JPH0475722B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rotary tiller and a method for automatically controlling tillage depth using its rear cover.

<Conventional technology> Changes in the depth of plowing by a rotary tiller are detected by vertically swinging the rotary rear cover (including the leveling plate) attached to the rotary tiller, and the detection signal is transmitted to the tractor body. There is a well-known means for automatically controlling the elevation of a rotary tillage machine by feedback to a control valve of a hydraulic cylinder device for lifting and lowering the work machine mounted above, so as to maintain the above-mentioned plowing depth constant at all times. The applicant also previously filed patent application No. 62-51485.
No. 62-31017 was proposed.

According to the configuration of this prior art, the rear end of the front sensor wire that feeds back the detection signal is stably held by the relay holder to the hitch frame for attaching and detaching the work equipment, and the The rear end of the front sensor wire attached to the rotary tiller and the front end of the rear sensor wire attached to the rotary tiller are separated in advance, and when the tiller is connected to the hitch frame, both sensors Since the wires automatically come into contact with each other and move forward and backward in an integrated manner, each time a tiller is attached to or detached from the hitch frame, the interconnection status of both sensor wires must be resolved one by one. There is no need to perform manual operations such as reconnecting or linking again, and in that sense, it can be said that it is extremely convenient in practice.

<Problems to be Solved by the Invention> However, as far as the configuration of the prior art described above remains, the rear sensor wire attached to the rotary tiller is embodied as a rigid form of the advancing/retracting rod. Since the rotary rear cover itself does not move forward in an oppressive manner, it is easy for the contact state between both sensor wires to be broken inadvertently during tilling work, and the limit of detection due to excessive rise of the rotary rear cover is not specified. Since there is a lot of so-called play, it is not possible to improve the response performance within a practically effective detection range, and there is a problem that the accuracy of the plowing depth control effect is reduced.

In particular, in order to make the above-mentioned rotary rear cover widely applicable to various working conditions and soil conditions such as normal tilling, rough tilling, ultra-fine soil tilling, paddy plowing, etc. using the tilling machine, the present applicant has already proposed a Utility Application filed in 1983.
For special types of rotary tillers, such as No. 31018, in which the hanging height from the rotary front cover is adjusted and set by changing the height in advance, each time the rear cover is changed, The working length of the rear sensor wire in the form of a rigid rod must be manually adjusted one by one by, for example, turning a turnbuckle.

If you do not close the lid and adjust the working length of the rear sensor wire to match the height change of the rotary rear cover to maintain a reliable connection with the front sensor wire, the detection signal will not be correctly fed back to the tractor body. This is because it is impossible to do so, resulting in control errors.

Further, even if such extremely troublesome adjustment operation were to be performed, it would be difficult to obtain a precise adjustment state using stepwise manual adjustment means such as rotation of the turnbuckle.

<Means for solving the problems> The present invention aims to fundamentally solve these problems while ensuring the advantages of the above-mentioned prior art, and provides a rotary tiller for automatic control of plowing depth. First, the rear cover, which also covers the back surface of the rotation trajectory, is attached to the rear end of the front cover fixedly held on the rotary main frame by the first pivot pin so as to cover the rotation trajectory of the tilling claws from above. Then, determine the hanging height from the front cover.
This model is assembled in a suspended state so that the height can be adjusted and set by changing the height in advance by operating the switching lever, and after the setting is done, it can be used for up and down swinging around the first pivot pin during tilling work. Assuming that, the lower end of the rotating arm is pivotally connected to the rear end of the front cover by a third pivot pin arranged on the same axis as the first pivot pin, and the rear cover is located in a corresponding position. a connecting plate is integrally erected from the front end of the connecting arm, and the front end of the connecting arm bridging between the connecting plates is connected to the upper end of the rotating arm by a fourth pivot pin;
Similarly, the rear end of the connecting arm is attached to the upper end of the connecting plate by the fifth pivot pin so that it can rotate freely in the front and rear directions, while the support that extends downward from this is fixed to the rotary main frame. on the plate,
The lower end of the pressing arm corresponding to the rotating arm is pivotally connected by a sixth pivot pin, and the middle part of the pressing arm and the middle part of the rotating arm are connected to each other through a reciprocating rod. By pivotally connecting the rear cover to the first pivot pin, the movement of the rear cover that swings up and down around the first pivot pin is detected, and the detection signal is fed back forward. In addition to forming a feedback link mechanism that moves forward and backward, the position of the fifth pivot pin at the time when the suspension height of the rear cover is adjusted to be low is set to A, and the position of the fifth pivot pin is set to A when the suspension height is adjusted to be high. Assuming that the position of the fifth pivot pin is B and the position of the fourth pivot pin is C, an imaginary triangle in side view surrounded by a line connecting the three positions has position C as its apex. By forming a vertical isosceles triangle with the base thereof and positioning the fourth pivot pin at the C position of the apex, the above-mentioned It is characterized by the fact that the forward and backward action of the feedback link mechanism in the front and rear direction remains constant at all times, and in the rotary tiller of the same type as the above, the second feature is that the amount of forward and backward movement of the feedback link mechanism in the front and back direction remains constant. The lower end of the rotating arm is pivotally connected to the rear end of the front cover by a third pivot pin disposed in the rear cover, and a connecting plate is integrally erected from the front end of the rear cover in a corresponding position. The front end of the connecting arm bridging between them is connected to the upper end of the rotating arm by a fourth pivot pin, and the rear end of the connecting arm is connected to the upper end of the connecting plate by a fifth pivot pin, While each is assembled so that it can rotate freely in the front and rear directions, it is fixed to the rotary main frame by attaching it to a support plate that extends downward.
The lower end of the pressing arm corresponding to the rotating arm is pivotally connected by a sixth pivot pin, and the rear end of the reciprocating rod interposed between the pressing arm and the rotating arm is rotated. It is assembled in a fixed state with the rear holding piece that is pivotally connected to the midway part of the arm, and the front end of the advance/retreat rod is passed through in a loose state with the front holding piece that is also pivotally connected to the midway part of the press arm. At the same time, by inserting and installing a compression coil spring between the two holding pieces, the movement of the rear cover that swings up and down around the first pivot pin is detected, and the detection signal is fed back forward. In order to achieve this, in conjunction with the rocking motion, we created a feedback link mechanism that moves forward and backward under the constant elastic force of a compression coil spring, and adjusted and set the hanging height of the rear cover to a low level. Assuming that the initial position of the 5th pivot pin is A, the initial position of the 5th pivot pin after adjusting the hanging height is B, and the position of the 4th pivot pin is C, The virtual triangle in side view surrounded by the line segments connecting the three positions is C
By forming a vertical isosceles triangle with its base at the apex, and by positioning and setting the fourth pivot pin at the apex of the triangle, it is possible to prevent changes in the suspension height when the rear cover is initially set. Regardless, the present invention is characterized in that the amount of movement of the feedback link mechanism in the longitudinal direction remains constant at all times.

Furthermore, as a method for automatically controlling the plowing depth using the rear cover of the rotary tillage machine, the rotary rear cover is attached to the rear end of the rotary front cover fixedly held on the rotary main frame, and the rotary rear cover is suspended with a first pivot pin for height adjustment. The suspension height relative to the front cover can be adjusted and set by changing the height of the front cover in advance using a switching lever, and after setting, during tilling work, the vertical swinging motion around the first pivot pin can be set. A rotary tiller of a type that can be used in a suspended state is removably connected to a hitch frame that is raised and lowered by a hydraulic cylinder device on the tractor body, and changes in plowing depth by the rotary tiller are controlled by the rotary tiller. The vertical tilling operation of the rear cover is detected, and the detection signal is fed back to the control valve of the hydraulic cylinder device, which automatically controls the rotary tiller itself in order to maintain the tillage depth constant at all times. When controlling the elevation, a third pivot pin is placed on the same axis as the first pivot pin for assembling the rear cover to the front cover of the rotary tilling machine, and the third pivot pin is used to attach the rear cover to the front cover of the rotary tilling machine. The lower end of the rotating arm is pivotally connected to the end, and a connecting plate is integrally erected from the front end of the rear cover located corresponding to the lower end of the rotating arm, and the front end of the connecting arm bridging between them is connected to the fourth To the upper end of the rotating arm by means of a pivot pin,
Similarly, the rear end of the connecting arm is attached to the upper end of the connecting plate using the fifth pivot pin so as to be freely rotatable in the front and rear directions, and the support plate is fixed to the rotary main frame and extends downward from this point. To,
The lower end of the pressing arm corresponding to the rotating arm is pivotally connected by a sixth pivot pin, and the middle part of the pressing arm and the middle part of the rotating arm are connected to each other through a reciprocating rod. By pivotably connecting the rear cover to the first pivot pin, it forms a feedback link mechanism that moves forward and backward in conjunction with the movement of the rear cover that swings up and down around the first pivot pin, and also increases the suspension height of the rear cover. The position of the 5th pivot pin when the hanging height was adjusted to a low level is A, the position of the 5th pivot pin when the hanging height was adjusted to a high level is B, and the position of the 4th pivot pin is B. When it is assumed that While positioning and setting the four pivot pins, contact the press arm of the feedback link mechanism with the hitch frame on the tractor body side,
A pressure-receiving arm that rotates in the front-rear direction in integral connection with the pressure-receiving arm is pivotally held, and a sensor wire that is moved forward and backward by the pressure-receiving arm is inserted between the pressure-receiving arm and the hydraulic control valve. By inserting the rear cover into the rear cover, the hydraulic control valve automatically controls the elevation of the rotary tiller by feedbacking a constant detection signal regardless of changes in the suspension height when the rear cover is initially set. It is characterized by this.

<Example> Hereinafter, the configuration of the present invention will be specifically described in detail based on the illustrated example. FIGS. 1 to 3 schematically show the state in which the rotary tiller is connected to the tractor and the state in which it is disassembled. I is a general term for rotary tillage machines, T is also the tractor body, and 10 is a top link mounting base attached and fixed to the rear of the machine T, and one top link 11 that comes out from this to the rear. A three-point linkage mechanism L for towing a working machine is formed by a pair of left and right lower links 12 that also extend rearward from the tractor body T itself. The three-point link mechanism L is lifted and lowered by a hydraulic cylinder device 13 for lifting and lowering the work equipment mounted on the tractor body T via a pair of left and right lift arms 14 and a lift rod 15. The hydraulic control valve attached to the cylinder device 13 is not shown.

16 is a PTO shaft that extracts rotational power from the rear of the tractor body T, and 17 is a universal joint shaft that connects the PTO shaft 16 with the input shaft of the rotary tiller I, which will be described later. It is suggested by F is a hitch frame that allows the rotary tiller I to be quickly attached and detached to the rear end of the three-point link mechanism L, and when viewed from the front and back, it has an almost A-shape as shown in Figure 9. The frame is integrated with a pair of left and right skirt arms 18 that widen downward.

It is connected to the rear end of the top link 11 at its center upper end and to the rear end of the lower link 12 at its left and right lower ends by pivot pins 19 and 20, respectively. Hanging hooks 21 and 22 are also integrally attached to the upper end and both left and right lower ends, respectively, and extend rearward.

On the other hand, regarding the rotary tiller I, 23 is a rotary main frame that is horizontally suspended along the left and right direction, and a gear case 24 is fixedly installed in the middle part of the rotary main frame. Reference numeral 25 denotes an input shaft projected forward from the gear case 24, and as described above, this is detachably connected to the PTO shaft 16 of the tractor body T.

26 is a rotary chain case that hangs down from one end of the main frame 23, 27 is a side plate that also hangs down from the other end parallel to the chain case 26, and both lower ends of the side plate 27 and the chain case 26 are connected. A tilling claw shaft 28, which is horizontally suspended, is rotatably driven by the power from the input shaft 25 via a transmission chain (not shown). In other words, although the figure shows a side drive type rotary tiller I, it goes without saying that a center drive type may be adopted as the tiller I.

29 is a plurality of tilling claws that are integrally planted from the claw shaft 28, and 30 is a support arm that is integrally extended forward from the middle of the rotary main frame 23 as a pair of left and right facing each other with the gear case 24 in between. Each of these is made up of a set of two plates, and a lower pin 31 is installed between the sets in a horizontal penetrating state.

A top link holder 32 is integrally extended forward and upward from the gear case 24, and is also made of a set of two plates, the upper end of which is a support that stands up integrally from a pair of left and right support arms 30. It is connected and fixed by a horizontal top pin 34 that intersects with the mast 33 and passes through the intersection. The top pin 34 and lower pin 31 are removably engaged with a pair of upper and lower lifting hooks 21 and 22 attached to the hitch frame F, and the entire rotary tiller I is mounted on the tractor body T. It is designed to be raised and lowered by a hydraulic cylinder device 13.

Reference numeral 35 designates a hanger frame for a rotary cover that is projected rearward from the support arm 30, and is designed to be raised and lowered by a rotary screw handle 36 using its front end as a fulcrum. A tailwheel 37 as suggested in FIG. 2 may also be attached. 38 is the screw handle 3
A stay integrally erected from the top link holder 32 in order to support the link holder 6 is shown.

Further, numeral 39 is a rotary front cover disposed in an arc shape along the rotation locus of the tilling claws 29 so as to cover the upper surface of the locus, and is fixedly held in a so-called suspended state from the main frame 23. And that front cover 3
At the rear end of 9, there is a rotary rear cover 40 that also covers the rear surface of the rotation locus, and the front cover 3
The hanging height h from the front cover 39 can be adjusted and set in advance to a high or low level, and when used in the adjusted state, it can freely swing up and down as if rotating against the front cover 39. The pivot is maintained so that work can be carried out.

That is, in FIGS. 4 to 7, where this is clear, 4
1 is a band-shaped flexible membrane of a certain length connecting the front cover 39 and the rear cover 40, and is made of an elastically deformable material such as rubber or synthetic resin.
Both front and rear ends thereof are fastened and fixed to both covers 39, 40 by pressing plates 42, 43 from below and a plurality of bolts 44, 45, respectively. Reference numeral 46 denotes a pair of both-end connecting pieces located near both left and right ends of the front cover 39 and integrally extending upward from the rear end, each of which is made of a set of two plates.

Reference numeral 47 denotes a pair of left and right connecting plates that correspond to the connecting piece 46 and are erected integrally upward from the front end of the rear cover 40 and taller than the connecting piece 46 on the front cover 39 side. , is composed of a set of two plates that are generally fan-shaped when viewed from the side, and each has a receiving hole 48 for a switching lever, which will be described later, opened at a mid-height position.

49 is a pair of left and right bridge arms bridging the front cover 39 and the rear cover 40;
Each of them is assembled and integrated with a pair of two plate pieces curved in an arch shape when viewed from the side, and a pair of front and rear shaft cylinders interposed between the two plate pieces. The connecting pieces 4 at both ends of the front cover 39 are
6, and a second pivot pin 51 that passes through another shaft cylinder at the mid-back and extends horizontally to the rear cover 4.
They are each rotatably connected to connecting plates 47 at both ends of 0.

Reference numeral 52 denotes a height adjustment elongated hole formed through one of the plate pieces at the rear lower end position of each bridge arm 49, and has a locus along a constant rotation radius r around the second pivot pin 51. It is arranged in the form of a circular arc opening. Reference numerals 53 and 54 denote a pair of front and rear height adjustment round holes that are formed through the remaining plate piece at a constant distance, facing both ends of the opening of the elongated hole 52; A switching lever 55 for adjusting the hanging height is provided between either one of the elongated holes 52 and the lever receiving hole 48.
is hung horizontally on a skewer. 5
6 is a retaining pin installed in the lever 55;
57 is a coil spring that similarly presses the lever 55 in the direction of pushing into the round holes 53, 54 and the elongated hole 52.

In that case, the distance W1 between the first pivot pin 50 and the front adjustment round hole 53 is also shorter than the distance W2 between the first pivot pin 50 and the rear adjustment round hole 54, and The length of the bridge arm 49 is set in advance to be shorter than a certain length of the flexible membrane 41, and the lower surface of the bridge arm 49 is a concave curved surface that can smoothly receive and retreat the flexible membrane 41. A certain escape gap S is created between the upper and lower parts facing each other.

Therefore, by placing the switching lever 55 in a penetrating position from the lever receiving hole 48 of the both-end connecting plate 47 to the adjustment round hole 54 and adjustment slot 52 on the rear side, the bridge arm 49 and rear cover 4
When the connection state with 0 is locked, the flexible membrane 41 expands as shown in FIG. The above-mentioned hanging height h of the rear cover 40 with the first pivot pin 50 for connection as a reference plane is reduced, and the rotary tiller I is suitable for use in such operations as tilling thin soil and plowing paddy fields. The result is that the shallow plowing depth d1 can be dealt with.

Conversely, by similarly positioning the switching lever 55 to extend from the lever receiving hole 48 to the adjustment round hole 53 and the adjustment slot 52 on the front side, when the bridge arm 49 and the rear cover 40 are connected and locked, the fifth As shown in FIG. 7, the flexible membrane 41 is contracted and deformed into a convex curve that enters the escape gap S, and the bridge arm 49 and rear cover 4 are
0 is reduced to an acute angle, so to speak, the suspension height h of the rear cover 40 is increased, and the rotary tiller I is used for normal tillage, rough tillage, etc. deep plowing depth d
The optimum set state is reached for 2.

In other words, depending on the desired plowing depth of the rotary tiller I, the hanging height h of the rear cover 40 is selectively switched to the plural adjustment round holes 53 and 54 by the switching lever 55. Although the rear cover 40 can be adjusted to a high or low position in advance, no matter which setting is performed, the rear cover 40 will not move until the switching lever 55 passes through the lever receiving hole 48 and adjustment round holes 53 and 54.
The rear cover 40 and the bridge arm 49 are connected to the bridge arm 49 in a fixed and locked state at the so-called two-point position with the second pivot pin 51. are integrated with each other around the first pivot pin 50 for vertical swinging motion.

This does not change even if a separate grounding plate 58 is attached to the rear lower end position of the rear cover 40. Reference numeral 59 designates a pair of left and right spring receiving rods which are pivotally erected from the mid-back part of the rear cover 40, and are assembled and held in the above-mentioned rotary cover hanger frame 35 so as to be movable up and down at their mid-height positions. . 60 is the leveling plate 5
A coil spring that applies grounding back pressure to 8,
They are each wrapped around a spring receiving rod 59, and the strength of the spring tension can be adjusted.

Furthermore, the rotary tiller I as described above is capable of always correctly detecting the up-and-down rocking motion during use, regardless of whether the suspension height h of the rear cover 40 is adjusted to high or low. A feedback link mechanism is also equipped to feed back the detection signal to the control valve of the hydraulic cylinder device 13 mounted on the tractor body T, and the valve controls the plowing depth of the rotary tiller I. It is now possible to maintain and control it automatically, keeping it constant at all times.

That is, in FIGS. 1 to 10, which clearly show the feedback link mechanism, the subsequent reference numeral 61 is located approximately midway in the left-right direction (longitudinal direction) of the rotary front cover 39 and integrally hangs upward from the rear end. This intermediate connecting piece stands upright and is made of a set of two plates similar to the above-mentioned both end connecting pieces 46, to which the lower end of the rotating arm 62 is assembled by a third pivot pin 63. There is.
In this case, as suggested from FIGS. 2 and 4, the third pivot pin 63 is disposed on the same axis X-X as the first pivot pin 50, and in that respect, both It is also possible to suspend the pivot pins 50, 63 horizontally as one whole.

Reference numeral 64 designates an intermediate connecting plate 64 that stands tall and integrally upward from the front end of the rotary rear cover 40, similar to the above-mentioned both end connecting plates 47, so as to correspond correctly to the intermediate connecting piece 61. Consists of board material. Reference numeral 65 is a connecting arm that bridges the front and back of the rotating arm 62 and the intermediate connecting plate 64, and its bifurcated front end is connected to the fourth pivot pin 6.
6 to the upper end of the rotating arm 62, and the forked rear end thereof to the upper end of the intermediate connecting plate 64 by a fifth pivot pin 67, respectively, so as to be freely rotatable. Therefore, when the rear cover 40 swings up and down around the first pivot pin 50 with respect to the front cover 39, the pivot arm 62 automatically rotates in the front-back direction about the third pivot pin 63. It will be used for operation.

Further, as described above, the support arm 30 is projected forward from the rotary main frame 23, and the plate material forming the support arm 30 includes the support plate 6 of the pressing arm 68.
9 is integrally joined with a plurality of bolts 70 and the like in a downwardly extending state. and,
A lower end portion of the pressing arm 68 is attached to the protruding tip of the support plate 69 by a sixth pivot pin 71 so as to be freely rotatable in the front-rear direction.
In that case, the pressing arm 68 and the rotating arm 62
are arranged correspondingly on the same straight line along the front-rear direction when viewed from the plane of FIG. 2, and moreover, when viewed from the side in FIGS. 1 and 8, they face each other at approximately the same height position.

Reference numeral 72 denotes a reciprocating rod of a certain length that operatively connects the pressing arm 68 and the rotating arm 62, and its front end is a front holding piece that extends rearward from the mid-height position of the pressing arm 68. 73 in a loose state, and the rear end portion is also provided with a screw fastening means for a rear holding piece 74 that protrudes forward from the corresponding mid-height position of the rotating arm 62. It is removably fixed by etc.
75 and 76 are seventh and eighth pivot pins for assembling the pair of front and rear holding pieces 73 and 74 to the pressing arm 68 and the rotating arm 62, respectively; 77 is a rod receiving hole opened through the front side holding piece 73; 78
is the advancing/retracting rod 7 which is engaged with the receiving hole 77.
2 is a retaining stopper, 79 is a rear holding piece 74
This is a fixing nut for the forward and backward movement rod 72.

Further, reference numeral 80 denotes a compression coil spring which is interposed between the front and rear of both the holding pieces 73 and 74 and is wound around the forward/backward rod 72.
The operating length of the rotary rear cover 40 rises excessively and is pushed forward by the pressing arm 68, which will be described later. Sometimes, on the contrary, it exerts a forceful force, as if pulling the reciprocating rod 72 backward. In other words, the coil spring 8
0 to maintain a constant distance between the front and rear of the pressing arm 68 and the rotating arm 62, and
A tractor body T whose pressing arm 68 will be described later.
This allows it to be in constant, reliable contact with the side pressure-receiving arm.

Moreover, the elastic force can be adjusted in strength by means of an adjustment nut 81 screwed onto the threaded shaft portion of the reciprocating rod 72. The working length of the advancing/retracting rod 72 can also be adjusted in advance to a longer or shorter length by means of the fixing nut 79 which can be moved forward or backward along its threaded shaft. In addition, the forward and backward movement rod 72 passes through the vertical gap between the rotary main frame 23 and the front cover 39.
Its operational safety is indicated by FIG.

As mentioned above, the suspension height h of the rear cover 40 relative to the rotary front cover 39 can be adjusted and set in advance to be high or low as shown in FIGS. 6 and 7 according to various work conditions and soil conditions. Then, the rotating arm 62 and the pressing arm 68
In addition, the amount of movement of the feedback link mechanism formed by the movement rod 72 and the like in the front and back direction is different between when the suspension height h is set to a high value and when it is set to a low value.
It is no longer possible to constantly detect the up-and-down movement of the rotary rear cover 40 in use without too much or too little, and to correctly feed back the detection signal to the hydraulic control valve on the tractor body T side by the link mechanism. Furthermore, in order to prevent this, it is necessary to manually adjust the operating length of the intermediate advance/retreat rod 72 in the feedback link mechanism at all times.

Therefore, regardless of whether the hanging height h of the rotary rear cover 40 is adjusted to high or low,
It is necessary to keep the forward and backward action of the feedback link mechanism constant and constant so that they are equal to each other.
4, the fourth pivot pin 66 of the rotating arm 62 and the connecting arm 65 is positioned and set as follows.

That is, in the schematic diagram of FIG. 10, which is an enlarged version of this diagram, the position of the fifth pivot pin 67 at the time when the hanging height h of the rotary rear cover 40 was initially set to be low is designated as A, and when the hanging height h of the rotary rear cover 40 is also set to be high. The initial position of the fifth pivot pin 67 is B, and the position of the fourth pivot pin 66 is C.
Assuming that, the virtual triangle △ABC surrounded by line segments connecting the three positions becomes an isosceles triangle in side view with the apex at position C, and the base AB of the isosceles triangle is connected to the vertical line Y-Y. So that
At the C position, the upper end of the rotating arm 62 and the front end of the connecting arm 65 are assembled using the fourth pivot pin 66. At this time, the upper end of the rotating arm 62, whose lower end is pivotally connected to the intermediate connecting piece 61, is set in advance in an upright state in which it is tilted backward by a certain angle γ.

With such an assembly configuration, regardless of changes in the hanging height h of the rotary rear cover 40, the movement of the rotating arm 62, which is pivotally connected via the intermediate connecting plate 64 and the connecting arm 65, is always maintained. As a result, when the rear cover 40 is used in this initial set state and the rear cover 40 performs up and down rocking operations during the tilling operation,
Rotary tiller I detected by this
The plowing depth change signal is transmitted from the rotating arm 62 to the pressing arm 68 via the advance/retreat rod 72 as the accurate forward/backward movement of the feedback link mechanism, and is fed back to the front of the tractor body T side. It will become.

A rotating arm 62 and a moving rod 7 form a feedback link mechanism that can move forward and backward.
2 and the pressing arm 68 are attached to the rear cover 40.
In the sense that it is installed on the attached rotary tiller I side, it functions as a transmitting system for the above-mentioned plowing depth detection signal, but the configuration that becomes the receiving system for this is installed on the tractor body T side as follows. ing.

That is, the reference numeral 82 in FIGS. 8 and 9 is a relay stand that is attached and fixed to the mid-height position of the hitch frame F from the front by welding or the like, and this is a wire holder 83 that is U-shaped when viewed from the front.
is fixedly installed using a plurality of bolts 84 or the like. Reference numeral 85 denotes a pressure receiving arm corresponding to the above-mentioned pressing arm 68, which is made of a substantially L-shaped plate piece when viewed from the side, and is attached to the upright wall surface of the wire holder 83 in the front-rear direction by a pivot pin 86 at its front upper end position. It is assembled and held so that it can rotate freely.

Moreover, at the rear lower end position of the pressure receiving arm 85,
Idle roller 87 that comes into contact with the pressing arm 68
is pivoted. Reference numeral 88 is a stopper piece that restricts excessive forward rotation of the pressure receiving arm 85 (excessive rise of the rotary rear cover), and is integrally projected forward from the lower end of the hitch frame F, and is attached to the above-mentioned roller 87. It's starting to hit me. The pressure-receiving arm 85 is set in relation to the stopper piece 88 so that it collides with the stopper piece 88, so when it is pushed forward by the presser arm 68 and collides with the stopper piece 88, it is compressed as described above. A rearward elastic force is generated by the coil spring 80, and the rotary rear cover 40 is lowered by the retracting rod 72 that moves backward.

Reference numeral 89 denotes a locking pin that extends horizontally from the mid-height position of the pressure receiving arm 85 toward the U-shaped interior of the wire holder 83, and a connecting cap 91 of the sensor wire 90 is connected to the locking pin. There is. The cap 91 is stably positioned and fixed to the lower horizontal wall surface of the wire holder 83.
The locking pin 89 of the sensor wire 90 has
The upper end of the coil spring 92 that pulls the wire 90 back forward is also locked.

Therefore, the pressure-receiving arm 85 that receives the tensile elastic force is in a state where it always rotates toward the rear. Moreover, as described above, the pressing arm 68
Since the roller 87 of the pressure-receiving arm 85 and the pressing arm 68 are subjected to an opposite rotational force directed toward the front, the rollers 87 of the pressure-receiving arm 85 and the pressing arm 68 never separate from each other even though they encounter vibrations and shocks during tilling work. This makes it possible to maintain a stable and reliable contact state.

In addition, as long as the rotary tiller I is connected to the hitch frame F on the tractor body T side,
Accurate contact action between the pressure receiving arm 85 and the pressing arm 68 can also be achieved automatically. The lower end of the tension coil spring 92 is connected to the base 9.
Like 1, it is locked to the lower horizontal wall surface of the wire holder 83.

The front end of the sensor wire 90 is pivotally connected to a sensor lever 93 that is extended from a control valve of the hydraulic cylinder device 13 in the tractor body T. In that case, in the figure, a rotatable piece 94 in the front-rear direction that is pivotally supported by the tractor body T and a forward-retreat arm 95 that pivotally connects the rotary piece 94 with the sensor lever 93 are used. Of course, the configuration is not limited to this.

Also, although the joint operation mechanism between the sensor lever 93 and the hydraulic control valve is not shown, in short, if the rotary tiller I sinks excessively during tilling work, for example, if the cultivated land is soft and the rotary tiller I sinks excessively, The amount of plowed soil mass piled up by machine I has increased, and the rotary rear cover 4
0 rises, the detection signal of the rise is fed back to the front of the tractor body T side, and the hydraulic control valve causes the rotary tiller I itself to rise. When the rear cover 40 is lowered excessively due to the lowering of the rear cover 40, the hydraulic cylinder device 13 is controlled by the control valve so that the detection signal of the lowering is fed back and the rotary tiller I is also operated to lower it. Therefore, it is sufficient that the tilling depth of the rotary tiller I can be maintained constant at all times. In this sense, not only mechanical means but also electronic circuit means can be employed as a mechanism for operating the control valve in response to the detection signal. It goes without saying that the hydraulic control valve is maintained in its normal neutral state by the return spring attached to it.

<Function> According to the above configuration, the rotary rear cover 4
Regardless of the height change of the hanging height h at 0,
When this is attached and set to the front cover 39, the pressing arm 68 forms the feedback link mechanism on the side of the rotary tiller I,
Since the pressure-receiving arm 85 holding the sensor wire 90 on the side of the tractor body T is automatically maintained in a state of active integral connection in which they are always in proper contact with each other, the rear cover 40 is now rises as shown by arrow P in FIG.
⇒The pressing arm 68 is pushed forward through the advancing/retracting rod 72, and the sensor wire 9 is pushed forward.
This will pull 0 backwards in the direction of the opposite arrow R.

The detection signal that acts in this way is fed back to the control valve attached to the hydraulic cylinder device 13 of the tractor body T, and under the control of that valve, the rotary tiller I itself is also raised by the amount that the rear cover 40 is raised. This allows the plowing depth to be maintained at a constant level.

Furthermore, when the rear cover 40 descends in the opposite direction of the arrow P, the pressing arm 68 on the rotary tiller I side moves backward, and the sensor wire 90 on the tractor body T side is pushed forward in the opposite direction. Therefore, due to the feedback of such a detection signal, the rotary tiller I itself is lowered by the amount by which the rear cover 40 is lowered, and as a result, the tillage depth is automatically maintained at a constant level. becomes. In any case, it goes without saying that the desired plowing depth to be maintained is set to a constant value in advance by a manual operation lever attached to the hydraulic control valve, the tail wheel 37, or the like.

Such a control effect can be obtained even if the rotary rear cover 40 is attached to the front cover 39 in advance so that it is suspended high as shown in FIG. Even if the rotary tiller I is installed and set to a lower adjustment state, it will be equally and precisely achieved during its use, and therefore the rotary tiller I can be used for normal tillage, rough tillage, fine soil tillage, and paddy plowing. This means that it can be widely adapted to various types of work such as

In that case, the rotating arm 62 and the pressing arm 68 of the feedback link mechanism installed in the rotary tiller I are kept in a non-rigid, elastic state by the compression coil spring 80 of the reciprocating rod 72 interposed between them. Since the press arm 68 is operatively and pivotally connected to the The attached free rotating rollers 87 not only make it more effective, but also prevent the rear cover 40 from rising excessively.
It can be regulated by the repressive action of

Furthermore, the hitch frame F on the tractor body T side
, where the pressure receiving arm 85 is pivotally mounted so as to be freely rotatable in the front and back direction, a stopper piece 88 for restricting excessive forward rotation is also installed on the hitch frame F, so that the rear cover 40 can be rotated freely. Excessive rise can be defined, and the accuracy of detecting the up-and-down movement and the accuracy of the plowing depth control effect can be improved, and in conjunction with the elastic action of the compression coil spring 80, the rear cover 40 that has risen excessively can be prevented. can be lowered quickly, improving control response performance within the originally effective detection range.

<Effects of the Invention> As described above, in the present invention, as a rotary tiller for automatic control of tillage depth, the front cover is fixedly held on the rotary main frame 23 so as to cover the rotation locus of the tiller claws 29 from above. To the rear end of 39, a rear cover 40 that also covers the back surface of the rotation locus is attached by means of a first pivot pin 50, and its hanging height h relative to the front cover 39 can be changed in height in advance by operating a switching lever 55. The above-mentioned first pivot pin 50 is assembled in a suspended state so that the first pivot pin 50 can be adjusted and set, and during the tilling work after the setup, and can be vertically swung around the first pivot pin 50. The lower end of the rotating arm 62 is pivotally connected to the rear end of the front cover 39 by a third pivot pin 63 disposed on the same axis XX as the support pin 50, and the rear cover 40 is connected to the rear end of the front cover 39. A connecting plate 64 is integrally erected from the front end of the connecting arm 65, and the front end of the connecting arm 65 bridging between them is connected to the upper end of the rotating arm 62 by a fourth pivot pin 66. The rear end of 65 is connected to the fifth pivot pin 67
The connecting plate 64 is attached to the upper end of the connecting plate 64 so as to be rotatable in the front-rear direction, while the supporting plate 69 that extends downward from the rotary main frame 23 corresponds to the rotating arm 62. The lower end of the pressing arm 68 is pivotally connected by a sixth pivot pin 71, and the intermediate portion of the pressing arm 68 and the rotating arm 62 are operatively connected to each other via a reciprocating rod 72. By pivoting and connecting, the movement of the rear cover 40 that swings up and down around the first pivot pin 50 is detected, and the detection signal is fed back forward. In addition to forming a feedback link mechanism that moves forward and backward in the direction, the hanging height h of the rear cover 40 is adjusted to be low.The position of the fifth pivot pin 67 at the beginning of setting is A, and the hanging height h is also set to be high. Assuming that the position of the fifth pivot pin 67 at the beginning of the adjustment set is B, and the position of the fourth pivot pin 66 is C, a virtual triangle in side view surrounded by a line segment connecting the three positions. △ABC becomes a vertical isosceles triangle with the base AB having the apex at position C, and by positioning and setting the fourth pivot pin 66 at the apex of position C, the rear cover 40 is Regardless of changes in the suspension height h, the forward and backward movement of the above-mentioned feedback link mechanism in the front-rear direction always remains constant, thereby reliably solving the problems of the prior art mentioned at the beginning. There is an effect that can be done.

That is, even if the hanging height h of the rotary rear cover 40 is adjusted in advance to be higher or lower depending on various work conditions and soil conditions, each time the height is changed, additional artificial damage is caused. There is no need to make any adjustments, and the up and down movement of the rear cover 40 is automatically detected during tilling work, and the detected signal is used as the forward and backward movement of the feedback link mechanism to control the tractor body T. This allows accurate feedback to the front of the side.

In this case, especially the pressing arm 68 and the rotating arm 62
The front end of the reciprocating rod 72 interposed between the press arm 68 and the front holding piece 73 which is pivotally connected to the middle part of the press arm 68 is passed through in a loose state, while the rear end of the retracting rod 72 is It is assembled in a fixed state with the rear holding piece 74 which is also pivotally connected to the middle part of the rotating arm 62, and both holding pieces 7
A compression coil spring 80 is inserted between the front and rear of the coils 3 and 74, and the feedback link mechanism is operated under a constant elastic force by the coil spring 80.
If configured to move forward and backward in the front-back direction, excessive rise of the rear cover 40 during plowing work can be effectively absorbed and restricted, improving control response performance within a practically effective detection range. At the same time, it is possible to obtain a highly accurate plowing depth control effect without mistakes.

The hitch frame F on the side of the tractor body T contacts the pressing arm 68 of the feedback link mechanism of the rotary tilling machine I, and rotates in the front-back direction in integral connection with the pressing arm 68. The sensor wire 90, which is moved forward and backward by the pressure receiving arm 85, is supported between the pressure receiving arm 85 and the control valve of the hydraulic cylinder device 13 for lifting and lowering the working machine. By inserting the rotary tiller I into the hitch frame F and connecting it to the hitch frame F, the up and down rocking motion of the rotary rear cover 40 can be controlled by the tiller I's own plowing depth change signal. If the plowing depth is detected and controlled to maintain a constant plowing depth at all times, even if the tiller I is used for various tasks such as normal tillage, rough tillage, ultra-fine soil tillage, paddy plowing, etc.
In addition, even when used on cultivated land with various soil types that change in hardness and softness, it is possible to automatically maintain a constant plowing depth with high precision at all times regardless of these conditions, and for operation, it is possible to operate the tiller I by moving it to the tractor body T side. Simply attaching and detaching it to the hitch frame F will be sufficient.

[Brief explanation of the drawing]

Figures 1 and 2 are an overall schematic side view and a plan view showing how the rotary tiller is connected to the tractor, Figure 3 is an overall schematic side view of the rotary tiller in its disassembled state, and Figure 4 is an exploded view of the rotary front cover and rear cover. FIG. 5 is a partially enlarged sectional view taken along the - line in FIG. 2, FIGS. 6 and 7 are side views showing the set state in which the hanging height of the rear cover changes, and FIG. 9 is an enlarged partially cutaway side view showing the feedback link mechanism extracted, and FIG. 9 is a front view of FIG. 8 seen from the front.
FIG. 10 is a schematic side view showing how the rear cover is assembled to the front cover. F...Hitsuchi frame, L...3-point link mechanism, I
...Rotary tiller, T...tractor body,
13... Hydraulic cylinder device, 23... Rotary main frame, 29... Tilling claw, 30... Support arm, 39... Rotary front cover, 40...
Rotary rear cover, 41...Flexible membrane, 46, 6
DESCRIPTION OF SYMBOLS 1... Connection piece, 47, 64... Connection plate, 49... Bridge arm, 50... First pivot pin, 51... Second pivot pin, 55... Switching lever, 62... Rotating arm, 6
3...Third pivot pin, 65...Connection arm, 66...Fourth pivot pin, 67...Fifth pivot pin, 68...Press arm, 69...Support plate, 71...Sixth pivot pin, 72...Advance/retreat Rod, 73...Front holding piece, 74
...Rear side holding piece, 75...Seventh pivot pin, 76...Eighth
Pivot pin, 79...fixing nut, 80...compression coil spring, 81...adjusting nut, 82...relay stand, 83...
Wire holder, 85...Pressure receiving arm, 87...Idling roller, 88...Stopper piece, 90...Sensor wire, 92...Tension coil spring, h...Hanging height, d1...Shallow plowing depth, d2...Deep plowing depth, X-
X...Axis line, Y-Y...Vertical line.

Claims (1)

[Claims] 1. A rear cover 40, which also covers the back surface of the rotation trajectory, is attached to the rear end of the front cover 39 fixedly held on the rotary main frame 23 so as to cover the rotation trajectory of the tilling claws 29 from above. The suspension height h relative to the front cover 39 can be adjusted and set by changing the height in advance by operating the switching lever 55 using the pivot pin 50, and during the tilling operation after the setting. , in a type of rotary cultivating machine I that is assembled around the first pivot pin 50 in a suspended state capable of vertically swinging motion, and arranged on the same axis line X-X with the first pivot pin 50. The lower end of the rotating arm 62 is pivotally connected to the rear end of the front cover 39 by a third pivot pin 63, and a connecting plate 64 is integrally erected from the front end of the rear cover 40 in a corresponding position. , the front end of the connecting arm 65 bridging between them is connected to the upper end of the rotating arm 62 by a fourth pivot pin 66, and the rear end of the connecting arm 65 is connected to the fifth pivot pin 67.
The connecting plate 64 is attached to the upper end of the connecting plate 64 so as to be rotatable in the front-rear direction, while the supporting plate 69 that extends downward from the rotary main frame 23 corresponds to the rotating arm 62. The lower end of the pressing arm 68 is pivotally connected by a sixth pivot pin 71, and the intermediate portion of the pressing arm 68 and the rotating arm 62 are operatively connected to each other via a reciprocating rod 72. By pivoting and connecting, the movement of the rear cover 40 that swings up and down around the first pivot pin 50 is detected, and the detection signal is fed back forward. In addition to forming a feedback link mechanism that moves forward and backward in the direction, the hanging height h of the rear cover 40 is adjusted to be low.The position of the fifth pivot pin 67 at the beginning of setting is A, and the hanging height h is also set to be high. Assuming that the position of the fifth pivot pin 67 at the beginning of the adjustment set is B, and the position of the fourth pivot pin 66 is C, a virtual triangle in side view surrounded by a line segment connecting the three positions. (△ABC) becomes a perpendicular isosceles triangle with the base AB and the vertex at position C,
Moreover, by positioning and setting the fourth pivot pin 66 at the C position at the apex, the front and rear of the feedback link mechanism can be adjusted regardless of the change in the suspension height h when the rear cover 40 is initially set. A rotary tiller characterized in that the amount of forward and backward action along the direction remains constant and unchanged. 2. Attach the rear cover 40, which also covers the back surface of the rotation trajectory, to the rear end of the front cover 39 fixedly held on the rotary main frame 23 so as to cover the rotation trajectory of the tilling claws 29 from above, and to the first pivot pin 50. Therefore, the hanging height h with respect to the front cover 39 can be adjusted and set by changing the height in advance by operating the switching lever 55, and the first pivot pin can be adjusted during the tilling operation after setting. In the rotary cultivating machine 1 of the type assembled in a suspended state that can be used for up-and-down swinging around the rotary tiller 50, a third pivot pin 63 is disposed on the same axis line X-X as the first pivot pin 50. Accordingly, the lower end of the rotating arm 62 is pivotally connected to the rear end of the front cover 39, and the connecting plate 64 is integrally erected from the front end of the rear cover 40 located corresponding thereto, so that a bridge is formed between them. The front end of the connecting arm 65 is connected to the upper end of the rotating arm 62 by a fourth pivot pin 66, and the rear end of the connecting arm 65 is connected to the fifth pivot pin 67.
The connecting plate 64 is attached to the upper end of the connecting plate 64 so as to be rotatable in the front-rear direction, while the supporting plate 69 that extends downward from the rotary main frame 23 corresponds to the rotating arm 62. The lower end of the pressing arm 68 is pivoted by a sixth pivot pin 71, and the rear end of the reciprocating rod 72 interposed between the pressing arm 68 and the rotating arm 62 is
The front holding piece 73 is assembled in a fixed state with the rear holding piece 74 which is pivotally connected to the middle part of the rotating arm 62, and the front end of the advance/retreat rod 72 is also pivotally connected to the middle part of the pressing arm 68. and both holding pieces 73, 74.
By inserting and installing a compression coil spring 80 between the two, the movement of the rear cover 40 that swings up and down around the first pivot pin 50 is detected, and the detection signal is fed back forward. In conjunction with the rocking motion, a feedback link mechanism is formed that moves forward and backward under a constant elastic force from the compression coil spring 80, and the hanging height h of the rear cover 40 is adjusted to a low level. Assume that the position of the fifth pivot pin 67 is A, the position of the fifth pivot pin 67 at the beginning of adjusting and setting the suspension height h is B, and the position of the fourth pivot pin 66 is C. Then, the virtual triangle (△ABC) in side view surrounded by the line segments connecting the three positions becomes a vertical isosceles triangle with the base AB and the apex at the C position,
Moreover, by positioning and setting the fourth pivot pin 66 at the C position at the apex, the front and rear of the feedback link mechanism can be adjusted regardless of the change in the suspension height h when the rear cover 40 is initially set. A rotary tiller characterized in that the amount of forward and backward action along the direction remains constant and unchanged. 3 Screw the advancing/retracting rod 72 to the rear holding piece 74, and tighten the fixing nut 79 to secure the advancing/retracting rod 7.
The elastic force of the compression coil spring 80 is adjusted by an adjustment nut 81 which is separately screwed onto the forward/backward rod 72.
A rotary tiller according to claim 2, characterized in that the rotary tiller is set so that its strength can be changed. 4 To the rear end of the rotary front cover 39 fixedly held on the rotary main frame 23,
The rotary rear cover 40 is fixed by the first pivot pin 50 and the switching lever 55 for adjusting the hanging height.
Suspension height h relative to the front cover 39
A type of rotary tiller that can be adjusted and set by changing the height in advance, and is assembled in a suspended state around the first pivot pin 50 so that it can be swung up and down during tilling work after setting. The work implement I is removably connected to the hitch frame F which is raised and lowered by the hydraulic cylinder device 13 of the tractor body T, and changes in plowing depth by the rotary tiller I are used for the up and down swinging of the rear cover 40. Detected as,
The detection signal is fed back to the control valve of the hydraulic cylinder device 13, and the control valve automatically controls the elevation of the rotary tiller I itself in order to maintain the tillage depth constant at all times. In the method, a third pivot pin 63 is arranged on the same axis XX as the first pivot pin 50 for assembling the rear cover 40 to the front cover 39 of the rotary tilling machine I, and the third pivot pin 63 is arranged on the same axis XX. The lower end of the rotating arm 62 is pivotally connected to the rear end of the front cover 39 by a pin 63, and a connecting plate 64 is integrally erected from the front end of the rear cover 40 in a corresponding position, and a connection plate 64 is provided between the two. The front end of the bridging connecting arm 65 is connected to the rotating arm 62 by a fourth pivot pin 66.
Similarly, the rear end of the connecting arm 65 is attached to the upper end of the connecting plate 64 by the fifth pivot pin 67 so as to be rotatable in the front and back directions, and fixed to the rotary main frame 23. The lower end of the pressing arm 68, which corresponds to the rotating arm 62, is pivotally connected to the support plate 69 extending downward from the sixth pivot pin 71, so that the pressing arm 68 can rotate with the middle part of the pressing arm 68. By operatively pivotally connecting the middle part of the arm 62 with the arm 62 via the reciprocating rod 72, it can move forward and backward in conjunction with the movement of the rear cover 40 that swings up and down around the first pivot pin 50. In addition to forming a feedback link mechanism that moves forward and backward in the direction, the hanging height h of the rear cover 40 is adjusted to be low.The position of the fifth pivot pin 67 at the beginning of setting is A, and the hanging height h is also set to be high. Assuming that the position of the fifth pivot pin 67 at the beginning of the adjustment set is B, and the position of the fourth pivot pin 66 is C, a virtual triangle in side view surrounded by a line segment connecting the three positions. (△ABC) becomes a perpendicular isosceles triangle with the base AB and the vertex at position C,
While positioning and setting the fourth pivot pin 66 at position C at its apex, the fourth pivot pin 66 is brought into contact with the press arm 68 of the feedback link mechanism on the hitch frame F on the tractor body T side, and the press arm 68 and A pressure-receiving arm 85 that rotates in the front-rear direction in an integrally connected manner is pivotally held, and a sensor wire 90 that is moved forward and backward by the pressure-receiving arm 85 is attached to the pressure-receiving arm 85.
and the above-mentioned hydraulic control valve, and regardless of changes in the hanging height h when the rear cover 40 is initially set, a constant detection signal is always fed back, and the hydraulic control valve A method for automatically controlling plowing depth using a rear cover of a rotary tiller I, characterized by automatically controlling the elevation of the rotary tiller I. 5 The pressure receiving arm 85 is brought into contact with the pressing arm 68 via the freely rotating roller 87 pivotally supported at the rear end, and the excessive forward rotation of the pressure receiving arm 85 is prevented by a stopper piece attached to the hitch frame F. 8. A method for automatically controlling plowing depth using a rear cover of a rotary tiller according to claim 4, characterized in that the plowing depth is regulated by Patent No. 88. 6. The pressure arm 68 is always biased to rotate forward by the compression coil spring 80 wrapped around its advance/retraction rod 72, while the tension coil spring 92 to which the pressure receiving arm 85 is locked is always biased to rotate the pressure arm 68 forward. Cultivation by the rear cover of a rotary tiller according to claim 4, characterized in that the arms 68, 85 are urged to rotate rearward and come into contact with each other in a pressing manner. Automatic depth control method.