JP6539613B2 - lawn mower - Google Patents

Description

  The present invention relates to a lawn mower that performs cutting using a rotary blade attached in the horizontal direction and a fixed blade arranged to press against the cutting edge of the rotary blade.

  In the mower, a rotary blade provided with a plurality of spiral blades is arranged horizontally on the main body frame, and a fixed blade is arranged to abut on the rotational trajectory of the cutting blade of the rotary blade which is the tip of the spiral blade. A mower is known which reaps by means of a rotary blade and a fixed blade. In this type of lawn mower, as disclosed in Patent Document 1, it is common to adjust the clearance between the cutting edge of the rotary blade and the cutting edge of the fixed blade so as to maintain a spring suitable condition for cutting. is there. At this time, the fixed blade is prevented from protruding into the rotation trajectory of the rotary blade to prevent biting. That is, it adjusts to a minute clearance.

If the object to be cut enters into the clearance between the cutting blade of the rotary blade and the fixed blade, a good cutting state can not be realized. Therefore, it is preferable from the viewpoint of the cutting function that the cutting blade of the rotary blade and the fixed blade are always in contact or in a pressed state. However, when the fixed blade is in a pressing state with respect to the rotary blade, the fixed blade may bite into the spiral blade when the contact position of the fixed blade moves to a contact state with the next spiral blade. There was a sex.
In Patent Documents 2 and 3, a disk-like biting prevention plate is disposed at one end of the rotary blade, and the fixed blade is brought into the rotation trajectory of the rotary blade by bringing the fixed blade into contact with the biting prevention plate. The idea of preventing the fixed blade from biting into the rotary blade is disclosed.

  By supporting the fixed blade at one end of the rotary blade, the conventional technique for preventing the fixed blade from biting can not completely prevent the fixed blade from being bitten on the opposite side of the biting prevention plate. In particular, in order to complete cutting of the turf, the risk of biting increases when pressing with a strong force, and the same position of the end of the fixed blade always abuts, so fixation The blade may be partially worn away. Patent Document 3 discloses a concept of realizing a stable cutting condition by pressing a fixed blade against a rotary blade with a weak force by a component force of an elastic force of a spring.

JP, 2013-13380, A Utility model registration No. 3030764 JP 2007-166987A

As disclosed in Patent Document 3, even if the fixed blade is always pressed against the rotary blade by the component force of the spring, the biting prevention plate disposed at one end of the rotary blade is also intended to prevent biting. Since it is difficult to completely prevent biting of the fixed blade, and because the contact position between the biting prevention plate and the fixed blade is the same position, the part is easily worn away. In addition, when the pressing force is weak, there is a disadvantage that the cutting force of grass etc. is inferior.
In view of the above-mentioned drawbacks, the present invention more reliably prevents biting of the fixed blade and the rotary blade, and presses the rotary blade and the fixed blade with a relatively large force so as to cut a good cutting force, for example, hard grass It is an object of the present invention to realize a lawn mower that can easily perform the Another object of the present invention is to realize a structure capable of avoiding partial abrasion of the fixed blade and maintaining a stable cutting state.

A lawn mower according to the present invention as set forth in claim 1, which achieves the above object, comprises: a rotary blade 2 having a plurality of spiral blades 3, 3 mounted in the horizontal direction of the main body frame 1; The fixed blade 6 is disposed in parallel with the rotary blade 2 so as to press the cutting blade 3 a which is the tip of the spiral blade 3, and cutting is performed between the fixed blade 6 and the rotary blade 2.
The plurality of spiral blades 3, 3 are arranged at equal intervals on the concentric axis of the rotation shaft 4, and both ends of the spiral blades 3, 3 are of a fixed size from the center of the rotation shaft to the cutting blade 3a of the spiral blade 3. Form an arc-shaped extension 5 with an outer circumferential surface 5a equal to the dimension of. The extension 5 is joined to the next spiral blade 3 to form the cutting edge 3a of the spiral blade 3 and the outer peripheral surface 5a of the extension 5 flush with each other.

With respect to the shape of the extension 5 of the spiral blade, the extensions 5 formed at both ends of the spiral blade 3 extend from the both end positions of the spiral blade 3 toward the inner side of the next spiral blade, and the next spiral blade It is to join to the inward position rather than the outward end of.

The invention according to claim 2 relates to a support structure of the fixed blade 6. The fixed blade 6 is fixed to the flat plate portion 8a of the support plate 8 provided with the flat plate portion 8a along the support shaft 7 arranged in parallel with the rotary blade 2 and the vertical wall 8b at both ends of the flat plate portion 8a. Both ends of the support shaft 7 are pivotally supported by the vertical wall 8b of the main body 8, and a connecting plate 9 formed outward on the vertical wall 8b of the support plate 8 is bored in the side wall of the main body frame 1 through the window hole 10 The upper fixed plate 11 and the lower fixed plate 12 are made to project above the window hole 10 on the outer side surface of the main body frame 1 while projecting the frame 1 outward.
A through hole is formed in each of the connecting plate 9, the lower fixing plate 12 and the upper fixing plate 11, and the through hole 13 of the connecting plate 9 and the through hole 15 of the lower fixing plate 12 and the through hole 14 of the upper fixing plate 11 are penetrated. Let it hang up and attach the hanging rod 16. Upward retaining portion 17 is formed at the lower end of suspension rod 16 and large diameter portion 18 is formed at the upper end, and the through hole 15 of lower fixing plate 12 is fixed to the small diameter hole through which the shaft portion of suspension rod 16 passes. The through hole 14 of the plate 11 is a large diameter hole through which the large diameter portion 18 of the hanging rod 16 passes. In this state, a coil spring 19 is disposed between the lower fixed plate 12 and the large diameter portion 18 of the hanging rod 16, and the fixed blade 6 is constantly pressed against the rotary blade 2 by the elasticity of the coil spring 19.

  According to the lawnmower of the present invention according to claim 1, both ends of the fixed blade 6 always abut the extensions 5 and 5 of the spiral blade 3, that is, it is stably supported and the spiral of the fixed blade 6 does not rattle. Biting of the blade 3 can be effectively prevented. In addition, the fixed blade 6 is always pressed by the rotary blade, and both ends are supported by the extension 5 so that the pressed state of the spiral blade 3 and the fixed blade 6 becomes stable, and a constant cutting state (condition) is maintained. can do. That is, even if the fixed blade 6 is pressed by the rotary blade 2 because the outer peripheral surface of the extension 5 and the cutting blade 3a of the spiral blade 3 are flush, the fixed blade 6 and the rotary blade can be continuously formed. 2 abuts, there is little possibility of partial abrasion of the fixed blade 6, and a stable cutting state can be maintained.

And since the contact position of the fixed blade 6 and the extension part 5 of the rotary blade 2 always moves, partial abrasion of the fixed blade 6 can be reduced. In addition, movement of the contact position between the extension 5 and the fixed blade 6 causes a cutting action of the turf at this portion. In particular, since cutting is performed in a state in which the movement of the fixed blade 6 in the width direction is small with respect to the rotational speed of the rotary blade 2, a strong cutting force can be realized. Therefore, it is possible to make it difficult to cause uncuts on both sides of the rotary blade.

According to the second aspect of the present invention, the fixed blade 6 can always be pressed against the rotary blade 2 by the force of the coil spring 19, and a more stable cutting state can be realized. Further, the hanging rod 16 for pulling up the fixed blade 6 and pressing it to the rotary blade 2 supports the fixed blade 6 in a state of penetrating the through hole 14 of the upper fixed plate 11 and the through hole 15 of the lower fixed plate 12. In order to pull up the connecting plate 9 of the supporting plate 8, the fixed blade 6 can be stably operated without swinging. Also, the fixed blade 6 can be operated by the relatively strong force of the coil spring 19. That is, according to the present invention, even when the fixed blade 6 is pressed against the cutting blade 3a of the spiral blade 3 with a strong force, a good cutting state can be realized without biting.

FIG. 1 is a plan view of a mower showing an embodiment of the present invention; 2 is a side view of the mower shown in FIG. Fig. 3 is a side view showing the structure of the fixed blade of the mower shown in Fig. 1; 4 is a cross-sectional view taken along line IV-IV in FIG. Figure 5 is a perspective view of the rotary blade only; FIG. 6 is a front view of only the rotary blade.

Hereinafter, an embodiment of a lawn mower according to the present invention will be described based on the attached drawings.
FIG. 1 is a plan view of a lawn mower according to the present invention, FIG. 2 is a side view, and FIG. 3 is a structure of a fixed blade.

  The lawn mower of the illustrated embodiment forms the main body frame 1 by connecting the front portions of the left and right side plates 1a, 1a with a connecting member 1b. Between the side plates 1 a of the body frame 1, a rotary blade 2 having a plurality of spiral blades 3, 3 and five spiral blades in the illustrated embodiment is horizontally mounted between the side plates 1 a and 1 a The fixed blade 6 is disposed in parallel with the rotary blade 2 so as to be in contact with the rotational trajectory of the blade 3a. This lawn mower rotates the rotary blade 2 by moving the main body frame 1 so that the shearing action of the cutting blade 3 a at the tip of the spiral blade 3 constituting the rotary blade 2 and the cutting blade 6 a at the tip of the fixed blade 6 Mow the grass by

  A guide roller 21 is disposed on the side plate 1a of the main body frame 1 so as to support the wheels 20, 20 on the outer surface of the front half and to bridge the rear end of the side plates 1a, 1a of the main body frame 1 The rotary blade 2 is rotated by moving the main body frame 1 by grounding the guide roller 20 and the guide roller 21. That is, although not shown, an internal gear is formed inside the wheel 20 disposed on the outer surface of the main body frame 1, and a pinion mounted at the tip of the rotary shaft 4 of the rotary blade 2 is engaged with the internal gear. By rotating the rotary blade 2 in conjunction with the rotation of the wheel 20, the rotary blade 2 is rotated.

The fixed blade 6 disposed at a position in contact with the rotational trajectory of the cutting blade 3 a which is the tip of the spiral blade 3 forming the rotary blade 2 is disposed parallel to the rotary blade 2. I am able to do that.
That is, the fixed blade 6 is fixed to the support plate 8. The support plate 8 is composed of a flat portion 8a extending in the width direction of the main body frame 1 and a vertical wall 8b having its both ends bent, the fixed blade 6 is fixed to the flat portion 8a, and the vertical wall 8b is supported by the support shaft 7 It is pivotally supported by the main body frame 1. By rotating the support plate 8 axially supported by the support shaft 7 forward, the front end of the fixed blade 6 fixed to the support plate 8, that is, the cutting blade 6a is the cutting blade 3a of the spiral blade 3 of the rotary blade 2. Can be pressed.

On the support plate 8, as is understood from FIG. 3, the connection plates 9, 9 are formed so as to project outward. That is, the connection plate 9 is bent outward on the upper edge front portion of the vertical wall 8b located at both ends of the flat portion 8a of the support plate 8, and the connection plate 9 is formed on the side plate 1a of the main body frame 1 It is made to project outward from the perforated window hole 10.
A pair of upper and lower fixed plates 11 and 12 is made to project outward on the side plate 1 a of the main body frame 1 at a position immediately above the window hole 10 where the connecting plate 9 projects outward. In the illustrated embodiment, a member having a substantially U-shaped cross section is welded to the side plate 1a, and the upper side of the U-shaped member is an upper fixed plate 11 and the lower side is a lower fixed plate 12. Of course, the upper fixed plate 11 and the lower fixed plate 12 may be separated.

In the upper fixed plate 11, lower fixed plate 12 and connection plate 9, through holes 14, 15 and 13 are respectively formed in a straight line in the vertical direction, and the through holes are penetrated to set a hanging rod 16 There is. The hanging rod 16 has a large diameter portion 18 at the upper end of the shaft portion 16a, and can be fitted with the retaining portion 17 at the lower end. For example, a hexagonal socket bolt is used as the hanging rod 16.
The through holes 13 of the connection plate 9 through which the suspension rod 16 penetrates and the through holes 15 of the lower fixing plate 12 have a hole diameter through which the shaft 16a of the suspension rod 16 passes freely without a large gap, for example, the shaft 16a The through hole has a diameter about 1 mm larger than the diameter of In particular, the size of the through hole 15 of the lower fixing plate is such that when the coil spring 19 is attached to the shaft portion 16a, the shaft portion 16a passes and the coil spring 19 is supported without passing. On the other hand, the through hole 14 of the upper fixing plate 11 is a large diameter hole through which the large diameter portion 18, in the illustrated embodiment, the head of the hexagonal hole bolt passes.

In order to mount the support plate 8 to which the fixed blade 6 is fixed to the main body frame 1, the coil spring 19 is inserted into the shaft portion 16 a of the suspending rod 16, and the coil spring 19 is supported by the large diameter portion 18. The wedge 16 is inserted through the through hole 14 of the upper fixing plate 11, the through hole 15 of the lower fixing plate 12 and the through hole 13 of the connecting plate 9, and the tip of the shaft 16a Secure the nut.
The suspension rod 16 supporting the connection plate 9 of the support plate 8 by the retaining portion 17 is biased upward by a coil spring 19 inserted between the lower fixing plate 12 and the large diameter portion 18. That is, the support plate 8 is always pulled upward by the elasticity of the coil spring 19 and pressed by the rotary blade 2.
At this time, since the hanging rod 16 penetrates the through holes 13, 14 and 15, it is stably held, and no excessive force acts on the coil spring 19. In particular, when the upper fixed plate 11 and the lower fixed plate 12 are formed in a substantially U-shaped cross section as in the illustrated embodiment, the coil spring 19 itself is protected from the outside.

The rotary blade 2 that rotates in conjunction with the rotation of the wheel 20 is, as shown in FIGS. 5 and 6, disc-shaped mounting plates 22 and 22 disposed at three locations at equal intervals in the axial direction of the rotary shaft 4. In addition, the spiral blades 3 are fixed at equal intervals on the circumference (every 72 degrees in the illustrated example). The number of the spiral blade 3 is five in the illustrated embodiment, and the fixed blade 6 disposed parallel to the rotary blade 2 is always arranged at one position of the spiral blade 3 so that a twist of 72 degrees is provided between both ends of the spiral blade 3. In order to maintain a stable rotation without variation in contact resistance.
Both ends of the spiral blade 3 are following the arc-shaped extension 5 having an outer peripheral surface 5a which has a constant dimension (radial direction) from the center of the rotary shaft 4 and is equal to the dimension from the cutting edge 3a of the spiral blade 3 Form towards the spiral blade. The extension 5 is joined to the next spiral blade 3 so that the cutting edge 3a of the spiral blade 3 and the outer peripheral surface 5a of the extension 5 are flush with each other.

With the above configuration, the fixed blade 6 always abuts and slides on the outer peripheral surface 5 a of the extension 5 formed at both ends of the spiral blade 3. That is, both ends of the fixed blade 6 are supported by the extension 5 and there is no possibility of moving in the central direction of the diameter of the rotary blade 2, ie, there is no possibility of biting. Therefore, even if the fixed blade 6 continues to be pressed by the relatively strong force of the coil spring 19, it does not bite, and there is an effect that cutting of the object to be cut can be made reliable. In the illustrated embodiment, since any part of the spiral blade 3 always abuts on the cutting blade 6 a of the fixed blade 6 and contributes to the cutting action, the cutting resistance is stabilized and the possibility of uncut is small. .
The contact position between the fixed blade 6 and the rotary blade 2 that perform the cutting action does not have to be always limited to one place, and cutting is always performed at multiple positions depending on the helical angle of the spiral blade and the axial dimension of the rotary blade. You can also

  The extension direction of the extensions 5 formed at both ends of the spiral blade 3 may be orthogonal to the rotation axis 4. In this case, the extension 5 appears in an annular shape at both ends of the spiral blade 3 to function as a biting prevention plate, and the fixed blade 6 is supported at both end positions of the spiral blade 3. If the outer peripheral surface 5a of the extension 5 continues to be in contact with the fixed blade 6 at the same position in a thin state with a narrow width, the contact portion of the fixed blade may be worn away, but as in the illustrated embodiment When the extension 5 extends inward, the contact position between the fixed blade 6 and the extension 5 changes. Thereby, partial abrasion of the fixed blade 6 can be reduced.

  The extension 5 may be in a direction orthogonal to the rotation axis 4, but as shown in the illustrated embodiment, the extensions 5 formed at both ends of the spiral blade 3 are next to each other in the spiral blade from both end positions. It is preferable to extend inward and to join at an inner position rather than the outer end of the next helical blade. That is, in the case where the extension is formed inward from one end of the spiral blade to form the extension toward the next spiral blade, the next spiral blade is joined to the inside more than one end. From one end of the spiral blade where the extension is joined to the inside from the one end, as is understood from FIGS. 5 and 6, the extension is further formed toward the spiral blade in the next position.

  In the embodiments shown in FIG. 5 and FIG. 6, the spiral blade 3 of the rotary blade 2 always contacts the fixed blade 6. Then, the contact position between the fixed blade 6 and the extension 5 changes in the axial direction of the rotation shaft 4. Therefore, the possibility of partial abrasion of the fixed blade 6 is reduced, and even if the fixed blade 6 is strongly pressed against the rotary blade 2, it can be smoothly rotated. In addition, axial movement of the contact position of the extension of the rotary blade with respect to the fixed blade contributes to cutting of the workpiece although it is partial. Since the axial movement of the contact position is a small distance, a strong cutting force can be exerted to cut strong grass or the like moved to one end of the rotary blade.

  In addition, in the figure, reference numeral 23 denotes a support arm of the guide roller 21. The support shaft 24 of the guide roller 21 is supported at the tip portion, and the rotary blade 2 and the fixed blade 6 are rotated by pulling the knob 25 to rotate the support arm. The height of the cutting position can be changed to adjust the height of the grass cutting.

DESCRIPTION OF SYMBOLS 1 ... Body frame, 1a ... Side plate, 1b ... Connection member, 2 ... Rotary blade, 3 ... Spiral blade, 3a ... Cutting blade, 4 ... Rotational axis, 5 ... Extension part, 5a ... Outer peripheral surface, 6 ... Fixed blade, 6a ... Cutting blade 7. support shaft 8 support plate 8a flat portion 8b vertical wall 9 connection plate 10 window hole 11 upper fixed plate 12 lower fixed plate 13, 14 DESCRIPTION OF SYMBOLS 15 ... Through-hole, 16 ... Suspension rod, 17 ... Detachment prevention part, 18 ... Large diameter part, 19 ... Coil spring, 20 ... Wheel, 21 ... Guide roller, 22 ... Mounting plate, 23 ... Support arm, 24 ... Support shaft , 25 ... picking.

Claims (2)

A fixed blade is disposed parallel to the rotary blade so as to press the rotary blade provided with a plurality of spiral blades in the horizontal direction of the main body frame and a cutting blade which is the tip of the spiral blade of the rotary blade, In mowers that reap between rotating blades,
An arc having a plurality of spiral blades arranged at equal intervals on the concentric axis of the rotation axis and having an outer peripheral surface at both ends of the spiral blade having a constant dimension from the center of the rotation axis and equal to the size to the cutting edge of the spiral blade Forming an extension portion of the spiral blade, and joining the extension portion to the next spiral blade to form a cutting edge of the spiral blade and an outer peripheral surface of the extension portion flush with each other ;
The extensions formed at both ends of the spiral blade are extended from the both ends toward the inner side of the next spiral blade and are joined to the inner position than the outer end of the next spiral blade. Lawn mower. The fixed blade is fixed to a flat plate portion along a support axis arranged parallel to the rotary blade, and a flat plate portion of a support plate provided with vertical walls at both ends of the flat plate portion, and the support shaft is fixed to the vertical wall of the support plate. And a connecting plate formed on the vertical wall of the support plate so as to axially support both ends of the support plate so as to protrude outward of the main body frame from a window hole bored in the side wall of the main body frame The upper fixing plate and the lower fixing plate are projected above the window hole, and through holes are formed respectively in the connecting plate, the lower fixing plate and the upper fixing plate, and the through holes of the connecting plate and the lower fixing plate A hanging rod is attached by penetrating the through hole of the upper fixing plate, an upward retaining portion at the lower end of the hanging rod and a large diameter portion at the upper end, and the through hole of the lower fixing plate is suspended In the small diameter hole through which the shaft of the shaft passes, the through hole of the upper fixed plate is a large diameter hole through which the large diameter portion of the hanging rod passes, The coil spring is disposed between the large diameter portion of the rod hanging and Teiita, lawn mower according to claim 1, characterized in that it pressed constantly rotating blade of the fixed blade by the elasticity of the coil spring.

Images