JPS6146062Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an axle movement regulating device for a walk-behind cultivator that can change the longitudinal center of gravity of the machine body.

Generally, the center of gravity of a walk-behind tiller is set at the rear of the machine so that the rotary can be prevented from jumping up during operation and the tiller can be easily tilled. Therefore, when turning the tiller, the operator had to support an extremely large amount of weight in order to lift the rear part of the tiller using the handle and pull the rotary out of the field. Therefore, the axle case is provided to be swingable, and the swing of the axle case is restricted by a stopper, and the rocking end is locked by a locking device. A balance spring that acts in the opposite direction with a small force is stretched between the aircraft body and the axle case, and by using a small force, the aircraft body is moved forward and backward relative to the axle to change the center of gravity, and when turning A walk-behind tiller with improved operability has been proposed. However, in this tiller, the stopper, locking device, and balance spring are all exposed to the outside and are installed separately, making it difficult to assemble them in a narrow space. The adjustment work is complicated and troublesome, and furthermore, it is difficult to take measures against mud and water, and there is a risk that malfunction may occur during long-term use.

Due to the above-mentioned circumstances, the present invention solves the above-mentioned problems by arranging an axle movement regulating device consisting of a cylinder and a plunger between the axle case and the machine body, and arranging a locking device and a balance spring within the cylinder. The object of the present invention is to provide an axle movement regulating device for a walk-behind tiller.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the walk-behind cultivator 1 has a body 3 suspended by left and right drive wheels 2. Engine 5 is installed in the front of aircraft 3,
Further, a transmission 7 to which power is transmitted from the engine 5 via a belt transmission device 6 is arranged in the middle, and a handle 9 extends further behind it, and a handle 9 is provided at the rear of the fuselage 3. A rotary 10 is mounted and fixed below. An axle case 11 is swingably supported on the case 7a of the transmission 7, and an axle movement regulating device 12 according to the present invention is further provided between the axle case 11 and the machine body 3.
is located. That is, mission 7 is the third
As shown in the figure, it has intermediate shafts 15 that are driven via left and right clutch gears 13 and gears 14, and each of the left and right intermediate shafts 15 protrudes from the case 7a and is connected to a gear in the axle case 11. It is connected to left and right axles 16 protruding from the left and right axle cases 11 via gears in the axle case 11, and left and right drive wheels 2 are fixed to the axles 16, respectively. Further, the axle case 11 is rotatably supported by the transmission case 7a via the liner 17 of the intermediate shaft 15, that is, around the intermediate shaft 15, and the two axle cases 11, 11 are connected below the axle case 11. A connecting pipe 19 is fixedly installed. Furthermore, a plunger 22 of the movement regulating device 12 is pivotally supported in the center of the connecting pipe 19 by a bolt 20, and as shown in FIG. It is pivotally supported on the body 3 by inserting a pin 3c between the provided pipes 3b. As shown in FIG. 2, the cylinder 21 has one end closed and the other end open, with a small diameter hole 21a on the closed side and a large diameter hole 21b on the open side. is formed. Also,
A plunger 22 is disposed within the cylinder 21, and the plunger 22 is connected to a large diameter portion 22 that is slidably supported by a small diameter portion 21a of the cylinder.
a and a small diameter portion 22b located on the large diameter portion 21b side of the cylinder. Further, a lid 23 is attached to the open end of the cylinder 21 by a seal 25 to connect the plunger 2.
It is fixed in a sealed state between 2 and
In the large diameter portion 21b of the cylinder, a double structure balance spring 26 is inserted along the axis of the plunger between a lid 23 and a collar 24 fitted to the stepped portion 22c of the plunger so as to surround the small diameter portion 22b of the plunger 22. It has been reduced in size. Also,
A boss portion 21d protruding in the radial direction is formed in the small diameter portion 21a of the cylinder.
The guide sleeve 27 is made of a hard material.
are fitted. Further, a U-shaped mounting bracket 29 is fixed to the upper end of the boss portion 21d, and the sleeve 2
7 from being pulled out upward, one end of the mounting fitting 29 fixes the outer end 30a of the wire 30, and the other end fixes the fulcrum boss 31a of the link 31. One end of the wire 30 is connected to the tip of a link 31, and the other end is connected to an operating lever 32 provided on the handle 9. Further, a lock fitting 33 is pivotally supported in the middle of the fork-shaped link 31, and the other end of the lock fitting 33 is provided with a trapezoidal convex tooth 35 whose side surface is an inclined surface with a predetermined angle. ing. Moreover, the upper surface of the convex tooth 35 and the guide sleeve 2
A set spring 36 with a predetermined biasing force is compressed between the bottom of the lock fitting 33 and the bottom of the lock fitting 33.
slides in a direction perpendicular to the axial direction of the plunger 22, and the convex teeth 35 at the tip thereof are pressed so as to mesh with the concave teeth 37 formed on the large diameter portion 22a of the plunger. Similar to the convex teeth 35, the concave teeth 37 are formed in a trapezoid having an inclined surface at a predetermined angle.
Further, similar concave teeth 37' are formed on the end side of the plunger 22 via a flat portion 39 of a predetermined width. Further, a boss portion 21e is formed on the opposite side of the boss portion 21d of the cylinder 21.
A stopper pin 40 is fitted into 1e.
The pin 40 has a protrusion 40a fixed at an eccentric position on one end, and a plate 40b fixed on the other end.
0a is engaged with a stopper groove 41 formed in the large diameter portion 22a of the plunger. Furthermore, pin 4
0, the position of the protrusion 40a can be changed by rotating the plate 40b 180 degrees, the amount of protrusion of the protrusion 40a can be adjusted by changing the position of the collar 42 and tightening the bolt 43, and the stopper groove 41 can be adjusted in length. It is composed of grooves with two different depths. In addition, 45 in the figure is an O-ring. Then, as shown in Fig. 5, the axle case 1
1 is swung such that the axle 16 is at a distance l or L at a position rearward with respect to the intermediate shaft 15,
Moreover, as shown in FIG.
The force S is always slightly smaller than the horizontal component force F based on the weight of the horizontal force F.

Since this embodiment has the above configuration, during normal tilling work, the rotation of the engine 5 is transmitted to the mill 7 via the belt transmission device 6.
Furthermore, the left and right side clutch gears 13 and the intermediate shaft 1
5 etc., to the axle 16 to drive the wheels 2 to run the tiller 1, and also to drive the rotary 10.
Power is also transmitted to the farm to perform tillage work. At this time, the axle case 11 is in the front rising position l, as shown by the solid line in FIG.
Since the rotary body 3 is engaged by the spring 36 and locked in this position, the center of gravity G of the body 3 is located slightly behind the axle 16, and the rotary 10 is prevented from jumping up.

Next, when turning the tiller 1 on the headland, when the operating lever 32 is pulled, the lock fitting 33 is lifted up against the set spring 36 via the wire 30, and the convex teeth 35 and concave teeth 37 are engaged with each other. When released, the plunger 22 is free to move. Then, the axle case 11 is rotated at a moderate speed as shown by the chain line in FIG. It moves forward with respect to the axle 16 and is further stopped at a predetermined position by engagement between the projection 40a of the stopper pin 40 and the stopper groove 41 of the plunger 22. At this time, even if you release your hand from the operating lever 32, the convex teeth 35 of the lock fitting 33 only come into contact with the flat surface 39 of the plunger 22, and the concave teeth 37
Furthermore, in the normal setting position of the stopper pin 40, it does not mesh with the concave teeth 37'. In the position L where the axle case 11 is tilted significantly backward, the center of gravity G is located in front of the axle 16, so the driver can easily lift the handle 9 and easily rotate the tiller 1. can be directed towards

Further, when the rotation of the tiller 1 is completed and the tiller 1 is to start the tilling operation again, the handle 9 is continued to be pulled against the driving force of the wheels 2. Then, the lock fitting 3
In a state where the convex teeth 35 of No. 3 are on the flat part 39 of the plunger 22, that is, in a state where the axle case 11 can swing freely, the drive reaction force from the wheels 2 acts, so the axle case 11 moves the intermediate shaft 15. It rotates forward about the center and returns to the above-mentioned standing position l. At this time, the balance spring 26 in the fuselage 3
Regardless of the rotation angle of the axle case 11, only a small horizontal component of force is applied, so the fuselage 3 is easily
can be moved rearwardly relative to the axle 16. At a predetermined position where the stopper pin 40 abuts the end of the stopper groove 41, the set spring 36 engages the convex teeth 35 of the lock fitting 33 with the concave teeth 37, and the axle case 11 is locked in the raised position l.

Note that when entering and exiting the field, when climbing over large grooves or ridges, or when obstacles such as stones are encountered during rotary work, overload will occur on the movement regulating device 12, but the convex teeth 35 of the locking fitting 33 and the plunger 2
When a load equal to or greater than the specified frustration load acts between the concave teeth 37 and the concave teeth 37 of
3 is lifted and the plunger 22 moves freely, the above-mentioned overload is absorbed, and damage to the movement regulating device 12, especially the front and rear pivot parts, which are weak in strength, can be prevented.

As explained above, according to the present invention, the aircraft 3
The lock fitting 37, the convex teeth 35, the concave teeth 37, and the set spring can be easily moved in the front and rear directions, and the tiller 1 can easily perform both normal tilling work and turning work. Since the locking device consisting of 36 etc. and the balance spring 26 are housed in the cylinder 21, waterproofing and mudproofing can be easily applied.
It is possible to prevent malfunctions from occurring over a long period of time. Furthermore,
Since the locking device, the balance spring 26, the stopper device consisting of the stopper pin 40 and the stopper groove 41 are combined into one axle movement regulating device 12, it can be assembled in a narrow space and adjustment work can be easily performed. be able to. In particular, if the guide boss 27 is prevented from coming off by using the U-shaped mounting bracket 29 to which the fulcrum boss 31a and the outer end 30a are fixed, even if the guide boss 27 protrudes due to the set spring 36, the mounting bracket 29 will be fixed by tightening the bolt. Since it is only necessary to do this, assembly becomes easy and a dedicated assembly jig is not required.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a walk-behind cultivator to which the present invention is applied, Fig. 2 is a cross-sectional view showing the axle movement regulating device according to the present invention, Fig. 3 is a cross-sectional view along the line shown in Fig. 1, 4 is a sectional view taken along the line in FIG. 1, FIG. 5 is a side view showing different operating states of the axle case, and FIG. 6 is a diagram showing the relationship between the horizontal component force due to the weight of the machine and the tension of the balance spring. 1...walking tiller, 3...body, 7a...
Mission case, 11...Axle case, 12...
... Axle movement regulating device, 16 ... Axle, 21 ... Cylinder, 22 ... Plunger, 33 ... Lock fitting, 35 ... Convex tooth, 36 ... Set spring, 37 ... Concave tooth, 33-37 ... locking device,
40...stopper pin.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An axle case is provided in a swingable manner relative to a transmission case, and the axle case is configured to be fixed by a locking device, and the horizontal component of the weight of the machine is In a walk-behind tiller equipped with a balance spring for balance, an axle movement regulating device consisting of a cylinder and a plunger is disposed between the axle case and the machine body, and an axle movement regulating device consisting of a cylinder and a plunger is further disposed within the cylinder in the axial direction of the plunger. A walk-behind cultivator comprising: a locking device having a locking fitting capable of moving in a direction perpendicular to the plunger and capable of engaging with the plunger; and a balance spring extending in the axial direction of the plunger so as to surround the plunger. Axle movement regulating device. (2) The locking device is constituted by convex teeth and concave teeth that are biased by a set spring and are formed on the lock fitting and the plunger and can mesh with each other, and furthermore, the side surfaces of these convex teeth and concave teeth are formed at a predetermined angle. An axle movement regulating device for a walk-behind tiller as claimed in claim 1 of the registered utility model claim, which has an inclined surface.