JP5859323B2 - Lawn mower - Google Patents

Description

  The present invention relates to a lawn mower that can adjust the cutting height.

  2. Description of the Related Art Conventionally, there is known a lawn mower capable of adjusting the cutting height of turfgrass by adjusting the distance between the lawn mower provided with a lawn mower and the ground. For example, in Patent Document 1 below, the cutting height is adjusted by rotating the rotary adjustment dial ("Control Knob" in Patent Document 1) to adjust the vertical position of the lawn mower wheel. ing. Further, in Patent Document 2 below, the cutting height is adjusted by rotating the rotary adjustment dial ("Mowing Height Adjustment Operation Unit" in Patent Document 2) to adjust the vertical height position of the bottom plate portion of the lawn mower. Is adjusted.

  In the configuration of Patent Document 1, the rotation of the operation knob by the operator is converted into a reciprocating motion by a multi-threaded screw, and the crankshaft on which the wheel mounting plate is fixed is rotated by this reciprocating motion. The cutting position is adjusted by changing the height position. In this configuration, a multi-threaded screw is used to increase the amount of reciprocal movement relative to the amount of rotation of the operation knob, thereby adjusting the desired trim height adjustment range within one rotation of the operation knob. As a result, the convenience of trimming height adjustment work is achieved.

  Moreover, in the structure of patent document 2, rotation of the cutting height adjustment operation part by an operator is converted into a reciprocating movement by a multi-thread screw, and the vertical height position of the bottom plate part is changed by this reciprocating movement to reduce the cutting height. It is adjusted. In this configuration, a large cutting height adjustment amount can be obtained with a small amount of rotation of the cutting height adjustment operation unit by adopting a multi-thread screw to increase the amount of reciprocation relative to the rotation amount of the cutting height adjustment operation unit. As a result, the convenience of trimming height adjustment work is achieved.

  Some conventional lawn mowers adjust the cutting height by converting the rotation of the rotary adjustment dial into the rotation of the wheel mounting plate using a worm gear and a worm wheel. More specifically, the worm gear is connected to the rotary adjustment dial, the worm wheel is fixed to the support shaft on which the wheel mounting plate is fixed, and the rotation of the rotary adjustment dial is attached to the wheel by meshing the worm gear and the worm wheel. Some of them are converted to plate rotation to adjust the cutting height. In this configuration, the reduction ratio between the worm gear and the worm wheel is set to a small value so that a large cutting height adjustment amount can be obtained with a small rotation amount of the rotary adjustment dial, and the convenience of the cutting height adjustment work is improved. I am trying.

Japanese Patent No. 4315147 Japanese Patent No. 4045927

  However, when the multi-thread screw is employed as in the configurations of Patent Document 1 and Patent Document 2 described above, the self-locking effect of the screw is not sufficient because the lead angle is large, and the weight of the lawn mower and lawn mowing work Due to the internal vibration, the multi-thread screw may rotate and the cutting height may change. As a countermeasure, rotation resistance is applied to the multi-thread screw so that the multi-thread screw does not rotate due to the weight of the lawn mower or vibration during lawn mowing work. Since the rotation operation of the adjustment operation portion becomes heavy, the workability of trimming height adjustment is reduced. In addition, due to the use for many years, the applied rotational resistance is reduced, and there is a possibility that the multi-thread screw rotates due to the weight of the lawn mower and the vibration during the lawn mowing work and the cutting height changes.

  In addition, when the reduction ratio is set small as in the configuration of the worm gear and worm wheel described above, the lead angle (lead angle) of the worm gear increases, so the self-locking effect of the configuration of the worm gear and worm wheel is not sufficient. The worm gear may rotate and the cutting height may change due to the weight of the lawn mower or the vibration during the lawn mowing operation. As a countermeasure against this, a rotational resistance is applied to the worm gear so that the worm gear does not rotate due to the weight of the lawn mower or the vibration during the lawn mowing work, but the rotational operation of the rotary adjustment dial becomes heavy due to this rotational resistance. Therefore, the workability of trimming height adjustment is reduced. In addition, due to the use for many years, the applied rotational resistance is reduced, and there is a possibility that the worm gear rotates due to the weight of the lawn mower and the vibration during the lawn mowing operation and the cutting height changes.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a lawn mower equipped with a trimming height adjusting mechanism that has good workability and can maintain performance over a long period of time. .

The lawn mower according to the present invention is a lawn mower trimming height adjustment mechanism that is capable of adjusting the trimming height by adjusting the distance from the ground of the lawn mower provided with a lawn mowing blade. A rotary adjustment dial that is rotatably installed in the housing, a lock mechanism that allows the rotary adjustment dial to be locked and unlocked at a plurality of rotation positions, and a click that generates a click feeling at the lock position by the lock mechanism A sense generating mechanism, and an operation portion and a locking portion of the locking mechanism are provided on the rotary adjustment dial, and a plurality of locked portions that can be locked by the locking portion are: The click feeling generating mechanism is formed in the housing, and a ball disposed in the housing is locked by elastic force in a plurality of recesses formed in the rotary adjustment dial. In click feeling it is characterized that you have been configured to generate.

  ADVANTAGE OF THE INVENTION According to this invention, the lawn mower with the workability | operativity of trimming height adjustment can be provided.

It is a top view of the lawn mower which concerns on this embodiment, and is partially broken. It is a top view of the lawn mower according to the present embodiment. It is a bottom view of the lawn mower according to the present embodiment. It is a figure which shows the cross section AA in FIG. It is a principal part enlarged view of FIG. It is a figure which shows the cross section BB in FIG. It is a figure which shows the cross section CC in FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

  FIG. 1 is a plan view of the lawn mower according to the present embodiment, which is partially broken. FIG. 2 is a top view of the lawn mower according to the present embodiment. FIG. 3 is a bottom view of the lawn mower according to the present embodiment. 4 is a view showing a cross section AA in FIG. FIG. 5 is an enlarged view of a main part of FIG. 6 is a view showing a cross section BB in FIG. FIG. 7 is a view showing a cross section CC in FIG. Moreover, in this specification, for convenience of explanation, the direction of the lawn mower 1 is defined as shown in the figure. That is, when the operator performs the lawn mowing work with the lawn mower 1 of the present embodiment, “front, rear, left, right, up, down” is determined based on the traveling direction of the operator.

  As shown in FIGS. 1 to 4, the lawn mower 1 according to the present embodiment is mounted on a main body 10, a handle portion 30 that is rotatably supported with respect to the main body 10, and a rear portion of the main body 10. The glass catcher 33 is provided. The main body 10 includes a housing 11 made of resin, a reel blade 21 and a fixed blade 24 that are lawn mowing blades, front wheels 51 and 51, and a rear wheel 61. A large pulley 21b is fixed to the shaft end 21a of the reel blade 21, and is connected via a belt 23 and a small pulley 22a fixed to a motor shaft 22 of a motor (not shown). The handle portion 30 includes a grip portion 31 that is gripped by an operator and a switch 32 that can be operated by a finger that grips the grip portion 31. When the operator turns on the switch 32, a motor (motor shaft 22) is provided. Is rotated, and the reel blade 21 is rotated by being decelerated by the small pulley 22a, the belt 23, and the large pulley 21b. A fixed blade 24 slidably contacting the reel blade 21 is provided below the reel blade 21, and turf grass is cut by the reel blade 21 and the fixed blade 24. The cut turf grass is discharged from the rear of the main body 10 and is deposited on the glass catcher 33.

  The front wheels 51 and 51 are rotatably supported by front wheel support shafts 54 and 54 fixed to one end side of the front wheel mounting plates 53 and 53 made of a metal plate. Holes 53a and 53a are formed on the other end side of the front wheel mounting plates 53 and 53, and are fitted to the front fulcrum shafts 56 and 56 so as to be rotatable. The front fulcrum shafts 56 and 56 are fixed to front brackets 55 and 55 fixed to the housing 11. The left and right front wheel mounting plates 53, 53 are connected and fixed by a crankshaft 57 at a substantially intermediate position between the one end side and the other end side thereof, whereby the left and right front wheel mounting plates 53, 53 are integrated. The front fulcrum shafts 56 and 56 are rotated. Further, the central portion of the crankshaft 57 in the left-right direction is connected to a trimming height adjusting mechanism 70 described later. Further, as shown in FIG. 1, front link shafts 58, 58 are fixed above the holes 53 a, 53 a of the front wheel mounting plates 53, 53. The front end holes 59a and 59a of 59 are fitted so that rotation is possible. The rear ends of the links 59, 59 are connected to rear wheel mounting plates 63, 63 described later.

  The rear wheel 61 has a long outer peripheral surface in the left-right direction, and is rotatably supported by the connecting shaft 64. The connecting shaft 64 also has a function of connecting and fixing the left and right rear wheel mounting plates 63 and 63. Holes 63a and 63a are formed in the rear wheel mounting plates 63 and 63, and are fitted to the rear fulcrum shafts 66 and 66 so as to be freely rotatable. The rear fulcrum shafts 66 and 66 are fixed to rear brackets 65 and 65 fixed to the housing 11. With the above-described configuration, the left and right rear wheel mounting plates 63 and 63 are integrated and rotate around the rear fulcrum shafts 66 and 66. Rear link shafts 68 and 68 are fixed above the holes 63a and 63a of the rear wheel mounting plates 63 and 63, and rear end holes 59b and 59b of the links 59 and 59 are formed on the rear link shafts 68 and 68, respectively. It is pivotably fitted.

  In the above-described configuration, for example, when the position of the crankshaft 57 is moved downward by the trimming height adjusting mechanism 70 described later, the front wheel mounting plates 53 and 53 rotate clockwise around the front fulcrum shafts 56 and 56. Rotate to. Thereby, as shown by an imaginary line in FIG. 4, the front wheels 51 and 51 move downward. Further, since the front wheel mounting plates 53, 53 and the rear wheel mounting plates 63, 63 are connected via links 59, 59, the rear wheel mounting plates 63, 63 are also connected to the rear fulcrum shafts 66, 66. Rotate around. Thereby, as shown by an imaginary line in FIG. 4, the rear wheel 61 also moves downward. Due to the downward movement of the front wheels 51 and 51 and the rear wheel 61, the height of the reel blade 21 and the fixed blade 24 from the ground is relatively increased, and the cutting height is increased. Since the front wheels 51 and 51 and the rear wheel 61 support the weight of the lawn mower, an upward force is always applied to the cutting height adjusting mechanism 70 connected to the crankshaft 57. Become.

  Next, the trimming height adjusting mechanism 70 will be described with further reference to FIGS. In the present embodiment, a trimming height adjusting mechanism when a multi-thread screw is used will be described.

  The trimming height adjusting mechanism 70 in this embodiment includes a rotary adjustment dial 71 that is gripped and rotated by an operator, a lock mechanism 80 that locks the rotary adjustment dial 71 at a plurality of predetermined rotational positions, and a rotary adjustment. A click feeling generating mechanism 90 that generates a click feeling at the lock position of the dial 71 and a multi-threaded thread portion 95 are provided.

  As shown in FIG. 2, the rotary adjustment dial 71 has a collar portion 72 whose outer periphery is formed in a circular shape, and a gripping portion 73 that is projected on the upper portion of the collar portion 72 and is elongated in the left-right direction in FIG. 2. And have. The grip portion 73 is a portion that is gripped by the operator when adjusting the cutting height, and an operation portion 81a of a lock plate 81 described later protrudes from one end portion thereof. A numerical value (or symbol) indicating the cutting height is displayed on the housing 11 around the collar portion 72, and this numerical value (or symbol) is displayed on the operation portion 81 a of the lock plate 81 by rotating the rotary adjustment dial 71. ) Can be adjusted to the cutting height indicated by the numerical value (or symbol). In the present embodiment, the trimming height can be adjusted between 2.5 mm and 50 mm every 2.5 mm, that is, in 19 steps. Further, as shown in FIG. 7, a hexagonal portion 77 having a hexagonal outer peripheral surface is formed at the center of the bottom surface of the rotary adjustment dial 71, and further on a predetermined radius from the center. A plurality of recesses 74 are formed at a pitch of an angle α. In the present embodiment, 19 concave portions 74 are formed, and are indicated by reference numerals 74a, 74b, 74c,. On the bottom side of the rotary adjustment dial 71, guide walls 75, 75 project in parallel with the longitudinal center line X of the grip portion 73 with a predetermined interval. Further, in the longitudinal direction of the grip portion 73, contact walls 76, 76 project from the center of the rotary adjustment dial 71 on the side opposite to the side from which the operation portion 81 a protrudes.

  Next, the lock mechanism 80 will be described. As shown in FIGS. 5 and 7, the lock mechanism 80 includes a lock plate 81 and a compression spring 82. The compression spring 82 is installed between the lock plate 81 and the hexagonal portion 77 of the rotary adjustment dial 71 and extends in a direction in which the operation portion 81 a of the lock plate 81 protrudes from the grip portion 73 of the rotary adjustment dial 71. Energized. In addition, in order to restrict the installation position of the compression spring 82, the regulation walls 77a and 77a are formed in the hexagonal portion 77. The lock plate 81 is formed in an operation portion 81a that is pressed by an operator, a compression spring mounting hole 81b that is formed inside the operation portion 81a, and on which one end side of the compression spring 82 is mounted, and a lower portion of the operation portion 81a. And a locking portion 81 c that locks to the locked portion 13 formed in the housing 11. Further, a plate portion 81d is integrally extended on the hexagonal portion 77 side of the locking portion 81c, and a hexagonal connection hole 81e that is long in the direction of the pressing operation is formed in the central portion of the plate portion 81d. . The lock plate 81 is mounted on the rotary adjustment dial 71 so as not to be rotatable and movable in the direction of the pressing operation by fitting the connecting hole 81e to the hexagonal portion 77 of the rotary adjustment dial 71. . Further, the left and right end faces of the plate portion 81d are guided in sliding contact with the guide walls 75, 75, so that the lock plate 81 cannot rotate with respect to the rotary adjustment dial 71 more stably and is pressed. It will be arranged to be movable in the direction. Further, the rear outer peripheral surface of the plate portion 81c is formed with a predetermined gap between the contact walls 76 and 76.

  The locked portions 13 formed in the housing 11 are formed at a plurality of locations on the radius centered on the rotation center of the rotary adjustment dial 71 at a pitch of an angle α equal to the angular pitch of the recesses 74. In the present embodiment, 19 portions to be locked 13 are formed, which are indicated by reference numerals 13a, 13b, 13c,.

  Next, the click feeling generation mechanism 90 will be described. As shown in FIG. 6, the click feeling generation mechanism 90 includes a sphere 91 and a compression spring 92. The housing 11 has a bottomed hole 14 formed at a position corresponding to the recess 74 of the rotary adjustment dial 71, and a ball 91 and a compression spring 92 are inserted into the hole 14. In such a configuration, when the concave portion 74 and the position of the hole 14 coincide with each other by the rotation operation of the rotary adjustment dial 71, the ball 91 is locked to the concave portion 74 by the elastic force of the compression spring 92, thereby obtaining a click feeling. It is supposed to be. The locking force of the ball 91 to the recess 74 is set so as to be weak. Therefore, the rotation operation of the rotary adjustment dial 71 becomes heavy due to this locking force, and workability is not lowered.

  The multi-threaded screw portion 95 includes a male screw 96 and a female screw 97 screwed with the male screw 96. The male screw 96 and the rotary adjustment dial 71 are fixed by bolts 72 and are rotatably fitted in holes 12 formed in the housing 11 and are restricted from moving in the vertical direction with respect to the housing 11. Yes. The female screw 97 is formed in the housing 11 and is fitted in a hole 13 having a center line in common with the hole 12 so as not to rotate but to move in the vertical direction. A plate 98 is fixed to the lower part of the female screw 97, and the crankshaft 57 can move in the front-rear direction in a state where the vertical movement is restricted in the gap between the lower surface 97a of the female screw 97 and the plate 98. It is connected to. With the above-described configuration, when the rotary adjustment dial 71 is rotated, the crankshaft 57 moves in the vertical direction by the screwing of the female screw 97 into the male screw 96. An upward force corresponding to the weight of the lawn mower is applied to the lower surface 97 a of the female screw 97 via the crankshaft 57. This force component due to the lead angle of the male screw 96 acts to rotate the male screw 96.

  In the above configuration, the trimming height adjustment operation will be described. 1 to 7 show a state in which the trimming height is adjusted to 5 mm, which is the minimum. Therefore, for convenience of explanation, a case where the cutting height is increased from the minimum state will be described.

  First, the case where the trimming height is adjusted from 5 mm to 7.5 mm will be described. The operator presses the operation portion 81 a of the lock plate 81 against the elastic force of the compression spring 82 with a finger gripping the grip portion 73 of the rotary adjustment dial 71. By the pressing operation, the lock plate 81 moves until it abuts against the abutting walls 76, 76, and the locking between the locking portion 81c and the locked portion 13a is released, so that the rotary adjustment dial 71 is unlocked. It becomes a state. In this state, when the operator rotates the rotary adjustment dial 71 clockwise in FIG. 2, a click feeling is obtained by the click feeling generation mechanism 90 at a position rotated by an angle α. That is, the click feeling is generated by the sphere 91 engaging with the recess 74b. The position where the click feeling is obtained is a position where the trimming height is 7.5 mm, and also the position where the locking portion 81c can be locked to the next locked portion 13b. When the operator releases the pressing operation of the operation portion 81a at this position, the lock plate 81 is moved by the elastic force of the compression spring 82, and the locking portion 81c and the locked portion 13b are locked. The adjustment dial 71 is locked.

  Next, the case where the trimming height is adjusted from 5 mm to 10 mm will be described. The operator presses the operation portion 81 a of the lock plate 81 against the elastic force of the compression spring 82 with a finger gripping the grip portion 73 of the rotary adjustment dial 71. By the pressing operation, the lock plate 81 moves until it abuts against the abutting walls 76, 76, and the locking between the locking portion 81c and the locked portion 13a is released, so that the rotary adjustment dial 71 is unlocked. It becomes a state. In this state, when the operator rotates the rotary adjustment dial 71 clockwise in FIG. 2, the ball 91 is locked to the recess 74b at a position rotated by the angle α, so that a first click feeling is obtained. In this position, the pressing operation of the operation unit 81a is not released, but the angle α is further rotated, and the pressing operation of the operation unit 81a is released at a position where the second click feeling is obtained by the locking of the ball 91 to the recess 74c. To do. The position where the second click feeling is obtained is a position where the trimming height is 10 mm, and is also a position where the locking portion 81c can be locked to the next locked portion 13c. When the operator releases the pressing operation of the operation portion 81a at this position, the lock plate 81 is moved by the elastic force of the compression spring 82, and the locking portion 81c and the locked portion 13c are locked. The adjustment dial 71 is locked.

  In the above description, the case where the trimming height is adjusted from 5 mm to 7.5 mm and the case where the trimming height is adjusted from 5 mm to 10 mm have been described, but the desired trimming height is adjusted from any trimming height adjustment state. In this case, a similar operation is performed.

  Thus, in the lawn mower of the present invention, the lock mechanism 80 that locks the rotary adjustment dial 71 of the cutting height adjusting mechanism 70 at a plurality of predetermined rotational positions is provided. Stable mowing work is possible without change. Further, since a large rotational resistance is not given to the rotary adjustment dial 71, the rotary operation of the rotary adjustment dial 71 is not heavy and the operability is good. Furthermore, since the click feeling generating mechanism 90 that generates a click feeling at the lock position of the rotary adjustment dial 71 is provided, the lockable position can be easily found in the trimming height adjustment work, and the workability is good.

  The preferred embodiments of the present invention have been described above, but the technical scope of the present invention is not limited to the technical scope of the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. It is possible. For example, in the above embodiment, the case where the present invention is implemented in the trimming height adjusting mechanism using a multi-thread screw has been described, but the present invention may be implemented in a trimming height adjusting mechanism using a worm gear and a worm wheel. Is possible.

DESCRIPTION OF SYMBOLS 1 Lawn mower, 10 Main part, 11 Housing, 12 holes, 13 Locked part, 14 holes, 21 Reel blade, 21a Shaft end, 21b Large pulley, 22 Motor shaft, 22a Small pulley, 23 Belt, 24 Fixed blade, 30 handle part, 31 grip part, 32 switch, 33 glass catcher, 51 front wheel, 53 front wheel mounting plate, 53a hole, 54 front wheel support shaft, 55 front bracket, 56 front fulcrum shaft, 57 crankshaft, 58 front link Shaft, 59 link, 59a front end hole, 61 rear wheel, 63 rear wheel mounting plate, 63a hole, 64 connecting shaft, 65 rear bracket, 66 rear fulcrum shaft, 70 trimming height adjustment mechanism, 71 rotary adjustment dial, 72 bolt 73 gripping part 74 concave part 75 guide wall 76 contact wall 77 hexagonal part 77a Restriction wall, 81 lock plate, 81a operation part, 81b compression spring mounting hole, 81c locking part, 81d plate part, 81e connecting hole, 82 compression spring, 90 click feeling generating mechanism, 91 ball, 92 compression spring, 95 multiple threads Threaded part, 96 male thread, 97 female thread, 97a bottom surface, 98 plate

Claims (1)

In the mowing height adjustment mechanism of the lawn mower that can adjust the mowing height by adjusting the distance from the ground of the lawn mower with the lawn mower,
The trimming height adjustment mechanism includes a rotary adjustment dial that is rotatably installed in the housing ;
A lock mechanism capable of locking and unlocking the rotary adjustment dial at a plurality of rotational positions;
A click feeling generating mechanism that generates a click feeling at a lock position by the lock mechanism ,
The operation portion and the locking portion of the lock mechanism are provided on the rotary adjustment dial,
A plurality of locked portions that can be locked by the locking portion are formed in the housing,
The click feeling generating mechanism, wherein Rukoto the rotary disposed in the housing in a plurality of recesses formed in the adjusting dial sphere is configured as a click feeling by locking by the elastic force generated Lawn mower.

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