JP4315147B2 - Lawn mower - Google Patents

Description

  The present invention relates to a lawn mower capable of adjusting a lawn mower height.

  Japanese Patent Application Laid-Open No. 2004-151867 has conventionally known adjusting the lawn mower height of a lawn mower body by adjusting the mounting position of the wheel to the lawn mower body.

  In the conventional example shown in Patent Document 1, the adjustment knob is rotated to release the lock by pinching, and then the adjustment knob is moved along the longitudinal groove to move the height position of the wheel relative to the lawn mower body. Adjusts the height of the wheel relative to the lawn mower body in a stepless manner and adjusts the height of the lawn mower from the ground surface. Adjustment, that is, mowing height adjustment is performed.

  However, in the conventional example shown in Patent Document 1, in order to adjust the lawn mowing height, the unlocking operation by rotating the adjusting knob → the operation of moving the adjusting knob along the vertical groove → by rotating the adjusting knob. There is a problem that three operations of the lock operation are necessary and the operation is troublesome. Further, in the above-described conventional example that can be adjusted steplessly, there is a problem that the trimming height rapidly changes due to the movement of the adjustment knob along the longitudinal groove, and it is difficult to perform fine height adjustment.

  On the other hand, Patent Document 2 discloses that a lawn mowing height is adjusted steplessly by only one operation called a rotation operation. In the conventional example shown in Patent Document 2, a rotary body is rotatably attached to a lawn mower body, and a cutting height adjusting screw protruding upward from a dish-shaped bottom plate for grounding to a ground surface is used. By screwing the female thread part provided at the upper end part with the male thread part provided at the lower part of the rotating body, and manually picking and rotating the operation knob projecting from the upper surface of the lawn mower body at the upper part of the rotating body. The bottom plate is rotated and moved up and down to adjust the lawn mowing height.

  In the conventional example shown in Patent Document 2, the height of lawn mowing can be adjusted steplessly only by rotating the operation knob, but the bottom plate having a dish shape is grounded on the ground surface, and this bottom plate is attached to the ground plate. Mowing height is adjusted by moving up and down, and the lawn mower must be moved by moving the lawn mower with the bottom plate in contact with the lawn. There is a problem that it is difficult to move smoothly when mowing.

As described above, it is known that the lawn mower height is adjusted in a stepless manner. However, the height of the lawn mower is adjusted steplessly by adjusting the height position of the wheel with respect to the lawn mower body with only one simple operation such as a rotation operation. The current situation is that no adjustment has been proposed yet.
Japanese Patent Laid-Open No. 11-103634 JP 2004-159621 A

  The present invention has been invented in view of the above-described conventional problems, and can be used to adjust the height position of the wheel with respect to the lawn mower body in a single step and to adjust the lawn mowing height in a single step. It is an object to provide a machine.

  In order to solve the above-described problems, a lawn mower according to the present invention has a lawn mower main body 3 provided with a lawn mowing blade 2, and both ends of a crankshaft 31 whose middle part projects in a U-shape are rotatably attached. One end of a wheel mounting plate 32 is fixed to each end of the shaft 31, and a rotary shaft 33 provided at the center of the wheel 1 a is rotatably mounted to the other end of the wheel mounting plate 32, and rotated to the lawn mower body 3. The body 24 is mounted so as to be rotatable and does not move in the vertical direction. An operation knob 25 is provided on the upper surface of the lawn mower body 3 on the upper side of the rotary body 24, and the lower part of the rotary body 24 is The moving body 27 is not rotated but is screwed so as to be movable in the vertical direction, and a gap 29 which is elongated in the front-rear direction is formed at the lower end of the vertical moving body 27. In the gap 29, an intermediate portion of the crankshaft 31 is formed. Front and rear middle shaft portion 31a bent in a U shape It is characterized in that formed by movably inserted into the.

  With such a configuration, the rotary body 24 rotates only by rotating the operation knob 25, and the vertical moving body 27 screwed into the rotary body 24 by the rotation of the rotary body 24 does not rotate. The intermediate shaft portion 31a of the crankshaft 31 moves in the vertical direction and moves in the gap 29 in the front-rear direction by the vertical movement of the vertical moving body 27, and moves in the vertical direction and the front-rear direction of the intermediate shaft portion 31a. The movement causes the crankshaft 31 to pivot about the shaft support portion to the lawn mower body 3, and the rotation of the crankshaft 31 causes the wheel mounting plate 32 to rotate. The rotation of the wheel mounting plate 32 causes the wheel 1 a to rotate. The rotation position of the wheel 1a with respect to the lawn mower body 3 is adjusted steplessly by rotating the rotation shaft 33 provided at the center while changing its height position. Thus, the lawn mowing height of the lawn mowing blade 2 provided on the lawn mower main body 3 can be adjusted steplessly by one operation, ie, the rotation operation of the operation knob 25, and can be adjusted by the rotation operation of the operation knob 25. Therefore, there is no fear that the lawn mowing height will change suddenly during adjustment, and fine height adjustment can be easily performed.

  Moreover, it is preferable that the lower part of the rotary body 24 and the up-and-down moving body 27 are screwed by a multi-thread screw.

  With such a configuration, a large adjustment dimension of the wheel height can be obtained with a small rotation angle of the multi-thread screw, and the height adjustment of the lawn mowing blade 2 can be performed steplessly only by the rotation operation of the multi-thread screw. it can.

  According to the present invention, when adjusting the height position of the wheel steplessly and adjusting the lawn mowing height steplessly, it can be adjusted only by rotating the operation knob.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  As shown in FIGS. 1 to 4, the lawn mower 6 is provided with a handle 4 rotatably on a lawn mower body 3 having a traveling wheel 1 and a lawn mowing blade 2, and a grass collecting basket 5 is detachably attached. Configured.

  The lawn mower main body 3 is provided with a frame 14 inside, and the traveling wheel 1 is attached to the frame 14. The traveling wheel body 1 includes a wheel 1a to be a front traveling wheel body 1 and a roller 1b to be a rear traveling wheel body 1. The wheel 1a has a larger diameter than the roller 1b and has a lawn mower body. 3 on both sides of the front part. The roller 1b is provided in the rear part of the lawn mower body 3.

  The lawn mowing blade 2 is composed of a reel blade 2 a rotatably attached to the frame 14 and a fixed blade 2 b fixed to the frame 14.

  A motor 16 is fixed to the frame 14, and a belt 19 is wound around a small pulley 17 fixed to the motor 16 and an intermediate pulley 18 rotatably attached to the frame 14. Further, the intermediate pulley 18 and a reel A belt 21 is wound around a large pulley 20 fixed to the end of the blade 2a, and the rotation of the motor 16 is transmitted to the reel blade 2a via the small pulley 17, the belt 19, the intermediate pulley 18, and the large pulley 20. It is designed to rotate.

  As shown in FIG. 3, the lawn mower body 3 has a front portion provided with an insertion portion 22 that opens up and down or is entirely cylindrical, and a shaft support portion 23 is provided at the upper end opening portion of the insertion portion 22. The lower part of the rotating body 24 is inserted into the insertion part 22 and is rotatably supported on the shaft support part 23. The upper part of the rotating body 24 protrudes from the upper end opening of the insertion part 22 to the upper surface side of the front part of the lawn mower body 3. The upper part of the rotary body 24 is an operation knob 25 for gripping and rotating by hand, and the lower part is a male screw part 26 in which a male screw is engraved on the outer periphery. The lower surface of the operation knob 25 and the male screw The rotating body 24 is rotatably supported on the shaft support portion 23 by sandwiching the shaft support portion 23 in the up and down direction with the upper surface portion of the portion 26. A cylindrical vertical moving body 27 having a female screw part 27a on the inner periphery is inserted in the lower part of the insertion part 22 so that it cannot rotate with respect to the insertion part 22 but can move up and down. 27 a is screwed into the male thread portion 26 of the rotating body 24.

  As shown in FIG. 3 and FIG. 8, two pairs of ribs 28 facing the lower surface side of the up-and-down moving body 27 through the gap 29 in the front-rear direction are suspended downward. The lower plate 30 is fixed with screws so as to be bridged between the lower surfaces of the two plates.

  As shown in FIGS. 4 and 8, the frame 14 has a crankshaft 31 whose middle portion is bent in a U-shape in a hole serving as a bearing portion provided in the frame 14 positioned on the left and right of the front portion of the lawn mower body 3. The intermediate shaft portion 31a at the tip of the crankshaft 31 bent in a U-shape is inserted into the clearance 29 of the vertical moving body 27 in the clearance 29 in the vertical direction. Although it does not move, it is inserted so as to be rotatable and movable back and forth.

  As shown in FIGS. 2 and 8, one end of a wheel mounting plate 32 is fixed to each end of the crankshaft 31, and the other end of the wheel mounting plate 32 is provided at the center of the wheel 1a. A rotating shaft 33 is rotatably attached.

  Here, when the operation knob 25 is rotated to rotate the rotating body 24, the up-and-down moving body 27 in which the female screw portion 27a is screwed to the male screw portion 26 moves in the vertical direction. In conjunction with the vertical movement of the vertical moving body 27, the intermediate shaft portion 31a of the crankshaft 31 moves in the longitudinal direction in the gap 29 while moving in the vertical direction. The movement of the intermediate shaft portion 31 a is a rotational movement around the bearing portion of the frame 14 of the crankshaft 31, and therefore the crankshaft 31 rotates around the bearing portion of the frame 14. The wheel mounting plate 32 is rotated by the rotation of the crankshaft 31, and the wheel 1a having the other end portion of the wheel mounting plate 32 as the rotation center rotates about the end portion of the crankshaft 31 as a rotation center. The relative vertical height position of the wheel 1a with respect to the machine body 3 is adjusted.

  That is, in the present invention, the relative vertical height position of the wheel 1a with respect to the lawn mower body 3 is adjusted steplessly by only one operation of picking and rotating the operation knob 25 by hand. The height position of the lawn mower 2 provided on the lower surface side of the lawn mower body 3 when the wheel 1a is grounded to the ground surface 15 is steplessly adjusted by stepless adjustment of the relative vertical height position of the wheel 1a with respect to 3. This allows you to adjust the lawn mowing height steplessly.

  The male screw portion 26 and the female screw portion 27a are both multi-threaded screws (that is, the multi-threaded male screw portion 26 and the multi-threaded female screw portion 27a). When rotating 25, a large adjustment dimension of the wheel height can be obtained with a small rotation angle of the multi-thread screw, and the height of the lawn mower 2 can be adjusted steplessly only by the rotation operation of the multi-thread screw. The lawn mowing height can be adjusted easily and quickly.

  All of the wheels 1 a, the reel blades 2 a, and the rollers 1 b protrude downward from the lower opening 34 of the lawn mower body 3. The outer peripheral lower end of the reel blade 2a is positioned slightly above the line connecting the outer peripheral lower end of the wheel 1a and the outer peripheral lower end of the roller 1b, and the vertical height adjustment of the wheel 1a is performed as described above while satisfying this condition. Thus, the height of the reel blade 2a from the ground contact surface 15, that is, the grass cutting height is adjusted.

  As shown in FIG. 2, the lower end portion of the handle 4 is rotatably attached to the upper portion of the rear portion of the lawn mower body 3. As shown in FIG. 1, the handle 4 has a pair of rod-like arm portions 35 connected at the upper ends by upper horizontal bar portions 36, and a U-shaped grip on the upper surface of both end portions of the upper horizontal bar portion 36. Both ends of the portion 37 are connected by a connecting portion 37a, and a switch handle 39 is attached to the grip portion 37 so as to be movable in the vertical direction with respect to the grip portion 37. Further, between the upper portions of the pair of arm portions 35 (upper A handle stay 38 is constructed at a position slightly below the horizontal bar portion 36). The switch handle 39 is a member for operating a switch (not shown) for turning the motor 16 on and off.

  Shaft portions 40 are provided at the lower ends of the pair of arm portions 35 of the handle 4, and the shaft portions 40 at the lower ends of the pair of arm portions 35 are rotated around the bearing portions 41 provided at both upper portions of the rear portion of the lawn mower body 3. It is mounted freely.

  As shown in FIG. 5, a discharge opening 12 is provided on the rear surface of the lawn mower body 3 for discharging the lawn cut by the lawn mowing blade 2. A grass basket 5 having an open front side is detachably attached to the rear surface of the lawn mower body 3.

  As shown in FIGS. 1, 3, 5, and 6, a rising wall 47 projects upward from the rear end edge of the upper surface portion of the lawn mower body 3, and the rising wall 47 is formed from the lawn mower body. A notch 48 is formed at an intermediate portion in the left-right direction of 3 and the upper edge of the front opening 13 of the grass basket 5 is vertically contacted at a plurality of locations in the left-right direction on the front surface of the rising wall 47. A guide ridge 47a having a long linear shape in the vertical direction for guiding downwardly projects.

  Further, a protrusion 49 that is wider than the left and right width of the notch 48 protrudes upward at a position slightly ahead of the rising wall 47 in the intermediate portion in the left and right direction of the upper surface portion of the lawn mower body 3. is there. An insertion hole 50 is formed between the notch 48 and the rear surface of the protrusion 49 facing the notch 48. Here, at the center of the rear part of the protrusion 49, there is a recess 50a that opens in the vertical direction and the rear, communicating with the front half of the upper opening of the insertion hole 50, and both sides and the front inner surface of the recess 50a are respectively upward. The lead-in part 45 which consists of the inclined surface which inclined so that it may become an outer side as it goes to.

  A switch 60 is provided in the rear upper part of the lawn mower body 3 as shown in FIG. 7, and an operation button 61 for turning the switch 60 on and off is slidable in the front-rear direction on the lateral side of the switch 60. Is provided. A spring force is applied by a spring 62 so that the rear end of the operation button 61 protrudes into the insertion hole 50.

  As shown in FIG. 10B, the protruding position of the rear end of the operation button 61 into the insertion hole 50 is located below the notch 48, and the operation can be performed even if a finger is inserted from the notch 48. The button 61 cannot be operated. In addition, since the switch 60 does not directly face the insertion hole 50, foreign matter such as dust is difficult to enter the switch 60 from the insertion hole 50.

  The switch 60 is provided in the middle of the power circuit of the motor 16 that is turned on and off by the switch handle 39. When the switch 60 is off, power is not supplied to the power circuit, and the motor is operated even when the switch handle 39 is operated. On the other hand, when the switch 60 is on, power is supplied to the power supply circuit, and the motor 16 can be driven by operating the switch handle 39.

  As shown in FIGS. 1 and 11, the collecting basket 5 is configured by attaching a deformable bag 65 to a car frame 52. The car frame 52 is formed of a wire rod. The side frame portion 55 projects downward from both ends of the front end portion of the rectangular upper frame portion 54, and the substantially rectangular shape extends from the lower end of the side frame portions 55 toward the front. A lower frame portion 56 having a letter shape is protruded. A handle 57 is attached to a central portion of the front frame portion 54a of the upper frame portion 54 in the left-right direction, and a protruding portion 58a protrudes downward from the handle 57. The protruding portion 58a is a front frame portion 54a. Protrudes downwards. In order to attach the bag 65 to the car frame 52, the upper surface of the bag 65 opened at the front is attached to the rectangular upper frame 54, and the left and right side edges and the lower edge of the front opening 13 of the bag 65 are further attached. These are attached to the left and right side frame portions 55 and the lower frame portion 56, respectively. Accordingly, since only a part of the rear surface, side surface, and lower surface of the bag 65 is attached to the car frame 52, the bag hangs down under its own weight in a posture in which the upper frame portion 54 is on the upper side. In addition, the bag 65 can be folded so that the rear surface, side surface, and lower surface of the bag 65 overlap the car frame 52 side.

  As shown in FIGS. 2 and 3, with the grass cage 5 detachably attached to the rear of the lawn mower body 3, the lawn mower 6 is moved while grasping and pushing the grip part 37 of the handle 4 by hand. The switch handle 39 is operated to drive the motor 16 to cut the lawn with the lawn mowing blade 2, and the lawn cut with the lawn mowing blade 2 is stored in the grass collection basket 5 through the discharge opening 12.

  Here, in order to detachably attach the grass collecting basket 5 to the rear portion of the lawn mower main body 3 during use, the protruding portion 58a of the grass collecting basket 5 is inserted and locked into the insertion hole 50 from above and the front frame portion 54a is raised. By fitting and locking between the wall 47 and the protruding portion 49, and by fitting the left and right side frame portions 55 to the receiving portions 51 at the left and right ends of the rear surface of the lawn mower body 3, The grass collection basket 5 is attached so that the front opening 13 communicates with the discharge opening 12. In inserting and locking the protruding portion 58a into the insertion hole 50 from above, the lower end portion of the protruding portion 58a is inserted into a recess 50a provided at the center of the rear portion of the protruding portion 49, and the protruding portion 58a is used with the guide portion 45 as a guide. It can be inserted into the insertion hole 50 from above. In this case, the projecting portion 58a may be directly inserted into the recess 50a from above, but the notch 48 is provided at a position facing the rear surface portion of the projecting portion 49 of the rising wall 47. In this way, the protrusion 58a is inserted into the recess 50a by inserting the protrusion 58a forward from the notch 48, and is then dropped downward in this state, so that the guide hole 45 is guided to the insertion hole. 50 can be inserted more smoothly.

  As described above, the supported portion 59 including the front frame portion 54a, the left and right side frame portions 55, and the protruding portion 58a provided on the grass collecting basket 5 is inserted into the insertion hole 50, the rising wall 47, the protrusion provided in the lawn mower body 3. It is detachably attached to the support portion 7 composed of the portion 49, the receiving portion 51 and the like. However, when the protrusion 49 is inserted into the insertion hole 50, the operation button 61 is pushed as shown in FIGS. When the switch 60 is turned on and the attachment of the grass basket 5 to the lawn mower body 3 is detected, and the switch 60 is turned on in this way, the attachment of the grass basket 5 is detected. The motor 16 can be driven by operating the handle 39. Therefore, in a state where the grass basket 5 is removed from the lawn mower body 3 or a state where the supported portion 59 is not correctly attached to the support portion 7 (a state where the grass basket 5 is not correctly attached to the lawn mower body 3), Even if the switch handle 39 is operated, the motor 16 cannot be driven, and safety is ensured.

  By the way, as described above, the protruding portion 58a of the collecting basket 5 is inserted and locked into the insertion hole 50 from above, and the front frame portion 54a is fitted between the rising wall 47 and the protruding portion 49 and locked. The left and right side frame portions 55 are fitted and locked to the receiving portions 51 at the left and right end portions of the rear surface of the lawn mower body 3, so that the grass collecting basket 5 is attached to the lawn mower body 3 by insertion from above. However, in some cases, the front frame portion 54a may be attached in a non-regular attachment state while the long front frame portion 54a is locked to the left and right of the grass collection basket 5 in the middle of the front surface of the rising wall 47. This is because when the long front frame portion 54a is dropped to the left and right of the grass basket 5 along the front surface of the rising wall 47, the front frame portion 54a is long to the left and right, so that the frictional resistance with the front surface of the rising wall 47 is large. It stops in the middle of dropping downward, causing the user to feel as if it is in a normal mounting state, and may be used as it is. Therefore, in the present invention, the operation button 61 cannot be pushed as described above unless the protruding portion 58a is in a proper insertion state, and thus the grass collection basket 5 is not correctly attached in a normal state. In this case, the motor 16 cannot be driven even if the switch handle 39 is operated, and safety is ensured.

  Further, in the present invention, the guide protrusion 47a for guiding the upper edge of the front opening 13 of the collecting basket 5 downward by the line contact in the vertical direction is provided on the front surface of the rising wall 47. Using the guide ridge 47a as a guide, the upper edge of the front opening 13 of the collecting basket 5 is brought into contact with the line contact in the vertical direction, and it is lowered to its proper mounting position by its own weight without being caught in the middle. Can be done.

It is a disassembled perspective view of the lawn mower of the present invention. It is a partially broken side view same as the above. It is a sectional side view same as the above. It is a bottom view same as the above. It is a rear view of the state which removed the grass collection basket same as the above. It is a top view of the state which removed the grass collection basket same as the above. It is a plane sectional view of the principal part same as the above. It is a disassembled perspective view of a lawn mower main body same as the above. It is a perspective view which shows the attachment of the grass collection basket same as the above. (A) is principal part sectional drawing which shows the state which attached the grass collection basket same as the above, (b) is principal part sectional drawing of the state which removed the grass collection basket. The grass basket used for the above is shown, (a) is a plan view, and (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Wheel 2 Lawn mowing blade 3 Lawn mower main body 24 Rotating body 25 Operation knob 27 Vertical moving body 29 Gap 31 Crankshaft 31a Intermediate shaft 32 Wheel mounting plate

Claims (2)

  Both ends of a crankshaft whose middle portion is bent in a U-shape are rotatably attached to a lawn mower body provided with a lawn mowing blade, and one end of a wheel mounting plate is fixed to each end of the crankshaft. A rotary shaft provided at the center of the wheel is rotatably attached to the other end of the mounting plate, and the rotary body is attached to the lawn mower body so that the rotary body can rotate freely and does not move in the vertical direction. An operation knob is provided in the exposed part on the upper surface side of the rotary body, and the vertical moving body is screwed into the lower part of the vertical moving body in the front-rear direction while the vertical moving body is screwed so as to be movable in the vertical direction without rotating. A lawn mower characterized by comprising an intermediate shaft portion at the tip bent in a U-shape at the intermediate portion of the crankshaft so as to be movable in the front-rear direction.   The lawn mower according to claim 1, wherein the lower part of the rotating body and the vertically movable body are screwed by a multi-thread screw.

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