JP5029888B2 - Tillage claw mounting structure - Google Patents

Description

  The present invention relates to a tilling claw attachment structure on a tilling shaft of a tilling work machine.

  Conventionally, as a structure for attaching a tilling claw on a tilling shaft of a rotary tiller, a plurality of tilling claws are fastened and fixed by bolts and nuts to a flange provided around the tilling shaft as described in Patent Document 1, respectively. There is a flange system.

  The flange method is easy to manufacture because the tilling nail is directly fastened to the flange, which is a flat steel plate. However, the tilling nail is sometimes subjected to extremely abnormal loads during leveling work. Various troubles and damages to components have occurred during work, such as deformation, damage, flange deformation, bolt deformation, damage, and the like.

  Possible abnormal loads include when the field is clayey and dry and hard, and when the tilling claws collide with gravel, tree roots, etc. existing in the field. In fact, this phenomenon is often seen in open and improved fields.

  Such an abnormal load is not only excessive in comparison with a normal load, but is sometimes shocking and may cause damage that cannot be considered in common sense.

  In addition, it has recently been clarified that this abnormal load is largely related as a cause of looseness which is the most problematic in screw fastening bodies. In particular, measures have been taken for the initial loosening in the automobile industry, but no measures have been taken for the attachment structure of the tilling nail.

In the initial loosening, when slight wear occurs between the joint surfaces of the screw fastening body, a slight change occurs in the distance between the joint surfaces, and plastic deformation such as sag and conformance occurs, and the tightening force decreases rapidly and loosens. This is a phenomenon, but as a phenomenon, the nut does not rotate at all, so it cannot be detected visually. However, as a matter of fact, since it is loose as a screw fastening body, it proceeds to the loosening that the nut rotates. In general, the method of preventing the rotation of the nut is still called “loosening prevention”, and it is currently inspected for looseness with a mark such as I mark to check whether it is loose or not. Measures for initial loosening, that is, non-rotational loosening are not taken, which is the same for the attachment of tillage claws.
Japanese Utility Model Publication No. 63-181203

  Therefore, the present invention has a structure that can reasonably handle mechanically even when an abnormal load is applied to the tilling nail, and has a structure that makes it easier to handle without causing deformation or damage to the screw fastening body. The issue is to provide.

  In order to solve the above problems, the present invention takes the following technical means.

The cultivation claw attachment structure of this invention is a cultivation claw attachment structure for attaching a cultivation claw (3) to the flange (2) fixed to a cultivation axis | shaft (1), Comprising: A flange (2) and a cultivation claw (3) The nuts (7) are screwed into the bolt insertion holes (4), (5) provided in the nuts (7), and the tillage claws (3) are attached to the flanges (2). (2) has a first stopper (9a) that comes into contact with the tillage claw (3) at a position closer to the outer peripheral edge than the bolt insertion hole (4) on the tillage claw mounting surface (8), and bolt insertion As having a second stopper (9b) that contacts the tilling claw (3) at a position closer to the tilling shaft (1) than the hole (4), the load applied to the tilling claw (3) is absorbed.
A cylindrical portion (11) that fits outside the tilling shaft (1) is provided around the tilling shaft through hole (10) of the flange (2), and a second stopper (9b) is provided on the base (3a) of the tilling claw (3). ) And the cylindrical portion (11) are in contact with each other, and the cylindrical portion (11) is formed integrally with the flange (2) main body, and the base (3a) The portion that comes into contact with the tubular portion (11) has a curved shape along the outer peripheral surface of the tubular portion (11), and the base portion (3a) and the tubular portion (11) are formed at the contact portion. Are in contact with each other, and the abutting portion is a side edge on the same side as the abutting side of the first stopper (9a) in the vicinity of the end of the base portion (3a) .

  Further, in the vicinity of the bolt insertion holes 4, 5, it has a portion where a gap 13 is generated between the flange 2 and the tilling claw 3, and has a contact portion 14 between the flange 2 and the tilling claw 3 on the outside thereof, The flange 2 or the tilling claw 3 can be elastically deformed to compensate for a decrease in the axial force of the bolt 6 (Claim 2).

Moreover, the said cylindrical part (11) is formed so that it may extend at right angles to the tilling nail attachment surface (8) of a flange (2), and its back surface, and it is on one surface side or both surface side of a flange (2). The tilling nail attachment structure according to claim 1 or 2, which is formed to extend.

  The tillage claw mounting structure of the present invention has the above-described configuration, and loads applied to the tillage claw 3 are first and second stoppers 9a and 9b, which are located outside and inside the bolt insertion hole 4, respectively. Since the external force is not directly applied to the bolt 6 by receiving, deformation, damage, and the like of the bolt 6 and the fastening portion between the flange 2 and the tilling claw 3 are prevented.

  Further, in the vicinity of the bolt insertion holes 4, 5, it has a portion where a gap 13 is generated between the flange 2 and the tilling claw 3, and has a contact portion 14 between the flange 2 and the tilling claw 3 on the outside thereof, If the flange 2 or the tilling claw 3 is elastically deformed to compensate for a decrease in the axial force of the bolt 6 (Claim 2), the friction force acting between the flange 2 and the tilling claw 3 is caused by the contact portion 14. Since the contact portion 14 is located at a position away from the bolt insertion holes 4 and 5 while being secured, a predetermined resistance torque is obtained, and the decrease in the axial force of the bolt 6 is compensated, so that the flange 2 and the tillage are secured. The joining state with the claw 3 can be maintained.

  Further, a cylindrical portion 11 that is fitted around the tillage shaft 1 is provided around the tiller shaft through hole 10 of the flange 2 so that the second stopper 9b and the tubular portion 11 are brought into contact with the base portion 3a of the tillage claw 3. (Claim 3), the tilling claw 3 can be stably attached at a predetermined position. Furthermore, since the cylindrical part 11 extends in the axial direction of the tilling shaft 1 and supports the flange 2, the flange 2 can be stably attached to the tilling shaft 1 and can be easily and accurately attached. Installation cost can be reduced.

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

  1 is a front view of a tillage claw attachment structure according to an embodiment of the present invention (cultivation claw attachment surface 8 side), FIG. 2 is a rear view thereof, FIG. 3 is a right side view thereof (cultivation claw 3 is omitted), and FIG. FIG. 5 is a perspective view of the flange 2, and FIG. 5 is a cross-sectional view of a joint portion between the flange 2 and the tilling claw 3.

[Basic configuration]
This tillage claw attachment structure is a tillage claw attachment structure for attaching a tillage claw 3 to a flange 2 fixed to the tillage shaft 1, and bolts are inserted into bolt insertion holes 4 and 5 provided in the flange 2 and the tillage claw 3, respectively. The tillage claw 3 is attached to the flange 2 by screwing the nut 7 through 6, and the flange 2 is positioned closer to the outer peripheral edge than the bolt insertion hole 4 on the tillage claw attachment surface 8. The first stopper 9a that abuts the tilling claw 3 and the second stopper 9b that abuts the tilling claw 3 at a position closer to the tilling shaft 1 than the bolt insertion hole 4 is provided. It is supposed to absorb.

  1 and 2 show a state in which only one tilling claw 3 is attached to the flange 2, a plurality of tilling claws 3 are actually attached. Moreover, the tilling nail attachment surface 8 can be provided not only on one side of the flange 2 but also on both sides.

  Each tillage claw 3 is fastened and fixed to the flange 2 by bolts 6 and nuts 7 respectively, and the tip side protrudes outside the flange 2 and becomes radial. Moreover, the tilling shaft 1 can be provided with a plurality of flanges 2 at appropriate intervals in the axial direction.

  The flange 2 is a disc-shaped member provided around the tilling shaft 1. A plurality of bolt insertion holes 4 are attached to the intermediate positions between the tilling shaft 1 and the outer peripheral edge. Stoppers 9 a and 9 b described later are provided on the claw mounting surface 8. Each bolt insertion hole 4 is provided at equal intervals in the circumferential direction around the tilling shaft 1.

  The flange 2 can be a high-strength elastic body that is obtained by subjecting a suitable material to a heat treatment. The shape of the flange 2 is not limited to a disk shape, but may be a polygonal shape, and the number of bolt insertion holes 4 and the number of tilling claws 3 attached using the bolt insertion holes 4 can be appropriately determined.

  Further, the flange 2 is provided with a cylindrical portion 11 that is fitted around the tiller shaft 1 around the tiller shaft through hole 10 located at the center thereof. The tubular portion 11 is formed to extend perpendicular to the tillage claw attachment surface 8 of the flange 2 and the back surface thereof, that is, in the axial direction of the tillage shaft 1, and is an explanatory view schematically showing the cross section thereof as shown in FIG. As described above, the flange 2 forms a substantially T-shaped cross-sectional shape. The cylindrical part 11 is good to be integrally formed with the flange 2 main body by plastic working. Further, as shown in FIG. 7, the flange 2 is formed by joining a plurality of plates 2a and 2b, and the periphery of each tiller shaft through hole 10 of each plate 2a and 2b on both sides is perpendicular to each other outward. The part formed by bending may be the cylindrical part 11.

  The cylindrical portion 11 may be formed so as to extend only on one surface side of the flange 2. For example, in the configuration shown in FIG. 7, such a configuration can be obtained by making one of the plates 2a and 2b into a straight plate shape. About the flange 2 attached near the edge part of the tilling shaft 1, it is good for the cylindrical part 11 to extend only on the opposite side to the said edge part so that the cylindrical part 11 may not interfere with the bearing of the tilling shaft 1.

  The tilling claw 3 can be manufactured in the same manner as a conventionally known one. Specifically, the tilling claw 3 is heat-treated to an appropriate material and finished to a high-strength elastic body. The tilling claw 3 is composed of a base portion 3a and a blade portion 3b, and a bolt insertion hole 5 is formed in the central portion of the base portion 3a. It can be provided.

  Further, the tillage claw 3 in this embodiment has a substantially S-shaped or linear shape in which the blade portion 3b is curved to the left in FIG. 1, whereas the base portion 3a is gently curved to the opposite side to the blade portion 3b. can do. Further, the base portion 3 a can have a curved shape so that a portion where the cylindrical portion 11 of the flange 2 contacts is along the outer peripheral surface of the cylindrical portion 11.

  In the tillage claw attachment structure of this embodiment, the flange 2 is provided with a first stopper 9a and a second stopper 9b. The stoppers 9 a and 9 b are convex portions formed on the tillage claw attachment surface 8 of the flange 2, and come into contact with the tillage claw 3.

  When the flange 2 rotates and a load is applied to the tilling claw 3 due to a collision with soil, gravel, etc., the first stopper 9a abuts against a part of the left edge of the tilling claw 3 to receive pressure, and the second stopper 9b The pressure is received by contacting a part of the right edge of the claw 3.

  The 1st stopper 9a is a convex part of the fixed width along the outer periphery provided in the outer periphery of the tilling nail attachment surface 8 of the flange 2, The back side is a recessed part. The first stopper 9a is in contact with the left edge in FIG. 1 at a position near the blade 3b of the base 3a of the tilling claw 3 at the end 12 thereof.

  The 2nd stopper 9b is a substantially rectangular convex part provided in the location near the tilling axis | shaft 1 of the tilling nail attachment surface 8 of the flange 2. As shown in FIG. The second stopper 9b is the right edge in FIG. 1 near the end of the base 3a of the tillage claw 3 attached using the nearest bolt insertion hole 4, that is, the side opposite to the side on which the first stopper 9a abuts. It is provided so that it may contact | abut to the side edge of this tilling nail | claw 3.

  Furthermore, in the tilling claw attachment structure of this embodiment, the location where the cylindrical portion 11 of the flange 2 abuts on the base 3a of the tilling claw 3 is the left edge in FIG. The side edge of the tilling claw 3 on the same side as the side on which the stopper 9a abuts is used.

  It is desirable that the distance between the first stopper 9a and the second stopper 9b be as long as possible. Moreover, each stopper 9a, 9b is made into the shape suitable for the cultivation nail 3 so that it can respond to the shape of the cultivation nail 3 and the displacement of the cultivation nail 3 at the time of work. The required number of stoppers 9a and 9b can be installed at arbitrary positions on both surfaces of the flange 2 plate according to the number, type, installation position, and the like of the tilling claws 3 to be attached.

  In this tillage claw attachment structure, the main load applied to the tillage claw 3 is received by the stoppers 9a and 9b provided on the flange 2, and the flange 2 body having a large mass absorbs most of the load as well as the abnormal load. In addition, the pressure receiving surfaces of the stoppers 9a and 9b and a part of the tilling claw 3 may be plastically deformed by an impact force or an excessive load, which has a function of absorbing collision energy and is localized. And there is no practical problem.

  The main feature of this tillage claw mounting structure is not the conventional method that depends only on the frictional force between the flange and tillage claws by bolts and nuts and the strength of the bolts with respect to the load that the tillage claws 3 receive during work. The stoppers 9a and 9b receive most of the load directly by compressive stress, diffuse the compression energy into the large flange 2 body, and further join the flange 2 and the tilling claw 3 The maximum resistance torque is now being used.

  Due to the load countermeasures by the stoppers 9a and 9b, not only one bolt 6 is sufficient, but the bolt 6 has a very important significance that can be dedicated only for the purpose of screw fastening by its original tensile strength.

  Moreover, the cylindrical portion 11 of the flange 2 also serves as a protector that prevents direct contact between the tilling shaft 1 and the tilling claw 3, and damage to the tilling shaft 1 is prevented. Furthermore, since the cylindrical portion 11 extends in the axial direction of the tillage shaft 1 and supports the flange 2 in a state where the inner peripheral surface thereof is in contact with the outer peripheral surface of the tillage shaft 1, the flange 2 is stably attached to the tilling shaft 1. A state is obtained. Therefore, the attachment work of the flange 2 to the tilling shaft 1 can be performed easily and accurately, and the attachment cost can be reduced.

[About voids]
Moreover, in the cultivation nail attachment structure of this embodiment, as shown in FIG. 3, the concave part curved centering | focusing on the bolt insertion hole 4 is formed in the inner surface (side which contacts the cultivation nail 3) of the flange 2. As shown in FIG. In a normal state, a gap 13 exists between the flange 2 and the portion where the recess is formed. In addition, the outside of the concave portion is a contact portion 14 that contacts the tillage claw 3. In addition, the space | gap 13 can also be formed by providing a recessed part in the cultivation nail | claw 3 side. Or it can also form by providing a recessed part in both the flange 2 and the tilling nail | claw 3. FIG.

  In this tillage claw mounting structure, as described below, (1) the friction force acting between the flange 2 and the tillage claw 3 can be secured and a predetermined resistance torque can be obtained by providing the gap 13. (2) The lack of elastic deformation of the bolt 6 can be supplemented by the elastic deformation of the flange 2 or the tilling claw 3.

(1) Securing frictional force and resistance torque The frictional force generated when the gap 13 is present in the vicinity of the bolt insertion holes 4 and 5 and the flange 2 and the tilling claw 3 are in contact with each other is described below. As will be described, the resistance torque against the load torque can be maximized as much as possible.

  When an external force is applied to the tip of the tilling claw 3, the product of the force point and the distance to the center of rotation (bolt insertion hole 5) becomes the load torque, but this is countered by the stopper 9a first. 9b, and second, the friction torque generated between the two. The friction torque is the sum of products of the frictional force of the contact surfaces at the multiple locations and the distance to the rotation center.

  What should be noted here is that when the generated frictional force is the same, the torque value varies greatly depending on the distance to the center of rotation (hereinafter referred to as an arm). The frictional force generated near the center of rotation is close to zero as the torque value, but the torque value is the largest at the position where the arm is the longest, and if the friction surface is concentrated at this position, the best efficiency is achieved. Become. Therefore, in this tillage nail attachment structure, the intermediate part near the bolt insertion holes 4 and 5 at the joint between the flange 2 and the tillage nail 3 is defined as a gap 13, and the area near the stoppers 9a and 9b on the outside is a contact part. As shown in FIG. 14, the friction parts are concentrated at positions away from the bolt insertion holes 4 and 5.

  And since the area | region of both the friction parts in the flange 2 or the tilling nail | claw 3 can be specified by this, the surface process which enlarges a friction coefficient is attained. In the conventional flange method, the frictional force generated between the flange 2 and the tilling claw 3 is ignored only by relying on the fastening force of the bolt 6, and the contact portion between the flange 2 and the tilling claw 3 is accidental. Therefore, even if the bolt 6 is tightened strongly, the friction torque cannot be reliably obtained.

(2) Complementation of shortage of elastic deformation of bolt When using the working machine for tillage, the base 3a of the tilling claw 3 is tilted or displaced due to external force acting on the tilling claw 3, etc. An action that reduces the axial force works. In addition, the cause of the decrease in the axial force of the bolt 6 may be that a secondary reaction force or the like is involved in addition to the external force directly acting on the tilling claw 3.

  As the external force, the tilling resistance applied to the tilling claws 3 is mainly used. Tillage resistance is the resistance that is applied to the soil when it is driven into the soil, turned over or crushed, and released. The force that has a strong influence on the force is the working machine's traveling speed, traction force, weight of the tilling shaft 1, rotation speed, the shape of the tilling claws 3 and the number of attachments, etc. Field conditions, ie soil quality, soil properties, moisture content, etc.

  As the reactive force that is generated secondarily, it is conceivable that the tilling claw 3 attached to the tilling shaft 1 gives to other tilling claws 3. Many tilling claws 3 are attached to one flange 2, and each of the tilling claws 3 seems to rotate at a constant speed at a glance while receiving a change in load. However, when one of the tilling claws 3 collides with an obstacle (stone gravel, tree root, etc.) buried in the soil during the work, a sudden negative acceleration acts on the other tilling claws 3 become.

  In this way, the tilling claw 3 is continuously subjected to secondary inertia and recoil due to the influence of the other tilling claws 3, thereby causing a slight shift between the flange 2 and the tilling claw 3. May occur, the distance between the two may be reduced, and the axial force of the bolt 6 may be reduced.

  In addition, in the same phenomenon, possible causes of lowering the axial force of the bolt 6 are vibrations before and after, up and down, left and right generated on the tilling shaft 1, and in addition to this, rotational vibration due to rotation unevenness. Moreover, although the centrifugal force of the tilling nail | claw 3 centering on the rotating tilling axis | shaft 1 can be considered, the influence is weak.

  The axial force of the bolt 6 is determined by the amount of elastic deformation in the longitudinal direction of the bolt 6. Therefore, if the length of the bolt 6 is short, if the initial looseness occurs, it will be restored and the surplus energy (elastic deformation amount) to keep the tightening force will be insufficient. It progresses to a looseness. The length of the bolt 6 is structurally limited and cannot be longer than a certain length. In this embodiment, the flange 2 or the tilling claw 3 (either one or both) may be elastically deformed. Thus, the decrease in the axial force of the bolt 6 is compensated, and the frictional force between the flange 2 and the tilling claw 3 can be maintained.

  In other words, the total elastic deformation amount of the fastening body that combines the elastic deformation amount of the bolt 6 and the elastic deformation amount of the tilling claw 3 and the flange 2 is increased, and the amount of displacement of the tilling claw 3 due to the external force is used. The frictional force between the flange 2 and the tilling claw 3 is compensated for.

  As described above, this tillage claw attachment structure is applied to the bolt 6 and the nut 7 by receiving the load applied to the tillage claw 3 with the stoppers 9a and 9b positioned on the outer side and the inner side of the bolt insertion hole 4 of the flange 2, respectively. Since an external force is not directly applied, deformation, damage and the like of the fastening portion between the flange 2 and the tilling claw 3 are prevented, and the life can be extended.

  Moreover, since the structure is simple and only one set of bolts 6 and nuts 7 are used for fastening the flange 2 and the tilling claw 3, it is necessary to perform the mounting work as compared with the case of using a plurality of sets of bolts and nuts. Labor can be reduced.

  Since the area occupied for fastening the bolts 6 and nuts 7 on the tillage claw attachment surface 8 of the flange 2 is extremely small, a larger number of tillage claws 3 can be attached. Further, the width of the base portion 3a of the tillage claw 3 that overlaps the tillage claw mounting surface 8 of the flange 2 can be increased.

  Furthermore, the fastening between the flange 2 and the tilling claw 3 is achieved by making the best use of the frictional force and the resistance torque acting between the flange 2 and the tilling claw 3 due to the axial force of the bolts 6. Since the shortage of the elastic deformation amount of the bolt 6 is compensated by this, even if initial loosening (non-rotational loosening) occurs in the fastening by the bolt 6 due to an abnormal load, the flange, the tilling claw 3, the flange 2, and the tilling claw 3 is firmly maintained.

  The above is one embodiment of the present invention, but the present invention is not limited to the configuration of the above-described embodiment, and can be implemented by appropriately changing materials, shapes, dimensions, and the like.

It is a front view of the tilling nail attachment structure of an embodiment of this invention. It is a rear view of the tilling nail attachment structure of an embodiment of this invention. It is a right view (cultivation claw is abbreviate | omitted) of the cultivation claw attachment structure of embodiment of this invention. It is sectional drawing of the junction part of the flange and tilling nail in the tilling nail attachment structure of other embodiment of this invention. It is a perspective view of the flange in the tilling nail attachment structure of the embodiment of this invention. It is explanatory drawing of the cultivation nail attachment structure of embodiment of this invention. It is explanatory drawing of the tilling nail attachment structure of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tillage shaft 2 Flange 3 Tillage nail 4 Flange bolt insertion hole 5 Tillage nail bolt insertion hole 6 Bolt 7 Nut 8 Tillage nail attachment surface 9a 1st stopper 9b 2nd stopper 10 Tillage shaft through-hole 11 Flange cylindrical part 13 Air gap 14 Contact part

Claims (3)

A tillage claw attachment structure for attaching a tillage claw (3) to a flange (2) fixed to the tillage shaft (1), and a bolt insertion hole (4 provided respectively in the flange (2) and the tillage claw (3). ) The nut (7) is attached to the flange (2) by screwing the nut (7) through the bolt (6) to (5),
Furthermore, the flange (2) has a first stopper (9a) that comes into contact with the tilling claw (3) at a position closer to the outer peripheral edge than the bolt insertion hole (4) on the tilling claw mounting surface (8). Assuming that the second stopper (9b) that contacts the tillage claw (3) is provided at a position closer to the tillage shaft (1) than the bolt insertion hole (4), the load applied to the tillage claw (3) is absorbed. And
A cylindrical portion (11) that fits outside the tilling shaft (1) is provided around the tilling shaft through hole (10) of the flange (2), and a second stopper (9b) is provided on the base (3a) of the tilling claw (3). ) And the cylindrical portion (11) are in contact with each other,
The cylindrical part (11) is formed integrally with the flange (2) body,
Furthermore, the base (3a) has a curved shape such that the portion that comes into contact with the tubular portion (11) is along the outer peripheral surface of the tubular portion (11), and the base (3a) ) And the cylindrical portion (11) are in surface contact, and the abutting portion is a side edge on the same side as the side where the first stopper (9a) abuts near the end of the base portion (3a). tilling claws mounting structure, characterized in that.   In the vicinity of the bolt insertion hole (4) (5), there is a portion where a gap (13) is generated between the flange (2) and the tilling claw (3), and on the outside, the flange (2) and the tilling claw (3) 2. The tilling claw according to claim 1, wherein the flange (2) or the tilling claw (3) is elastically deformed to compensate for a decrease in the axial force of the bolt (6). Mounting structure. The cylindrical portion (11) is formed to extend at right angles to the tillage claw mounting surface (8) of the flange (2) and the back surface thereof, and extends to one surface side or both surface sides of the flange (2). The cultivation nail attachment structure according to claim 1 or 2 currently formed in.

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