JPS6327531Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is an automatic plowing depth control device for agricultural tractors that uses a sensor to sense the relationship between the work implement and the field, and controls the height of the work implement from the ground to maintain a constant plowing depth. This invention relates to a release device.

Generally, the ground height sensor of an automatic tillage depth control device is configured with a rotary rear cover that also serves as a leveler, but since conventional automatic tillage depth control devices do not have a release device for this, the sensor is The automatic plowing depth control device raises the working implement when it comes into contact with the ridge, making it impossible to till the area where the sensor rests on the ridge.

Therefore, the present invention connects a link and a hydraulic control arm via a clevis having an elongated hole and a pin, and further fixes a cam and a lever to a shaft that is fitted into the elongated hole and is pivotally supported by the link. Further, a toggle spring is stretched between the lever and the link, and the cam further includes a holding surface that abuts the pin and holds the shaft at the end of the elongated hole, and a holding surface that receives the pin and holds the shaft along the elongated hole. and a protrusion that contacts the pin and switches the biasing direction of the toggle spring, and when the pin is received in the recess of the cam, the sensor is The biasing direction of the toggle spring is configured to be switched in a direction in which the pin is held on the holding surface of the cam by the contact between the protrusion and the pin,
The automatic plowing depth control device is equipped with a release device for the automatic plowing depth control device, which allows the automatic plowing depth control device to be canceled to perform furrow work, and also automatically returns to the automatic plowing depth control when the furrow work is completed. The purpose is to provide

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

As shown in FIG. 1, the agricultural tractor 1 has a body 2, and a top link bracket 3 is fixed to the rear of the body 2. A rotary working machine 7 is attached to the top link 5 pivotally supported by the bracket 3 and a lower link 6 pivotally supported below the rear of the machine body. A lift arm 9 operated by a hydraulic system is connected via a rod 10. Further, the working machine 7 has a main body 11 and a rotary 12, and behind the rotary 12 is a rear cover 1 whose upper end is pivotally supported by the main body 11.
Covered by 3. The rear cover 13 is pressed downward by a spring 15, and serves not only as a leveler for leveling the soil tilled by the rotary 12, but also as a height sensor for the automatic plowing depth control device. That is, the ground height sensor 13 is connected to a wire 19 via a rod 16 and an arm 17, and transmits the rotation amount of the cover 13 and the ground height H of the work implement 7 to the automatic plowing depth control device. There is.

On the other hand, as shown in FIGS. 3 and 4, a link 20 made of two plates is rotatably supported on the top link bracket 3 by a shaft 21.
The other end of the wire 19 is connected to one end of the link 20, and a spring 22 is stretched between the link 20 and the body 2 to bias the wire 19 in a pulling direction. Further, a shaft 23 is provided at the other end of the link 20.
is rotatably supported, and a lever 25 is fixed to the shaft 23 outside the link 20, and a cam 26 is fixed inside the link 20. Further, a clevis 27 is disposed in contact with the inside of the link 20, and the shaft 23 is fitted into a long hole 27a formed in the clevis 27.
is connected to link 20, and clevis 27
The hydraulic control arm 3 is connected via a rod 29 to a valve that controls the hydraulic system of the lift arm 9.
Connected to 0. The cam 26 has a protrusion 26a protruding toward the outer diameter side on one side, a holding surface 26b adjacent to the protrusion 26a which is an arcuate surface having a predetermined height, and a large holding surface 26b adjacent to the holding surface 26b. It consists of a recessed part 26c and a protrusion 26d protruding outward on the other side, and a spring 31 is tensioned between the lever 25 and the shaft 21, and the spring 31 is It constitutes a toggle spring that switches the biasing direction. Further, a roller pin 32 is arranged on both side plates of the clevis 27.
The pin 32 can abut the cam 26.

Since this embodiment has the above-described configuration, when the tractor 1 performs tilling work in the field as shown in FIG. 1, the lever 25 is rotated in the direction of arrow A by the spring 31 as shown in FIG. is in a dynamically biased position, in which one protrusion 2 of the cam 26 is
6a abuts the roller pin 32 and holds the pin 32 on the holding surface 26b. In this state, the shaft 23 is located at one end of the long hole 27a of the clevis 27, and the clevis 27 is non-slidably and rotatably connected to the link 20. Therefore, when the rear cover 13 constituting the ground height sensor rotates in the direction of arrow B in FIG. and clevis 27
to move the rod 29 in the direction of arrow D, operate the control arm 30 to control the lift arm 9 in the upward direction, and move the work implement 7 so that the plowing depth H reaches the set value.
rise. Conversely, when the rear cover 13 rotates in the direction opposite to arrow B, the rod 29 similarly moves in the direction opposite to arrow D, and the lift arm 9 is controlled in the downward direction to perform work so that the plowing depth reaches the set value. machine 7
descend.

On the other hand, when the tractor 1 intends to till the ridges as shown in FIG. 2, the lever 25 is rotated in the direction of arrow E as shown in FIG. Then, the spring 31 moves beyond the thinking point and pushes the lever 25.
Therefore, the cam 26 is urged in the direction of arrow E', and in this state, the roller pin 32 is attached to the protrusion 26d on the other side of the cam 26.
abuts to receive the pin 32 in the recess 26c, and the shaft 23 can freely slide along the elongated hole 27a. In this state, when the rear cover 13 is placed on the ridge 35, the rear cover 13 rotates greatly in the direction of arrow B, and as shown in FIG. However, the link 20 and clevis 27 are rotated so that the roller pin 32 is in the recess 26c of the cam 26.
Since it is accepted by the link and slides freely, the link 20
The movement of is not transmitted to clevis 27. Thereby, the rotary work machine 7 can be lowered without operating the automatic plowing depth control device based on the rear cover 13, and the ridge work can be performed at a predetermined plowing depth. At this time, by receiving the roller pin 32 into the recess 26c of the cam 26, the pin 32 comes into contact with the protrusion 26d on the other side of the cam 26 and rotates the cam 26 in the direction of arrow F.
The lever 31 integral with the lever 6 rotates in the same direction, and the spring 31 is again urged to rotate in the direction of the arrow A beyond the point of consideration. Then, when the ridge work is completed,
The rear cover 13 is separated from the ridge 35 and the rear cover 1
3 falls and hits the field. Then, if the plowing depth is set shallow, leave it as it is, or if it is set deep, raise the work machine slightly, and the rear cover 13 will rotate significantly in the opposite direction of arrow B, thereby removing the wire 19, etc. As shown in FIG.
6 rotates and the roller pin 3 is placed on the holding surface 26b.
Hold 2. As a result, the link 20 and the clevis 27 are connected, and the automatic plowing depth control is automatically restored.

As explained above, according to this review committee, the link 20 and the clevis 27 are connected through the elongated hole 27a and the shaft 23, and the holding surface 26b is attached to the shaft 23, which can hold the shaft at the end of the elongated hole. Since the lever 25 is fixed to the cam 26, which has a concave portion 26c that allows the shaft to freely slide along the elongated hole, and a protrusion 26d that switches the biasing direction of the toggle spring 31, the lever and therefore the cam can be used for ridge work. By rotating the sensor 13, the connection between the link and the clevis can be disconnected and the automatic tilling depth control device can be disconnected.
It is possible to perform tilling work to a predetermined tilling depth. Further, a toggle spring 31 is stretched between the lever 25 and the link 20, and when the sensor 13 rises by a predetermined amount, the pin 32 comes into contact with the protrusion 26d of the cam 26, and the pin 32 is pressed against the holding surface 26b of the cam 26. Since the biasing direction of the toggle spring 31 is switched in the direction in which the sensor 13 is held, the toggle spring is automatically switched when the sensor 13 rests on the ridge, etc., and when the ridge work is completed, it remains in that state. clevis 27 and link 20 by slight work such as raising the work equipment 7 slightly for a short time.
are connected, so there is no need to manually operate the lever, and automatic plowing depth control can be automatically returned.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the rear of the tractor to which the present invention is applied, Fig. 2 is a side view showing the ridge work, Fig. 3 is a perspective view showing the release device of the automatic plowing depth control device, Figure 4 is a side view showing the automatic tilling depth control in operation, Figure 5 is a side view showing the automatic tilling depth control being released, and Figure 6 is automatically returning to the automatic tilling depth control. FIG. 1...Tractor, 7...Work machine, 12...Rotary, 13...Sensor (rear cover), 20...
...Link, 23...Shaft, 25...Lever, 26...
...Cam, 26b... Holding surface, 26c... Recess, 2
6d... projection, 27... clevis, 27a... long hole, 30... hydraulic control arm, 31... toggle spring, 32... pin.

Claims (1)

[Scope of claim for utility model registration] (1) The height of the work equipment above the ground is detected by a sensor,
In an automatic plowing depth control device that transmits the movement amount of the sensor to a hydraulic control arm via a link and controls the elevation and descent of a working machine to maintain a constant plowing depth, the link and the hydraulic control arm have a long hole and a pin. A cam and a lever are connected via a clevis, and a cam and a lever are fixed to a shaft that is inserted into the elongated hole and pivotally supported by the link, and a toggle spring is stretched between the lever and the link, and the cam is , a holding surface that abuts the pin and holds the shaft at the end of the elongated hole;
The cam includes a recess that receives the pin and allows the shaft to freely slide along the elongated hole, and a protrusion that contacts the pin and switches the biasing direction of the toggle spring, and the pin is received in the recess of the cam. automatic plowing depth configured to switch the biasing direction of the toggle spring in a direction in which the pin is held on the holding surface of the cam due to contact between the protrusion and the pin based on the upward movement of the sensor. Control device release device. (2) The release device for an automatic tillage depth control device according to claim 1, wherein the sensor is constituted by a rotary rear cover that also serves as a leveler.