JPS606185Y2 - Mower shock mitigation device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a shock absorbing device for a mower, which alleviates the shock when an overload is applied to a cutter by sliding between the cutter and the cutter shaft, and also controls the adjustment of the shock by sliding between the cutter and the cutter shaft. This can be done easily from above.

A mower has a cutter shaft mounted on a mower deck so as to be rotatable around a vertical axis, and has a drive pulley at the upper end of the cutter shaft and a cutter at the lower end, which are connected to the drive pulley via a winding transmission mechanism such as a belt. This power is used to drive the cutter around the cutter axis.

In this type of mower, when an overload occurs due to the cutter coming into contact with an obstacle, etc., the cutter was conventionally fixed to the cutter shaft, so the impact was transmitted through the cutter shaft and drive pulley to the winding transmission mechanism. There have been problems such as belts breaking due to abnormal tension or gears in the drive system being damaged.

The present invention solves these conventional problems, and its feature is that a cutter is provided at the lower end of a cutter shaft that is rotatably supported around the vertical axis of the mower deck. In a cutting mower, the cutter is rotatable relative to the cutter shaft, and a tightening bolt that elastically tightens the cutter with respect to the cutter shaft is passed through the cutter shaft in the vertical direction, and the tightening bolt protrudes. This is because an adjustment nut is screwed onto the part.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
In the figure, 1 is a tractor body, 2 is a front wheel, and 3 is a rear wheel.

4 is a midmount mower, mower deck 5,
A plurality of cutters 7 are attached to the mower deck 5 via a cutter shaft 6, and gauge wheels 8 for regulating the cutting height are arranged at the front and rear of the mower deck 5. It is attached to the lower abdomen of the tractor body 1 so as to be movable up and down.

The gauge wheel 8 can be adjusted up and down by an adjustment lever 10.

11 is a front power take-off device;
The cutter shaft 6 is configured to be driven from the drive shaft 12 through a belt transmission mechanism 13.

As shown in FIG.
5.16, it is rotatably supported.

The cutter shaft 6 has a spline portion 17 at its upper end and a tapered portion 18 at its lower end. A mounting boss 20 of a drive pulley 19 is fixed to the spline portion 17 by spline fitting. A cutter receiver 21 that receives the cutter 7 is tapered and fitted through the tapered hole 22.

A wrap prevention wall 23 for preventing grass etc. from wrapping around the cutter receiver 21 is formed so as to fit loosely into the lower end of the bearing case 14, and a sintered alloy or the like is formed on the flat surface of the lower end. A wear-resistant material 24 is attached in the form of a thin plate.

A tightening bolt 25 is inserted concentrically from below into the through hole 26 of the cutter shaft 6, and a friction washer 28 is interposed between the head 27 of the tightening bolt 25 and the cutter receiver 21.

As shown in FIG. 3, the friction washer 28 has a flange 29 and a spline-shaped engagement boss 30, and a wear-resistant material 31 such as a sintered alloy is attached to the flange 29 so as to be in sliding contact with the cutter 7. In addition, the engagement boss portion 30 is engaged with a corresponding engagement recess 32 formed in the cutter receiver 21 so as not to be relatively rotatable, and a collar 33 is interposed between the engagement boss portion 30 and the cutter 7 so as to be relatively rotatable.

The tightening bolt 25 has a threaded portion 34 at its upper end, into which an adjusting nut 35 and a locking nut 36 are screwed.

A washer 37, a coil spring 38, and a washer 39 are interposed between the adjustment nut 35 and the upper end surface of the cutter shaft 6, and the cutter 7 is fastened to the cutter shaft 6 side by the elastic force of the coil spring 38. ing.

40 is a belt cover attached to the mower deck 5, and this belt cover 40 is provided with an adjustment hole 41 facing the tightening bolt 25.

42 is a belt hung around the drive pulley 19.

In the above configuration, the cutter 7 is held and integrated between the cutter receiver 21 and the friction washer 28 by the elastic force of the coil spring 38, and therefore, when power is transmitted to the drive pulley 19 via the belt 42, the cutter 7 7 is a cutter holder 21 around the cutter shaft 6. It rotates integrally with the friction washer 28 and the like to reap the object to be reaped.

Therefore, if the cutter 7 is overloaded due to a cause such as coming into contact with an obstacle, slippage will occur between the cutter receiver 21 and friction washer 28 and the cutter 7 against the elastic force of the coil spring 38, and the cutter 7 will slip. Since the shaft 6 side rotates idly, the impact at the time of overload can be alleviated and absorbed.

The torque when this slippage occurs is generated from above the mower deck 5 by the adjustment nut 35.

That is, since the adjustment nut 35 is screwed into the upper end of the tightening bolt 25 passing through the cutter shaft 6, the mower deck 5
You can easily adjust the torque from the top.

Further, since the tightening bolt 25 is made to protrude upward from the cutter shaft 6, and a spring 38 is interposed at the protruding end, a coil spring can be used as the spring 38. The limit torque when hip slip occurs is extremely stable compared to the one with a spring interposed.

Note that instead of this coil spring 38, a combination of a plurality of disc springs may be used.

Note that the friction washer 28 of the above embodiment and the head 27 of the tightening bolt 25 may be integrated.

The cutter shaft 6 and cutter receiver 21 may be spline coupled.

Further, as shown in FIG. 4, the cutter receiver 21 is tapered fitted to the cutter shaft 6, and
The cutter 7 is slidably held between the cutter holder 21 and the washer 43, and when overloaded, the cutter 7 slips between the cutter receiver 21 and the washer 43, which may seize or cause foreign matter to bite. If the cutter shaft 6 and the cutter receiver 21 do not slide, the cutter shaft 6 and the cutter receiver 21 may be caused to slip.

However, it is necessary to use a wear-resistant material for the washer 43.

In this invention, the cutter shaft and the cutter are relatively rotatable, and the cutter is elastically tightened and fixed to the cutter shaft with a tightening bolt, so slippage occurs between the cutter shaft and the cutter when overloaded. However, this makes it possible to soften and absorb the impact, thereby preventing damage to the cutter, drive system, etc.

Further, no special equipment is required, and the manufacturing cost is low.

Moreover, since the tightening bolt passes through the cutter shaft in the vertical direction and the adjusting nut is screwed onto the protruding portion thereof, the torque can be easily adjusted from above the mower deck.

[Brief Description of the Drawings] Fig. 1 is a partially cutaway side view showing one embodiment of the present invention, Fig. 2 is a partially cutaway side view showing an embodiment of the present invention;
The figure is an enlarged sectional view of the main part, Figure 3 is a perspective view of the friction washer,
FIG. 4 is a sectional view showing another embodiment. 1...Tractor body, 4...Mitsudo mount mower 5...Mower deck, 6...
...Cutter shaft, 7...Cutter, 14...
...bearing case, 19...drive pulley,
21...Cutter holder, 25...Tightening bolt, 28...Friction washer, 35...Adjusting nut, 38...Coil spring.

Claims (1)

[Scope of utility model registration request] In a mower equipped with a cutter at the lower end of a cutter shaft that is rotatably supported around a vertical axis by a mower deck, the cutter is rotatable relative to the cutter shaft, and
A shock mitigation method for a mower, characterized in that a tightening bolt for elastically tightening the cutter with respect to the cutter shaft passes vertically through the cutter shaft, and an adjustment nut is screwed onto a protrusion of the tightening bolt. Device.