JPH0687699B2 - Mower cutter blade mounting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a mower cutter blade mounting device.

(Prior Art) As a cutter blade attachment device for various mowers, there is one disclosed in, for example, Japanese Utility Model Laid-Open No. 59-6440. In this attachment device, a blade receiver is spline-coupled to a spline shaft portion at a lower end portion of a rotating shaft, and a cutter blade is fitted to the spline shaft portion below the blade receiver so as to be rotatable relative to the rotary shaft. The cutter blade is pressed and fixed to the lower surface of the blade receiver via a disc spring by a fastener screwed to the lower end of the blade.

(Problems to be solved by the invention) In cutting work such as lawn, if the rotating cutter blade hits an obstacle such as a stone, the cutter blade and the rotating shaft relatively move against the pressing load of the disc spring. Rotate to absorb the impact.

However, conventionally, since the disc spring is directly in contact with the head of the fastener, when the disc spring relatively rotates together with the cutter blade, the rotational torque acts on the fastener. Therefore, the fastener may rotate together in the tightening direction or the loosening direction, the tightening force of the fastener may change, and the fastener may become unremovable.

In view of the conventional problems, the present invention provides a cutter blade attachment device that can prevent the tightening tool from rotating together.

(Means for Solving the Problem) According to the present invention, the blade receiver 53 is spline-coupled to the spline shaft portion 56 at the lower end of the rotary shaft 9, and the spline shaft portion 56 is provided below the blade receiver 53. Cutter blade 10
Are rotatably fitted relative to each other, and the disc spring 49 is pressed against the lower surface of the cutter blade 10 and the cutter blade 10 is pressed and fixed onto the lower surface of the blade receiver 53 by a fastener 58 screwed to the lower end of the rotary shaft 9. In the cutter blade mounting device for the mower, a collar 47 which is fitted into the disc spring 49 so as to be relatively rotatable is spline-coupled to the lower end of the spline shaft portion 56, and the collar 47 has a head of a fastener 58. A pressing portion 48 that is in contact with 51 and presses the disc spring 49 from below is provided.

(Operation) Since the collar 47 having the pressing portion 48 for pressing the disc spring 49 from below is spline-coupled to the spline shaft portion 56 of the rotary shaft 9, the cutter blade 10 and the disc spring 49 are opposed to the rotary shaft 9. Even if it rotates, the fastener 58 does not rotate together. Further, since the collar 47 is between the cutter blade 10 and the head 51 of the fastener 58 and is not fitted inside the cutter blade 10, the hole of the cutter blade 10 can be made small, and therefore the periphery of the hole of the cutter blade 10 can be obtained. Breakage at parts is reduced.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
In FIG. 2 and FIG. 2, reference numeral 1 denotes a vehicle body, which is a front wheel 2 and a rear wheel 3.
Have. 4 is a steering wheel, 5 is a driver's seat, and 6 is a grass container.

Reference numeral 7 denotes a front mower, which is mounted in front of the vehicle body 1 via a link mechanism and can travel following the ground by a gauge wheel. The mower 7 has a mower deck 8 having a mountain shape in plan view, and three cutter blades 10 supported by the mower deck 8 via a vertical rotation shaft 9. The cutter blades 10 are driven by the power transmitted from the vehicle body 1 to the gear case 11 side on the mower deck 8 via a universal joint shaft (not shown) and rotate in the directions of the arrows. At the rear end of the mower deck 8, a discharge port 12 for discharging the grass cut by the cutter blade 10 rearward,
An opening / closing plate 13 for opening / closing the discharge port 12 is provided. As shown in FIG. 4, the opening / closing plate 13 has a pivot 14 at the upper end side.
It is pivotally supported in an openable and closable manner by and is biased in a closed state by a spiral spring 15a.

A feeding device 15 is mounted on the mower deck 8 between the three cutter blades 10 and the discharge port 12 at the rear end. The feeding device 15 has a casing 17 mounted corresponding to the opening 16 of the mower deck 8 and a plurality of blades 19 provided on a disc 18 in the casing 17, and the blade 19
Rotate to suck the grass through the opening 16
The grass is forcibly fed into the grass container 6 from a duct 20 tangentially connected to the grass. Disk 18 is the axis of rotation
It is attached to the lower end of 21, and this rotary shaft 21 has pulleys 22,23,
It is interlockingly connected to the rotary shaft 9 via a drive system including a belt 24. As shown in FIG. 3, the belt 24 has a support shaft 25.
Tension arm pivotally supported on the mower deck 8 by
Twenty-six pulleys 27 are provided so as to be able to come into contact with and separate from each other, and the tension arm 26 is urged by a spring 28 so that the pulley 27 comes into pressure contact with the belt 24. Tension arm 26 is Bowden wire
It is connected to the clutch operating lever (clutch operating system) 30 via 29, and therefore the tension arm 26 and the pulley 27 are connected.
The tension clutch 31 is configured by the above. The operation lever 30 is arranged on one side of the driver's seat 5 on the vehicle body 1,
As shown in FIG. 3, it is pivotally supported by a pivot shaft 32 so as to be swingable back and forth, and engaged with engagement portions 34, 35 formed on a guide plate 33 at an engagement position A and a disengagement position B of the clutch. It can be stopped. Further, the operation lever 30 is connected to the bracket 37 of the opening / closing plate 13 via the Bowden wire 36, and the clutch 31
The opening / closing plate 13 can be opened / closed by the operation lever 30 so that the opening / closing plate 13 is closed when the clutch is connected and is opened when the clutch 31 is disconnected. The Bowden wires 29 and 36 are
It has inners 38, 39 and outers 40, 41, and outers 40, 4
One end of 1 is fixed to the vehicle body 1 side by a metal fitting 42, and the other end is fixed to the mower deck 8 side by metal fittings 43 and 44.

The attachment device of the cutter blade 10 to the rotating shaft 9 is as shown in FIG. As shown in FIG. 5, the rotating shaft 9 is rotatably supported by a bearing case 54 mounted on the mower deck 8 via a ball bearing 55. The rotary shaft 9 has a spline shaft portion 56 at its lower end, and a blade receiver 53 which is fitted in the bearing case 54 so as to be rotatable relative to the spline shaft portion 56 is spline-coupled and fixed by a snap ring. .

The cutter blade 10 has a mounting hole 57, and the spline shaft portion 56 is inserted into the mounting hole 57 so as to be relatively rotatable. A bolt 58 as a fastener is screwed to the lower end of the spline shaft portion 56, and two disc springs 49 and a collar 47 are interposed between the head 51 of the bolt 58 and the cutter blade 10. Has been done. The collar 47 is spline-coupled to the spline shaft portion 56, and a pressing portion 48 for pressing the disc spring 49 from below is integrally formed in a brim shape. Therefore, the spline shaft 56
When the bolt 58 is fastened to the head 58 of the bolt 58, the holding portion 48 of the collar 47, which is in contact with the head 51 of the bolt 58, presses the disc spring 49 so that the disc spring 49 can rotate relative to the plate spring 49. The receiving surface 45 of the receiving body 53 is rotatably pressed from below, whereby the cutter blade 10 is attached to the spline shaft portion 56.

In the above-mentioned configuration, when cutting grass, etc., each cutter blade 10 of the mower 7 is driven by power from the vehicle body 1 side.
While being rotated in the direction of the arrow, the mower 7 follows the ground and runs. Then, the grass mowed by the cutter blade 10 is sent to the rear side of the mower deck 8.

At this time, if the operation lever 30 is set to the entry position A,
Since the blades 19 of the feeding device 15 rotate and the opening / closing plate 13 is in the closed state, the grass is sucked into the feeding device 15 through the opening 16,
It is sent to the grass container 6 via the duct 20, and
Simultaneously with mowing, the grass can be collected in sequence.

Further, if the operation lever 30 is set to the cut position B, the feeding device 15 is stopped and the opening / closing plate 13 opens rearward as shown by a virtual line against the spring 15a. Is directly discharged from the discharge port 12 to the ground behind.

If the cutter blade 10 contacts an obstacle such as a stone during the mowing operation, the cutter blade 10 resists the pressing load of the disc spring 49.
10 rotates relatively around the rotating shaft 9. At this time, Belleville
Even if 49 rotates together with the cutter blade 10, the disc spring 49 is held by the holding portion 48 of the collar 47 splined to the spline shaft portion 56, so that the turning torque is transmitted to the head 51 of the bolt 58. Instead, the bolt 58 can be prevented from turning together.
Therefore, the tightening force of the bolt 58 does not change, the load when the cutter blade 10 rotates can be made substantially constant, and the bolt 58 can be easily removed even when the cutter blade 10 is replaced. Color 47 is a cutter blade
Between the 10 and the head 51 of the bolt 58, the cutter blade
Since it is not fitted inside the mounting hole 57 of 10, the cutter blade
The mounting hole 57 of 10 can be made smaller according to the spline shaft portion 56 of the rotary shaft 9. Therefore, the mounting hole 57 of the cutter blade 10
The strength of the periphery is increased, and breakage of the cutter blade 10 at the periphery of the mounting hole 57 can be reduced.

(Effect of the Invention) According to the present invention, a disc spring 49 is provided at the lower end of the spline shaft portion 56.
A collar 47 which is fitted in a relatively rotatable manner is spline-coupled to the collar 47, and this collar 47 is provided with a holding portion 48 that is in contact with the head 51 of the fastener 58 and presses the disc spring 49 from below. Therefore, the cutter blade 10 contacts the obstacle and the rotating shaft 9
Even if the disc spring 49 rotates together with the disc spring 49, the torque of the disc spring 49 is cut off by the collar 47 and tightened.
Since it is not transmitted to the head 51 of 58, over-tightening or loosening of the fastener 58 can be prevented. Also, color 47 is a cutter blade
Since it is not fitted inside 10, the mounting hole for cutter blade 10
57 can be made smaller and cutter blades around the hole
10 breakage etc. can be reduced.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a sectional side view,
2 is a plan view, FIG. 3 is a configuration diagram of a main part, FIG. 4 is a cross-sectional view of the opening / closing plate pivotally supporting portion, and FIG. 5 is a cross-sectional view of a cutter blade attaching device. 9 …… Rotary axis, 10 …… Cutter blade, 47 …… Color, 48 …… Holder, 49 …… Disc spring, 51 …… Head, 56 ……
Spline shaft, 58 …… Bolt (fastener).

Claims (1)

[Claims] 1. A blade receiver (53) is splined to a spline shaft portion (56) at a lower end portion of a rotating shaft (9), and the spline shaft portion (56) is below the blade receiver (53). ), The cutter blade (10) is relatively rotatably fitted, and the disc spring (49) is pressed against the lower surface of the cutter blade (10) by the fastener (58) screwed to the lower end of the rotating shaft (9). And the cutter blade (10) is attached to the blade receiver (5
In the mower cutter blade mounting device that is pressed and fixed to the lower surface of 3), a collar (47) that is relatively rotatably fitted in the disc spring (49) is spline-coupled to the lower end of the spline shaft portion (56). The collar (47) is provided with a holding portion (48) which is in contact with the head portion (51) of the fastening tool (58) and presses the disc spring (49) from below. A mower cutter blade mounting device.