JPH04158713A - Rear discharge type cutter housing of lawn mower - Google Patents

Abstract

PURPOSE:To arrange right and left discharge flows for discharging mowed grass by disposing discharge scroll guide plates in a specific state from positions around right and left blade-rotating shafts to rear discharging openings. CONSTITUTION:Scroll guide plates 35 for discharging mowed grass are disposed under the upper wall of a cutter housing, and approximately cylindrical members 36,36 disposed inside the inner rotation tracks of the mowing blades 23, 23, approximately straight line members 37, 37 and grass-discharging dividing plates 39, 39 are responded to the rotation directions R, R of the right and left blades, respectively.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a rear discharge type cutter housing for a lawn mower, and more particularly, the present invention relates to a rear discharge type cutter housing for a lawn mower, and in particular, the cutter housing is provided at the bottom of a substantially vertical rotating shaft and rotates substantially horizontally. This is a cutter housing in which two cutter housings are arranged side by side in the direction and a discharge port is opened in the rear wall, and the cutter housing hangs from the vicinity of the left and right rotational shafts to the center of the lateral force circuit inside the common discharge port provided at the rear. This invention relates to a scroll guide plate for discharge.

[Prior Art] In a lawn mower equipped with this kind of rear discharge type cutter housing, the blade rotation direction on the right side in the direction of travel is clockwise in plan view, and the blade rotation direction on the left side in the direction of travel is counterclockwise in plan view. U.S. Patent No. 3,157
, 014 and Japanese Unexamined Patent Publication No. 129907/1983.

The device shown in the specification of US Pat. No. 3,157,014 has independent left and right discharge ports at the rear of the cutter housing, and
In the device disclosed in Japanese Patent No. 907, the inside of a common discharge port is divided into left and right sides by partition plates.

[Problem to be Solved by the Invention] For example, as shown in FIG. 5, when mowing the lawn by moving the lawnmower forward (in the direction of arrow F) using the left and right cutter blades b and b housed in the cutter housing h, Considering, the left and right front wheels f.

The grass is trodden at f and falls forward as shown in FIG. 6, after which the grass is mowed by the cutting blades C1C of the cutter blades b and b.

When the cutting blade C of the cutter blade b passes in the forward direction r, which is the same as the advancing direction F, as shown in Fig. 7, the grass is further laid down by the wind caused by the rotation of the blade Therefore, by rotating the cutter blade b in the backward direction R opposite to this, the fallen grass is raised from the front by the wind generated by the rotation of the blade and can be cut by the cutting blade C, resulting in a better finish.

Therefore, as shown in FIG. 5, it is preferable that the blade rotation direction R on the right side of the traveling direction F is clockwise, and the blade rotation direction R on the left side of the traveling direction F is counterclockwise.

When the blade rotation direction is set as described above, the discharge performance can be improved by forming independent left and right discharge passages in the cutter housing.

However, as mentioned above, in the past, independent outlets were provided on the left and right sides of the rear part of the cutter housing, or the common outlet was divided into left and right sides by partition plates. However, it was not possible to obtain an independent discharge function corresponding to the direction of rotation of the left and right plates, and the grass from the left and right sides interfered with each other in front of the discharge port.

Therefore, an object of the present invention is to provide a lawn mower that reliably cuts the grass that has been stepped forward by one wheel with the left and right cutter blades, and that also provides a lawn mower that is capable of reliably cutting the grass that has fallen forward due to being stepped on by one wheel. To provide a rear discharge type cutter housing capable of providing independent discharge functions corresponding to left and right plate rotation directions within a common discharge port provided rearward from the periphery.

[Means for Solving the Problems] To solve the above-mentioned problems, the present invention has two cutter blades installed in a lower part of a substantially vertical rotating shaft and rotating substantially horizontally, which are housed side by side in a substantially horizontal direction. Equipped with a cutter housing,
In this rear discharge type lawn mower having a discharge port opened in the rear wall of the cutter housing, the rotation direction of the cutter blade on the right side in the direction of travel is clockwise in plan view, and the rotation direction of the cutter blade on the left side in the direction of travel is clockwise. As viewed counterclockwise in a plan view, the upper wall of the cutter housing i′i″if includes left and right substantially cylindrical portions that hang down around the left and right rotational axes, respectively, and a lateral force circuit center in the discharge port. A discharge outlet formed by continuously forming a discharge opening partitioning part that hangs down from the discharge opening partition part, and left and right substantially linear parts respectively hanging between the front part of the discharge opening partition part and the outer rear part of each of the left and right substantially cylindrical parts. The feature is that a scroll guide plate is provided.

More specifically, each of the left and right cutter blades is arranged so that the cutter blades are aligned in the front-rear direction, and their respective rotation trajectories overlap approximately the center line in the lateral direction of the cutter housing, In the scroll guide plate, the left and right substantially linear parts have different lengths in the front-rear direction, and the discharge opening partition part is located behind the intersection of the extension lines in the respective length directions. The continuous portion between the rear portion of each substantially linear portion and the front portion of the discharge port partition portion is a smooth curved portion.

[Operations] First, in plan view, the rotation direction of the blade on the right side of the direction of travel is clockwise, and the direction of rotation of the blade on the left side of the direction of travel is counterclockwise. This allows you to reap each crop reliably.

The upper wall of the cutter housing has a discharge scroll guide plate that hangs down from the vicinity of the left and right blade rotation shafts to the rear discharge port, that is, the left and right approximately cylindrical parts around the left and right rotation shafts. , the discharge opening partition part in the horizontal direction substantially central part within the discharge opening, and the left and right substantially linear parts between the front part of this discharge opening partition part and the outer rear part of each of the left and right substantially cylindrical parts are connected continuously. Since a discharging scroll guide plate is provided inside the cutter housing, an independent discharging function can be obtained from the vicinity of the left and right blade rotation axes to the common discharge port in correspondence with the left and right blade rotation directions. .

By arranging the positions of the left and right plates in the front-rear direction so that their respective rotation trajectories overlap the approximate center line of the housing in the lateral direction, no uncut material is left between the left and right blades.

Moreover, in the case of this blade arrangement, the lengths of the left and right approximately linear parts of the discharge scroll guide plate are different in the front-rear direction, and the force of the discharge flow from the shorter side is greater than that from the side with a longer distance to the discharge port. is strong and this has a negative effect on the discharge of the long side, or it can be eliminated by the discharge port partition.

Then, the discharge opening partition section is positioned behind the intersection of the extension lines in the length direction of the left and right substantially straight sections having different lengths, and the front part thereof is connected to the rear part of the left and right substantially straight sections. By connecting them with smooth curved portions, the left and right discharge flows can be rectified, respectively, and good discharge can be achieved.

[Example] Examples will be described below based on the accompanying drawings.

In FIG. 1 showing a rear discharge type lawn mower as an example to which the present invention is applied, 1 is a riding lawn mower, and 10 is a cutter housing.

The riding lawn mower 1 is equipped with an engine 2 at the front, a handle 3, a seat 4, left and right front wheels 5, 5, and rear wheels 6.6, and a front and rear parallel link 7 below the approximate center of the vehicle body. .7.
The cutter housing 10 is supported via 8.

As shown in FIGS. 2 to 4, the cutter housing 1
0 from the top wall 11 to the front wall 12 and the left and right side walls 1
3, 14, the rear wall part 15 is hung down and opened downward, and the rear wall part 15 has a discharge port 16 that protrudes rearward at approximately the center in the lateral direction and opens between the left and right rear wheels 6, 6. are doing.

A chute 18 is connected to this discharge port 16, and the chute 1
A glass bag 19 is connected to the rear of the bag 8.

Inside this cutter housing 10, two left and right rotating shafts 21.21 are disposed passing through the upper wall portion 11 thereof. Rotational driving force is transmitted from the belt pulley device 40, which will be described later.

A cutter blade 22 is attached at the center to the lower end of the rotating shaft 21, and the cutter blade 22 has a cutting blade 23 and a substantially upwardly rising portion 24 at both ends thereof.

Here, the left and right cutter blades 22,22 are arranged so that their respective rotational trajectories are close to each other and are shifted back and forth so as to overlap the left and right center line C of the cutter housing 10. As a result, both power vine plate 2
2. Only uncut areas are left between 2 and 22 hours.

Also, the cutter housing 100 is provided with a pair of front and rear anti-skull rollers 25° 25 on both side walls of the cutter housing 100. The height is adjusted via the link 27 by a swinging operation. 28 is a lever locking plate that restricts the lever 26 to an arbitrary swinging position.

The rotation direction of each cutter blade 22.22 on the left and right with respect to the direction of movement shown by arrow F is as shown by arrow R in plan view, the rotation direction of the right blade is clockwise, and the rotation direction of the left blade is counterclockwise. It is clockwise.

Therefore, the grass that has been stepped on by the left and right front wheels 5.5 and has fallen forward can be moved by positioning each rotating shaft 21, 21 inside the front widths 5, 5, so that the respective rotational trajectories of the grass are The left and right cutter blades 22.2 pass along the travel trajectory of .5.
2 rotation, it is raised from the front by the wind blowing action of the substantially upright portions 24, and the cutting blades 23 can reliably cut the grass.

In addition, in the cutter housing 10, the front wall portion 1 of the cutter housing 10 is
A substantially triangular space is formed between the cutter blades 22 and the respective rotation loci of the left and right cutter blades 22.22. The left and right separator plates 31, 31, which partition this space from the rear and form a scroll, are connected to the cutter housing upper wall 1.
1, the left and right double-handed twine blades 22, 22 are formed to hang substantially close to the outside of each rotation locus. The two separator plates 31,31 are continuous with each other and connected to the front wall 12 of the cutter housing.

Therefore, in the front part, the wind flow by the cutter blades 22, 22 rotating in opposite directions outwards from each other is directed outward from the continuous base point A in front of the two separator plates 31, 31 in the front part. It can be rectified on both the left and right sides.

Furthermore, discharge passage bulges 17.17 are formed on both left and right sides of the upper wall portion 11 of the cutter housing, and are gradually raised from the front toward the rear discharge port 16. This bulging part 17.17 for both the multiple outlet passages is continuous at the upper part of the outlet 16, and the part of this outlet 016 is the highest. Bulging part 1
The part surrounded by 7.17 is a low flat part 11a.

Therefore, both the left and right forces are exerted on both the outer and rear parts.
In accordance with the rotational direction R, R of the blades 22.22, left and right discharge passages are obtained whose upper surfaces gradually become higher and the cross-sectional area becomes larger. via glass bag 19
Lawn grass can be efficiently accumulated and stored inside.

The heel-boot device 40 also includes a drive pulley 41 attached to the lower part of the output shaft 2a that protrudes from the lower surface of the engine 2 and faces the lower front of the vehicle body, and a cutter housing upper wall portion 1.
Driven pulleys 42, 42 are attached to the upper portions of the left and right rotating shafts 21.21, which protrude above the low plane portion 11a surrounded by the bulging portions 17.17 for the exit passages 17. Two tension pulleys 43 and 44, front and rear, and an idler pulley 45 whose axis is inclined, which is disposed behind them.
It is composed of one double-sided V-belt 46 wrapped around all of the above-mentioned boots.

In this way, on the cutter housing 10, the discharge passage bulges 17.17 are formed on the left and right sides of the upper wall portion 11.
Using the space S on the low flat part 11a between the blades, driving force is transmitted from the engine 2 at the front of the vehicle body to the two left and right blade rotating shafts 21, 21 that rotate in reverse using one double-sided V-belt 46. Since the belt booby device 40 is arranged and stored, there is no need to increase the ground clearance of the vehicle body so much even though the discharge passage bulge 17.17 is not provided on the upper wall portion 11 of the cutter housing. Therefore, miniaturization can be maintained.

Inside the cutter housing 10, a discharge scroll guide plate 35 is provided that extends from the vicinity of each of the left and right rotating shafts 21, 21 to the center of the rear discharge port 16.

That is, the discharge scroll guide plate 35 is suspended from the upper wall portion 11 of the cutter housing, and is located above each cutter blade 22, 22, and is connected to the cutting blades 23, 23.
The left and right substantially cylindrical portions 36 facing inward from the inner rotation locus of.
36, approximately linear portions 37.38 of different lengths on the left and right sides, which are continuous to the outer rear part of each of the approximately cylindrical portions 36.36 and have an intersection point B of the extended line on the left and right center line C at the rear, respectively; The intersection B is continuous to the rear of each of the substantially linear parts 37 and
Further rearward, left and right discharge port partitions 39 and 39 are connected to each other and partition the inside of the discharge port 16 into left and right parts at the center. The front part of each discharge port partition part 39.39 is a curved part 39a, 39a that smoothly continues to the rear part of each substantially straight part 37.38.

Note that the discharge scroll guide plate 35 may be integrally molded with the cutter housing 10.

In this way, the discharging scroll guide plate 35 is formed in the cutter housing 10, extending from the vicinity of the left and right rotational shafts 21, 21 into the discharging port 16 and hanging from the upper wall portion 11, so that the following effects can be achieved. Obtainable.

That is, in the vicinity of each rotating shaft 21.21, left and right substantially cylindrical portions 36.36 are located above each cutter blade 22.22 and face inward from the inner rotation locus of the cutting blade 23.2B.
and a discharge port partition portion 3 located approximately in the center of the discharge port 16 in the horizontal direction.
9, and the left and right substantially linear portions 3 between the front portion of this discharge port partition portion 39 and the outer rear portions of the left and right substantially cylindrical portions 36 and 36.
7. Scroll guide plate 3 for discharging which is continuous with 38
5, inside the cutter housing 10, the cutting blades 23, 2 of each cutter blade 22° 22 correspond to the left and right blade rotation directions R, R, respectively.
The lawn grass cut by 3 is passed from the outer circumferential surface of each substantially cylindrical part 36, 36 above the rotation trajectory to each substantially straight part 37, 36, respectively.
38 to the left and right outer surfaces of the partition part 39, an independent discharge passage can be formed on the left and right sides, and therefore the discharge performance can be improved by the left and right independent discharge functions. There is.

Here, in the embodiment, the left and right cutter blades 22, 22 are
are shifted in the front-rear direction, and their respective rotation trajectories overlap the left and right center line C of the cutter housing 10. In such a blade arrangement, each of the left and right substantially linear portions of the discharge scroll guide plate 35 37 and 38 have different lengths in the front-back direction, and the discharge flow is along the outer surface of the left substantially linear portion 38 where the distance to the discharge port 16 is long.
The force of the discharge flow along the outer surface of the short right-hand substantially linear portion 37 is strong, and if the partition portion 39 is not provided, the discharge from the long left-hand substantially linear portion 38 will be adversely affected. This problem can be solved by the discharge port partition part 39.

Further, as described above, the left and right substantially linear portions 37 have different lengths.
The discharge opening partition part 39 is located behind the intersection point B of the extension lines in the length direction of 38, and the front part thereof and the rear part of each of the left and right substantially linear parts 37 and 38 are formed into smooth curved parts. 39a
, 39a, each substantially linear portion 37
．． When reaching the left and right outer surfaces of the partition portion 39 through the outer peripheral surface of the partition portion 38, the left and right discharge streams are rectified along the outer surfaces of the respective curved portions 39a, 39a, so that there is no grass clogging. Good release takes place.

Therefore, as described above, the lawn grass cut by the left and right cutter blades 22 and 22 is efficiently delivered to the chute 18 from the respective discharge ports 16 by the left and right independent discharge passages defined by the discharge scroll guide plate 35 without interfering with each other. It can be stored in the glass bag 19 via the glass bag 19.

In the embodiment, an integrated type with a glass bag provided at the rear of the vehicle body is used, but the present invention is not limited to this, and a type without the glass bag may be used. Further, the lawn mower may be another tractor or a walking type lawn mower.

[Effects of the Invention] As described above, according to the present invention, in the rear discharge type cutter housing, the rotating direction of the blade on the right side of the traveling direction is clockwise in plan view, and the rotating direction of the blade on the left side of the traveling direction is counterclockwise in plan view. Therefore, grass that has been stepped on by the front wheels and tipped forward can be reliably cut by the left and right cutter blades, respectively, improving the finishing quality. Since a discharging scroll guide plate is provided that hangs down from the inside of the discharge port at the rear, inside the cutter housing, it is possible to independently extend from the vicinity of the left and right blade rotation axes into the common discharge port, corresponding to the rotation direction of the left and right blades. Therefore, the release performance can be improved.

Furthermore, if the positions of the left and right blades are shifted in the front-rear direction as described in claim 2, and their respective rotation trajectories are overlapped with the approximate center line of the housing in the lateral direction, uncut areas will not be left between the left and right blades. In the case of the blade arrangement, the lengths of the left and right substantially linear parts of the discharge scroll guide plate are different in the front-rear direction, and the force of the discharge flow from the short side is stronger than the longer distance to the discharge port. This has a negative effect on the discharge of the longer side, but this can be resolved by the discharge port partition. If the front part and the rear part of each of the left and right substantially linear parts are connected by a smooth curved part, the left and right discharge flows can be rectified, respectively, and good discharge can be performed.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view showing a rear discharge type lawn mower as an example of the present invention, Fig. 2 is a partially cutaway enlarged side view showing the cutter housing, belt boob device, etc., and Fig. 3 is 4 is a cross-sectional plan view of the interior of the cutter housing, FIG. 5 is an explanatory diagram showing the running trajectory of the front wheel and the direction of rotation of the blade, FIG. 6 is an explanatory diagram showing the falling of grass by the front wheel, and FIG. FIG. 2 is an explanatory diagram showing the direction in which the blade passes through the grass in a state of falling forward. DESCRIPTION OF SYMBOLS 1... Lawn mower, 6... Front wheel, 10... Cutter housing, 11... Upper wall part, 15... Rear wall part, 16
...Discharge port, 21... Rotating shaft, 22... Cutter blade, 35... Discharge scroll guide plate, 36
...Substantially cylindrical part, 37.38...Substantially linear part, 39
...Discharge port partition part, 39a...Curved shape part.

Claims (2)

[Claims] (1) A cutter housing is provided, in which two cutter blades that are installed at the bottom of a substantially vertical rotating shaft and rotate substantially horizontally are housed in parallel, and a discharge port is opened in the rear wall of the cutter housing. In a rear discharge type lawn mower, the rotation direction of the cutter blade on the right side in the direction of travel is clockwise in plan view, and the rotation direction of the cutter blade on the left side in the direction of travel is counterclockwise in plan view, and the upper wall of the cutter housing is The left and right substantially cylindrical portions respectively hang around the left and right rotational shafts, a discharge port partition portion that hangs down approximately at the center in the lateral direction within the discharge port, and a front portion of the discharge port partition portion. and the outer rear parts of the left and right substantially cylindrical parts, respectively, and a discharge scroll guide plate that is continuous with left and right substantially linear parts that hang down, respectively. cutter housing. (2) The left and right cutter blades are shifted in position in the front-rear direction, and are arranged so that their respective rotation trajectories overlap approximately the horizontal center line of the cutter housing, and the discharge scroll guide plate The left and right substantially linear portions have different lengths in the front-back direction, and the discharge port partition portion is located behind the intersection of the extension lines in the respective length directions, and each of the left and right substantially linear portions 2. The rear discharge type cutter housing for a lawn mower according to claim 1, wherein a continuous portion between the rear portion of the cutter housing and the front portion of the discharge opening partition portion is a smoothly curved portion.