JPH0520102Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a telescopic guide structure for a hydraulic cylinder in a tractor.

Recently, small tractors with a low vehicle height and a short distance between the front and rear wheels have become popular mainly for indoor work.In this type of tractor, a hydraulic cylinder for raising and lowering the lifting rod is installed diagonally at the rear of the machine. (If the vehicle was housed in the space below the seat like in the past, the vehicle height would not be as low as desired).

In this way, the hydraulic cylinder itself is protected by the mast, and there is no need to convert the small stroke of the hydraulic cylinder into a large lift amount of the lifting rod as in the conventional case, and this lift amount and the stroke of the hydraulic cylinder are There are almost corresponding advantages, but as the stroke of the hydraulic cylinder increases, a smooth guiding mechanism becomes necessary.

This idea was created by accommodating the hydraulic cylinder in the mast, and also cleverly utilizing the cross-sectional shape of the mast to devise a smooth telescoping guide mechanism and derive the accompanying effects. .

Embodiments of this invention will be described below with reference to the drawings. Among the accompanying drawings, Fig. 1 is a side view of a tractor connected to a working machine, Fig. 2 is a vertical sectional view of the mast, and Fig. 3 is a side view of a tractor connected to a working machine. 2 is a cross-sectional view, and FIG. 4 is a side view showing the relationship between the hydraulic cylinder and the position control device.

Tractor A has a machine body 1 with front wheels 2, 2, rear wheels 3,
3, with a seat 4 above the rear wheels 3 and 3.
In addition to installing a handle 5 in front of the handle.

Work machine B is also equipped with a rotary 7 at the bottom of the main body 6, and behind this is a rear cover 8 and tail wheels 9, 9.
etc.

The working machine B is connected to the tractor A by connecting lower links 10, 10 and an upper link 11 provided at the rear of the tractor A to a hit point of the working machine B. In addition,
Both A and B are also connected monetarily by the drive shaft 12.

By the way, this type of tractor A has a low vehicle height mainly for indoor work, so the hydraulic cylinder 1 for raising and lowering the work equipment B is
3 from the space 14 below the seat 4, which is the original installation location, and installed the mast 1 diagonally at the rear of the aircraft 1.
It is housed in 5. Specifically, the lower end of the hydraulic cylinder 13 is pivotally supported on a mast 15, and the upper ends of lifting rods 17, 17 are pivotally connected to the tip of a piston rod 16 (hereinafter referred to as rod 16).

Here, we will explain the configuration in a little more detail as follows.

That is, the mast 15 has a square pipe shape with a hollow interior, and an opening groove 18 is formed at the center of the back surface from which the lifting rods 17, 17 are connected.
can hang down. Therefore, the cross section of the mast 15 is more accurately said to have a lip groove shape.

At the tip of the rod 16 of the hydraulic cylinder 13, rollers 20, 20 roll on the inner surfaces 19 of both lip portions of the mast 15, and rollers 20, 20 roll on the inner surfaces 19 of both flange portions of the mast 15.
1 and 21 are also provided with a telescopic guide mechanism 24 having a structure in which four rollers 23 roll in front and behind a pin 22 installed at right angles to the rod 16. As a result, in the vertical direction, the lifting rod 1
Due to the weight of the rods 7, 17, etc., the rollers 20, 20 are rolling on the inner surfaces 19 of both lip portions, and in the left and right direction, both rollers 23 are rolling on the inner surfaces of both flange portions. This means that you can move smoothly up and down, left and right, without shaking.

Next, this working machine B is in the position where the plowing depth setting lever (position lever) 25 is located.
While the height of the working machine is provided with a position control device 26 that is fixed in accordance with this position, the plowing depth is controlled so that the plowing depth can be kept constant in certain cases.

The mechanism is shown in Figure 4, but the main point is:
A link mechanism 27 is attached to the rod 16 of the hydraulic cylinder 13.
The amount of expansion and contraction of this rod 16 is fed back to the rotation of the disk plate 28 loosely fitted into the position lever 25. There are two switches 29a and 2 on the disk plate 28.
9b is provided, and its switches 29a, 29b
The cam plate 30, which moves toward and away from the position, is tightly fitted to the position lever 25. Therefore, now,
When the position lever 25 is set to a certain plowing depth position (this is engraved as a scale on the guide plate 31 into which the position lever 25 is fitted), the cam plate 30 on the corresponding side switches one switch 29a,
29b is activated, the solenoid valve is activated, and the hydraulic cylinder 13 is expanded or contracted to the corresponding side. When the hydraulic cylinder 13 is expanded or contracted to the position of the position lever 25, the operation of the switches 29a and 29b is stopped, so the operation of the switches 29a and 29b is stopped. It stops.

Furthermore, it is possible to control the plowing depth to set the plowing depth to a predetermined value by using input (sensor) signals that take into account the amount of expansion and contraction of the hydraulic cylinder 13, the amount of inclination of the tractor A body back and forth, the amount of plowing depth setting, etc. It's getting old.

That is, the zone where the position lever 25 is located on the guide plate 31 is determined by the switch 32 or the like,
Using this as a gate signal, the plowing depth is subsequently controlled by the sensor signal. In other words, if the position lever 25 is in the a zone in FIG. 4, the position control is performed, and if it is in the b zone, the plowing depth is controlled. By the way, when employing the tillage depth control as described above, it is necessary to detect the amount of expansion and contraction of the rod 16 of the hydraulic cylinder 13 as one of the sensor signals, but this can be done by using the potentiometer 33. It is possible. On the other hand, if these potentiometers 33 and the like are also housed in the mast 15, related equipment can be housed in a compact manner, and the mast 15 acts as a protective material to provide waterproof and damage prevention effects.
At this time, the potentiometer 33 expands and contracts due to the presence of the rollers 20, 20, 23, . . . and the smooth movement of the telescopic guide mechanism 24, so reliable operation can be expected and the service life is long.

In addition, by connecting the telescopic guide mechanism 24 and the telescopic rod 35 of the potentiometer 33 via a spring 36, the potentiometer 33 can be
does not require the full stroke S of the rod 16,
It is sufficient to cover the plowing depth control range L (when the position lever 25 is in zone b in Fig. 4), and the insufficient stroke (S-L) is covered by the extension of the spring 36. Since this can be achieved, the capacity of the potentiometer 33 may be small, and the cost is also low in this respect.

As described above, this invention is based on the hydraulic cylinder 13.
A telescopic guide mechanism 24 is used at the tip of the rod 16, and a link mechanism 27 of the potentiometer 33 and position control device 26 is used.
The coupling links 34 connected to the hydraulic cylinder 13 are housed in the mast 15 in parallel with the hydraulic cylinder 13. Note that the telescopic rod 35 of the potentiometer 33 is connected to the above-mentioned telescopic guide mechanism 24 via a spring 36, and also to the connecting link 34.
is similar, and one end is connected to the telescopic guide mechanism 24, while the other end is connected to the link mechanism 2 outside the mast 15.
It is linked to number 7.

As mentioned above, this idea is as follows.
That is, first, the rod 16 of the hydraulic cylinder 13
Because it rolls and moves vertically and horizontally within the mast 15 by the telescopic guide mechanism 24,
Its movements are smooth and light.

Furthermore, since the telescopic guide mechanism 24 rolls vertically and horizontally within the mast 15, the head-side pivot structure of the hydraulic cylinder 13 may be rough.
Since precise centering is not required, it can be manufactured at low cost, and the overall structure is also compact.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention,
Figure 1 is a side view of a tractor connected to a working machine, Figure 2 is a vertical sectional view of the mast, and Figure 3 is the same as in Figure 2.
The sectional view and FIG. 4 are side views showing the relationship between the hydraulic cylinder and the position control device. Code, 1...Airframe, 13...Hydraulic cylinder, 1
5... Mast, 16... Rod, 17... Lifting rod, 19... Inner surface of both lips, 20... Roller, 21... Inner surface of both flanges, 23... Roller, 24... Telescopic guide mechanism, 26 ...Position control device, 27...Link mechanism, 33...
...Potentiometer, 34...Connection link.

Claims (1)

[Scope of utility model claims] By raising and lowering the lifting rods 17, 17, work machine B
In a tractor A which is a tractor for raising and lowering a vehicle, a mast 15 having a rip-groove cross section is obliquely installed at the rear of the body 1, and a hydraulic cylinder 13 for raising and lowering the lifting rods 17 and 17 is housed in the mast 15.
At the tip of the piston rod 16 of this hydraulic cylinder 13, there are rollers 20, 20 that roll on the inner surfaces 19 of both lip portions of the mast 15, and
A telescopic guide structure for a hydraulic cylinder for lifting and lowering a working machine in a tractor, characterized in that a telescopic guide mechanism 24 having rolling rollers 23 is provided on inner surfaces 21, 21 of both flange portions.