JP6362841B2 - Mower unit - Google Patents

Description

  The present invention relates to a mower unit that includes a blade unit having a blade that rotates about a vertical axis in the blade housing.

  Japanese Patent Application Laid-Open No. 2004-151867 discloses a mower having only a plurality of air intake ports formed on the top plate of a blade housing in order to increase the total air volume of the conveying air. In this mower, the cut grass cut by each of the two blades arranged side by side is placed on the conveying wind generated by each blade. The supply source of this conveying air is the outside air sucked from the gap between the blade housing and the ground and the air intake. The conveying air generated by each blade joins in the overlapping area of the two blade rotation trajectories, is discharged from the cut grass discharge port provided by cutting out the blade housing top plate, passes through the discharge cover, and then collected in the subsequent collection. It flows into the transport duct that leads to the grass container. In this structure, the suction of the outside air that is the source of the transport air can be replenished from the air intake, but special measures are taken to increase the air volume for the transport air at the time of merging and the transport air after the merging. Therefore, there is a possibility that the air volume in the transport air flow path from the discharge cover to the transport duct becomes insufficient.

JP 2010-161972 A

  In view of the above situation, there is a demand for a mower unit that can increase the amount of conveying air generated by the blade unit, in particular, the amount of conveying air in the conveying air flow path from the discharge cover to the conveying duct, and smoothly convey cut grass in this region. Yes.

A mower unit according to the present invention rotates around a first axis extending vertically and has a rotating wind function, and rotates around a second axis extending vertically and rotates. And a blade unit in which the first blade and the second blade are arranged in parallel in a horizontal direction,
Inside the side plates hanging down from the top plate and the top plate which is formed between the mowing grass discharge port for discharging clippings mowing grass by the blade unit and the first axis and the second axis A blade housing that forms a mowing space for accommodating the front blade unit;
A discharge cover that surrounds the opening edge of the cut grass discharge port and forms a discharge conveyance channel that communicates with the grass cutting space through the cut grass discharge port,
Wherein the mowing space, the first axis and the second axis and between a and the first blade and said second blade rotation path to be above the upper area in which cutting grass discharged before mowing plane defined by the a And at least one intake section having an outside air intake opening that opens into a cut grass discharge space consisting of a region and a cut grass discharge area that is a region near the cut grass discharge port in the discharge transport channel,
One of the intake portions is a through-hole whose outside air intake port is provided in a central portion in the front-rear direction of the discharge cover,
A tongue piece overlapping the through hole in plan view is provided in the through hole .
It should be noted that “front and rear”, “lateral”, and “up and down” described in the present invention mean a positional relationship in the vehicle body traveling direction, the vehicle body transverse direction, and the vehicle body ground height direction, respectively.

  According to this configuration, the conveying wind created by the rotation of the first blade and the conveying wind created by the rotation of the second blade begin to merge with the area before cutting grass discharge and the conveying wind that passes through the cutting grass discharge port while joining. Outside air is supplied by an outside air inlet opening in one or both of the areas after the cut grass discharge after completion of the merging. As a result, the amount of air with respect to the conveying wind at the time of merging or the conveying air after the merging increases, and the cutting grass is smoothly conveyed in the conveying air flow path from the discharge cover to the conveying duct.

Since the conveying wind has a high speed when passing through the cut grass outlet, the outside air intake force of the conveying wind is also large. Therefore, it is preferable that the tongue piece is an air guide surface having a top plate of the discharge cover as a base end and a distal end entering the discharge conveyance channel side with respect to the top plate. Further, the guide direction of the air guide surface from the base end to the tip of the tongue piece is along the flow direction of the discharge / conveyance channel, and the tip of the tongue piece enters the discharge / conveyance channel. It is preferable.
Thereby, high efficiency of outside air intake from the outside air intake port is obtained.

Since the outside air intake port communicates between the outside and the inside of the mower unit, there is a possibility that foreign matters such as pebbles may be discharged or intruded from outside to inside or from inside to outside through the outside air intake port. In order to avoid this as much as possible and to ensure a sufficient flow area of the outside air intake port, the through hole is a slit-like through hole extending in the vehicle body lateral direction on the top plate of the discharge cover, and the tongue piece is It is preferable to configure so as to have the same width as the through hole in the lateral direction of the vehicle body .

In order to increase the air volume with respect to the conveying wind that has passed through the cut grass discharge port, it is preferable that a plurality of the through holes are arranged in parallel in the longitudinal direction of the vehicle body.

And another one of the intake portions is a gap that the outside air intake port opens forwardly created between the front opening edge of the cut grass discharge port and the base end portion of the discharge cover, or the It is preferable that it is the base end opening provided at the base end portion of the discharge cover and opens forward or both. Further, it is more preferable that the gap or the base end opening is provided at a position overlapping the rotation locus of the first blade or the rotation locus of the second blade in plan view.

Furthermore, it is preferable that one of the other air intake portions is a through-hole provided in a portion of the side plate of the blade housing facing the area before the cut grass discharge.

It is a schematic diagram explaining the basic principle of this invention in the mower unit provided with the several blade located in a line. It is a schematic diagram explaining the basic principle of this invention in the single blade type mower unit provided with the single blade. 1 is an overall side view of a riding mower. 1 is an overall plan view of a riding mower. It is a top view of a mower unit. It is a partial cross section top view of a mower unit. It is sectional drawing of a blade unit. It is a partial vertical side view of a mower unit. It is a perspective view of the upper structure of a discharge cover. It is a schematic diagram which shows a some intake part. It is a schematic diagram which shows a preliminary | backup air intake part. It is a schematic diagram which shows a preliminary | backup air intake part. It is a schematic diagram which shows a preliminary | backup air intake part. It is a schematic diagram which shows a preliminary | backup air intake part. It is a schematic diagram which shows a cylinder guard.

Before describing a specific embodiment of the mower unit according to the present invention, the basic principle of the increase in the amount of the conveying air by the intake section characterizing the present invention will be described with reference to FIGS.
First, FIG. 1 schematically shows a plan view (FIG. 1A) and a cross-sectional view (FIG. 1B) of a mower unit having a plurality of (two in this case) blades arranged side by side. Has been.

  The mower unit 20 includes a blade housing 21 that houses the blade unit 70. The blade unit 70 includes a first blade 72 that rotates around a first axis 71 that extends vertically, and a second blade 74 that rotates around a second axis 73 that also extends vertically. The first shaft core 71 and the second shaft core 73 are positioned at a distance shorter than the blade diameter in the lateral direction of the vehicle body, and the rotation locus of the first blade 72 and the rotation locus of the second blade 74 are predetermined from the ground. Create the same plane (mowing plane 75) at intervals. Therefore, the rotation locus of the first blade 72 and the rotation locus of the second blade 74 partially overlap between the first axis 71 and the second axis 73. Each of the first blade 72 and the second blade 74 has a rotating wind generating function for generating a conveying wind by rotating. The rotating wind function can be easily obtained by providing a wind blade at the blade tip. The rotation directions of the first blade 72 and the second blade 74 are opposite to each other, and a confluence region is formed between the first shaft core 71 and the second shaft core 73 to the rear of each conveying wind. In order to discharge the combined conveying air from the blade housing 21, a cut grass discharge port 29 is provided.

  In the blade housing 21, an auxiliary fan unit SF having an auxiliary fan that rotates integrally with each blade is disposed directly above each blade in order to enhance the conveying air generated by the first blade 72 and the second blade 74. ing. Although not shown here, an opening for taking in outside air is provided at a position facing the auxiliary fan of the top plate of the blade housing.

  The blade housing 21 has a top plate 21a and a side plate 21b hanging from the periphery of the top plate 21a, and an internal space bounded by the top plate 21a and the side plate 21b is a mowing space 8. The cut grass discharge port 29 is created by cutting out the central portion of the top plate 21a in the lateral direction of the vehicle body. A discharge cover 27 that surrounds the opening edge of the cut grass discharge port 29 and forms a discharge transfer channel 90 that communicates with the mowing space 8 through the cut grass discharge port 29 is formed on the outer surface of the blade housing 21. It is attached. The rear end of the discharge cover 27 is connected to the transport duct 6.

  A specific region or space where the conveying wind in the mower unit 20 in the present invention exists is defined in advance. In the mowing space 8 described above, a lower region below the mowing plane 75 defined by the rotation trajectories of the first blade 72 and the second blade 74 between the first shaft core 71 and the second shaft core 73. This is the air suction area Z1, and the upper area above the mowing plane 75 is the area before cutting grass discharge Z2. A region in the discharge transport channel 90, particularly in the vicinity of the cut grass discharge port 29, is a post-cut grass discharge region Z3. The area obtained by combining the area before cutting grass discharge Z2 and the area after cutting grass discharge Z3 is the cut grass discharge space 9.

  Therefore, the intake section 2 that supplies outside air to the conveying wind at the time of merging or the conveying wind after the merging has an outside air intake opening that opens to the cut grass discharge space 9. Although at least one intake section 2 is sufficient, in the example of FIG. 1, it is provided at a plurality of locations. First, the first intake portion 2 is an intake portion in which the outside air intake port 2 a is a gap created between the front opening edge of the cut grass discharge port 29 and the base end portion of the discharge cover 27. Here, the gap (outside air intake port 2a) extends over almost the entire width of the cut grass discharge port 29, and has a slit-shaped flow cross section that is narrow in the vertical direction. The second air intake portion 2 is an air intake portion whose outside air intake port 2 b is a base end opening provided at the base end portion of the discharge cover 27. The base end opening (outside air intake port 2b) also has a slit-shaped flow cross section extending in substantially the entire width of the cut grass discharge port 29 and having a narrow vertical direction.

  Further, in the example of FIG. 1, an intake portion 2 is also provided in which a plurality of through holes provided in a front-rear row at the center portion in the front-rear direction of the discharge cover function as the outside air intake port 2 c. Further, the intake section 2 can be formed in the blade housing 21 as long as the condition that the outside air can be supplied to the conveying wind at the time of merging or the conveying wind after the merging is satisfied. FIG. 1 (b) also shows an intake portion 2 in which a through hole provided in a portion of the side plate facing the area before the cut grass discharge functions as an outside air intake port 2d. Although not shown in FIG. 1, a flange member may be provided for avoiding the entry of foreign matter into the through hole (outside air intake port 2 d). Similarly, although not shown in FIG. 1, an auxiliary intake portion having an auxiliary intake opening that opens into the mowing space 8 may be formed in the blade housing 21.

  FIG. 2 schematically shows a plan view (FIG. 1A) and a cross-sectional view (FIG. 1B) of a single blade type mower unit 20 having a single blade. The single blade type mower unit 20 also includes a blade housing 21, a cut grass discharge port 29, and a discharge cover 27, similarly to the mower unit 20 described above. In the mower unit 20, the mowing space 8 is a space bounded by the top plate and the side plate hanging from the top plate, and the cut grass discharge port 29 is formed by the cutout of the top plate 21a. In the mowing space 8, the mowing grass discharge area Z2 that is the upper area above the mowing plane 75 defined by the rotation locus of the blade 72, and the mowing grass that is the area near the cutting grass discharge port 29 in the discharge transport channel 90. The cut grass discharge space 9 including the post-discharge area Z3 is defined in the same manner. The discharge cover 27 surrounds the opening edge of the cut grass discharge port 29 and forms a discharge conveyance channel 90 communicating with the grass cutting space 8 through the cut grass discharge port 29. Here, the outside air inlet 2 a of the intake portion 2 is a gap formed between the top plate 21 a of the blade housing 21 and the front edge of the discharge cover 27 that opens into the cut grass discharge space 9. The outside air inlet 2 b of the intake portion 2 is a through hole provided in the discharge cover 27.

  In addition, the single blade type mower unit 20 is provided with a return duct RD in which the conveying air is circulated and the conveying air reaching the grass collecting container is returned to the mowing space 8 again. The open end of the RD is connected to the intake section 2. In the example of FIG. 2, the open end is connected to the outside air inlet 2b of the intake section 2, but it may be connected to the outside air inlet 2a instead. Alternatively, the open end of the return duct RD may be formed in a bifurcated shape so that it can be connected to both the outside air inlet 2a and the outside air inlet 2b. In this way, by flowing the circulating transport air that has circulated through the intake section 2, air is supplied from the intake section 2 with a stronger pressure than normal outside air, and the increase in wind power of the internal transport wind is strengthened. .

  In addition, such a conveying air circulation type can also be adopted in the mower unit 20 illustrated in FIG. 1, and at this time, the open end of the return duct RD is one of the outside air intake ports 2a, 2b, 2c, and 2d. Or connected to some or all of them.

  The mower unit 20 illustrated in FIG. 1 has two blades 72 and 74, and the mower unit 20 illustrated in FIG. 2 has one blade 72, but three or more The present invention is also applicable to the mower unit 20 provided with a blade. Since the cut grass discharge port 29 and the discharge cover 27 are provided at a location where the conveyance air created by the plurality of blades merges, the intake section 2 that supplies outside air to the conveyance air at the time of merging or the conveyance air after the merging is also provided. It can be provided similarly.

Hereinafter, an example of a specific embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is an overall side view of a mid-mount riding mower equipped with a mower unit 20 at the center. As shown in this figure, this riding-type mower is self-propelled by a pair of left and right front wheels 1a that can be steered and a pair of left and right rear wheels 1b that can be driven. A driving section having a driving seat 4a is arranged in the rear half of the body frame 4 of the riding mower. The mower unit 20 is suspended from the vehicle body frame 4 via the link mechanism 10 in the region between the front wheel 1a and the rear wheel 1b.

  The engine 5 is mounted on the front portion of the vehicle body frame 4 via rubber. Below the engine 5, an input shaft 41 that receives the output of the engine 5 via the transmission belt 42 and a power take-out shaft 43 connected to the input shaft 41 are horizontally disposed. Further, the engine power is transmitted from the power take-out shaft 43 to the blade drive mechanism 22 of the mower unit 20 via the rotation shaft 46.

  The link mechanism 10 includes a pair of left and right front swing links 11 that are supported by the vehicle body frame 4 so as to freely swing up and down, a front intermediate link 11a that is connected to the front swing link 11, and a body frame 4 that swings up and down. A pair of left and right rear swing links 12 that are freely supported, a rear intermediate link 12 a connected to the rear swing link 12, and a pair of left and right interlocking links 13 are provided.

  The front end portion of the front swing link 11 is connected to a pair of left and right front connection members 23 located at the front portion of the blade housing 21 of the mower unit 20 via the front intermediate link 11a. The front end portion of the rear swing link 12 is connected to a pair of left and right rear connection members 24 located at the rear portion of the blade housing 21 via an intermediate link 12a. The left interlocking link 13 interlocks the left front swing link 11 and the rear swing link 12, and the right interlock link 13 interlocks the right front swing link 11 and the rear swing link 12. Yes. A lift cylinder 15 is connected to one of the pair of left and right front swing links 11, 11. Furthermore, a pair of left and right fixed links 10 a extending in the front-rear direction are provided so as to connect the rear portion of the blade housing 21 and the rear end of the vehicle body frame 4.

  With the above-described configuration, when one of the front swing links 11 is swing-operated by the lift cylinder 15, the link mechanism 10 swings integrally with the pair of left and right front swing links 11 for interlocking with the rotation support shaft 14. By moving and bending with respect to the front intermediate link 11a, the body frame 4 swings up and down, and at the same time, the pair of left and right rear swing links 12 and the rear intermediate link 12a also swing up and down. As a result, the mower unit 20 operates between a lowered working state in which the ground gauge wheels 25 supported on the front and rear sides of the blade housing 21 are in contact with the ground, and a non-working state in which each ground gauge wheel 25 is lifted from the ground. Go up and down. At that time, the displacement of the mower unit 20 in the front-rear direction is regulated by the fixed link 10a. In other words, the distance between the mower unit 20 and the front wheel 1a is maintained almost constant regardless of the lift position, so that the distance between the mower unit 20 and the front wheel 1a can be reduced.

  As apparent from FIG. 5, a blade unit 70 is disposed inside the blade housing 21 of the mower unit 20. The blade unit 70 of this embodiment is a double blade type including a first blade 72 and a second blade 74 arranged in a transverse direction with respect to the traveling direction. The first blade 72 and the second blade 74 are provided with rotating wind wings that generate wind by rotating. The blade driving mechanism 22 rotates the first blade 72 around the first axial core 71 facing up and down, and the second blade 74 rotates around the second axial core 73.

  When the riding mower travels while driving the blade unit 70 in the lowering work state of the mower unit 20, mowing is performed by the first blade 72 and the second blade 74. The cut mowing grass reaches the discharge cover 27 located at the upper part of the blade housing 21 by the wind generated by the rotation of the first blade 72 and the second blade 74, and is discharged upward and rearward of the vehicle body from the discharge cover 27. .

  The cut grass discharged from the discharge cover 27 is provided by the conveying action by the conveying wind created by the first blade 72 and the second blade 74 and the self-propelled vehicle passing between the left and right rear wheels 1b in the longitudinal direction of the vehicle body. By the guiding action by the transport duct 6, the grass collection container 32 constituting the mowing grass collection device 30 is sent to and collected by the grass collection container 32.

  The mowing grass recovery device 30 includes a link mechanism 33 that connects a support frame 31 connected to the vehicle body frame 4 and a grass collection container 32, and the link mechanism 33 is swung by an elevating cylinder 34, thereby collecting grass. The container 32 is displaced between the descending grass collection position and the ascending discharge position.

Next, the mower unit 20 will be described in detail with reference to FIGS.
The blade housing 21 of the mower unit 20 includes a top plate 21a and a side plate 21b connected to the peripheral edge of the top plate 21a. The mowing space 8 is created by the top plate 21a and the side plate 21b. Here, since the double blade type blade unit 70 is adopted, the mowing space 8 is divided into a first mowing chamber 81 for accommodating the first blade 72 and a second mowing chamber 82 for accommodating the second blade 74. It is divided. The first blade 72 and the second blade 74 are respectively rotatable integrally with a first shaft 71a having a first shaft 71 passing through the top plate 21a of the blade housing 21 and a second shaft 73a having a second shaft 73. It is supported by. The first mowing chamber 81 and the second mowing chamber 82 are formed side by side in the vehicle body lateral direction. The blade drive mechanism 22 includes an input shaft 22a interlocked with the rotary shaft 46, and a bevel gear 22b and a spur gear 22c that transmit power from the input shaft 22a to the first shaft 71a and the second shaft 73a ( (See FIG. 5). In the space of the boundary region between the first mowing chamber 81 and the second mowing chamber 82, the first blade 72 and the first blade 72 are arranged so that the rotational wind generated by the first blade 72 and the second blade 74 merges and flows upward rearward. The rotation direction of the second blade 74 is determined.

  In this embodiment, the boundary region between the first mowing chamber 81 and the second mowing chamber 82, that is, the space between the first shaft core 71 and the second shaft core 73, and the first blade 72 and the second blade 74, The upper region of the rotation trajectory plane is regarded as the above-mentioned region before cutting grass discharge Z2. Further, in the mowing space 8, the region below the rotation locus surface is regarded as the air suction region Z1.

  The top plate 21a is cut out in the longitudinal direction of the vehicle body with a narrower width in the lateral direction of the vehicle body than the area Z2 before the cut grass discharge, and the cut grass discharge port 29 is created. The mowing space 8 composed of the first mowing chamber 81 and the second mowing chamber 82 opens toward the ground on the lower end side of the blade housing 21 and communicates with each other at a central portion of the blade housing 21 in the lateral direction of the vehicle body. Yes. The cut grass discharge port 29 communicates with the first mowing chamber 81 and the second mowing chamber 82. Therefore, the cut grass passes through the cut grass discharge port 29 from the pre-cut grass discharge region Z2 by the air sucked from the air suction region Z1.

  The cut grass that has passed through the cut grass discharge port 29 flows into the post-cut grass discharge area Z3 that is created by the discharge cover 27 and that is the internal space of the discharge cover 27 together with the conveying wind generated by the blade unit 70.

  In this embodiment, as can be understood from FIGS. 5 and 6, and FIGS. 8 and 9, the discharge cover 27 is a lower portion provided by attaching sheet metal to the blade housing 21 on both sides of the cut grass discharge port 29. The structure 50 includes an upper structure 52 connected to a pair of left and right support portions 21 c provided at the front end portion of the blade housing 21 via a connecting piece 52 a via a pivot pin 51. The pair of left and right lower structural members 50 constitute the lower left and right side walls of the discharge cover 27, and the upper structural body 52 constitutes the upper left and right side walls and the top wall of the discharge cover 27. The pair of left and right lower structural members 50 includes rear guide plates 53 that connect lower portions on the rear end sides of each other (see FIG. 6).

  As is apparent from FIGS. 8 and 9, the upper structural body 52 has a two-part configuration in the vehicle body front-rear direction composed of a base end portion 52A and a main body portion 52B. The base end portion 52A is a plate material that is slightly curved in an arch shape, and connecting pieces 52a are fixed to the side portions at both ends. The main body 52B is composed of a pair of left and right lateral plates 52b and a top plate 52c connected to the upper ends of the pair of left and right lateral plates 52b. Further, the upper structure 52 of the discharge cover 27 is supported by the blade housing 21 so as to be swingable up and down around a horizontal shaft that is formed by the left and right horizontal shafts formed by the shafts of a pair of left and right pivot pins 51 and 51. At that time, as shown in FIG. 8, the upper structural body 52 is supported so that a gap is formed between the distal end edge of the base end portion 52A and the upper surface of the top plate 21a. This gap is elongated in a slit shape with substantially the entire width of the discharge cover 27, and functions as an outside air inlet 2 a of the intake portion 2.

  The base end portion 52A and the main body portion 52B constituting the upper structure 52 are such that the rear portion of the base end portion 52A and the front portion of the main body portion 52B are positioned so that the main body portion 52B is on the upper side and the base end portion 52A. Are overlapped so as to form a gap between the upper surface of the main body 52B and the lower surface of the main body 52B, and are joined by welding or bolts at a plurality of appropriate locations. The elongated slit-like gap extending substantially over the entire width of the discharge cover 27 functions as the outside air intake port 2 b of the second intake section 2. That is, the second intake portion 2 is formed by the rear upper surface of the base end portion 52A and the front lower surface of the main body portion 52B. As can be understood from FIG. 10, the outside air inlet 2a is located on the upstream side of the outside air inlet 2b in the cut grass flow direction and is at a lower position. Further, although the lateral lengths of the flow cross sections of the outside air inlet 2a and the outside air inlet 2b are substantially the same, the length of the flow section in the height direction is greater in the outside air inlet 2b than in the outside air inlet 2a. large.

  Due to the structure of the discharge cover 27 described above, the cut grass discharged from the cut grass discharge port 29 is increased in air volume by the outside air sucked from the outside air intake ports 2 a and 2 b of the two intake portions 2 provided in the discharge cover 27. Using the transported air, the fluid is guided backward and upward, and is sent to the transport duct 6.

  In this embodiment, as apparent from FIGS. 8 and 9, a slit-like through hole extending in the vehicle body lateral direction is formed in the top plate 52 c of the main body 52 </ b> B of the upper structure 52, so that the additional air intake 2 A plurality of outside air inlets 2c are arranged side by side in the longitudinal direction of the vehicle body. The outside air inlet 2c is formed by making a U-shaped cut in the top plate 52c of the main body 52B, and bending the elongated tongue created by this cut inward, so that the tongue piece and the remaining top plate 52c It is an opening formed between them. At that time, the tongue piece functions as an air guide surface.

  Furthermore, in this embodiment, as shown in FIG. 10, the fourth intake portion 2 is provided in a portion of the side plate 21 b on the front side of the blade housing 21 near the top plate 21. A curved plate member 21r that is curved in a convex shape toward the corner portion is fixed to most of the corner region formed by the top plate 21a and the side plate 21b of the blade housing 21. Thereby, the surface of the curved plate 21r facing the mowing space 8 becomes a concave curved inner surface, and the mowing grass flows smoothly, so that the clumping of the mowing grass is suppressed. An annular corner space having a substantially triangular cross section is created between the curved plate member 21r, the top plate 21a, and the side plate 21b. Note that, in the front center region of the blade housing 21 shown in FIG. 10, the curved plate material 21r is missing, and an opening in the annular corner space is created at the ends of the curved plate materials 21r on both sides.

  The outside air intake port 21s of the fourth intake section 2 is a through hole provided in the side plate 21b and extending in the lateral direction. The outside air intake port 21s opens to the annular corner space. Therefore, the air that has entered from the outside air inlet 21s passes through the annular corner space, and flows from the opening of the annular corner space into the front area of the area before cutting grass discharge Z2. In FIG. 10, only one outdoor air inlet 21 s is provided with a hook-like cover (saddle member) 200 that hangs downward from the top and covers the outdoor air inlet 21 s. A saddle-shaped cover 200 is prepared at both the outside air inlets 21s. The bowl-shaped cover 200 has an internal shape in which a gap is formed between the lower end edge of the bowl-shaped cover 200 and the side plate 21b, and a communication space is created between the gap and the outside air intake port 21s. The saddle-like cover 200 prevents foreign matter from entering the annular corner space directly from above through the outside air inlet 21s.

  As shown in FIG. 3, the blade housing 21 is supported by a rod-shaped spring holder 55 erected and fixed to the top plate 21 a on both sides of the upper structure 52, and each spring holder 55. And a lifting operation spring 56 formed of a coil spring. Each of the lifting operation springs 56 is configured to be slidably fitted to the spring holder 55 and acts on a spring receiving body (not shown) provided on the side plate 52b (see FIG. 9) of the upper structure 52. The upper structure 52 is urged upwardly around the axis of the pivot pin 51 (see FIG. 8).

  In other words, the discharge cover 27 is configured by the upward biasing by the upward operation spring 56 of the upper structural body 52 regardless of the change in the vertical distance between the blade housing 21 and the transport duct 6 due to the elevation of the mower unit 20 with respect to the self-propelled vehicle body. The rear end side of the body 52 is maintained in contact with the inner surface of the transport duct 6. Accordingly, the cut grass discharged from the cut grass discharge port 29 is sent out to the transport duct 6 so as not to leak from between the discharge cover 27 and the transport duct 6.

  Further, a hook-shaped lock fitting 62 that can be rotated around the fulcrum shaft 61 is attached to the outer surface of the left lower structure 50, and the upper structure 52 is pushed down so that the lock fitting 62 is attached to the spring receiver 57. By locking, the top plate 52c of the upper structure 52 can be maintained in a lowered posture. Thereby, the upper structure 52 can be taken out without interfering with the transport duct 6.

  In this embodiment, as is apparent from FIG. 6, a spare outside air inlet 21d that functions as an outside air inlet of the spare air intake section 2Z is further provided in the top plate 21a. The spare outside air intake port 21d is centered on the second shaft core 73 and the circumferential direction with the diameter of about half the diameter of the first blade 72 centered on the first shaft core 71 of the top plate 21a of the blade housing 21. The second blade 74 is formed in the circumferential direction with a diameter of about ½ of the diameter of the second blade 74. Furthermore, it is important that the spare outside air inlet 21d is positioned so as to open to the mowing space 8 other than the area before cutting grass discharge Z2 in order to avoid competition of the air intake portion 2 having the outside air inlet 2a. . That is, air supply to the conveying wind (air flow) flowing into the post-cut grass discharge area Z3 from the cut grass discharge port 29 is performed through the outside air intake port 2a of the intake section 2.

  An opening degree adjusting tool 35 for adjusting the opening degree of the auxiliary outside air inlet 21d is provided. The opening adjustment tool 35 includes an opening adjustment plate 36 having an opening having the same shape as the auxiliary outside air inlet 21d, a guide hole 37 for determining the opening and closing direction thereof, an operation knob 38 as an operation portion, and a screw. And a fixing bracket 39. Further, a transparent resin cover 58 is provided above the auxiliary outside air inlet 21d, and an operation knob 38 is integrally formed on the cover 58. The cover 58 has an opening adjustment plate in a state where a space of about 1 cm is opened between the upper surface of the opening adjustment plate 36 and the lower surface of the cover 58 so as not to hinder the inflow of air to the spare outside air inlet 21d. It stands from 36. The top plate 21a of the blade housing 21 is provided with a plurality of auxiliary outside air intake ports 21d, and the cover 58 covers the plurality of auxiliary outside air intake ports 21d with an interval upward from the top plate 21a. Thereby, it can prevent that a foreign material permeates from the spare external air inlet 21d.

  Although not provided in this embodiment, the blade housing 21 may be provided with an auxiliary intake portion 2X that plays an auxiliary role of the intake portion 2. Such auxiliary intake parts 2X are listed below.

  (1) The auxiliary intake portions 2X shown in FIG. 11 are provided at both end portions on the front side of the side plate 21b. The lower end regions of both end portions are cut out, and the cut-out portion functions as the auxiliary outside air intake port 21e of the auxiliary intake portion 2X. However, the auxiliary outside air intake port 21e is surrounded by a cover 201 with a hole so that foreign matter or the like is less likely to enter from the auxiliary outside air intake port 21e. The perforated cover 201 has an upper surface portion and a side surface portion, and a slit for air circulation is provided on the upper surface portion. The cover 201 with a hole can create a space in the inside thereof in a state of being screw-connected to the side plate 21b so as to protrude from the side plate 21b. Thereby, the slit of the upper surface portion and the auxiliary outside air intake port 21e communicate with each other, and air circulation between the air suction area Z1 in the mowing space 8 of the blade housing 21 and the outside is enabled.

  (2) The auxiliary intake section 2X shown in FIG. 12 is similar to the auxiliary intake section 2X shown in FIG. Similarly, a notch is provided in the lower end region of the side plate 21b as the auxiliary outside air inlet 21e. However, a slit is not formed in the cover body 202 surrounding the side plate 21b but is formed in a slit shape between the side plate 21b. A recess that creates a gap is formed.

  (3) The auxiliary intake portion 2X shown in FIG. 13 is provided on the rear side surface of the side plate 21b located on the left and right sides with the discharge cover 27 interposed therebetween. Here, U-shaped cuts are made at three locations in the center of the side plate 21b, and an opening is formed between the tongue piece and the remaining side plate 21b by bending the tongue piece created by the cut inward. It is formed. This opening functions as the auxiliary outside air intake port 21f of the auxiliary intake unit 2X here. The tongue piece functions as an air guide surface. The auxiliary outside air inlet 21f is also surrounded by a cover 203 connected to the side plate 21b while maintaining a gap between the surface of the side plate 21b by a bolt and a spacer. As a result, the gap between the side plate 21b and the cover 203 and the auxiliary outside air inlet 21f communicate with each other, and air flow between the mowing space 8 of the blade housing 21 and the outside becomes possible.

  (4) The auxiliary intake portion 2X shown in FIG. 14 is formed in the gap between the gauge wheel bracket 25a for attaching the ground gauge wheel 25 and the top plate 21a of the blade housing. The auxiliary intake port 21g of the auxiliary intake unit 2X is a through hole provided in the top plate 21a that communicates with the gap between the gauge wheel bracket 25a and the top plate 21a. In addition, an auxiliary intake portion 2X in which the notch becomes the auxiliary external air intake port 21e can be provided in the lower end region of the side plate 21b as described in FIG. 12 also around the gauge wheel bracket 25a. The notch (auxiliary outside air inlet 21e) extends to the travel locus region of the ground gauge wheel 25 and can be covered by the cover body 202. This notch (auxiliary outside air intake port 21e) is cut to the height of the blade 72, which improves the posture of the grass to be mowed (does not cut into the ground) and improves the uncut mow. The

  When the blade unit 70 that generates the conveyance air by rotational driving is employed, noise such as blade wind noise or air passing sound at the intake location may increase. Since such noise has a predetermined frequency, it is possible to reduce noise using the principle of active silencing. In other words, the blade housing 21, the discharge cover 27, and the transport duct 6 are provided with a resonator that takes in noise and transmits the half-wavelength of the frequency that matches the frequency of the noise. For example, a U-shaped pipe having an inlet for carrying air (noise) and an outlet for carrying air (noise canceling sound) is attached so that the inlet and the outlet are opened in the carrying air circulation space. The shape of the U-shaped pipe is designed so that the frequency of the carrier air discharged from the outlet is shifted by half a wavelength compared to the frequency of the carrier air taken in at the inlet.

  Although not shown in FIG. 3, as schematically shown in FIG. 15, a cylinder guard 63 is provided on the elevating cylinder 34 that swings the link mechanism 33 of the mowing grass collection device 30. The cylinder guard 63 also has a lock function for locking the extended lift cylinder 34 during maintenance inspection. The cylinder guard 63 includes a rod-shaped guard body 64, a fixing bracket 65, a guide member 66, and a hook 67. The fixed bracket 65 is fixed to the cylinder bracket 34 a that connects the piston of the elevating cylinder 34 to the lower link 33 a of the link mechanism 33. One end of the guard body 64 is fixed to the fixed bracket 65. The guide member 66 has a hole through which the guard body 64 can be inserted, and is fixed to the elevating cylinder 34. The hook 67 has a hole through which the guard body 64 is inserted, and the guard body 64 can slide between the fixed bracket 65 and the guide member 66. The hook 67 is rotatable around the guard body 64, and has a hook arm 67a formed with a hook recess that engages with the piston of the elevating cylinder 34 at a predetermined rotation position. Further, the hook 67 includes a lock pin for fixing the hook 67 to the guard body 64 at a predetermined slide position (here, the position where the lifting cylinder 34 is extended to the maximum). With the above configuration, the cylinder guard 63 protects the piston of the lift cylinder 34 and locks the movement of the lift cylinder 34 by fitting the hook recess of the hook arm 67a into the piston of the lift cylinder 34 extended to the maximum. To do.

  The present invention can be applied not only to a mid-mount riding mower, but also to a front-mount riding mower and a walking mower.

2: Air intake part 2X: Auxiliary air intake part 2Z: Preliminary air intake parts 2a, 2b, 2c, 2d: Outside air intake 6: Transfer duct 8: Mowing space 9: Mowing grass discharge space (area before cutting grass discharging Z2 + after cutting grass discharging) Region Z3)
20: Moor unit 21: Blade housing 21a: Top plate 21b: Side plate 21c: Support portion 21d: Preliminary outside air inlet 21e: Auxiliary outside air inlet 21g: Auxiliary outside air inlet 21g: Auxiliary outside air inlet 21r: Curved plate material 21s: Outside air Inlet 27: Exhaust cover 29: Mowed grass outlet 30: Mowed grass collection device 50: Lower component 51: Pivoting pin 52: Upper component 52A: Base end 52B: Main body 52a: Connecting piece 52b: Side plate 52c : Top plate 53: Rear guide plate 70: Blade unit 71: First shaft core 71a: First shaft 72: First blade 72: First blade 72: Blade 73: Second shaft core 73a: Second shaft 74: First 2 blade 75: mowing plane 81: first mowing chamber 82: second mowing chamber 90: discharge conveyance channel 200: hook-shaped cover 201: cover 2 with a hole 2: Cover 203: Cover RD: return duct Z1: (space below the mowing grass plane) air suction region
Z2: Area before cut grass discharge (between the first axis and the second axis in the space above the cut grass plane)
Z3: Area after cut grass discharge (inside area of discharge cover)

Claims (8)

A first blade that rotates around a first axis extending in the vertical direction and has a rotating wind function, and a second blade that rotates around a second axis extending in the vertical direction and has a rotating wind function And a blade unit in which the first blade and the second blade are arranged side by side in a horizontal direction,
Inside the side plates hanging down from the top plate and the top plate which is formed between the mowing grass discharge port for discharging clippings mowing grass by the blade unit and the first axis and the second axis A blade housing that forms a mowing space for accommodating the blade unit;
A discharge cover that surrounds the opening edge of the cut grass discharge port and forms a discharge conveyance channel that communicates with the grass cutting space through the cut grass discharge port,
Wherein the mowing space, the first axis and the second axis and between a and the first blade and said second blade rotation path to be above the upper area in which cutting grass discharged before mowing plane defined by the a And at least one intake section having an outside air inlet opening into a cut grass discharge space consisting of a region and an area after cut grass discharge that is a region near the cut grass discharge port in the discharge transport channel,
One of the intake portions is a through-hole whose outside air intake port is provided in a central portion in the front-rear direction of the discharge cover,
The mower unit in which the said through-hole is provided with the tongue piece which overlaps with the said through-hole by planar view . 2. The mower unit according to claim 1, wherein the tongue piece is an air guide surface with a top end of the discharge cover as a base end and a distal end entering the discharge conveyance channel side with respect to the top plate . The guide end of the air guide surface from the base end to the tip end of the tongue piece is along the flow direction of the discharge transfer passage, and the tip end of the tongue piece enters the discharge transfer passage. The mower unit according to 2 . The said through-hole is a slit-like through-hole extended in the vehicle body horizontal direction in the top plate of the said discharge cover, The said tongue piece has the same width as the said through-hole in the vehicle body horizontal direction, The any one of Claim 1 to 3 The mower unit according to one item. The mower unit according to any one of claims 1 to 4, wherein a plurality of the through holes are arranged side by side in the longitudinal direction of the vehicle body . Another one of the air intake portions is a gap in which the outside air intake port opens forwardly created between a front opening edge of the cut grass discharge port and a base end portion of the discharge cover, or the discharge cover The mower unit according to any one of claims 1 to 5, wherein the mower unit is a base end opening provided at a base end portion of the base end portion, or both of them. The mower unit according to claim 6, wherein the gap or the base end opening is provided at a position overlapping the rotation locus of the first blade or the rotation locus of the second blade in plan view. 8. The air intake according to claim 1, wherein the air intake port is a through hole provided in a portion of the side plate of the blade housing facing the area before the cut grass discharge. The mower unit described in.

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