Offset Machine

Abstract

To prevent trouble occurring when a working part comes into contact with an obstacle.SOLUTION: An offset work machine comprises a frame, a working part receiving power from a traveling machine body to perform farm work, an offset mechanism coupling the frame with the working part and offset-moving the working part in a horizontal direction, and an escape mechanism for escaping and moving the working part when external force more than prescribed force is applied to the working part. The offset mechanism has a first coupling part to be coupled with the escape mechanism. The escape mechanism has a movement restriction part coupled with the first coupling part and restricting a moving range of the first coupling part, and an elastic member generating elastic force for pressing the first coupling part toward the movement restriction part. The elastic member is rotationally turned to the frame, and the working part escapes and moves by an event that the first coupling part moves in a direction different from an extension / contraction direction of the elastic member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an offset working machine, and more particularly to an offset-type working machine that is attached to the rear of a traveling machine body and performs agricultural work to the side of the traveling machine body. [Background technology]

[0002] Conventionally, mowers are known as working machines that perform grass cutting work to remove weeds from farm roads and wastelands. Generally, mowers are attached to a traveling body such as a tractor, and proceed with grass cutting work by operating a working unit while moving together with the traveling body. In recent years, offset type mowers have been known in which the working unit that performs grass cutting work moves offset to the side of the traveling body, and performs grass cutting work to the side of the traveling body (Patent Documents 1 and 2). The mowers described in Patent Documents 1 and 2 are provided with a parallel link mechanism between the attachment unit attached to the traveling body and the working unit that cuts grass, and the parallel link mechanism enables the working unit to be offset to the side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-39941 A [Patent Document 2] JP 2012-191864 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the grass cutters described in Patent Documents 1 and 2, when mowing the grass at an offset position that protrudes laterally from the running body, the working part may get caught on an obstacle such as a root stone or a stump hidden in the grass. In this case, a large load is applied to the frame of the working part and the electric cylinder, which may cause damage to the grass cutter. In addition, since a load is also applied to the running body, it may lead to damage to parts of the running body. Furthermore, if the running body continues to run with the working part caught on an obstacle, the running body will turn around the obstacle, causing a large change in the direction of travel, which may lead to an accident.

[0005] The present invention has been made in consideration of the above problems, and one of its objects is to prevent problems that occur when a working unit comes into contact with an obstacle. [Means for solving the problem]

[0006] In one embodiment of the present invention, an offset work machine comprises a frame, a working unit that receives power from a traveling body to perform agricultural work, an offset mechanism that connects the frame and the working unit and offsets and moves the working unit in the left and right direction, and an escape mechanism that causes the working unit to move away from the work when an external force of a predetermined force or greater acts on the working unit, wherein the offset mechanism has a first connecting part connected to the escape mechanism, and the escape mechanism has a movement limiting part connected to the first connecting part and limiting the movement range of the first connecting part, and an elastic member that generates an elastic force that presses the first connecting part against the movement limiting part, the elastic member is rotatable relative to the frame, and the first connecting part moves within the movement limiting part in a direction different from the extension and contraction direction of the elastic member, thereby causing the working unit to make the escape movement.

[0007] In one embodiment of the present invention, an offset work machine comprises a frame, a working unit that receives power from a traveling body to perform agricultural work, an offset mechanism that connects the frame and the working unit and offsets the working unit in the left and right direction while maintaining its orientation relative to the direction of travel of the working unit, and an escape mechanism provided on the frame, wherein the offset mechanism has a first connecting part that includes a fulcrum for the offset movement, and the first connecting part is connected to the escape mechanism, and the escape mechanism has a movement limiting part that limits the movement range of the first connecting part, and an elastic member that generates an elastic force that presses the first connecting part against the movement limiting part, the elastic member is rotatable relative to the frame, and the working unit moves in an escape manner when the first connecting part moves within the movement limiting part in a direction different from the extension and contraction direction of the elastic member.

[0008] The movement limiting portion may be an inner wall of a groove having a longitudinal direction, the first connecting portion may be movable while sliding along the inner wall of the groove, and the extension / contraction direction may be different from the longitudinal direction of the groove.

[0009] The elastic member may press the first connecting portion against the movement restricting portion to maintain a position of the first connecting portion on the movement restricting portion.

[0010] The offset mechanism may have a first link arm and a second link arm parallel to each other, the first link arm having a first end and a second end, the first end being rotatably connected to a fixed position of the working unit and the second end being rotatably connected to a fixed position of the frame, the second link arm having a third end and a fourth end, the third end being rotatably connected to the fixed position of the working unit or to the other of the link arms, one of which is connected to the first end, and the fourth end being connected to the movable first connecting portion.

[0011] The movement restricting portion may restrict movement of the first connecting portion to a first direction and a second direction different from the first direction.

[0012] The escape mechanism may further have a pivotable connecting member that is rotatable around a rotation center, and the pivotable connecting member may be connected to the first connecting portion at a first connection portion and connected to the second connecting portion of the elastic member at a second connection portion.

[0013] The second coupling portion may be movable at the second connection portion such that a distance between the second coupling portion and the center of rotation changes. Effect of the Invention

[0014] The offset working machine in one embodiment of the present invention can prevent malfunctions that occur when the working part comes into contact with an obstacle. [Brief description of the drawings]

[0015] [Figure 1] 1 is a plan view showing a configuration of an offset working machine according to an embodiment of the present invention. [Diagram 2] 1 is a plan view showing a configuration of an offset working machine according to an embodiment of the present invention. [Diagram 3] 5A to 5C are diagrams illustrating states before and after a working unit of the offset working machine according to one embodiment of the present invention comes into contact with an obstacle. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Diagram 5] 5A to 5C are diagrams illustrating states before and after a working unit of the offset working machine according to one embodiment of the present invention comes into contact with an obstacle. [Figure 6] FIG. 6 is a partially enlarged view of FIG. [Figure 7] 11 is a diagram showing the positional relationship between the connecting portion and the movement restricting portion after the working portion comes into contact with an obstacle in the offset working machine according to one embodiment of the present invention. FIG. [Figure 8] 1 is a diagram showing a state after a working unit of the offset working machine according to one embodiment of the present invention has come into contact with an obstacle. FIG. [Figure 9] FIG. 9 is a partially enlarged view of FIG. 8. [Figure 10]1 is an explanatory diagram showing a state before a working unit of the offset working machine according to one embodiment of the present invention comes into contact with an obstacle. FIG. [Figure 11] 11 is an exploded view of the flat plate member and the pivot connector in FIG. 10. FIG. [Figure 12] 1 is an explanatory diagram showing a state after a working unit of the offset working machine according to one embodiment of the present invention has come into contact with an obstacle; FIG. [Figure 13] 1 is an explanatory diagram showing a state after a working unit of the offset working machine according to one embodiment of the present invention has come into contact with an obstacle; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the offset working machine of the present invention will be described with reference to the drawings. However, the offset working machine of the present invention can be implemented in many different forms, and should not be interpreted as being limited to the description of the examples shown below. In the drawings referred to in this embodiment, the same parts or parts having similar functions are given the same reference numerals, and repeated explanations thereof will be omitted. In this specification and each figure, elements similar to those described above with respect to the previous figures are given the same reference numerals followed by alphabets, and detailed explanations may be omitted as appropriate.

[0017] For ease of explanation, terms indicating directions such as "up," "down," "front," "rear," "right," and "left" are used, but for the offset work machine of the present invention, the direction in which gravity acts is "down," and its opposite is "up." Furthermore, the direction in which the traveling body moves is "front," and its opposite is "rear." Furthermore, when facing "front," the right side is "right," and the left side is "left." The side closer to the center line of the offset work machine is called the "inner" and the side farther away is called the "outer."

[0018] [1. First embodiment] [1-1. Configuration of offset machine] 1 is a plan view showing the configuration of an offset working machine 100 according to a first embodiment. In this embodiment, an offset type mower is illustrated as an example of the offset working machine 100. However, the offset working machine 100 is not limited to a mower, and may be other offset type working machines such as a ridger or a plow.

[0019] As shown in Fig. 1, the offset work machine 100 of this embodiment includes a mounting unit 10, an offset mechanism unit 20, a power transmission unit 30, a working unit 40, and an escape mechanism unit 50. The offset work machine 100 is connected to a traveling machine body (not shown) such as a tractor by the mounting unit 10. The mounting unit 10 and the working unit 40 are connected via the offset mechanism unit 20 and the power transmission unit 30. With this configuration, the offset work machine 100 moves forward as the traveling machine body travels. While the offset work machine 100 moves, the working unit 40 operates by power received from the traveling machine body to perform grass cutting work.

[0020] The mounting part 10 is a part that is connected to a three-point link mechanism (not shown) provided on the traveling machine body. Specifically, the mounting part 10 of this embodiment includes a front frame 11, a top link connection part (top mast) (not shown), a lower link connection part (lower link pin) 13, an input shaft 14, a power transmission means 15, and an output shaft 16. The top link connection part and the lower link connection part 13 may be connected to the three-point link mechanism of the traveling machine body via an auto hitch arm (not shown). In this embodiment, the output shaft 16 is provided at a position offset from the input shaft 14 in the left-right direction. The front frame 11 is a member that extends in the left-right direction, and the top link connection part and the lower link connection part 13 are provided on the front frame 11.

[0021] The offset mechanism 20 is disposed between the mounting unit 10 (front frame 11) and the working unit 40, connects the mounting unit 10 and the working unit 40, and moves the working unit 40 in the left-right direction by rotating with respect to the mounting unit 10. In this embodiment, the offset mechanism 20 includes a parallel link mechanism rotatably connected to the front frame 11 and the working unit 40. That is, by rotating the offset mechanism 20 with respect to the front frame 11, the working unit 40 can be moved in the left-right direction (D2 direction) while maintaining the orientation of the working unit 40 with respect to the traveling direction (D1 direction). That is, the offset mechanism 20 can offset and move the working unit 40 to the side with respect to the traveling direction of the traveling machine body.

[0022] 2 is a plan view of the offset work machine 100 of the first embodiment, omitting the illustration of the power transmission unit 30. As shown in FIG. 2, the offset mechanism unit 20 of this embodiment has a first link arm 21, a second link arm 22, a third link arm 23, and an expandable member 24.

[0023] 1. One end on the front side of the first link arm 21 is rotatably connected to the front frame 11 of the mounting unit 10 at a connection part 201, and the other end on the rear side of the first link arm 21 is rotatably connected to the third link arm 23 and the working unit 40.

[0024] The second link arm 22 is disposed approximately parallel to the first link arm 21 at a position spaced apart from the first link arm 21, and has a length approximately equal to that of the first link arm 21. One end on the front side of the second link arm 22 is rotatably and movably connected to the escape mechanism 50 provided on the front frame 11 of the mounting unit 10, and the other end on the rear side of the second link arm 22 is rotatably connected to the third link arm 23. Note that, as will be described in detail later, one end on the front side of the second link arm 22 is rotatably connected to a pin-shaped connecting portion 203, and the second link arm 22 is configured to be rotatable relative to the escape mechanism 50 via the connecting portion 203. In other words, the connecting portion 203 provided at one end on the front side of the second link arm 22 functions as a fulcrum for the offset movement.

[0025] The third link arm 23 is disposed approximately parallel to the front frame 11, and connects the first link arm 21 and the second link arm 22 to each other. One end of the third link arm 23 connected to the first link arm 21 is fixed to the working unit 40, and is configured so that the positional relationship between the third link arm 23 and the working unit 40 does not change.

[0026] With the above configuration, the front frame 11, the first link arm 21, the second link arm 22, and the third link arm 23 form a quadrilateral link mechanism with each of the front frame 11, the first link arm 21, the second link arm 22, and the third link arm 23 as sides. With this link mechanism, the offset mechanism unit 20 can offset and move the working unit 40 in the left-right direction while maintaining the orientation of the working unit 40 so that the longitudinal direction of the working unit 40 is approximately parallel to the left-right direction.

[0027] The telescopic member 24 is a power source (actuator) that drives the offset mechanism unit 20, and is composed of, for example, an electric cylinder, a hydraulic cylinder, or the like. One end of the telescopic member 24 is rotatably connected to the connecting portion 203 together with the front end of the second link arm 22. As described above, the connecting portion 203 is connected to the escape mechanism unit 50, and the front end of the second link arm 22 is connected to the front frame 11 via the escape mechanism unit 50 (a pair of flat plate-shaped members 570). The other rear end of the telescopic member 24 is connected to the first link arm 21 via a bracket provided near the center of the first link arm 21 (or slightly behind the center). The telescopic operation of the telescopic member 24 rotates the first link arm 21, and the offset mechanism unit 20 is driven. The offset amount (the amount of movement in the offset direction) of the working unit 40 is controlled by the amount of extension and contraction of the telescopic member 24.

[0028] Returning to Fig. 1 for the explanation, the power transmission unit 30 is a mechanism for transmitting the power transmitted from the traveling machine body via the input shaft 14 of the mounting unit 10, the power transmission means 15 (sprocket 152 and intermediate shaft 154), and the output shaft 16 to the working unit 40. As described above, the power transmission unit 30 is disposed overlapping a part of the offset mechanism unit 20, specifically, the upper side of the first link arm 21.

[0029] The offset work machine 100 of this embodiment uses a chain drive mechanism as the power transmission unit 30. Specifically, the power transmission unit 30 has at least a driving sprocket 31, a driven sprocket 32, and a roller chain 33. The roller chain 33 is configured to be wound around a pair of sprockets (the driving sprocket 31 and the driven sprocket 32).

[0030] The driving sprocket 31 is a gear that rotates in engagement with the rotating output shaft 16, thereby transmitting the power received from the output shaft 16. The driven sprocket 32 ​​is a gear that rotates passively by the power transmitted from the driving sprocket 31 via a roller chain 33. The roller chain 33 is a member that transmits power as tension. Note that the power transmission unit 30 is not limited to a chain drive mechanism, and may be configured as a belt drive mechanism using a pair of pulleys and a belt.

[0031] The front of the power transmission unit 30 is rotatably connected to the mounting unit 10 (front frame 11), and the rear of the power transmission unit 30 is rotatably connected to the working unit 40. In this embodiment, the rotation center of the power transmission unit 30 relative to the mounting unit 10 coincides with the rotation center of the drive sprocket 31. In other words, the rotation center of the power transmission unit 30 relative to the mounting unit 10 coincides with the rotation center of the output shaft 16. In addition, the rotation center of the power transmission unit 30 relative to the working unit 40 coincides with the rotation center of the driven sprocket 32.

[0032] Furthermore, the rotation center of the power transmission unit 30 relative to the mounting unit 10 coincides with the rotation center of the offset mechanism unit 20 (specifically, the first link arm 21) relative to the mounting unit 10. In this manner, in this embodiment, the first link arm 21, which is a part of the offset mechanism unit 20, and the power transmission unit 30 rotate integrally relative to the mounting unit 10 (front frame 11), so that a large offset amount can be ensured without being restricted by a bending angle as occurs when a universal joint is used for transmitting power. Also, when the working unit 40 is stored (when not working), it is possible to arrange the working unit 40 close to the traveling machine body in the front-rear direction.

[0033] The working unit 40 is a part that performs grass cutting work, and includes a work rotor 41 and a blade drive unit 42. The working unit 40 performs grass cutting work by the blade drive unit 42 receiving power transmitted from the power transmission unit 30 and driving the work rotor 41. The work rotor 41 includes a claw shaft 41a and a plurality of blades 41b radially provided on the claw shaft 41a. The claw shaft 41a extends in the left-right direction so as to be substantially perpendicular to the traveling direction of the traveling machine body. The work rotor 41 performs grass cutting by rotating the plurality of blades 41b together with the claw shaft 41a. The blade drive unit 42 transmits the power transmitted by the power transmission unit 30 to the claw shaft 41a of the work rotor 41. The blade drive unit 42 may be a chain drive mechanism having a configuration similar to that of the power transmission unit 30, or may be a belt drive mechanism.

[0034] The escape mechanism 50 is provided on the front frame 11. The escape mechanism 50 includes a pair of flat plate-like members 570, an elastic member 60, a rotating shaft member 610, a contact member 620, and a shaft member 630. The pair of flat plate-like members 570 are provided parallel to the upper surface of the front frame 11 and sandwich the front frame 11 from above and below. Each flat plate-like member 570 is provided with a groove 580 (see FIG. 4) having a longitudinal direction in the D1 direction, and the connecting portion 203 is inserted into the groove 580. The groove 580 is composed of a first groove 581 and a second groove 582 (see FIG. 7(C)). Although details will be described later, the connecting portion 203 is configured to be able to slide on the inner wall of the groove 580 (the first groove 581 and the second groove 582), and the groove 580 limits the movement range of the connecting portion 203. For this reason, in this specification, the groove 580 may be referred to as a movement limiting portion 500. Further, the inner wall of groove 580 abuts against connecting portion 203 and functions as a guide portion that guides its movement, and the inner wall of groove 580 may be referred to as the guide portion. During storage (when the offset amount is zero) or during normal grass cutting work, connecting portion 203 is biased against the end of movement restricting portion 500 by elastic member 60. In this embodiment, the position of connecting portion 203 is fixed by elastic member 60 biasing connecting portion 203. Therefore, elastic member 60 may be referred to as the "biasing member."

[0035] Here, the structure of the elastic member 60 will be described with reference to Fig. 4. Fig. 4 is a partially enlarged view of Fig. 3. Fig. 4 illustrates a state in which a part of the upper flat-plate member 570 of the escape mechanism portion 50 has been removed, and shows the structure below the upper flat-plate member 570. As shown in Fig. 4, the longitudinal direction of the groove 580 and the direction in which the elastic member 60 expands and contracts are different. Therefore, the elastic member 60 rotates depending on the position of the connecting portion 203 in the groove 580, and the angle between the longitudinal direction of the groove 580 and the direction in which the elastic member 60 expands and contracts changes.

[0036] The elastic member 60 is provided between the rotating shaft member 610 and the abutting member 620, and presses these members. The abutting member 620 is fixed to the connecting portion 203, and presses the connecting portion 203 by the elastic force of the elastic member 60. This pressing presses the connecting portion 203 against the movement limiting portion 500. In other words, the rear end (the end on the abutting member 620 side) of the elastic member 60 presses (biases) the connecting portion 203, and the front end (the end on the rotating shaft member 610 side) of the elastic member 60 presses (biases) the rotating shaft member 610. The shaft member 630 penetrates the rotating shaft member 610, is inserted into the inside of the elastic member 60, and is connected (fixed) to the abutting member 620. The shaft member 630 slides against the inner wall of the through hole provided in the rotating shaft member 610, causing the elastic member 60 to expand and contract. The elastic member 60, the abutment member 620, and the shaft member 630 rotate about the rotating shaft member 610. In other words, the elastic member 60, the abutment member 620, and the shaft member 630 are connected to the pair of flat plate-shaped members 570 so as to be able to rotate.

[0037] In this embodiment, the pair of flat plate-like members 570 are provided separately from the front frame 11 and are bolted, but the present invention is not limited to this configuration. For example, the pair of flat plate-like members 570 may be welded to the front frame 11 or may be integrally formed with the front frame 11. When the pair of flat plate-like members 570 are integrally formed with the front frame 11, a groove corresponding to the movement limiting portion 500 may be formed in a part of the front frame 11. As described above, since the pair of flat plate-like members 570 are fixed to the front frame 11, it can also be said that the elastic member 60 is rotatable with respect to the front frame 11.

[0038] The connecting portion 203 is provided so as to be movable while sliding on the movement limiting portion 500. With this configuration, the movement range of the connecting portion 203 is limited by the movement limiting portion 500. In the example of Fig. 4, since the groove has a longitudinal direction in the D1 direction, the movement of the connecting portion 203 is also limited in the D1 direction.

[0039] [1-2. Operation of the offset mechanism when contacting an obstacle] The operation of the offset mechanism 20 when it comes into contact with an obstacle will be described with reference to Figs. 3 and 4. Fig. 3 is a diagram showing a state (A) before the working unit comes into contact with an obstacle and a state (B) immediately after the working unit comes into contact with the obstacle when the offset working machine 100 advances in the D1 direction in an offset working machine according to an embodiment of the present invention. As shown in Fig. 3, when the working unit 40 collides with an obstacle 399, the parallel link of the offset mechanism 20 is broken by the escape mechanism 50, and the direction of the working unit 40 changes. Specifically, before the collision with the obstacle 399, the working unit 40 faces the D1 direction (the claw shaft 41a is parallel to the D2 direction), whereas after the collision with the obstacle 399, the direction in which the working unit 40 faces is shifted obliquely backward from the D1 direction (the claw shaft 41a and the D2 direction form an angle α), and the working unit 40 escapes backward from the obstacle 399. As described above, the escape mechanism 50 functions to cause the working unit 40 to escape backward, which is called "escape movement." In this embodiment, the escape mechanism 50 functions by moving the connecting portion 203, which functions as a fulcrum in the offset movement of the offset mechanism 20, along the movement limiting portion 500, thereby realizing the "escape movement" of the working unit 40. However, the configuration of the escape mechanism 50 is not limited to the configuration shown in this embodiment. As the orientation of the working unit 40 changes due to the collision with the obstacle 399, the inclination of the longitudinal direction of the offset mechanism 20 and the power transmission unit 30 with respect to the D1 direction changes. Specifically, with respect to the angle β between the longitudinal direction of the offset mechanism 20 and the D1 direction, the angle β after the collision with the obstacle 399 is smaller than the angle β before the collision. In other words, the longitudinal direction before the collision is closer to the D2 direction than the longitudinal direction before the collision.

[0040] FIG. 4, like FIG. 3, is a diagram showing a state (A) before the working unit comes into contact with an obstacle and a state (B) immediately after the working unit comes into contact with the obstacle. In the state (A) before the working unit comes into contact with the obstacle, the elastic force of the elastic member 60 causes the connecting part 203 to press the rear end of the movement limiting part 500 and to be held in this position. In this state, the offset mechanism 20 constitutes a parallel link mechanism. When an obstacle comes into contact with the working unit and an external force exceeding a predetermined threshold is applied to the working unit 40, the connecting part 203, which receives the force via the second link arm 22, moves in the D1 direction along the movement limiting part 500 (using the inner wall of the groove 580 as a guide). When the connecting part 203 moves in the D1 direction, the parallel link mechanism of the offset mechanism 20 collapses and the direction of the working unit 40 changes. In FIG. 3 and FIG. 4, the second link arm 22 overlaps with the expandable member 24 and is not shown.

[0041] As described above, the direction in which the elastic member 60 presses the connecting portion 203, that is, the direction in which the elastic member 60 expands and contracts, is different from the longitudinal direction of the movement limiting portion 500 (groove 580). Therefore, when an obstacle or the like comes into contact with the working portion 40 and a force is applied to the working portion 40 from the front, the connecting portion 203 pushed by the second link arm 22 moves while being guided by the inner wall of the groove 580, and moves in a direction different from the direction in which the elastic member 60 expands and contracts. Therefore, the movement amount of the connecting portion 203 in the movement limiting portion 500 can be made larger than the amount of expansion and contraction of the elastic member 60. As a result, the inclination of the working portion 40 can be made larger. The movement of the connecting portion 203 in a direction different from the direction in which the elastic member 60 expands and contracts is made possible by the elastic member 60 rotating about the pivot member 610 with respect to the pair of flat plate-like members 570 (front frame 11) as the connecting portion 203 moves.

[0042] Moreover, the force acting on the connecting portion 203 via the second link arm 22 acts on both the inner wall of the groove 580 and the elastic member 60. Therefore, if the force received by the inner wall of the groove 580 can be increased, the force applied to the elastic member 60 can be reduced, and if the force received by the inner wall of the groove 580 is reduced, the force applied to the elastic member 60 increases. The magnitude of the force received by the inner wall of the groove 580 from the second link arm 22 depends on the angle between the second link arm 22 and the inner wall of the groove 580 at the contact point between the connecting portion 203 and the inner wall of the groove 580 when the connecting portion 203 abuts against the inner wall of the groove 580. Specifically, if the angle between the second link arm 22 and the inner wall of the groove 580 at the contact point increases, the force received by the inner wall of the groove 580 increases, and if the angle between the second link arm 22 and the inner wall of the groove 580 is reduced, the force received by the inner wall of the groove 580 decreases.

[0043] Conventionally, the direction of the elastic member (60) was the same as the longitudinal direction of the groove (580) provided in the escape mechanism (50), so that the angle between the second link arm 22 and the inner wall of the groove (580) when the connecting part 203 abutted against the inner wall of the groove (580) was relatively small. Therefore, when an external force was applied, the force that could be received by the inner wall of the groove (580) was relatively small, so that in order to move the connecting part (203) and the working part (40) only when an external force exceeding a predetermined threshold value was applied, it was necessary to increase the force received by the elastic member 60. As described above, it is preferable that the offset mechanism part (20) constitutes a parallel link mechanism except when the working part (40) collides with the obstacle (399), so that the conventional elastic member (60) was required to have a strong elastic force (biasing force) that can sufficiently withstand the force received from the front during normal work. In addition, among the above conventional configurations, the members corresponding to the offset working machine 100 of this embodiment are indicated with the symbols corresponding to this embodiment in parentheses after the names of the members.

[0044] On the other hand, as shown in the above embodiment, in the present invention, the elastic member 60 is configured to be rotatable with respect to the front frame 11 (the pair of flat plate-shaped members 570), so there is no need to limit the movement direction of the connecting portion 203 to the direction in which the elastic member 60 expands and contracts, and the degree of freedom in designing the movement direction of the connecting portion 203 (the arrangement of the groove 580) can be increased. Therefore, it becomes possible to design taking into consideration the angle between the second link arm 22 and the inner wall of the groove 580 when the connecting portion 203 abuts against the inner wall of the groove 580, and by designing this angle to be large, the elastic force required for the elastic member 60 can be reduced. As a result, it is possible to use an elastic member 60 having a weaker elastic force than before.

[0045] [2. Second embodiment] [2-1. Operation of the offset mechanism] An offset working machine 100A according to the second embodiment will be described with reference to Figs. 5 and 6. The offset working machine 100A is similar to the offset working machine 100 shown in Figs. 3 and 4, but the configuration of the movement limiting unit 500A provided in the escape mechanism unit 50A of the offset working machine 100A is different from the configuration of the movement limiting unit 500 of the offset working machine 100. As a result, when an obstacle 399A collides with the working unit 40A, the change in the direction of the working unit 40A is larger than the change in the direction of the working unit 40 shown in Fig. 3. In this embodiment, the alphabet "A" may be added after the same reference numerals as those in the first embodiment to omit the description of the configuration having the same shape and function as those in the first embodiment.

[0046] Fig. 5 is a diagram showing a state (A) before the working unit comes into contact with an obstacle and a state (B) immediately after the working unit comes into contact with an obstacle when the offset working machine 100A advances in the D1 direction in an offset working machine according to an embodiment of the present invention. Fig. 6 is a partially enlarged view of Fig. 5. Fig. 7 is a diagram showing the positional relationship between the connecting part and the movement limiting part after the working unit comes into contact with an obstacle in the offset working machine according to an embodiment of the present invention.

[0047] As shown in FIG. 7C, the movement limiting portion 500A has a shape in which a first groove 581A having a longitudinal direction in the D1 direction and a second groove 582A having a longitudinal direction in the D3 direction are connected at their respective ends. The second groove 582A is slightly inclined forward from the front end of the first groove 581A in the left-right direction, and has a longitudinal direction in the D3 direction from the front end of the first groove 581A toward the outside of the offset working machine 100A. As described above, the movement limiting portion 500A has a substantially L-shaped shape and limits the movement of the connecting portion 203A in the D1 direction and the D3 direction. The end of the movement limiting portion 500A close to the offset mechanism portion 20A is referred to as the first end portion 510A, and the end far from the offset mechanism portion 20A is referred to as the second end portion 520A. A sliding portion 530A is provided between the first end portion 510A and the second end portion 520A. As will be described in detail later, in the movement limiting portion 500A, the portion of the groove having a longitudinal direction in the D3 direction is longer than the portion of the groove having a longitudinal direction in the D1 direction. In the second groove 582A having a longitudinal direction in the D3 direction, the front inner wall is straight and the rear inner wall is curved into a concave shape.

[0048] As shown in (A) of each of Figures 5 and 6, before the obstacle 399A collides with the working unit 40A, the connecting part 203A is located at the first end 510A. On the other hand, as shown in (B) of each of Figures 5 and 6, after the obstacle 399A collides with the working unit 40A, the connecting part 203A moves to the second end 520A. Note that, like the elastic member 60 of the offset working machine 100, the elastic member 60A shown in Figures 5 and 6 also rotates around the rotating shaft member 610A.

[0049] [2-2. Positional relationship between the connecting part and the movement limiting part during operation of the offset mechanism] 7, (A) is a diagram showing a state before working unit 40A comes into contact with obstacle 399A, (B) is a diagram showing a state immediately after working unit 40A comes into contact with obstacle 399A, and (C) is a diagram showing a state in which working unit 40A is further pushed backward from the state of (B). In (A) to (C) of FIG. 7, arrow P toward connecting part 203A indicates the direction in which second link arm 22A pushes connecting part 203A as working unit 40A comes into contact with obstacle 399A. In FIG. 5(A) and FIG. 6(A), second link arm 22A overlaps with expandable member 24A, although not shown.

[0050] As shown in FIG. 7A, before the working unit 40A comes into contact with the obstacle 399A, the connecting unit 203A is pressed against the movement limiting unit 500A at the first end 510A by the elastic member 60A. In this state, when the connecting unit 203A is pressed in the direction of the arrow P by the second link arm 22A, the connecting unit 203A abuts against the sliding unit 530A, so that the force in the direction of the arrow P acts on both the sliding unit 530A and the elastic member 60A. If the magnitude of the force in the direction of the arrow P is smaller than a predetermined threshold value, the position of the connecting unit 203A is held at the first end 510A and does not move within the movement limiting unit 500A. As a result, the offset mechanism unit 20A maintains the parallel link mechanism.

[0051] When the working part 40A comes into contact with the obstacle 399A and the connecting part 203A receives a force from the second link arm 22A in the direction of the arrow P that exceeds a predetermined threshold value, as shown in (B) of Figure 7, the position of the connecting part 203A moves away from the first end 510A and in the direction D1 until it abuts against the foremost position (contact point CP2) of the first groove 581A, which corresponds to the connection position between the first groove 581A and the second groove 582A (Figure 7 (B)).

[0052] Then, due to the force of arrow P, the connecting portion 203A moves from the state shown in Figure 7 (B) in the direction D3 toward the outside of the offset work machine 100A while sliding along the front inner wall surface (movement limiting portion 500A) of the second groove 582A and contracting the elastic member 60A, and reaches the second end portion 520A of the second groove 582A as shown in Figure 7 (C).

[0053] In the above operation, in the state of Fig. 7A, the angle between the direction of tangent line TAN1 at contact point CP1 between connecting part 203A pushed in the direction of arrow P and sliding part 530A and the direction of arrow P (direction in which second link arm 22A pushes connecting part 203A) is larger than the angle between the direction of tangent line TAN2 at contact point CP2 between connecting part 203A and movement limiting part 500A and the direction of arrow P in which connecting part 203A is pushed in the state of Fig. 7B. Therefore, when the same magnitude of force is applied from connecting part 203A via second link arm 22A, the force received by the inner wall of first groove 581A (sliding part 530A) in the state of Fig. 7A is larger than the force received by the inner wall of second groove 582A in the state of Fig. 7B.

[0054] In the state of FIG. 7A, even if the elastic force of the elastic member 60A is relatively small, the position of the connecting portion 203A is maintained at the first end portion 510A by the elastic member 60A.

[0055] On the other hand, in the state of FIG. 7B, the angle between the direction of the tangent line TAN2 at the contact point CP2 between the connecting part 203A and the movement limiting part 500A and the direction of the arrow P in which the connecting part 203A is pushed is very small. Therefore, most of the force that the connecting part 203A receives from the second link arm 22A is applied to the elastic member 60A. In other words, in the state of FIG. 7B, the connecting part 203A moves in the movement limiting part 500A with a force smaller than a predetermined threshold value required to move from the state of (A) to the state of (B). In addition, in the movement limiting part 500A, the part having the longitudinal direction in the D3 direction is longer than the part having the longitudinal direction in the D1 direction, and a large amount of movement of the connecting part 203A can be secured, so that the parallel link of the offset mechanism part 20A can be greatly broken. As a result, the direction of the working part 40A can be greatly tilted as shown in each of FIG. 5 and FIG. 6B.

[0056] Furthermore, since the rear inner wall of the portion of the movement limiting portion 500A having a longitudinal axis in the D3 direction is curved into a concave shape, when the connecting portion 203A moves from the second end 520A to the sliding portion 530A, the force of the elastic member 60A can be efficiently transmitted in the direction of movement.

[0057] [3. Third embodiment] [3-1. Configuration of offset machine] An offset working machine 100B according to the third embodiment will be described with reference to Figs. 8 and 9. The offset working machine 100B is similar to the offset working machine 100 shown in Figs. 1 and 2, but is different from the offset working machine 100 in that a universal joint is used as the power transmission unit 30B, and the positional relationship between the first link arm 21B and the second link arm 22B in the left-right direction is reversed. Fig. 8 is a diagram showing a state after the working unit has come into contact with an obstacle in an offset working machine according to an embodiment of the present invention. Fig. 9 is a partially enlarged view of Fig. 8. In this embodiment, the alphabet "B" may be added after the same reference numerals as those in the first embodiment to omit the description of the configuration having the same shape and function as those in the first embodiment.

[0058] In the third embodiment, a parallel link mechanism is configured by a first link arm 21B and a second link arm 22B. The first link arm 21B is rotatably connected to the front frame 11B at a connection portion 201B, and is rotatably connected to the working unit 40B at a connection portion 205B. The second link arm 22B is connected to the escape mechanism portion 50B at a coupling portion 203B, and is rotatably connected to the working unit 40B at a connection portion 207B. A universal joint is used as the power transmission portion 30B. The power transmission portion 30B is connected to the blade driving portion 42B, and the working unit 40B is driven via the universal joint through the blade driving portion 42B.

[0059] As shown in Fig. 9, the movement limiting portion 500B has a shape in which a groove having a length in the D1 direction and a groove having a length in the D2 direction are connected at their respective ends, and the movement limiting portion 500B has a substantially L-shaped shape. When viewed from above, the end of the movement limiting portion 500B that is closer to the center of the offset working machine 100B in the left-right direction is referred to as a first end 510B, and the end that is farther from the center of the offset working machine 100B is referred to as a second end 520B. A bent portion 540B is provided between the first end 510B and the second end 520B.

[0060] The elastic member 60B is provided between the first stopper 640B and the second stopper 650B. The first stopper 640B and the second stopper 650B are provided on the shaft member 630B so as to sandwich the elastic member 60B, and engage the elastic member 60B. The first stopper 640B is attached to the shaft member 630B so as to be slidable in its longitudinal direction. The second stopper 650B is fixed to the shaft member 630B, and moves together with the shaft member 630B. The elastic member 60B rotates around the rotating shaft member 610B. The shaft member 630B is inserted into the inside of the elastic member 60B, passes through a through hole provided in the rotating shaft member 610B, and is connected to the connecting portion 203B via the connecting portion 660B. In other words, the shaft member 630B moves together with the connecting portion 203B, and the force of the movement rotates the rotating shaft member 610B.

[0061] 9, the second link arm 22B and the connecting portion 203B, each indicated by a "dotted line", show the state before the working unit 40B collides with an obstacle. The second link arm 22B and the connecting portion 203B, each indicated by a "solid line", show the state after the working unit 40B collides with an obstacle. In this embodiment, when the working unit 40B collides with an obstacle, the second link arm 22B is pulled in the direction of the arrow P.

[0062] Referring to second link arm 22B and connecting portion 203B indicated by a dashed line showing the state before the collision, even if connecting portion 203B is pulled in the direction of arrow P by second link arm 22B, connecting portion 203B abuts against bent portion 540B, so that if the magnitude of the force in the direction of arrow P is smaller than a predetermined threshold value, the position of connecting portion 203B is held at first end portion 510B and does not move within movement limiting portion 500B. As a result, offset mechanism portion 20B maintains the parallel link mechanism.

[0063] When the working unit 40B comes into contact with an obstacle and the connecting part 203B receives a force from the second link arm 22B in the direction of the arrow P that exceeds a predetermined threshold value, the position of the connecting part 203B moves away from the first end 510B, as shown by the solid line in Fig. 9. Then, when the position of the connecting part 203B passes the bent part 540B, the connecting part 203B slides against the movement limiting part 500B and moves while contracting the elastic member 60B, and reaches the second end 520B. In other words, the offset working machine 100B according to this embodiment can provide the same effect as the offset working machine 100A according to the second embodiment.

[0064] [4. Fourth embodiment] [4-1. Configuration of offset machine] An offset working machine 100C according to the fourth embodiment will be described with reference to Figs. 10 to 13. The offset working machine 100C is similar to the offset working machines 100 and 100A according to the first and second embodiments, but is different from the offset working machines 100 and 100A in that a pivotal connecting member 700C is provided between the second link arm 22C and the elastic member 60C. Figs. 10, 12, and 13 are diagrams respectively showing a state before the working unit comes into contact with an obstacle, a state immediately after an obstacle collides with the working unit 40C from the state of Fig. 10, and a state in which the working unit 40C is pushed further backward from the state of Fig. 12, and are explanatory diagrams showing the positional relationship between the grooves 583C and 584C formed in a pair of flat plate-like members 570C, the groove 721C formed in the pivotal connecting member 700C, the connecting portion 203C connected to the second link arm 22C, and the connecting portion 603C connected to the elastic member 60C. Fig. 11 is an exploded view of the flat plate member 570C and the rotational connecting member 700C in Fig. 10. The enlarged views of Figs. 10, 12, and 13 are views in which the upper flat plate member 570C of the pair of flat plate members 570C is omitted.

[0065] As shown in FIG. 10 and FIG. 11, the escape mechanism 50C has a rotating connection member 700C. The rotating connection member 700C is sandwiched between a pair of upper and lower flat plate-like members 570C, and is rotatably connected to the flat plate-like members 570C via a rotation center 705C. The rotating connection member 700C has a first connection portion 710C and a second connection portion 720C. The first connection portion 710C is rotatably connected to the connecting portion 203C. The second connection portion 720C is connected to the connecting portion 603C of the elastic member 60C. The second connection portion 720C includes a groove 721C having a longitudinal direction, and the rotation center 705C is provided on the extension line of the longitudinal direction. In this embodiment, as in the first embodiment, an abutting member 620C having an insertion hole through which the connecting portion 603C is inserted is fixed to one end of the rotating shaft member 610C through which the elastic member 60C is inserted. The abutting member 620C is connected to the second connecting portion 720C via a pin-shaped connecting portion 603C. That is, the connecting portion 603C is inserted into a groove 721C provided in the second connecting portion 720C and moves (slides) within the groove 721C, whereby the connecting portion 603C is rotatably and movably connected to the rotating connecting member 700C.

[0066] The flat plate-like member 570C is provided with a groove 583C functioning as the first movement limiting portion 502C, a groove 584C functioning as the second movement limiting portion 503C, and an insertion hole 505C through which a pin-shaped member serving as a rotation center 705C is inserted. The first movement limiting portion 502C limits the movement range of the connecting portion 203C connected to the second link arm 22C, and the movement of the connecting portion 203C is limited by the connecting portion 203C sliding on the inner wall of the groove 583C. The groove 583C is provided in an arc shape centered on the rotation center 705C. The second movement limiting portion 503C limits the movement of the connecting portion 603C inserted into the abutting member 620C, and the movement of the connecting portion 603C is limited by the connecting portion 603C sliding on the inner wall of the groove 584C. The groove 584C has a shape in which a first groove 585C (having a long side) extending in the D4 direction, which is (approximately) the front-rear direction, and a second groove 586C (having a long side) extending in the D5 direction are connected at their respective ends. Note that the D4 direction is not limited to (approximately) the front-rear direction.

[0067] The front end of the first groove 585C may be referred to as the first end 511C, and the rear end of the second groove 586C may be referred to as the second end 521C. The part where the first groove 585C and the second groove 586C are connected may be referred to as the bent portion 515C. The distance between the first groove 585C and the rotation center 705C gradually increases from the first end 511C toward the bent portion 515C. Also, the distance between the second groove 586C and the rotation center 705C gradually increases from the second end 521C toward the bent portion 515C. That is, the distance between the connecting portion 603C of the elastic member 60C and the rotation center 705C when the connecting portion 603C is present at the bent portion 515C is larger than the distance between the connecting portion 603C and the rotation center 705C when the connecting portion 603C is present at the first end 511C and the second end 521C.

[0068] The elastic member 60C has a function of applying a predetermined compressive force to hold the connecting portion 603C at the first end 511C when an external force exceeding a predetermined threshold value is not applied to the working portion 40C. That is, the elastic member 60C indirectly biases the connecting portion 203C via the connecting portion 603C and the rotating connecting member 700C so that the connecting portion 203C is held at a predetermined position (in this embodiment, the rear end position) of the first movement limiting portion 502C (groove 583C). The rotating shaft member 610C is inserted through a rotation center 590C rotatably provided on the flat plate-shaped member 570C, and the elastic member 60C rotates around the rotation center 590C with respect to the flat plate-shaped member 570C as the connecting portion 603C moves in the groove. In this way, the elastic member 60C is configured to be rotatable with respect to the flat plate-like member 570C (front frame 11C) and can rotate following the movement of the connecting portion 603C. Therefore, the connecting portion 603C can move not only in one direction but also in a plurality of directions (in this embodiment, the D4 direction and the D5 direction). Therefore, it is possible to design the movement direction of the connecting portion 603C and the connecting portion 203C without being limited to the biasing direction (expansion direction) of the elastic member 60C.

[0069] When an obstacle collides with the working unit 40C in the state of FIG. 10 and an external force exceeding a predetermined threshold value is applied to the working unit 40C, the force applied to the connecting unit 603C via the connecting unit 203C exceeds the force that tries to hold the connecting unit 603C to the first end 511C, that is, the force acting due to the compressive force of the elastic member 60C and the force received by the second movement limiting unit 503C (the inner wall of the first groove 585C), and the connecting unit 203C moves forward in the first movement limiting unit 502C as shown in FIG. 12. With this forward movement of the connecting unit 203C, the rotating connecting member 700C rotates (counterclockwise) around the rotation center 705C, and the connecting unit 603C provided on the second connecting unit 720C moves backward in the second movement limiting unit 503C. Because the groove 583C is arc-shaped, the distance of the connecting unit 203C to the rotation center 705C does not change. On the other hand, the connecting portion 603C moves from the first end 511C toward the bent portion 515C and the second end 521C from the fourth direction to the fifth direction while being guided by the inner wall of the groove 584C, and the distance of the connecting portion 603C from the rotation center 705C gradually becomes shorter as the connecting portion 603C moves from the bent portion 515C toward the second end 521C in the second movement limiting portion 503C, the connecting portion 603C moves (slides) in the second connecting portion 720C (groove 721C) of the rotating connecting member 700C from the position farthest from the rotation center 705C of the second connecting portion 720C (groove 721C) in the direction approaching the rotation center 705C.

[0070] When the working unit 40C is further pushed backward from the state of FIG. 12, as shown in FIG. 13, the connecting part 203C moves further forward inside the first movement limiting part 502C. With this forward movement of the connecting part 203C, the rotating connecting member 700C further rotates counterclockwise around the rotation center 705C, and the connecting part 603C moves further backward inside the second movement limiting part 503C while moving in a direction approaching the rotation center 705C inside the second connecting part 720C. That is, the distance between the connecting part 603C and the rotation center 705C becomes smaller. By the above operation, the offset working machine 100C according to this embodiment can obtain the effect of breaking the parallel link and moving the working unit 40 to escape, similar to the offset working machines 100A and 100B according to the second and third embodiments.

[0071] Although the present invention has been described above with reference to the drawings, the present invention is not limited to the above-mentioned embodiments, and can be modified as appropriate without departing from the spirit of the present invention. For example, a person skilled in the art can add, delete, or modify components based on each embodiment as appropriate, and the scope of the present invention is included as long as the gist of the present invention is met. Furthermore, the above-mentioned embodiments can be combined as appropriate as long as there is no mutual contradiction, and technical matters common to each embodiment are included in each embodiment even if not explicitly stated.

[0072] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those which are clear from the description in this specification or which can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0073] 10: mounting portion, 11: front frame, 13: lower link coupling portion, 14: input shaft, 15: power transmission means, 16: output shaft, 20: offset mechanism portion, 21: first link arm, 22: second link arm, 23: third link arm, 24: expandable member, 30: power transmission portion, 31: driving sprocket, 32: driven sprocket, 33: roller chain, 40: working portion, 41: working rotor, 41a: claw shaft, 41b: cutting blade, 42: cutting blade drive portion, 50: escape mechanism portion, 60: elastic member, 100: offset working machine, 201: connection portion, 203: coupling portion, 205B: connection portion, 207B: connection portion, 399: obstacle, 500: movement limiting portion, 501: see-through area, 502C: first movement limiting portion, 503C: second movement limiting portion, 505C: insertion hole, 510A, 511C: first end portion, 520A, 521C: second end portion, 530A: sliding portion, 540B, 515C: bending portion, 570: flat plate-shaped member, 580: groove, 581A, 585C: first groove, 582A, 586C: second groove, 583C, 584C: groove, 590C: rotation center, 603C: connecting portion, 610: rotation shaft member, 620: abutment member, 630: shaft member, 640B: first stopper, 650B: second stopper, 660B: connection portion, 700C: rotation connecting member, 705C: rotation center, 710C: first connection part, 720C: second connection part, 721C: groove, CP1: contact, CP2: contact, TAN1: tangent, TAN2: tangent

Claims

1. A frame, A working unit that receives power from the traveling machine body and performs agricultural work; an offset mechanism that connects the frame and the working unit and offsets and moves the working unit in the left-right direction; and an escape mechanism for moving the working unit to escape when an external force equal to or greater than a predetermined force acts on the working unit, The offset mechanism has a first connecting portion connected to the relief mechanism, the relief mechanism includes a movement limiting portion that limits a movement range of the first connecting portion, and an elastic member that generates an elastic force that presses the first connecting portion against the movement limiting portion, The elastic member is rotatable relative to the frame, An offset working machine in which the working part makes the escape movement by the first connecting part moving within the movement limiting part in a direction different from the expansion and contraction direction of the elastic member.

2. A frame, A working unit that receives power from the traveling machine body and performs agricultural work; an offset mechanism that connects the frame and the working unit and offsets and moves the working unit in the left-right direction while maintaining the orientation of the working unit with respect to the traveling direction; a relief mechanism provided on the frame, the offset mechanism has a first connection portion including a fulcrum for the offset movement, The first connecting portion is connected to the escape mechanism portion, the relief mechanism includes a movement limiting portion that limits a movement range of the first connecting portion, and an elastic member that generates an elastic force that presses the first connecting portion against the movement limiting portion, The elastic member is rotatable relative to the frame, An offset working machine in which the working unit moves to escape by the first connecting portion moving within the movement limiting portion in a direction different from the extension / contraction direction of the elastic member.

3. The movement limiting portion is a groove having a longitudinal direction, The first connecting portion is movable while sliding on an inner wall of the groove, The offset work machine according to claim 1 or 2, wherein the extension / contraction direction is different from a longitudinal direction of the groove.

4. An offset working machine as described in any one of claims 1 to 3, wherein the elastic member presses the first connecting portion against the movement limiting portion, thereby maintaining the position of the first connecting portion in the movement limiting portion when the working portion is not receiving a force greater than a predetermined force.

5. The offset mechanism includes a first link arm and a second link arm that are parallel to each other, the first link arm having a first end and a second end; the first end is pivotally connected to a fixed portion of the working portion; the second end is pivotally connected to a fixed portion of the frame; the second link arm includes a third end and a fourth end; the third end is pivotally connected to a fixed position of the working unit or to the other end of a link arm, one end of which is connected to the first end; The offset work machine according to claim 1 , wherein the fourth end is connected to the movable first connecting portion.

6. The offset work machine according to claim 1 , wherein the movement limiting portion limits the movement of the first connecting portion to a first direction and a second direction different from the first direction.

7. The escape mechanism further includes a rotation connecting member that is rotatable about a rotation center, The offset work machine according to claim 1 or 2, wherein the pivotable connecting member is connected to the first connecting portion at a first connecting portion and is connected to the second connecting portion of the elastic member at a second connecting portion.

8. The offset work machine according to claim 7 , wherein the second coupling portion is movable at the second connection portion such that a distance between the second coupling portion and the center of rotation changes.

Images