DE1970755U - DEVICE FOR THE INDEPENDENT DEPTH ADJUSTMENT OF TRACTOR-DRAWN AGRICULTURAL EQUIPMENT. - Google Patents

Description

Description of the utility model

ο he company PIAT Societa per Azioni, Turin / ITALY

concerning

"Device for automatic depth adjustment of tractor-drawn agricultural implements "

PRIORITY: July 10, 1964 - ITALY

The innovation relates to a device for adjusting the load responsiveness of depth control devices for tractor-drawn agricultural equipment.

For pulling an agricultural one that digs into the ground The tractor must generate a force equal to the depth

is proportional to the furrow and strength of the ground. To keep the tractive effort of the tractor at an almost constant level To keep the value, the agricultural implement is automatically raised or lowered, so that it is more solid To penetrate the soil less deeply than in less firm soil.

For this purpose it has already been proposed the agricultural To connect the device to a hoist, which consists of three essentially parallel to each other arranged in a triangular formation Lever consists of one end on the rear of the tractor and the other end on the agricultural Device are articulated.

The two levers arranged at the bottom of this triangular arrangement are driven by a servomotor, from which they and so that the agricultural implement can be raised or lowered with respect to the tractor. The one above this lever at the top of this arrangement arranged third lever is pivotally mounted on a carrier on the Rear part of the tractor is attached by means of a spring, which changes according to the force exerted by the tractor Pulling the agricultural implement reaching into the earth is deformed. The deformation of this spring causes the control valve of the servomotor operated via a corresponding drive.

The stress responsiveness of the previously known devices depends exclusively on their sensitivity Spring off.

However, the known devices speak neither to the weight of the device nor to the type of linked changes to the work to be carried out.

Tests have shown that a lifting device with a Sensitivity commensurate with the weight of a given device can become overly sensitive when paired with a heavier device is connected, resulting in a pronounced exceeding of the setting process of the control or at least can lead to excessive use of the hydraulic control, which is a nuisance for the tractor driver and affects the service life of all parts of the lifting device.

The aim of the present innovation is to create a lifting device of the type mentioned above which is provided with means is through which the depth control and readiness to use the lifting device expand within Limits are adjustable.

Another goal of the innovation is to create a simple one Control of said means to facilitate the load responsiveness of the lifting device.

For this purpose, the innovation is based on a device for automatic depth adjustment of tractor-drawn agricultural vehicles Devices., In which three levers essentially parallel to one another in a triangular arrangement at one end €> er Rear of the tractor and its opposite other end articulated to the agricultural implement are, two of these levers controlled by a hydraulic of a distribution valve for a pressure medium Servomotor can be actuated and with an optionally displaceable control element for the movement of this distribution valve in a first operating position in which the servomotor is connected to the supply line for the pressure medium or in a second operating position in which the servomotor is connected to the drain line or in a third operating position is provided, in which the servomotor is shut off from the supply line and the discharge line, wherein said third operating position is between the first and the second operating position and the third of the said three levers with a bracket attached to the tractor by means of a spring that is deformable proportionally to the tensile force

is connected and wherein between this spring and the control member for the distribution valve connecting parts for transmission the deformations of the spring on this control member and intended to move the valve into one of its three operating positions are and is characterized essentially by the fact that on the distributor valve one to be actuated from outside the same Device for moving the control member is provided in different operating positions. Other features of the The innovation relates to advantageous structural details of this device.

The innovation is described below with reference to schematic drawings, in which an embodiment of the innovation is shown.

In the drawings shows

1 is a schematic view of a tractor with a conventional lifting device for a plow,

Fig. 2 is a schematic view of the new control for the lifting device,

Fig. 3 is a section through a distribution valve for the new Contraption,

Pig. 4, 5 and 6 sections along the line IV-IV of Fig. ^ For different operating positions,

7, 8 and 9 sections along the line VII-VII in FIG. 3 for corresponding operating positions.

In the drawings, a tractor 1 is shown with a conventional lifting device 2 is provided, which is connected to an agricultural implement 3, the one The furrow S digs in the soil. The lifting device 2 has three levers 4, 5 and 6 which run essentially parallel and are arranged at the tips of an isosceles triangle.

The levers 4 and 5 * which are arranged on the base of the triangle are, are pivotally mounted at their ends at the rear of the tractor at 7, the opposite Lever ends on the frame 9 of the plow 3 can be pivoted at 8 are stored.

The third lever 6, which is arranged at the apex of the triangle, is provided with a screw coupling 10 through

which the length of the lever can be changed.

The lever 6 is at one end on a pivot 11, in the middle section a carrier in the form of a two-armed lever 12, 12a pivotably mounted, the latter being supported by a pivot pin 13 pivotally mounted on the rear part of the tractor 1 is. The end of the arm 12- is on the tractor by means of a U-shaped Fastened spring 14 so that the lever 12, 12a can be pivoted about the pivot 3 with the deformation of the spring 14 can.

The other end of the lever 6 is pivotably mounted on the frame 9 by means of a pivot pin 15.

At the middle portion of the lever 4 is one end of a rod 16 pivotably mounted, the other end of which is pivotably mounted on an arm 17 which in turn is wedged onto a shaft 18 which is rotatably mounted in a bearing 19 which is attached to the rear part of the tractor 1.

An arm 20 is carried by the shaft 18 and connected to the rod of a hydraulic servo motor 22, the one Has piston 23 which is displaceable in a cylinder 24 is arranged. The cylinder 24 is connected by a supply line and an outlet line 26 to a valve 27, the

u has a movable control member 28.

The valve 27 is in turn via a line 29 with a Feed pump 30 connected, the oil from an oil tank 31 promotes, with which the valve 27! additionally via a drain line J2 is connected.

The control member 28 is mife. the lever on the support 12 operatively connected by a drive which comprises a rod 33, with one of its ends to the arm 12a and the other end to an arm of a support hinged to 34, the other arm via a rod 35 ^m it an arm 36 ', which is attached to the control member 28. The carrier 34 is pivotably connected to a crank 37 which is eccentrically carried by a shaft 38, which in turn can be rotated about its axis by a lever 39 being displaceable by hand within the limits determined by an adjusting arc 40.

The valve 27 is in Pig. 3 shown schematically, wherein For the sake of clarity, all lines are shown in the plane of the drawing.

The valve has a body 41 with a bore 42, which at both ends with the threaded sections 43, 44

as well as a chamber 45 is provided which extends transversely between the threaded portions 43, 44 extends.

A control member 28 is rotatably and slidably disposed in the bore; the lever 36 is on a front pin 52 of the Member 28 arranged in the chamber 45, being in the wall an opening (not shown) is provided through which the rod 35 for the rotation of the control member 28 is sealed extends.

The end 46 of the control member is provided with a slot 47 which receives one end of a coil spring 48 while its other end engages in a slot 49 which is provided in a threaded plug 50, which in turn is in the threaded section 44 to close off one side of the bore 42 and to form a chamber 51 in the bore is.

The spring 48 presses the end of the pin 5 ^{2 of} the control member 28 against an axially displaceable abutment which is formed by a stop 53 and is fastened to a screw 5 ^ which is screwed into the threaded section 4J to close the other end of the bore 42 .

The screw 5 ^ is provided with a manually operated lever 55, by means of which the screw 5k can be rotated, the control member being displaced axially.

To avoid unscrewing the screw 5-4, the rotary motion is of the lever 55 limited by a stop 56 which is attached to the valve body 4l.

The control member 28 has three cylindrical sections 57 * 58, 59 with a diameter which corresponds to the bore Λ2 , whereby they are held at a distance from one another by two cylindrically tapered sections 50, 6l which have annular grooves 62, 63.

The cylindrical sections 57 * 59 * which are arranged at the ends of the link 28 each have an axial bore 64, 65 which is connected to corresponding circular grooves 62, 63, while the central cylindrical section 58 has a diametrical channel 66 , the is provided with axially elongated openings 67, 68 (Pigi 4) and with two axial grooves 69, 70 which are arranged on diametrically opposite sides of the cylindrical portion 58 and are in communication with the annular groove 62. The groove 69 is separated from the opening 67 and the opening 68 by a surface 71 and similarly the groove 70 by a surface 72

The cylindrical portion 6l has a slope 73., The inclines in the direction of the longitudinal axis of the control member 28 and a slope 74 on one of its edges, so that a cylindrical surface only on the circumference of the section 6l 85 is present.

The supply line 29 is connected to the line 25 through a line connected. Which are provided in the body 41 of the valve 27 and is controlled by a check valve 7ßa., while the Drain line 32 with a line 26 connecting lines 76, 77i 78 controlled by a valve 79 .sind.

The normally closed valve 79 has a piston 80; which has a mushroom-shaped valve member 8l, which from Pressure medium pressure in line 78 and from a spring 83 is pressed onto a seat 82 to interrupt the connection between lines 78 and 77.

The piston 80 is on the side facing away from the spring 83 provided with an actuating part in the form of a finger 84, the longitudinal axis of which is eccentric to the axis of rotation of the control member 28 is arranged.

The finger 84 protrudes so far freely into the groove 63 that the valve 79 remains closed while the finger 84 is at a distance

from the skew 74 when it faces the finger 84 (FIG. 6); the valve 79 thus remains closed.

As a result of the clockwise rotation of the control member 28, the slope 73 comes into a position in which it is with the Finger 84 (Fig. 8) comes into contact. As the link 28 continues to rotate, the slope 75 (FIG. 9) presses the finger 84, to open valve 79. With the further rotation of the limb 28 comes the cylindrical surface 85 of the section 61 with the finger 84 in contact and presses the same so that the valve 79 remains open.

The valve 27 and the servomotor 22 are through an overflow element 86 protected against overpressure, which is controlled by a spring-loaded valve 87, the lines 78 and 76 directly connects.

The conduit 76 is connected by a conduit 89 to the chamber 51 which encloses the spring 48, which chamber is connected to the chamber 45 by a conduit 90 which in turn is connected to the conduit 75 through an opening 91 which opens on the the side facing the line 90 is provided with a seat 92 for a mushroom-shaped valve member 93 of a valve 94.

The valve member 93 is attached to a piston 95, the is arranged in a cylinder 96, the diameter of which is larger is than that of bore 91-

The valve member 93 is held on its seat 92 by a spring 97 pressed between the piston 95 and the bottom of the cylinder 96 is arranged, the stroke of the piston 95 in opposite Direction is limited by a stop 98.

The portion of the cylinder 96 containing the spring 97 is connected to the bore 42 by a line 99 which has an opening 100 opening into the bore 42.

The bore 42 is connected to the line 75 by a line 101 which has an opening 102 which opens into the bore 42 diametrically opposite the opening 100. The opening 100 is, depending on the position of the control member 28, either in connection with the opening 6 ¹ J , or it is closed by the surface 71, or it is in connection with the groove 69. At the same time, the opening 101 is in communication with the opening 68 or it is closed by the surface 72 or is in communication with the groove 70.

The device described above operates as follows. The reaction R (Fig. 1 and 2) of the tractor pulled plow to

Digging the furrow S creates at the moment M around the pivot pin 8 and a force P, which by pressing the lever 12 the Compresses spring 14 until the reaction of spring 14 equals the force P.

The deformation of the spring 14 is caused by the levers 12, 12a, the bar 33. » the bracket 34, the rod 35, and the arm 36 transmitted to the control member 28 of the valve 27.

As a result of the force exerted on the lever 39, the valve 27 is moved into its rest position in which the control member 28 assumes the position shown in FIGS. 4 and 7.

In this position, the grooves 69 and 70 of the cylindrical Section 58 partially free the openings 100 and 102 and connect the corresponding lines 99 and 101 with it the annular groove 62, which is through the axial bore 64 with the chamber 45 in connection, which in turn the line 90 with the drain line 32 is in communication. The delivery pressure of the oil in the line 75 thus acts through the opening 9I to the valve member 92 and opens the valve 94, the piston 95 being raised against the action of the spring 97 and the cylinder 96 is emptied through line 99,

As a result, the pressure medium oil flows out of the line 75 through the opening 91 to the line 90 and to the drain line As a result of the pressure drop in the line 75, the valve 70a is closed, so that the drainage of oil from the servomotor 22 is avoided by the line 25.

At the same time, the slope 73 is at a distance from the finger 84 and hold spring 83 and oil pressure in line 78 the valve 79 closed so that the oil can not flow out of the servomotor 22, which remains hydraulically locked and the Plow 3 stops in furrow S at the desired depth.

In the case of an instantaneous & n oil pressure increase above the predetermined Limit in the cylinder 24 of the servomotor 22, the valve 87 opens and the oil flows through the lines 26, 78, 86, 76 and 32 into the oil tank 3I.

If the plow 3 digs in solid soil, the force P increases and upon further compression of the spring 14, the rod 35 moves to the right (Fig. 2) and rotates the control member 28 in the direction of its conveying position shown in FIGS. 5 and 8.

The lines 101 and 99 are in communication through the passage 66 , so that oil is supplied to the cylinder 96 and the valve 94

is closed. As a result, the oil pressure in the line 75 * rises so that the valve 76a opens and oil the cylinder 24 of the servo motor 22 is supplied, the drainage of oil from the cylinder 24 of the servo motor 22 being avoided, insofar as the flow between lines 78 and 77 is inhibited by the valve 79, whereby the pinger 84 from the obliqueness 74 (Pig. 8) is at a distance.

Under these circumstances, the arms 20, 17 and the rod 16 acting rod 21 raises the servomotor 22 the plow 5 until the force P decreases to the betting, corresponding to the predetermined compression of the spring 14, so that the valve in its rest position is brought back, in which the servomotor is again locked hydraulically and the plow 3 digs a shallower purchase.

If the J5 plow hits a less firm soil, it takes the Force P ab and the spring 14 expands and moves the control member 28 of the valve 27 into its position in FIG. 6 and 9 shown drainage position, in which the "lines 99 and 101 with the grooves 67, 68 are connected., wherein the oil located in chamber 45 under drain pressure.

As a result, the valve 9 ^ is open and the valve 76a held closed in the position already described,

* the suppressed while the bevel 73 on the pingers 84, holds the valve 16 open, oil from the cylinder 24 of the servo motor 22 through the lines 26, 78, 77, 76, 32 flows and the plow 3 is lowered until the force P and the reaction of spring 14 will re-equilibrate and return valve 27 to its rest position.

To change the stress responsiveness of those described above Device are provided means for changing the extent of the angular displacement, which is from the control member 28 is carried out so that the valve 27 from a position in which the pressure oil the cylinder 24 of the servo motor 22 is supplied, is moved into a position in which oil flows out of the servomotor.

When screwing in the screw 54 through the lever 55 the control member 28 is axially displaced against the action of the spring 48 and the thicker end of the slope 73 approaches the finger 84, whereby in the rest position of the valve 27 the distance between the bevel 73 and the finger 84 decreases.

As a result, the slope 73 presses on the finger 84 around the valve 79 after a small angular advance of the control member 28 open.

Conversely, the spring 48 expands when unscrewing the screw 5 ^ and moves the control member 28 axially in opposite direction, so that in the rest position of the valve 27, the distance between the slope 73 and the Pinger 84 increases and the control member 28 has a greater angular displacement must perform to open the valve 79 and to allow the oil to drain from the servomotor 22.

PROTECTION CLAIMS:

Claims (3)

r.A. 501211 * 8/30/67 - 19 - PROTECTION CLAIMS; 1. Device for automatic depth adjustment of tractor-drawn agricultural implements, in which three substantially parallel levers arranged in a triangle at one end with the rear of the tractor and their opposite other end are articulated to the agricultural implement, two of which Lever actuated by a hydraulic servomotor controlled by a distribution valve for a pressure medium are and where an optionally displaceable control member for moving this distribution valve into a first operating position-, in which the servomotor is connected to the supply line for the pressure medium, or in a second operating position, in which the servomotor is connected to the drain line, or in a third operating position is provided, in which the servomotor is shut off from the supply line and the discharge line, said third operating position is located between the first and the second operating position and the third of the said three Lever is connected to a carrier attached to the tractor by means of a spring that is deformable proportionally to the tensile force and between this spring and the control member for the distribution valve connecting parts for transmitting the defor- Provisions of the spring on this control member and for moving the valve in one of its three operational divisions are, characterized in that on the distributor valve (27) a device (33 40) to be operated from outside the same for moving the control member (28) into different ■ Operating positions are provided. 2. Device according to claim 1, characterized in that that the control member (28) of the distributor valve (27) is rotatable and is arranged axially displaceably in the valve body (4l) and has a bevel (73) which is inclined to The longitudinal axis of the control member (28) runs and, with reference to an actuating member (84), one in the valve body (4l) arranged, the outflow of the pressure medium from the cylinder of the servomotor (22) controlling valve (79) a distance when the control member (28 ") is in its aforementioned third operating position, and that parts (53-55) are provided for changing the distance between the bevel (73) and the actuating member (28). 3. Device according to claim 2, characterized in that that the parts for changing the distance between the bevel (73) and the actuating member (28) have a stop (53), with respect to the valve body (4l) means one to be operated from the outside, from the valve body (4l) recorded screw (54) held axially displaceable is, and that the control member (28) axially against the stop (53) pressing spring (48) between one end of the Control member (28) and the valve body (4l) arranged DR.-1NG. H. FINCKE, DIPL.-ING. H. BOHR DIPL-ING. S. STAEGEa si Dies "Unte'ioge (BesdveiDuno jnc 'Schutronsof.) Is * Jie. «Uletz * 4in <? Insure w veiofe? m efe- '"' -fossimc oe · ursorunoucr. smoe ^ sicnter. Jn'e'iooer: t Die (eontliene 'iedeuTono tie- λ;» »; -;, -«: »j»> is ¹ ni-, ; '«T« »vS' ⁵ · D ^; s urbpru ^ .oiicr, s noe-ecnteri jn'sriooer bemoer-; tcr. R Jsr ^ mnoKiec.iie 'w · **'» '. , T * i * : r. * r ohns. "-'- vi - * ;!« eiv>a>ti'jr ^ b'Vteii ! nieressev aeounrenite. 'sinqesener veraer. W Xnrrao ve-owi ' favnx ! äcn, ³ ®r - vi> p - ** 3.4 »· ^ *, ro nec» l · »·« ^ us wt. uoiiohiäf. hsiser- qeliefen deutsches, 'oroftraw.