30. The raising / lowering mechanism of the cutting blade motor 30 mainly includes a substantially cup-shaped dial tube portion 60 having an opening 60a on the lower side, a substantially cup-shaped motor tube portion 70 having an opening on the upper side, and a motor tube portion 70. The support cylinder portion 15b is configured to hold the outer portion of the support portion 15b so as to allow movement only in the axial direction and prevent rotation in the circumferential direction. The motor cylinder part 70 is composed of two parts, a cylindrical part 71 and a motor housing 80. The motor housing 80 is attached so as to cover the lower opening of the cylindrical portion 71, a disk portion 81 that forms the bottom surface of the motor cylinder portion 70 is formed on the lower side, and the cutting blade motor 30 is accommodated above the disk portion 81. A motor cover 82 is formed. The disk part 81 and the motor cover 82 are manufactured by integral molding of a synthetic resin such as plastic, and are manufactured in two parts by a vertical surface passing through the rotating shaft 30c, and are joined to each other by screws or other fixing methods. Is done. In the center of the disk part 81, a through hole 81a is formed through the rotary shaft 30c of the cutting blade motor 30, and the disk part 81 is fixed to the cylindrical part 71 by screws 84 at three locations on the outer peripheral part.

In the present embodiment, a dial blade portion 60 having an opening portion 60a on the lower side and a motor tube portion 70 having an opening portion 70a on the upper side are overlapped in a direction in which the respective opening portions face each other. A closed space for accommodating 30 was formed. The diameters of the dial tube portion 60 and the motor tube portion 70 are made different, and the overlapping state is such that the cylinder portion 71 of the motor tube portion 70 is located on the radially outer side and the dial tube portion 60 is located on the radially inner side. Be placed. In the present embodiment, the motor cover 82 is further disposed in the closed space defined by the two containers, and the cutting blade motor 30 is accommodated therein. In the present embodiment, a support cylinder portion 15b manufactured integrally with the undercover 14 is further formed, and the motor cylinder portion 70 is arranged on the inner peripheral side of the support cylinder portion 15b. Therefore, at the BB cross-sectional position in FIG. 5, the support cylinder portion 15b, the motor cylinder portion 70, and the dial cylinder portion 60 are formed from the outer peripheral side, and a triple structure is formed in which the respective cylinder portions overlap in the radial direction. Here, the support cylinder portion 15b is a fixed member that does not move in the axial direction or the circumferential direction. The motor cylinder 70 can move only in the axial direction but does not rotate in the circumferential direction. The dial tube portion 60 cannot move in the axial direction (vertical direction) with respect to the main body chassis 10 but can rotate by a predetermined rotation angle in the circumferential direction (rotation direction around the central axis of the cutting blade motor 30). is there.

Protrusions (here, depressions 64a to 64c and steel balls 68a to 68c) are provided on one surface side of the overlapping portion of the dial tube portion 60 and the motor tube portion 70, and a locking portion (here, lift guide) is provided on the other surface side. Ribs 72 to 74) are provided so that the locking portions engage with the protrusions. The elevating guide ribs 72 to 74 are arranged at equal intervals in the circumferential direction, are formed to extend obliquely toward the circumferential direction of the inner wall side surface, and the steel balls 68 a to 68 c and the elevating guide ribs 72 to 74 contact with each other in the circumferential direction. By changing the position, the axial distance between the dial tube portion 60 and the motor tube portion 70 is made different. Since the dial cylinder portion 60 and the motor cylinder portion 70 are overlapped in this way, a lifting mechanism for the cutting blade motor 30 and the cutting blade 35 can be realized, and the grass, dust, water splashed by the cutting blade 35 can be realized. Etc. can be greatly reduced, and the durability of the cutting blade motor 30 can be greatly increased.

Three steel balls 68a to 68c (only 68b can be seen in the figure) are provided between the dial cylinder part 60 and the cylindrical part 71 (diameter clearance), and the convex lifting guide rib 73 of the cylindrical part 71 is provided. Is located above the steel ball 68b. That is, the inwardly protruding portions of the cylindrical portion 71 by the lifting guide ribs 72 to 74 are positioned above the steel ball 68b, so that the cylindrical portion 71 is suspended (locked) to the dial tube portion 60. Thus, the cylindrical portion 71 is held so as not to fall down. Further, by forming the lifting guide ribs 72 to 74 with an angle in the circumferential direction, a cam mechanism with the steel balls 68 a to 68 c can be formed, and the rotational movement of the dial tube portion 60 can be performed on the cylindrical portion 71. It was possible to convert it to a vertical movement. Note that although the operator rotates the dial cylinder portion 60, the rotation may be controlled by a microcomputer using a dedicated electric motor.

The support cylinder part 15b located on the radially outer side of the dial cylinder part 60 is cylindrical, and a key groove (not shown) is formed on the inner peripheral surface thereof. The key groove engages with convex keys 79a to 79c (described later) formed in parallel with the axial direction formed on the outer peripheral side of the cylindrical portion 71, thereby preventing the cylindrical portion 71 from rotating. While performing the function, only the vertical movement (axial direction) of the cylindrical portion 71 is allowed. The support cylinder portion 15b is manufactured by synthetic resin integral molding, and may be formed as a part of the synthetic resin undercover 14 attached to the lower surface of the main body chassis 10 (of course, it may be formed separately). . On the upper side of the support cylinder portion 15b, a cylindrical extension portion 15a having substantially the same diameter as the support cylinder portion 15b is formed. A slide member 67 is disposed in the opening of the extension portion 15a, and the guide groove portion 62a of the dial cylinder portion 60 is provided. To support. The slide member 67 is a low friction member that improves sliding so that the dial tube portion 60 can rotate smoothly.

The rotary shaft 30c of the cutting blade motor 30. The upper side is rotatably held with respect to the motor cover 82 by the bearing 32a and the lower side by the bearing 32b. The cutting blade 35 is directly attached to the rotary shaft 30c of the cutting blade motor 30 without using a speed reduction mechanism. Therefore, the rotation speed of the cutting blade motor 30 and the rotation speed of the cutting blade 35 are equal. The cutting blade 35 has a disc portion 35a made of synthetic resin, and metal blades 35b are pivotally supported by screws 35c at several locations (here, four locations) on the outer peripheral side thereof. The blade 35b can rotate around the screw 35c, and when the cutting blade 35 rotates at a high speed, the blade 35b is maintained at an optimum angle for cutting grass by centrifugal force.

Next, the shape of the dial tube portion 60 will be described with reference to FIG. The dial tube portion 60 is manufactured by integral molding of synthetic resin such as plastic, and has a rotary dial knob 61 on the upper surface, and a cylindrical portion 63 is formed below the rotary dial knob 61. The dial knob 61 is a convex portion that is substantially rectangular when viewed from above in the radial direction, and has a depression 61a for a pointer at one end. An annular flange portion 62 is formed so as to surround the outer peripheral side of the dial knob 61. A guide groove portion 62 a formed so as to be continuous in the circumferential direction is formed below the flange portion 62. A plurality of slits 62 b provided in the circumferential direction are disposed between the guide groove 62 a and the cylindrical portion 63, and an air passage communicating with the flange 62 in the vertical direction is secured.

As shown in FIG. 6 (2), a wiring lead-out hole 65 for taking out the wiring to the cutting blade motor 30 is formed near the upper side of the cylindrical portion 63. Although the cutting blade motor 30 moves in the axial direction with respect to the rotation axis, its position does not change in the rotation direction. However, since the dial tube portion 60 moves (rotates) in the rotation direction, the relative positions of the wiring drawn from the cutting blade motor 30 and the wiring drawing hole 65 vary. Therefore, the wiring lead-out hole 65 is prevented from interfering with the wiring by a circumferentially elongated notch and the rotation of the dial tube portion 60. The lower end side of the dial tube portion 60 is an opening 60a, and hemispherical depressions 64a to 64a for holding steel balls 68a to 68c (see FIG. 5) are provided on side surfaces slightly above the opening 60a. 64c is formed (however, the depression 64c is not visible in FIG. 6).

FIG. 7 is a perspective view showing a cylindrical portion 71 forming the motor cylinder portion 70. The cylindrical portion 71 is located on the outer peripheral side of the cylindrical portion 63 of the dial cylindrical portion 60, and convex keys 79a to 79c continuous in the axial direction are formed on the outer peripheral portion. Keys 79a to 79c are anti-rotation mechanisms for preventing the cylindrical portion 71 from rotating relative to the main body chassis 10 in the circumferential direction, and a key groove (not shown) formed on the inner peripheral side of the support cylinder portion 15b. ). On the inner peripheral side (inner wall side) of the cylindrical portion 63, elevating guide ribs 72 to 74 (73 and 74 are not visible in the figure) positioned above the steel balls 68a to 68c (see FIG. 5) are formed. Here, the cylindrical portion 71 is suspended from steel balls 68a to 68c (see FIG. 5) projecting radially outward from the cylindrical portion 63 by a hemisphere or less by using the lifting guide ribs 72 to 74, and the motor The cylindrical portion 70 is configured to be held.

FIG. 8 is a developed view in which the inner wall surface of the cylindrical portion 71 in FIG. 7 is developed. Here, since three steel balls 68a to 68c (see FIG. 5) are used at intervals of 120 degrees in the circumferential direction, three corresponding lifting guide ribs 72 to 74 are also formed. The position of the steel ball 68a in the lifting guide rib 72 is illustrated by a dotted line, and the lifting guide ribs 72 to 74 receive the downward load by the steel balls 68a to 68c (see FIG. 5) at the held rotational position. . Thereby, a plurality of height positions can be provided, and the positions when the trimming height is 20, 30, 40, 50, and 60 mm are 91 to 95, respectively. The movable range (up-down direction range) with which the steel balls 68a to 68c abut is a range indicated by an arrow 77, and this movable range corresponds to a so-called cam groove portion. Here, in the movable range 77 of the steel ball 68a, the upper position is limited by the lifting guide rib 72, and the lower position is determined by limiting the relative movement of the motor cylinder portion 70 by a stopper (not shown). When the steel ball is at the 91 position (when the cutting height is 20 mm), it can be moved to the 91 'position, and when the steel ball is at the 93 position (when the cutting height is 40 mm), the range is 93'. It can be moved with. In the case of the steel ball position 95 (when the cutting height is 60 mm), the cutting blade motor 30 cannot move upward because it is already at the lower end position of the movable range 77 of the steel ball 68a. Here, the front lower end 2c of the main body cover 2 is provided with a gap of a predetermined distance H between the main body cover 2 and the ground. The distance H1 between the cutting blade 35 and the ground is small when the steel ball is at position 91, and is large when the steel ball is at 95. Further, the distance H1 when the steel ball is at 95 is substantially the same as the distance H of the front lower end 2c. Therefore, the cutting blade 35 can be retracted from a position lower than the distance H between the front lower end 2c of the main body cover 2 and the ground to a position substantially the same as the distance H.

Here, ribs (for example, 74 b to 74 e) extending in the radial direction are formed on the upper portions of the lifting guide ribs 72 to 74. These engage with a click mechanism (not shown) provided on the base portion 21 to hold the dial tube portion 60 so as not to rotate with respect to the main body chassis 10 (or the base portion 21). Grooves 75a to 75c for inserting steel balls are formed so as to be adjacent to the highest positions (for example, 74a) of the elevation guide ribs 72 to 74. The steel ball is positioned in the movable range 77 through the grooves 75a to 75c. Further, the lower surface of the highest position of the lifting guide ribs 72 to 74 is a curved stopper as indicated by an arrow 74f. Further, a notch 76 for drawing out the wiring from the cutting blade motor 30 is formed at one place in the circumferential direction of the cylindrical portion 71. The notch 76 is disposed at a position corresponding to the wiring lead hole 65 (see FIG. 6B). With the inner wall structure as described above, the cylindrical portion 71 can be easily manufactured by integral molding of synthetic resin, and the lightweight and highly rigid motor cylinder portion 70 can be formed without having a dividing surface. .

FIG. 9 is a view showing a state where the cutting blade motor 30 is set at the uppermost position. As shown in (1), the dent 61a for the dial tube portion 60 has a cutting height 60 (mm) of the base portion 21. ). At this time, as shown in FIG. 9 (2), the cutting blade motor 30 is positioned on the uppermost side, and the position of the steel ball 68a is at a position 95 in FIG. Although not shown, at this position, a part of the motor housing 80 abuts on a part of the dial cylinder part 60, thereby acting as a stopper that limits the range of movement of the motor cylinder part 70 in the upward direction. Fulfill. That is, the motor housing 80 cannot move upward from the state of FIG. 9B (the upward movable amount is 0).

FIG. 10 is a view showing a state in which the cutting blade motor 30 is set at the lowest position. As shown in (1), the dent 61a for the dial of the dial tube portion 60 has a cutting height 20 ( mm). At this time, as shown in FIG. 10 (2), the cutting blade motor 30 is positioned on the lowermost side, and the position of the steel ball 68c is at a position corresponding to the position 91 of FIG. Although not shown, at this position, a part of the motor housing 80 can move upward by a predetermined amount until the part of the motor housing 80 comes into contact with a part of the dial tube portion 60 (movable amount S = 40 mm). This movement state is shown in FIG. FIG. 11 is a view for explaining the operation when the lifting mechanism of the cutting blade motor 30 receives a thrusting force from the cutting blade. (1) is a sectional view in a normal state where no external force is received. ) Is a cross-sectional view showing a state where the motor cylinder portion 70 is moved upward by receiving an external force from the lower side.

In FIG. 11 (1), the downward movement of the motor housing 80 is performed by the weight of the cutting blade motor 30. Here, when an upward pushing force is applied to the cutting blade 35, the engagement position of the steel ball 68c and the motor cylinder part 70 changes as shown in (2), and the lifting guide rib 72 is separated from the steel ball 68c. The motor housing 80 can easily move upward. Further, since the raising / lowering guide rib 72 is merely on the steel ball 68c, the upward movement of the motor housing 80 is not hindered and can be moved smoothly. The external force transmitted to 10 can be effectively absorbed. When the upward push-up force with respect to the cutting blade 35 disappears, the motor housing 80 is lowered by the dead weight of the cutting blade motor 30 and the cutting blade 35, and returns to the state shown in FIG.

In FIG. 11, the cylindrical portion 71 is positioned on the outer side (outer peripheral side) and the dial cylindrical portion 60 is positioned on the inner side (inner peripheral side), and between the inner peripheral surface of the cylindrical portion 71 and the outer peripheral surface of the dial cylindrical portion 60. In addition, it will be understood that the structure has a gap for interposing the steel balls 68a to 68c. At this time, hemispherical depressions for the steel balls 68a to 68c are formed on the outer peripheral surface of the dial cylinder portion 60, and the lifting guide ribs 72 to 74 are formed on the inner peripheral surface of the cylindrical portion 71. The relationship on the side where the lifting guide rib is provided may be reversed. That is, elevating guide ribs 72 to 74 are formed on the outer peripheral surface of the dial cylinder portion 60, and hemispherical depressions for the steel balls 68 a to 68 c are formed on the inner peripheral surface of the cylindrical portion 71. It may be located below 68a-68c. Further, the steel balls 68a to 68c are not used, and a protrusion corresponding to the steel balls 68a to 68c or some convex portions are formed so as to be brought into contact with the upper or lower surfaces of the lifting guide ribs 72 to 74. The elevating mechanism can be realized. However, when a steel ball is used, the movement of the cylindrical portion 71 becomes very smooth. Therefore, when replacing this, it is advisable to give a sufficient slidability.

Referring to FIG. 11, the space between the outer wall of the dial tube portion 60 and the inner peripheral surface of the cylindrical portion 71 has a sufficient distance with about half the diameter of the steel ball 68a. Anyway. Further, without using the motor cover 82, the cutting blade motor 30 may be mounted on the upper side of the disk portion 81 without a housing.

As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiment, the vertical movable amount S of the motor housing is changed from 0 mm (when the cutting height is 60 mm) to a maximum of 40 mm (when the cutting height is 20 mm), but the stroke when the cutting height is 60 mm. The amount may be about 10 mm, and the movable amount may be 10 to 50 mm. Further, the number of steel balls used may be four or more instead of three. Further, a spring may be interposed between the cylindrical portion 71 and the dial tube portion 60 so as to bias the cylindrical portion 71 downward.

DESCRIPTION OF SYMBOLS 1 ... Mower, 2 ... Main body cover, 2a, 2b ... Fender, 2c ... Lower front end (of main body cover), 3 ... Opening / closing cover, 4 ... Stop switch, 5 ... Opening part, 10 ... Main body chassis, 10a ... Tip part 11a, 11b ... mounting arm, 12a, 12b ... front wheel (driven wheel), 13a, 13b ... rear wheel (drive wheel), 14 ... under cover, 15a ... extension part, 15b ... support cylinder part, 16a, 16b ... motor 17a, 17b, 18a ... recess, 19a, 19b ... magnet, 21 ... base part, 22 ... container part, 23 ... lid part, 23a ... hinge, 24 ... keyboard, 25 ... display, 26 ... main board, 27a- 27c ... Motor drive circuit, 28 ... Battery pack, 29 ... Battery terminal, 30 ... Cutting blade motor, 30c ... Rotating shaft, 32a, 32b ... Bearing, 35 ... Cutting blade, 35 ... disk part, 35b ... blade, 35c ... screw, 37 ... (operating part), 41 ... power receiving terminal, 41a ... positive electrode terminal, 41b ... negative electrode terminal, 42 ... main switch, 45, 46 ... guide wire sensor, 47 ... lift sensor, 48 ... contact sensor, 49 ... tilt sensor, 60 ... dial tube, 60a ... opening, 61 ... dial knob, 62 ... flange, 62a ... guide groove, 62b ... slit, 63 ... cylindrical, 64a ˜64c: depression, 65: wiring drawing hole, 67 ... sliding member, 68a-68c ... steel ball, 70 ... motor cylinder portion, 71 ... cylindrical portion, 72-74 ... lift guide rib, 75a ... groove, 76 ... notch , 77, movable range, 79 a to 79 c, key, 80, motor housing, 81, disk portion, 81 a, through hole, 82, motor cover, 84, screw, 200, house, 10 ... garden, 250 ... AC adapter, 260 ... cable, 270 ... charging station, 280 ... guide wire, 290 ... mowing area, 301 ... mower, S ... (the motor housing 80) movable amount

Claims (14)

A main body chassis that can be driven by a driving wheel and a driven wheel, a motor that is held by the main body chassis, and a cutting blade that is attached to the tip of a rotating shaft that is driven by the motor and rotates on a surface substantially parallel to the ground. A self-propelled mower having a trimming height adjusting mechanism for adjusting a trimming height by the cutting blade and a main body cover covering the upper side of the main body chassis, wherein the trimming height adjusting mechanism has a force for lifting the trimming blade. A self-propelled mowing machine characterized in that the cutting blade can be moved in the upward direction when an action occurs. The trimming height adjusting mechanism includes either one of a locking portion having a plurality of height positions and a protrusion that engages with the locking portion in the chassis portion, and the other as a holding portion of the cutting blade. 2. The self-propelled mower according to claim 1, wherein the mowing blade holding part is held so as to be suspended from the chassis part. The self-propelled mower according to claim 2, wherein the trimming height adjusting mechanism is configured to move both the motor and the cutting blade. The trimming height adjusting mechanism includes a cup-shaped dial tube portion that is held by the main body chassis and has an opening on the lower side, and a cup-shaped motor tube portion that has an opening on the upper side and holds the cutting blade. The dial cylinder part and the motor cylinder part are arranged so that the diameters of the dial cylinder part and the motor cylinder part are different from each other, and the protrusion is provided on one surface side of the overlapping part of the dial cylinder part and the motor cylinder part. 4. The locking portion is provided on a side, and the motor tube portion is held so as to be suspended from the dial tube portion by engagement of the protrusion and the locking portion. Self-propelled mower. The said motor cylinder part accommodates the said motor inside, It arrange | positions so that the rotating shaft of the said motor may penetrate the bottom face of the said motor cylinder part, and may be extended below. 4. The self-propelled mower according to 4. The engaging part is formed obliquely so that the height position changes in the circumferential direction, and the engaging position of the engaging part and the projecting part is changed by rotating the dial tube part, and the lower part of the engaging part is The self-propelled mower according to claim 5, wherein a space in which the protrusion is movable is formed on a side. The protrusion is formed by a hemispherical recess formed on the outer peripheral surface of the dial tube portion and a steel ball disposed in the recess, and the locking portion has a diameter on the inner peripheral surface of the motor tube portion. The self-propelled mower according to claim 6, wherein the self-propelled mower is a guide rib protruding inward in the direction. Three indentations and three steel balls are arranged at equal intervals in the circumferential direction, and three of the guide ribs are arranged at equal intervals in the circumferential direction, and are formed to extend obliquely toward the circumferential direction of the inner wall side surface. The self-propelled mower according to claim 7. A click mechanism is provided at several locations in the circumferential direction of the dial tube portion and the motor tube portion to hold the rotational position of the dial tube portion in the circumferential direction, and the guide rib is the steel ball at the held rotational position. The self-propelled mower according to claim 8, wherein the load in the downward direction is received. The self-propelled mower according to claim 9, wherein a stopper for limiting a range of movement of the motor cylinder portion in the upward direction is provided on the dial cylinder portion or the main body chassis side. The self-propelled mower according to claim 10, wherein rotation prevention means is provided so that the motor cylinder portion does not rotate in the circumferential direction with respect to the main body chassis. The cutting height adjusting mechanism can set the cutting blade at a position lower than the height of the front lower end of the main body chassis, and when a force for lifting the cutting blade is applied, the cutting blade is moved to the front of the main body chassis. The self-propelled mower according to any one of claims 1 to 11, which is movable to a position substantially equal to a height of a lower end. A main body chassis that can be driven by a driving wheel and a driven wheel, a motor that is held so that the rotating shaft faces in the vertical direction, and a rotary type that is attached to the tip of the rotating shaft and rotates on a surface substantially parallel to the ground In the self-propelled grass mower having a cutting blade height adjusting mechanism for adjusting the cutting height by the cutting blade by moving the vertical direction of the motor, and a main body cover covering the upper side of the main body chassis, The trimming height adjusting mechanism has a cup-shaped dial tube portion having an opening on the lower side, and a cup-shaped motor tube portion having an opening on the upper side and a diameter larger than the cylindrical portion of the dial tube portion, The motor is housed inside the motor cylinder, a through hole is formed in the bottom surface of the motor cylinder to allow the rotation shaft of the motor to pass through, and the dial cylinder is formed outside the cylinder of the motor cylinder Arranged so that the cylindrical portion overlap, self-propelled mowing machine the motor cylinder unit, characterized in that it is held so as not to be relatively rotated around the central axis of the motor relative to the body chassis. A hemispherical recess is provided on the outer peripheral surface of the dial tube portion, a guide rib projecting radially inward on the inner peripheral surface of the motor tube portion is provided, and a steel ball is disposed between the recess and the motor tube portion. The self-propelled mower according to claim 13, wherein the trimming height adjusting mechanism is capable of moving the motor and the cutting blade upward when a force for lifting the cutting blade is applied. .

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