Lawn mower

Abstract

The present invention discloses a lawn mower, which is provided with a first air guide member and a second air guide member in the form of a V-shaped sheet, which, together with a chassis upper cover plate and an annular wall, form a cutting chamber with an outer edge in the shape of an 8 and opening downward, wherein the cutting chamber just covers the cutting areas of a pair of cutting knives, and constructs an air duct that matches the shape of the cutting area, wherein the first air guide member and the second air guide member both include straight line segments and arc segments, but have different angle sizes and vertex distributions, and form an expanded shape and a closed shape in the front and rear of the middle of the cutting chamber respectively, which guide and block the backflow of grass clippings that are blown from one side of the cutting chamber to the other side in a direction, thereby reducing the space and time for the retention of cut grass clippings, and improving the mowing efficiency of the cutting knives and the grass discharge efficiency of the cutting chamber. Therefore, the present invention achieves the coordinated improvement of the mowing performance and the grass discharge performance of the double-disc lawn mower by optimizing and improving the structural shape of the cutting chamber.

Description

Technical Field

[0001] The invention relates to the technical field of gardening equipment, in particular to a lawn mower. Background Art

[0002] In the prior art, large-sized walk-behind self-propelled lawn mowers of more than 20 inches are generally equipped with double blade discs, one of which is a double blade disc consisting of two cutting blades arranged side by side in the same cutting chamber and rotating in the same direction and at the same speed, wherein the cutting chamber opens downward, and its outer wall is provided with a rear outlet facing the rear of the fuselage and a side outlet facing the outside of the fuselage around one of the cutting blades. When the rear outlet is opened and the side outlet is closed, the cut grass clippings are blown into the grass collecting bucket at the rear of the fuselage through the rear outlet by the airflow brought about by the rotation of the cutting blade. When the side outlet is opened and the rear outlet is closed, the cut grass clippings are blown out of the outside of the fuselage through the side outlet by the airflow brought about by the rotation of the cutting blade. When the rear outlet and the side outlet are closed at the same time, the cut grass clippings are blown onto the grass through the open opening below the cutting chamber by the airflow brought about by the rotation of the cutting blade.

[0003] The working efficiency of the above-mentioned lawn mower is not only determined by its cutting performance, but also by its cutting performance and grass discharge performance. The two complement each other, because the finer the grass clippings are cut, the easier it is to discharge. The faster and more complete the grass clippings are discharged, the less the retention of the cut grass clippings can be, and the cutting efficiency of the grass clippings being cut can be improved. The cutting performance and grass discharge performance are mainly determined by the structural shape of the cutting blade and the cutting chamber. Therefore, in the research and development of lawn mowers, the optimization and improvement of the cutting chamber structural shape and the optimization and improvement of the cutting blade structural shape are equally important. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a lawn mower having an optimized and improved cutting chamber structure shape.

[0005] In order to achieve the above object, the technical solution adopted by the present invention to solve the technical problem is:

[0006] A lawn mower, comprising a driving assembly and a cutting assembly, wherein the cutting assembly comprises a chassis, a first cutting blade and a second cutting blade, the chassis is in the shape of a cover opening downward, and comprises a cover plate and an annular wall, the first cutting blade and the second cutting blade are both rotatably mounted on the lower wall of the cover plate, the driving assembly is fixedly mounted on the chassis and connected to the first cutting blade and the second cutting blade, and is used to drive the first cutting blade and the second cutting blade to always rotate in the same direction and at the same speed, the chassis is provided with a side discharge port and a rear discharge port at the outer side and rear side of the first cutting blade, respectively, and a first flow guide and a second flow guide are fixedly mounted on the lower wall of the cover plate, in front of and behind the middle of the first cutting blade and the second cutting blade, respectively, the first flow guide and the second flow guide are both in the shape of V-shaped sheets and are vertically connected to the cover plate, and are connected to the annular wall at both ends, the annular wall comprises a first wall section and a second wall section, the first wall section, the first flow guide, the second wall section and the second flow guide are connected in sequence, and form a cutting chamber with an outer edge in the shape of an 8 and opening downward with the cover plate;

[0007] The first flow guide is divided into a first arc segment and a first straight segment, the first arc segment and the first wall segment are both arcs, the two are connected and share a circle, the second flow guide is divided into a second arc segment and a second straight segment, the second arc segment and the second wall segment are both arcs, the two are connected and share a circle, and the first straight segment is located outside the circle where the second wall segment and the second arc segment are located;

[0008] The first arc segment and the first straight line segment are connected to form a first angle and a first vertex, and the second arc segment and the second straight line segment are connected to form a second angle and a second vertex, the first angle is greater than the second angle, the first vertex is located on the side where the short axis of the cover plate is facing the first flow guide member, and the second vertex is located on the side where the short axis of the cover plate is facing the second flow guide member.

[0009] In some embodiments, one end of the second straight line segment adjacent to the first wall segment is bent upward to form a turning portion, and one end of the turning portion adjacent to the first wall segment is adjacent to the edge of the rear opening.

[0010] In some embodiments, the first cutting blade and the second cutting blade are always perpendicular.

[0011] In some embodiments, the first cutting knife and the second cutting knife each include an upper blade and a lower blade stacked up and down and coaxially fixed.

[0012] In some embodiments, the angle between the upper blade and the lower blade in the same cutting knife is 10-20°.

[0013] In some embodiments, the upper blade is generally straight, with a first cutting edge portion on each of its two ends and a first fool-proof portion curved downward on each of its middle sides.

[0014] In some embodiments, the middle portion of the lower blade is generally straight, with both ends bent downward, a second cutting edge portion is provided on one side of both ends, and a second fool-proof portion bent downward is provided on both sides of the middle portion.

[0015] In some embodiments, both ends of the lower blade are raised upwards relative to one side of the second cutting edge to form a flange portion, and a notch is provided on the flange portion.

[0016] Due to the application of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0017] The present invention provides a first flow guide member and a second flow guide member in the form of a V-shaped sheet, which together with the upper cover plate of the chassis and the annular wall form a cutting chamber with an outer edge in the shape of an 8 and opening downward, and the cutting chamber just covers the cutting area of ​​a pair of cutting knives, constructing an air duct that fits the shape of the cutting area, wherein the first flow guide member and the second flow guide member both include straight line segments and arc segments, but have different angle sizes and vertex distributions, and form an expanded shape and a closed shape in the front and rear of the middle of the cutting chamber respectively, which guide and block the backflow of grass clippings that are blown from one side of the cutting chamber to the other side in a direction, thereby reducing the space and time for the retention of cut grass clippings, and improving the mowing efficiency of the cutting knife and the grass discharge efficiency of the cutting chamber. Therefore, the present invention achieves the synergistic improvement of the mowing performance and the grass discharge performance of the double-disc lawn mower by optimizing and improving the structural shape of the cutting chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention provides a lawn mower embodiment 1 of the three-dimensional Figure 1 .

[0019] Figure 2 It is a three-dimensional diagram of the first embodiment of the lawn mower provided by the present invention with the protective shell removed.

[0020] Figure 3 The present invention provides a lawn mower embodiment 1 of the three-dimensional Figure 2 .

[0021] Figure 4 It is a front view of the cutting assembly in the first embodiment of the lawn mower provided by the present invention.

[0022] Figure 5 It is a three-dimensional diagram of the first cutting blade in the first embodiment of the lawn mower provided by the present invention.

[0023] Figure 6 It is a top view of the first cutting blade in the first embodiment of the lawn mower provided by the present invention.

[0024] Figure 7 It is a front view of the first cutting knife in the first embodiment of the lawn mower provided by the present invention.

[0025] In the figure: 1, driving assembly; 2, cutting assembly; 3, chassis; 4, first cutting blade; 5, second cutting blade; 6, cover plate; 7, ring wall; 8, side outlet; 9, rear outlet; 10, first guide member; 11, second guide member; 12, first wall segment; 13, second wall segment; 14, cutting chamber; 15, first arc segment; 16, first straight segment; 17, second arc segment; 18, second straight segment; 19, first angle; 20, first vertex; 21, second angle; 22, second vertex; 23, turning part; 24, upper blade ; 25. Lower blade; 26. First blade portion; 27. First fool-proof portion; 28. Second blade portion; 29. ​​Second fool-proof portion; 30. Flanged portion; 31. Notch; 32. Handle assembly; 33. Main body; 34. Handle frame; 35. Control handle; 36. Cutting insurance; 37. Cutting switch; 38. Movement assembly; 39. Power source; 40. Transmission assembly; 41. Pulley mechanism; 42. Protective shell; 43. Side discharge cover; 44. Side discharge outlet; 45. Rear discharge cover; 46. Grass collecting bucket; 47. Roller; 48. Blade surface. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific embodiments:

[0027] Figures 1 to 7 The present invention discloses a first embodiment of a lawn mower.

[0028] Combination Figures 1 to 3 The first embodiment is a hand-held self-propelled double-disc lawn mower, comprising a handle assembly 32 and a body 33. The handle assembly 32 comprises a handle frame 34, a control handle 35, a cutting safety 36 and a cutting switch 37. The handle frame 34 is rotatably fixed to the body 33 for switching the use state and the storage state of the lawn mower and adjusting the user's hand-pushing height in the use state. The control handle 35 is slidably fixed to the handle frame 34 for the user to hold and push the body 33. The control handle 35 has a built-in elastic mechanism and adjusts the movement speed of the body 33 according to its own sliding amount. The faster the walking speed of the user when pushing, the greater the thrust applied to the control handle 35, the greater the sliding amount of the control handle 35 on the handle frame 34, and the greater the movement speed of the body 33, so that the user's walking speed and the movement speed of the body 33 are always consistent to realize the self-propelled function of the lawn mower. The cutting safety 36 is used to switch the locking state and the active state of the cutting switch 37. The cutting switch 37 is used to switch the switch state of the mowing function of the lawn mower.

[0029] The fuselage body 33 includes a driving assembly 1, a cutting assembly 2 and a moving assembly 38. The driving assembly 1 includes a power source 39 and a transmission assembly 40. The power source 39 is a gasoline engine. The power source 39 is connected to and drives the cutting assembly 2 and the moving assembly 38 through the transmission assembly 40. The cutting assembly 2 includes a chassis 3, a first cutting knife 4 and a second cutting knife 5. The chassis 3 is integrally formed and is in the shape of a cover opening downward. It includes a generally flat cover plate 6 and a ring wall 7 vertically surrounding the cover plate 6. The first cutting knife 4 and the second cutting knife 5 have the same size and the same structural shape. Both can be rotatably installed. On the lower wall of the cover plate 6, the sum of the diameters of the pair of cutting knives is greater than the maximum length on the chassis 3, that is, the first cutting knife 4 and the second cutting knife 5 have overlapping cutting areas, the driving assembly 1 is fixedly installed above the chassis 3, and the transmission assembly 40 includes a pulley mechanism 41, and the outer side of the pulley mechanism 41 is covered with a protective shell 42. The pulley mechanism 41 connects the first cutting knife 4 and the second cutting knife 5 and is used to drive the first cutting knife 4 and the second cutting knife 5 to always rotate in the same direction and at the same speed, that is, a pair of rotating shafts on the pulley mechanism 41 penetrate the cover plate 6 and are respectively rotatably connected to the first cutting knife 4 and the second cutting knife 5, and the pulley mechanism 41 enables A pair of rotating shafts always rotate synchronously, a side discharge port 8 and a rear discharge port 9 are respectively opened on the chassis 3 at the outside and rear of the first cutting knife 4, a side discharge cover 43 is hingedly installed at the side discharge port 8 on the chassis 3, and a side discharge outlet 44 is detachably installed, a rear discharge cover 45 is hingedly installed at the rear of the fuselage main body 33, and a grass collecting bucket 46 is detachably installed, and elastic mechanisms are provided at the hinges of the chassis 3 and the side discharge cover 43, and at the hinges of the fuselage main body 33 and the rear discharge cover 45. When the side discharge outlet 44 is loaded on the chassis 3, the side discharge cover 43 is lifted up and connected to the inside of the chassis 3 through the side discharge port 8, so as to be used for cutting grass from the fuselage main body when cutting grass. 33 side discharge grass clippings, when the chassis 3 is not loaded with the side discharge outlet 44, the side discharge cover 43 is pressed downward by the elastic force to just cover the side discharge port 8, when the grass collecting bucket 46 is loaded on the fuselage main body 33, the rear row cover 45 is lifted up to receive grass clippings discharged from the rear discharge port 9 when mowing, when the fuselage main body 33 is not loaded with the grass collecting bucket 46, the rear row cover 45 is pressed downward by the elastic force to cover the rear wall of the fuselage main body 33, the moving component 38 includes a plurality of rollers 47, and the plurality of rollers 47 can be fixed on the fuselage main body 33 in a synchronously lifting manner, so as to drive the fuselage main body 33 to move and adjust the height of the fuselage main body 33 and the mowing height.

[0030] Embodiment 1 has three grass discharge modes when mowing: when the rear discharge port 9 is opened and the side discharge port 8 is closed, the cut grass clippings are blown into the grass collecting bucket 46 through the rear discharge port 9 by the airflow brought by the rotation of the cutting knife; when the side discharge port 8 is opened and the rear discharge port 9 is closed, the cut grass clippings are blown out to the grass through the side discharge port 8 by the airflow brought by the rotation of the cutting knife; when the rear discharge port 9 and the side discharge port 8 are closed at the same time, the cut grass clippings are blown onto the grass through the opening below the chassis 3 by the airflow brought by the rotation of the cutting knife.

[0031] Recombination Figures 1 to 4 The cover plate 6 is a rectangle with two short sides being arcs, and the first cutting knife 4 and the second cutting knife 5 are arranged along the long axis of the cover plate 6 (see Figure 4 The first cutting blade 4 rotates along the middle axis and the second cutting blade 5 rotates along the middle axis about the short axis of the cover plate 6 (see Figure 4 The two cutting blades are symmetrical with respect to the middle dotted straight line b), and the lower edges of the pair of cutting blades do not exceed the lower edge of the annular wall 7. On the lower wall of the cover plate 6, in front and behind the middle of the first cutting blade 4 and the second cutting blade 5, the first flow guide 10 and the second flow guide 11 are fixedly installed respectively. The first flow guide 10 and the second flow guide 11 are both V-shaped sheets and vertically connected to the cover plate 6, and both ends are connected to the annular wall 7. The annular wall 7 includes a first wall section 12 and a second wall section 13. The first wall section 12, the first flow guide 10, the second wall section 13 and the second flow guide 11 are connected in sequence, and form a cutting chamber 14 with an 8-shaped outer edge and a downward opening together with the cover plate 6.

[0032] The first flow guide 10 is divided into a first arc segment 15 and a first straight segment 16. The first arc segment 15 and the first wall segment 12 are both arcs, which are connected and cocircular. The center of the larger arc formed by the two is on the rotation axis of the first cutting knife 4, and the radius is slightly larger than the maximum radius of the first cutting knife 4. The second flow guide 11 is divided into a second arc segment 17 and a second straight segment 18. The second arc segment 17 and the second wall segment 13 are both arcs, which are connected and cocircular. The center of the larger arc formed by the two is on the rotation axis of the second cutting knife 5, and the radius is slightly larger than the maximum radius of the second cutting knife 5. The first arc segment 15 and the first straight segment 16 are connected. A first angle 19 and a first vertex 20 are formed, and a second angle 21 and a second vertex 22 are formed at the connection between the second arc segment 17 and the second straight segment 18. The first angle 19 is greater than the second angle 21. The first vertex 20 is located on the side where the short axis of the cover plate 6 faces the first flow guide 10, and the second vertex 22 is located on the side where the short axis of the cover plate 6 faces the second flow guide 11. The first straight segment 16 is located outside the circle where the second wall segment 13 and the second arc segment 17 are located. The end of the second straight segment 18 adjacent to the first wall segment 12 is bent upward to form a turning portion 23, and the end of the turning portion 23 adjacent to the first wall segment 12 is adjacent to the edge of the rear row port 9.

[0033] The first cutting blade 4 and the second cutting blade 5 are always perpendicular to each other and rotate in the same direction and at the same speed. The rotation direction of the two is the connection sequence direction of the second flow guide 11, the second wall section 13 and the first flow guide 10 (see Figure 4 Based on the arrangement and movement of the pair of cutting knives and the flow guiding structure of the cutting chamber 14, the grass clippings cut by the second cutting knife 5 can be smoothly transferred from the second cutting knife 5 to the cutting chamber 14 by the airflow. Figure 4 The left space of the middle cutting chamber 14 is discharged into the right space, and then the grass clippings cut by the first cutting knife 4 are discharged from the left space of the middle cutting chamber 14. Figure 4The right side space of the middle cutting chamber 14 is discharged into the side discharge port 8 or the rear discharge port 9 or directly discharged onto the grass. The cutting chamber 14 with an overall 8-shaped shape just covers the cutting area of ​​a pair of cutting knives, constructs an air duct that fits the shape of the cutting area, reduces the space and time for the retention of cut grass clippings, improves the mowing efficiency of the cutting knives and the grass discharge efficiency of the cutting chamber 14, and the first arc segment 15 on the first guide member 10 and the second arc segment 17 on the second guide member 11 are important components of the shape. In addition, the flared shape formed at the first straight line segment 16 on the first guide member 10 plays a guiding role, effectively increasing the cut grass clippings from Figure 4 The efficiency of the left space of the middle cutting chamber 14 being discharged into the right space is improved, and the closing shape formed at the second straight line section 18 adjacent to the edge of the rear discharge port 9 on the second guide member 11 plays a blocking role, effectively reducing the cut grass clippings from Figure 4 The right side space of the middle cutting chamber 14 flows back to the left side space. In summary, the first embodiment improves its cutting performance and grass removal performance by optimizing and improving the structural shape of the cutting chamber 14.

[0034] Recombination Figures 1 to 7 , the first cutting knife 4 and the second cutting knife 5 both include an upper blade 24 and a lower blade 25 which are stacked up and down and fixed coaxially, that is, a double-layer blade technology. In the same cutting knife, the upper blade 24 and the lower blade 25 are each rotationally symmetrical and have a common rotation center axis. The upper blade 24 is generally straight, and a first cutting portion 26 is provided on one side of both ends. The middle part of the lower blade 25 is generally straight, and both ends are bent downward, and a second cutting portion 28 is provided on one side of both ends. The first cutting portion 26 and the second cutting portion 28 both include a cutting surface 48 with an inclined blade edge, so as to obtain a sharp end face with a significantly reduced thickness. A pair of first cutting portions 26 are at different ends and sides on the upper blade 24, and a pair of second cutting portions 28 are at different ends and sides on the lower blade 25. Both ends of the lower blade 25 are raised upward on one side relative to the second cutting portion 28 to form a flanging portion 30. In the same cutting knife, the same end cutting portions on the upper blade 24 and the lower blade 25 are arranged on the same side, and the angle between the upper blade 24 and the lower blade 25 is 10-20°.

[0035] The double-layer blade with a small angle can cut grass clippings multiple times at two different heights, one after the other. It has higher cutting efficiency, larger cutting area and better chopping effect than a single-blade cutting knife. Among them, the upper blade 24 with a flat blade structure rotates on the same plane so that it can fully chop grass clippings. When the lower blade 25 rotates, its upper flange portion 30 can generate an upward airflow to lift the cut grass clippings for repeated cutting, further improving the chopping effect. The finer the grass clippings, the easier it is to be discharged with the airflow. In summary, Example 1 improves its own cutting performance and grass discharge performance by optimizing and improving the structural shape of the cutting knife. In addition, a first anti-foolproof portion 27 bent downward is provided on both sides of the middle part of the upper blade 24, and a second anti-foolproof portion 29 bent downward is provided on both sides of the middle part of the lower blade 25, which is convenient for distinguishing the front and back during assembly. A number of notches 31 are provided on the flange portion 30, that is, the crocodile knife technology. The multiple notches 31 with regular shapes opened at the end reduce the weight of the blade end and the amplitude during high-speed rotation, thereby achieving a noise reduction effect.

[0036] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A lawn mower, comprising a driving assembly (1) and a cutting assembly (2), wherein the cutting assembly (2) comprises a chassis (3), a first cutting blade (4) and a second cutting blade (5), wherein the chassis (3) is in the shape of a cover opening downward, and comprises a cover plate (6) and an annular wall (7), wherein the first cutting blade (4) and the second cutting blade (5) are both rotatably mounted on the lower wall of the cover plate (6), wherein the driving assembly (1) is fixedly mounted on the chassis (3) and connected to the first cutting blade (4) and the second cutting blade (5), and is used for driving the first cutting blade (4) and the second cutting blade (5) to rotate in the same direction and at the same speed all the time, wherein the chassis (3) is provided with a side discharge port (8) and a rear discharge port (9) on the outer side and the rear of the first cutting blade (4), respectively, wherein: A first flow guide (10) and a second flow guide (11) are fixedly mounted on the lower wall of the cover plate (6) in front and in the rear between the first cutting blade (4) and the second cutting blade (5), respectively; the first flow guide (10) and the second flow guide (11) are both in the form of V-shaped sheets and vertically connected to the cover plate (6), and both ends are connected to the annular wall (7); the annular wall (7) comprises a first wall section (12) and a second wall section (13); the first wall section (12), the first flow guide (10), the second wall section (13) and the second flow guide (11) are connected in sequence and enclose, together with the cover plate (6), a cutting chamber (14) with an outer edge in the shape of an 8 and opening downward; The first flow guide (10) is divided into a first arc segment (15) and a first straight segment (16); the first arc segment (15) and the first wall segment (12) are both arcs, connected and in the same circle; the second flow guide (11) is divided into a second arc segment (17) and a second straight segment (18); the second arc segment (17) and the second wall segment (13) are both arcs, connected and in the same circle; the first straight segment (16) is located outside the circle where the second wall segment (13) and the second arc segment (17) are located; A first angle (19) and a first vertex (20) are formed at a connection point between the first arc segment (15) and the first straight segment (16); a second angle (21) and a second vertex (22) are formed at a connection point between the second arc segment (17) and the second straight segment (18); the first angle (19) is greater than the second angle (21); the first vertex (20) is located on a side of the short axis of the cover plate (6) facing the first flow guide member (10); and the second vertex (22) is located on a side of the short axis of the cover plate (6) facing the second flow guide member (11).

2. The lawn mower according to claim 1, characterized in that: One end of the second straight line segment (18) adjacent to the first wall segment (12) is bent upward to form a turning portion (23), and one end of the turning portion (23) adjacent to the first wall segment (12) is adjacent to the edge of the rear row opening (9).

3. The lawn mower according to claim 1, characterized in that: The first cutting knife (4) and the second cutting knife (5) are always vertical.

4. The lawn mower according to claim 1, characterized in that: The first cutting blade (4) and the second cutting blade (5) both comprise an upper blade (24) and a lower blade (25) which are stacked up and down and fixed coaxially.

5. The lawn mower according to claim 4, characterized in that: The included angle between the upper blade (24) and the lower blade (25) in the same cutting knife is 10-20°.

6. The lawn mower according to claim 4, characterized in that: The upper blade (24) is generally straight, with a first cutting edge (26) provided on one side of both ends and a first fool-proof portion (27) bent downwardly provided on both sides of the middle portion.

7. The lawn mower according to claim 4, characterized in that: The lower blade (25) is generally straight in the middle and bent downward at both ends. A second cutting edge (28) is provided on one side of both ends, and a second fool-proof portion (29) bent downward is provided on both sides of the middle.

8. The lawn mower according to claim 7, characterized in that: Both ends of the lower blade (25) are raised upwards relative to one side of the second cutting edge (28) to form a flange portion (30), and a notch (31) is provided on the flange portion (30).

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