JP7376930B2 - grass cutting machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an agricultural machine that is attached to a tractor, which is a running body, and performs mowing work such as grass.

A device for cutting plants on the ground is disclosed as a grass cutter in Patent Document 1. This mower is equipped with a rotary shaft equipped with a mowing blade inside the cover so as to be rotatable in a vertical plane. A guide plate is attached to the inside. Grass growing on the ground is taken in through the intake port at the front and is cut by the mowing blade inside the gutter-like body that is the cover body. The cut grass is discharged from a discharge port in a gap formed between the rear surface of the gutter-like cover body and the ground.

Japanese Patent Application Publication No. 11-103635

In the grass mower disclosed in Patent Document 1, when a large amount of grass is cut by the grass cutting blade, the grass cannot be discharged from the discharge port in time, and the cut grass accumulates inside the gutter-like body that is the cover body. Then, the mowed grass comes into contact with the mowing blade, creating rotational resistance of the mowing blade and increasing the power load. In order to withstand the power load, it is necessary to strengthen many of the members involved in power transmission, which poses a problem that leads to a rise in the price of the aircraft. Furthermore, when performing work without increasing the load using the mower of Patent Document 1, it is necessary to adjust the work speed while taking into account the rotational resistance of the mowing blade. However, it is difficult for the operator to judge the rotational resistance of the mowing blade, which is the working part, and the state of the cut grass inside the cover, which is the cause of this resistance.

Therefore, the present invention has been made in view of the above-mentioned problems, and provides a mowing machine that can judge the rotational load of the working part and smoothly discharge cut grass without reinforcing the transmission member. The purpose is to

In order to solve the above problems, one aspect of the present invention includes a working part that has a cutting blade around a rotating shaft and performs work by rotating; an opening/closing cover rotatable between a shielding position for shielding the working section and an open position for opening the cutting blade; a drive device for rotationally driving the opening/closing cover; A rotation sensor is installed to detect the rotational speed of the shaft and to transmit a signal detected by the rotational speed as a rotational signal. The gist is that the mowing machine is provided with a control section capable of driving a drive device according to the result of a comparison calculation between a certain first rotation signal and a second rotation signal that is a current rotation signal. do.

According to the present invention, it is possible to provide a mowing machine that can judge the rotational load of the working part and smoothly discharge cut grass without increasing the transmission member.

FIG. 2 is a front view of the mowing machine according to the embodiment of the present invention, viewed from the front toward the rear in the direction of travel, with a part of the cover section cut away. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a mowing machine according to an embodiment of the present invention, viewed from left to right in the direction of travel. FIG. 2 is a plan view of FIG. 1; FIG. 3 is a front view of FIG. 2 cut in the left-right direction with respect to the traveling direction, showing the opening/closing cover, the gauge part, and the press plate. FIG. 2 is a side view of FIG. 1 taken in the direction of travel, showing a state where the opening/closing cover is in a shielding position. FIG. 2 is a side view of FIG. 1 taken in the direction of travel, showing a state where the opening/closing cover is in a shielding position. 1 is a block diagram of a mowing machine that is an embodiment of the present invention. FIG. 3 is a control flow diagram related to the operation of the opening/closing cover using the load sensor of the mowing machine according to the embodiment of the present invention. FIG. 3 is a control flow diagram related to the operation of the opening/closing cover using the rotation sensor of the mowing machine according to the embodiment of the present invention.

An embodiment of the present invention will be described with reference to the drawings. In the description, the left side shown in FIG. 1 will be referred to as the right side with respect to the traveling direction, and the right side will be referred to as the left side with respect to the traveling direction. Further, the left side shown in FIG. 2 will be described as the front with respect to the traveling direction, and the right side will be described as the rear with respect to the traveling direction. In order to explain the internal structure, the belt cover is shown by a two-dot chain line in FIG. 1, and the belt cover is not shown in FIG. 2. In the description of the drawings, the same or similar parts may be designated by the same or similar symbols, and the description thereof may be omitted. In addition, the drawings used for the explanation are schematic, and the relationship between the dimensions of each part, etc. may differ from the actual drawings. Further, the technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

The mowing machine 1 is used for mowing work by being attached to a three-point link mechanism (not shown) that is a lifting device provided at the rear of a traveling machine (not shown) such as an agricultural tractor. A frame portion 2, which is a machine frame of the mowing machine 1, is connected to the three-point link mechanism. The frame section 2 is equipped with a transmission section 3 that acquires rotational power from the traveling machine body, changes speed, and transmits the power to the working section 4. The working unit 4 performs grass cutting work by disposing a plurality of cutting blades 42 on a rotating shaft 41, which is a horizontal axis long in the left and right directions of movement, and rotating the blades.

A cover part 5 is arranged from the front of the working part 4 through the upper part to the rear thereof, and covers the working part 4. An opening/closing cover 54 is disposed at the rear of the cover section 5 and is rotatable in the vertical direction, and can be rotated by a drive device 56 controlled by the control section 7 . The control unit 7 is connected to a load sensor 72 and a rotation sensor 74, and by detecting signals from these sensors, can drive a drive device 56 to rotate the opening/closing cover 54. By rotating the opening/closing cover 54, the mowing machine 1 can perform mowing work by opening or shielding the rear part of the working section 4.

The details of the mowing machine 1 will be explained below. The frame portion 2, which is the machine frame, includes two lower mounting bodies 22 for mounting on the lower links of the three-point link mechanism of the traveling aircraft, and one top mounting body 23 for mounting on the top link of the three-point link mechanism. Equipped with A pipe frame 21 is attached to the rear end portion of the lower mounting body 22. The pipe frame 21 is a pipe-shaped member that is long in the left and right directions in the direction of movement, and serves as the skeleton of the mowing machine 1. A gear case 31, which is one of the constituent members of the transmission section 3, is disposed at the center of the pipe frame 21 with respect to the left and right sides, and the top attachment body 23 is fixed to the gear case 31. It may be attached to the traveling aircraft via a connection frame called a quick coupler or an auto hitch.

One side of a side plate 24 is attached to both left and right ends of the pipe frame 21, and a working section 4, which will be described later, can be supported so as to span the other end.

The transmission section 3 acquires rotational power output from the traveling machine body, changes gears, and transmits this power to the working section 4. A rotatable input shaft 32 is attached toward the front from a gear case 31 arranged at the center of the left and right sides of the pipe frame 21. The input shaft 32 and a PTO shaft (not shown) of the traveling body are connected by a universal joint or the like (not shown), and rotational power is input and driven.

The rotational power acquired by the input shaft 32 is changed in speed by gears provided inside the gear case 31, and the direction of power transmission is changed. The direction of power transmission in the embodiment is changed toward the left of the gear case 31. The rotational power is transmitted by an output shaft (not shown) disposed within the pipe frame 21 facing toward the left side plate from the gear case 31. The tip of the output shaft reaches and penetrates the side plate 24, and a first pulley 33 is attached to this tip. A second pulley 34 is arranged below the first pulley 33 arranged at one end of the side plate 24. The second pulley 34 is disposed on the other end side of the side plate 24, which is the lower part, and the tip of a rotating shaft 41 of a working part 4, which will be described later, is fixed thereto. The second pulley 34 is rotatable integrally with the rotating shaft 41.

A transmission belt 35 is wound around the first pulley 33 and the second pulley 34 . The rotational power acquired by the input shaft 32 rotates the second pulley 34 via the transmission belt 35. An idler pulley 36 is arranged between the first pulley 33 and the second pulley 34 to keep the tension of the transmission belt 35 appropriate. The rotation of the second pulley 34 is transmitted to a rotating shaft 41, which will be described later, and the working unit 4 is rotationally driven. The first pulley 33, second pulley 34, transmission belt 35, and idler pulley 36 arranged on the side plate 24 are covered and protected by a belt cover 37.

The working part 4 has a plurality of cutting blades 42 arranged on a long rotating shaft 41 at intervals in the circumferential direction and the axial direction. The cutting blade 42 can cut grass by rotating together with the rotating shaft 41. The working unit 4 has a plurality of swingable cutting blades 42 arranged on a rotation shaft 41 in a horizontal direction perpendicular to the direction of travel of the tractor. 41 as an axis to cut grass leaves.

A rotating shaft 41 that is rotationally driven by the rotation of the second pulley 34 is arranged in the left and right horizontal directions, and both ends of the rotating shaft 41 are arranged so as to span over side plates 24 arranged at both left and right ends of the pipe frame 21. The rotating shaft 41 can be rotationally driven by the rotation of the second pulley 34 fixed to the end thereof.

A plurality of cutting blades 42 are attached to the rotating shaft 41. The rotating shaft 41 side of the cutting blade 42 is connected to the rotating shaft 41 by a hinge 43, and the cutting blade 42 is swingable with respect to the rotating shaft. When the cutting blade 42 collides with a hard stone or obstacle other than grass, the cutting blade 42 uses the hinge 43 as an axis to move the tip side relative to the rotation radius backward in the rotation direction to absorb the impact. can be alleviated.

The outer periphery of the rotation locus of the working part 4 is covered with a cover part 5 from the front part through the upper part to the rear part. The cover part 5 prevents the cut grass leaves from scattering and guides the cut grass leaves to the rear of the working part 4 and below the cover part 5. The cover part 5 is capable of covering the front part to the upper part of the outer periphery of the rotational trajectory of the working part 4 and the rear part of the outer periphery of the rotational trajectory of the working part 4, and the rear end of the cutting blade cover 51. The opening/closing cover 51 is provided so as to be movable up and down.

The cutting blade cover 51 covers the entire left and right width of the working part 4 from the front part to the upper part, thereby preventing the grass blades cut by the working part 4 from scattering forward and upward, and also prevents the cut grass leaves from scattering forward and upward. The grass leaves are guided to the rear side of the cutting blade cover 51 along the inner surface of the cutting blade cover 51. In the case of the embodiment, the cutting blade cover 51 is arranged so as to span the left and right side plates 24.

A flap cover 53 is attached to the front lower end of the cutting blade cover 51 so that the lower end hangs down so as to be rotatable toward the rear. By rotating rearward, the flap cover 53 easily guides grass that moves relatively from the front as the traveling aircraft advances to the working section 4. In addition, if there is no grass below the flap cover 53, the lower end of the flap cover 53 moves downward to cover the gap formed at the lower end of the front of the cutting blade cover 51, allowing the cut grass to move forward. Prevent scattering.

An opening/closing cover 54 is arranged at the rear end of the cutting blade cover 51. One end of the opening/closing cover 54 is made vertically rotatable by connecting a hinge 55 provided at the rear end of the cutting blade cover. The opening/closing cover 54 can be moved up and down between a shielding position where the rear side of the working section 4 is completely covered and an open position where the rear side of the working section 4 is completely opened. Further, the open/close cover 54 can be fixed at any position desired by the operator from the shielding position to the open position. That is, the opening/closing cover 54 is rotatable behind the working section 4 between the shielding position and the open position. In the case of the embodiment, the angle of the opening/closing cover 54 in the open position is rotated upward by about 20 to 30 degrees relative to the shielding position, as shown in FIG. The setting angle is not limited and can be arbitrarily determined.

A gap H is formed between the other end of the openable cover 54 and the ground G. The cut grass leaves are guided by the opening/closing cover 54 and then released or discharged from the gap H toward the ground G. The gap H is minimum when the open/close cover 54 is in the shielding position, and maximum when the opening/closing cover 54 is in the open position. The amount of cut grass leaves discharged from inside the cover part 5 is proportional to the size of the gap H formed by the rotation of the opening/closing cover 54. That is, when the gap H is small, the discharge amount is small, and conversely, when the gap H is large, the discharge amount is large.

When the opening/closing cover 54 is in the shielding position, the cut grass leaves that have moved along the inner surface of the cutting blade cover 51 fall along the cutting blade side surface of the opening/closing cover 54 and fall immediately behind the working part 4. can be done. When the opening/closing cover 54 is in the open position, the cut grass leaves that have moved along the inner surface of the cutting blade cover 51 are moved along the cutting blade side surface of the opening/closing cover 54 to the rear far away from the working part 4. can be dropped. As described above, the cut grass leaves can be dropped to any desired position by changing the rotation angle of the opening/closing cover 54.

The opening/closing cover 54 is rotated by a drive device 56. The drive device 56 uses a hydraulic cylinder. The drive device 56 has one end connected to a mounting portion 211 provided on the pipe frame 21, and the other end connected to a mounting plate 541 fixed upward from the opening/closing cover 54. The opening/closing cover 54 can be rotated from the shielding position to the open position as the drive device 56 expands and contracts. Moreover, by stopping the expansion and contraction of the drive device 56 and maintaining the expansion and contraction length, it is possible to fix the openable/close cover 54 at any position.

The hydraulic cylinder in the embodiment is equipped with an electric pump and can be operated by being connected to a power source without special arrangement of hydraulic piping. Further, in the drawings, the drive devices 56 are arranged at two locations on the left and right of the pipe frame 21 and the opening/closing cover 54, but the number is not limited. Further, the drive device 56 is not limited to a cylinder type, and a motor may be used, and the opening/closing cover 54 may be rotated using this rotational power.

A support member 57 is attached below the opening/closing cover 54. The support member 57 is a member that is long in the left-right direction, and fixes the rear portions of the left and right side plates 24 to each other. The support member 57 is located on the other end side of the opening/closing cover 54 in the shielding position, and when in the shielding position, the cut grass leaves are placed on the respective surfaces of the opening/closing cover 54 and the support member 57 on the working part 4 side. Along the line, it falls onto the ground G immediately behind the working section 4.

A gauge portion 6 is located at the rear and lower portion of the side plate 24. The gauge part 6 is arranged so as to span the left and right side plates, and a gauge roller 61 that can rotate while contacting the ground G is arranged. The gauge roller 61 is a round bar-shaped or round pipe-shaped member that is rotatable around a rotating shaft 62. Since the height of the work unit 4 from the ground G can be kept constant by the gauge roller 61, stable mowing work can be performed without the rotating cutting blade 42 coming into contact with the ground G.

The cut grass leaves guided along the opening/closing cover 54 are released toward the ground G from the other end side of the opening/closing cover 54. In this embodiment, the released grass leaves fall in front of the gauge section 6 along the front surface of the support member 57 when the open/close cover 54 is in the shielding position. Furthermore, the grass leaves released when the opening/closing cover 54 is rotated to an open position other than the shielding position pass through the rear of the support member 57 and fall to the rear of the gauge part 6.

When the open/close cover 54 is in the shielding position, cut grass leaves that have fallen in front of the gauge section 6 are released from the gap H to the outside of the cover section 5 as the mowing machine 1 moves. In the case of the embodiment to be described, the support member 57 and the gauge roller 61 of the gauge section 6 are located at the gap H, so the cut grass blades are placed at the height of the support member 57 and the gauge roller 61 from the gap H. It is released from the subtracted gap Ha. Furthermore, since the gauge roller 61 is configured to rotate as the aircraft advances, it can step on cut grass leaves accumulated on the ground G. Therefore, the cut grass blades are moved over by the gauge roller 61 and moved rearward relative to the mowing machine 1.

When the opening/closing cover 54 is in the shielding position, the gap H is the minimum, so if a large amount of cut grass leaves are present, they will not be discharged in time, and excessive amounts will accumulate behind the working section 4 and in front of the gauge section 6. There is. In this state, the cut grass leaves accumulate inside the cover part 5 and become a deposit T, as shown by the two-dot chain line in FIG. Since the deposit T is gradually compressed and becomes hard, when the deposit T comes into contact with the rotating region of the working part 4 shown by the dashed line in FIG. 5, a load is applied to the rotation of the working part 4. Then, the transmission section 3, particularly the transmission belt 35, is damaged or stretched, making it impossible to properly transmit power and reducing the rotation of the working section 4. If this state continues, the rotation of the working part 4 will continue to decrease, and eventually it will become impossible to continue the mowing work. In this case, if the deposit T is removed, the above-mentioned inconvenient condition will be resolved and the mowing operation can be continued.

Specifically, by rotating the opening/closing cover 54 to the open position side, as the mowing machine 1 advances, the cut grass leaves that are sent along the cutting blade cover 51 and the opening/closing cover 54 are removed. The deposit T is not deposited on the front of the gauge part 6, but is discharged to the rear. This prompts the discharge of the deposits T already deposited in front of the gauge section 6, and the accumulation of the deposits T inside the cover section 5 is eliminated.

For this reason, the mowing machine 1 includes a control unit 7 that controls the operation of the drive device 56 in order to automatically open and close the opening/closing cover 54. The control unit 7 in the embodiment is arranged near the top mounting body 23. The control section 7 is connected to a load sensor 72 that can detect the state of accumulation of deposits T inside the cover section 5 and a rotation sensor 74 that can detect the state of rotation of the rotation shaft 41 of the working section 4. There is. Further, the control unit 7 is connected to a drive device 56. The control unit 7 receives the signals transmitted from the load sensor 72 and the rotation sensor 74, and performs calculations based on these signals, thereby making the drive device 56 perform operations based on a prespecified control program. .

The load sensor 72 is arranged at a position behind the working part 4 and facing the working part 4. In the embodiment, the load sensors 72 use compression load cells, and two of them are arranged on the front surface of the support member 57. The load sensor 72 can transmit the load applied to the front surface to the control unit 7 as a load signal. When the deposit T accumulates and increases in volume, it contacts the load sensor 72, and as the volume continues to increase, it presses the load sensor 72. Since the load changes after pressing, this is also transmitted to the control unit 7 as a load signal. The control unit 7 constantly receives changes in the load applied to the deposit T by the load sensor 72. The control unit 7 recognizes the information indicated by the received load signal as a detected load value, and compares and calculates this detected load value with a predetermined set load value. The control unit 7 can cause the drive device 56 to operate according to a prespecified control program based on the result of the comparison calculation.

A pressing plate 73 is located in front of the load sensor 72. The pressing plate 73 is a member having a U-shaped cross section and having substantially the same length as the support member 57 and long in the left and right directions, and is provided so as to be able to come into contact with the pressure sensing portion of the load sensor 72. That is, the press plate 73 is provided so as to be movable back and forth. The pressure plate 73 allows the load at a location where the load sensor 72 is not located to be detected via the pressure plate 73.

Since the load sensors 72 are arranged so as to be divided almost equally in the longitudinal direction of the working section 4, the deposits T accumulated on the ground G behind the working section 4 and in front of the opening/closing cover 54 can be detected evenly. can do. Further, since the load sensor 72 is disposed within the gap H formed below the opening/closing cover 54 or close to the gap H, the degree of accumulation of the deposits T near the gap H can be immediately detected. In the case of the embodiment, since the load sensor 72 is attached to the support member 57 that is long in the left-right direction, it can be placed near the center in the width direction of the working section 4 where deposits T are likely to occur, and it is possible to improve the load detection accuracy. .

The load sensor 72 is not limited to the illustrated embodiment, and there are no limitations on the sensor type, installation location and orientation, and number of installations. That is, the load sensor 72 only needs to be able to detect the load and be located at a rear position facing the working section 4, and the number of installed sensors may be one or more. Specifically, although the embodiment has been described assuming that the support member 57 and the gauge section 6 are present, implementation is possible even when the support member 57 and the gauge section 6 are not present. In this case, it is desirable that the load sensor 72 and the press plate 73 be installed at the rear of the working section 4 of the opening/closing cover 54 and at a location facing the working section 4 . Although the load sensor has been explained as a load cell type, it may also be a switch that performs a simple on/off operation when a set load is applied. If the number of installed load sensors 72 is one or more, the load pressed by the pressing plate 73 can be detected. As the number of installed load sensors 72 increases, the detection accuracy can be expected to improve.

The rotation sensor 74 is a non-contact type sensor that detects the rotation speed of the rotation shaft 41 of the working part 4, and measures the rotation speed by detecting the number of rotation pulses. The rotation sensor 74 is disposed near the second pulley 34 and measures the number of rotations of the second pulley 34 that rotates together with the rotation shaft 41 of the working section 4 . The rotation sensor 74 directly measures the number of rotations of the rotation shaft 41 by detecting rotation pulses of a protrusion 75 attached to the second pulley 34 . The protruding piece 75 is provided so as to protrude outward from the rotational outer circumference of the second pulley 34 . The rotation sensor 74 is arranged close to the projection piece 75 that rotates together with the second pulley 34, and detects the number of pulses that is the number of times the projection piece 75 approaches the rotation sensor 74. The control unit 7 can recognize the detected number of pulses as the number of rotations.

The rotation sensor 74 is configured to always send a rotation signal to the control unit 7. The control unit 7 that has received the rotation signal recognizes the information indicated by the rotation signal as the detected rotation speed, and performs arithmetic processing based on this detected rotation speed. After the rotation sensor 74 detects the rotation speed of the rotating shaft 41, the control unit 7 performs a comparison calculation to determine whether there is a change in the detected rotation speed. Based on the result of the arithmetic processing, the drive device 56 can be caused to operate in accordance with a prespecified control program.

The rotation sensor 74 is not limited to the illustrated embodiment, and there are no limitations on the type and installation location of the sensor, as long as it can detect the rotation speed of the rotation shaft 41. Furthermore, since the detection accuracy of rotation speed detection by the rotation sensor 74 can be improved by directly detecting fluctuations in the rotation speed, it is possible to directly measure the rotation system of the work unit 4 that performs work. is desirable.

Next, a procedure for operating the drive device 56 by the control unit 7 based on the signals transmitted from the load sensor 72 and the rotation sensor 74 will be described. A program is incorporated in the control unit 7 so that the drive device 56 performs specified operations based on signals from the load sensor 72 and the rotation sensor 74.

The operating procedure of the drive device 56 when the load sensor 72 is used will be explained using FIG. 8. When the control is started, the drive device 56 is operated in step S1 to rotate the opening/closing cover 54 in the direction of the shielding position. That is, the opening/closing cover 54 is closed. At this time, the drive device 56 operates for a preset time and then stops. By this step S1, the open/close cover 54 is forced to the shielding position, and subsequent control operations are performed using this position as a reference position. Note that even if the opening/closing cover 54 physically reaches the shielding position or the limit position of rotation toward the shielding position, the drive device 56 operates only for a preset time.

When step S1 ends, the process moves to step S2. In step S2, the control unit 7 compares and calculates the detected load value indicated by the load signal received from the load sensor 72 and a set load value that is a preset load value. The comparison calculation in step S2 is referred to as a first load comparison. As a result of the first load comparison, if it is determined that the detected load value is larger than the set load value, the control unit 7 causes the process to proceed to step S3.

In step S3, based on the result of the first load comparison in step S2, the drive device 56 is operated to start rotating the opening/closing cover 54 toward the open position. Next, the control section 7 moves to step S4.

In step S4, the control unit 7 determines whether the elapsed time, which is the time that has elapsed since the start of the operation of the drive device 56 in step S3, has exceeded the set time, which is the set time. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 is less than the set time, the process returns to step S2 and the control steps are repeated. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 has exceeded the set time, the process moves to step S5.

When proceeding to step S5, the control section 7 stops the operation of the drive device 56. In other words, the rotation of the opening/closing cover 54 toward the open position is stopped. Next, the process moves to step S6. In step S6, the control unit 7 compares and calculates the detected load value indicated by the load signal received from the load sensor 72 and a set load value that is a preset load value. The comparison calculation is called a second load comparison. As a result of the second load comparison, if it is determined that the detected load value is larger than the set load value, the control unit 7 repeats the determination in step S6 again. As a result of the second load comparison, if it is determined that the detected load value is not larger than the set load value, the control section 7 returns to step S2 and repeats the control steps.

In step S2, if the control section 7 determines that the detected load value is not larger than the set load value as a result of the first load comparison, the control section 7 moves the process to step S7. In step S7, based on the result of the first load comparison in step S2, the drive device 56 is operated to start rotating the opening/closing cover 54 toward the shielding position. That is, the opening/closing cover is caused to close. Next, the control section 7 moves to step S8.

In step S8, the control unit 7 determines whether the elapsed time, which is the time that has elapsed since the start of the operation of the drive device 56 in step S7, has exceeded the set time, which is the set time. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 is less than the set time, the process returns to step S2 and the control steps are repeated again. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 has exceeded the set time, the process moves to step S9.

When proceeding to step S9, the control unit 7 stops the operation of the drive device 56. In other words, the rotation of the opening/closing cover 54 toward the shielding position is stopped. Next, the process moves to step S10. The control unit 7 in step S10 compares and calculates the detected load value indicated by the load signal received from the load sensor 72 and a set load value that is a preset load value. This comparison calculation is called a third load comparison. As a result of the third load comparison, if it is determined that the detected load value is not larger than the set load value, the control unit 7 repeats the third load comparison in step S10. If it is determined that the detected load value is larger than the set load value as a result of the third load comparison, the control unit 7 returns to step S2 and repeats the control sequentially from the control step of performing the first load comparison.

The second load comparison in step S6 and the third load comparison in step S10 follow the same judgment steps as the first load comparison in step S2, but the results of the comparison calculation between the detected load value and the set load value are The method of proceeding with the determined control step is different. Immediately after the first load comparison is completed, the control unit 7 operates the drive device 56 to rotate the opening/closing cover 54 to the open position or the shielding position, but after the second and third load comparisons are completed, does not operate the drive device 56 immediately.

Specifically, when it is determined in the first load comparison that the detected load value is larger than the set load value, the drive device 56 is operated to rotate the opening/closing cover toward the open position. In contrast to this first load comparison, in the second load comparison, if it is determined that the detected load value detected again is larger than the set load value, the second load comparison is repeated again without operating the drive device 56. The operation of the device 56 is put into a standby state. Similarly, if it is determined in the first load comparison that the detected load value is not larger than the set load value, the drive device 56 is operated to rotate the opening/closing cover toward the shielding position. In contrast to this first load comparison, in the third load comparison, if it is determined that the detected load value detected again is not larger than the set load value, the third load comparison is repeated again without operating the drive device 56. The operation of the drive device 56 is put into a standby state.

In other words, after the first load comparison, the control unit 7 again performs the second load comparison and third load comparison, which are similar judgments, and the results of the second load comparison and third load comparison are the same as those of the first load comparison. The second load comparison and the third load comparison can be repeated until a result different from the result shown in FIG. If the results of the second load comparison and the third load comparison are different from the results of the first load comparison, the first load comparison is performed again and the drive device 56 is operated.

By performing the second load comparison and the third load comparison, it is possible to prevent the drive device 56 from operating again immediately after the operation and stopping of the drive device 56 due to the first load comparison. In other words, after the opening/closing cover 54 is rotated toward the open position based on the result of the first load comparison, the pressing state of the load sensor 72 due to the deposit T is released, and if the load does not fall below the set load value, the next drive is performed. The control step for operating the device 56 is not allowed to proceed. Therefore, the opening/closing cover 54 is rotated to the open position side, and the deposit T is discharged from the inside of the cover part 5 while the gap H is secured. As long as the pressure on the load sensor 72 due to the deposits T is not released, the drive device 56 remains in a standby state. Further, during this standby state, the cover 54 can be immediately operated every time a change in the load inside the cover portion 5 occurs.

Furthermore, even after the opening/closing cover 54 is rotated toward the shielding position based on the result of the first load comparison, the load sensor 72 is similarly pressed by the deposit T, and the detected load value is lower than the set load value. If it does not become larger, the next control step for operating the drive device 56 cannot proceed. Therefore, the drive device 56 maintains the standby state unless the opening/closing cover 54 is rotated to the shielding position and the deposit T remains in the cover part 5 and a load condition is created on the working part 4. Further, during this standby state, the cover 54 can be immediately operated every time a change in the load inside the cover portion 5 occurs.

When the control unit 7 performs the first to third load comparisons, if it is determined that at least one of the detected load values detected based on the signals from the plurality of load sensors 72 is larger than the set load value, It is determined that the detected load values of all the load sensors 72 are larger than the set load value. Therefore, even if an unbalanced load state occurs in which only one of the load sensors 72 is loaded, the control unit 7 can correctly recognize the occurrence of deposits T in the cover part 5, and the rotation operation of the opening/closing cover 54 can be performed. becomes possible.

The operation of the drive device 56 using the load sensor 72 is extremely simplified so that it operates only for a preset operation time. By setting the operating time of the drive device 56 to an arbitrary time, it is possible to change the angle of the opening position of the opening/closing cover 54. Devices and members related to the operation of the drive device 56 can be omitted as much as possible, and the risk of malfunctions occurring in peripheral parts of the drive device 56 can be suppressed as much as possible.

The operating procedure of the drive device 56 when the rotation sensor 74 is used will be explained using FIG. 9. When the control is started, the drive device 56 is operated in step S101 to rotate the opening/closing cover 54 in the direction of the shielding position. That is, the opening/closing cover 54 is closed. At this time, the drive device 56 operates for a preset time and then stops. In this step S101, the open/close cover 54 is forced to the shielding position, and subsequent control operations are performed using this position as a reference position. Note that even if the opening/closing cover 54 physically reaches the shielding position or the limit position of rotation toward the shielding position, the drive device 56 operates only for a preset time.

When step S101 ends, the process moves to step S102. In step S102, the rotation sensor 74 measures pulses during a first time period, which is the detection time of the rotation sensor 74, and transmits it to the control unit 7 as a first rotation signal. When the control unit 7 receives the first rotation signal, it recognizes it as the first detected rotation number, which is the rotation number at the first time. Note that the first time can be set to any time, and is set to 3 seconds in the embodiment, but the time is not limited. If the detection time is short, the rotation speed can be detected in close to real time, and if the detection time is long, the acquisition of noise that may occur during measurement can be reduced.

When step S102 ends, the process moves to step S103. In step S103, similarly to step S102, the rotation sensor 74 measures pulses during the second time period, which is the detection time of the rotation sensor 74, and transmits it to the control unit 7 as a second rotation signal. When the control unit 7 receives the second rotation signal, it recognizes it as the second detected rotation number, which is the rotation number at the second time. Note that the second time can be set to any time, and is set to 3 seconds in the embodiment, but the time is not limited. If the detection time is short, the rotation speed can be detected in close to real time, and if the detection time is long, the acquisition of noise that may occur during measurement can be reduced. Furthermore, from the control flow shown in FIG. 9, it can be said that the first detected rotational speed was measured earlier than the second detected rotational speed.

When step S103 ends, the process moves to step S104. In step S104, the control unit 7 compares and calculates the first detected rotation speed and the second detected rotation speed measured by the rotation sensor 74. The comparison calculation in step S104 is referred to as a first rotation speed comparison. As a result of the first rotation speed comparison, if it is determined that the first detected rotation speed is larger than the second detected rotation speed, the control unit 7 causes the process to proceed to step S105. That is, it is determined that the current rotational speed of the working part 4 is lower than the past rotational speed due to the load, and the process moves to step S105.

In step S105, based on the result of the first rotation speed comparison in step S104, the drive device 56 is operated to start rotating the opening/closing cover 54 toward the open position. In other words, open the opening/closing cover. Next, the control unit 7 causes the process to proceed to step S106.

In step S106, the control unit 7 determines whether the elapsed time, which is the time that has elapsed since the start of the operation of the drive device 56 in step S105, has exceeded the set time, which is the set time. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 is less than the set time, the process returns to step S102 and the control steps are repeated. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 has exceeded the set time, the process moves to step S107.

When proceeding to step S107, the control unit 7 stops the operation of the drive device 56. In other words, the rotation of the opening/closing cover 54 toward the opening side is stopped. Next, the process moves to step S108.

In step S108, the rotation sensor 74 again performs pulse measurement during the first time period, which is the detection time of the rotation sensor 74, and transmits it to the control unit 7 as a first rotation signal. When the control unit 7 receives the first rotation signal, it recognizes it as the first detected rotation number, which is the rotation number at the first time.

When step S108 ends, the process moves to step S109. In step S109, the rotation sensor 74 measures pulses during a second time period, which is the detection time of the rotation sensor 74, and transmits the pulse measurement to the control unit 7 as a second rotation signal. When the control unit 7 receives the second rotation signal, it recognizes it as the second detected rotation number, which is the rotation number at the second time. Furthermore, from the control flow shown in FIG. 9, it can be said that the first detected rotational speed was measured earlier than the second detected rotational speed.

When step S109 ends, the process moves to step S110. In step S110, the control unit 7 compares and calculates the first detected rotation speed and the second detected rotation speed measured by the rotation sensor 74 in steps S108 and S109. The comparison calculation in step S110 is referred to as a second rotation speed comparison. As a result of the second rotation speed comparison, if it is determined that the first detected rotation speed detected in step S108 is larger than the second detected rotation speed detected in step S109, the control unit 7 returns to step S108 and repeats the control steps. . That is, it is determined that the current rotational speed of the working part 4 is lower than the past rotational speed due to the load, and the process returns to step S108 to repeat the control.

As a result of the second rotation speed comparison in step S110, if it is determined that the first detection rotation speed detected in step S108 is not larger than the second detection rotation speed detected in step S109, the control unit 7 proceeds to step S102. control to return and repeat the control steps. That is, it is determined that the current rotational speed of the working part 4 is the same as or higher than the past rotational speed, and the process returns to step S102 to repeat the control again.

In step S102, if the control unit 7 determines that the first detected rotational speed is not larger than the second detected rotational speed as a result of the first rotational speed comparison, the control unit 7 moves the process to step S111. That is, it is determined that there is no load on the working part 4 and the current rotational speed is the same as or higher than the past rotational speed, and the process moves to step S111.

In step S111, based on the result of the first rotation speed comparison in step S104, the drive device 56 is operated to start rotating the opening/closing cover 54 toward the shielding position. In other words, close the opening/closing cover. Next, the control unit 7 moves the control to step S112.

In step S112, the control unit 7 determines whether the elapsed time, which is the time that has elapsed since the start of the operation of the drive device 56 in step S111, has exceeded the set time, which is the set time. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 is less than the set time, the process returns to step S102 and the control steps are repeated. If the control unit 7 determines that the elapsed time from the start of the operation of the drive device 56 has exceeded the set time, the process moves to step S113.

When proceeding to step S113, the control unit 7 stops the operation of the drive device 56. In other words, the rotation of the opening/closing cover 54 toward the shielding position is stopped. Next, the process moves to step S114.

In step S114, the rotation sensor 74 measures pulses during a first time period, which is the detection time of the rotation sensor 74, and transmits it to the control unit 7 as a first rotation signal. When the control unit 7 receives the first rotation signal, it recognizes it as the first detected rotation number, which is the rotation number at the first time.

When step S114 ends, the process moves to step S115. In step S115, the rotation sensor 74 measures pulses during a second time period, which is the detection time of the rotation sensor 74, and transmits the pulse measurement to the control unit 7 as a second rotation signal. When the control unit 7 receives the second rotation signal, it recognizes it as the second detected rotation number, which is the rotation number at the second time. Furthermore, from the control flow shown in FIG. 9, it can be said that the first detected rotational speed was measured earlier than the second detected rotational speed.

When step S115 ends, the process moves to step S116. In step S116, the control unit 7 compares and calculates the first detected rotation speed and the second detected rotation speed measured by the rotation sensor 74 in steps S114 and S115. The comparison calculation in step S116 is referred to as a third rotation speed comparison. As a result of the third rotation speed comparison, if it is determined that the first detected rotation speed detected in step S114 is not larger than the second detected rotation speed detected in step S115, the control unit 7 returns to step S114 and performs the control step. repeat. That is, it is determined that there is no load on the working part 4 and that the current rotational speed is the same as or higher than the past rotational speed, and the process returns to step S114 to repeat the control.

As a result of the third rotation speed comparison in step S116, if it is determined that the first detected rotation speed detected in step S114 is larger than the second detected rotation speed detected in step S115, the control unit 7 returns to step S102. , control to repeat the control steps. That is, it is determined that the current rotational speed of the working part 4 is lower than the past rotational speed due to the load, etc., and the process returns to step S102 to repeat the control again.

The second rotation speed comparison in step S110 and the third rotation speed comparison in step S116 are performed using the same judgment steps as the first rotation speed comparison in step S104, but the control step is determined based on the result of the comparison calculation. The way of proceeding is different. After the first rotation speed comparison is completed, the control unit 7 immediately operates the drive device 56 to rotate the opening/closing cover 54 to the open position or the shielding position, but the second rotation speed comparison and the third rotation speed comparison After the completion of the process, the drive device 56 is not operated immediately.

Specifically, when it is determined in the first rotation speed comparison that the first detected rotation speed is larger than the second detected rotation speed, the drive device 56 is operated to rotate the opening/closing cover toward the open position. In contrast to this first rotation speed comparison, in a second rotation speed comparison, if it is determined that the first detected rotation speed detected again is larger than the second detected rotation speed, the second rotation speed is again determined without operating the drive device 56. By repeating the comparison, the operation of the drive device 56 is put into a standby state. Similarly, if it is determined in the first rotation speed comparison that the first detected rotation speed is not greater than the second detected rotation speed, the drive device 56 is operated to rotate the opening/closing cover toward the shielding position. In contrast to this first rotation speed comparison, in the third rotation speed comparison, if it is determined that the first detected rotation speed detected again is not larger than the second detected rotation speed, the third rotation speed is again performed without operating the drive device 56. By repeating the number comparison, the operation of the drive device 56 is put into a standby state.

In other words, after the first rotation speed comparison, the control unit 7 again performs the second rotation speed comparison and the third rotation speed comparison, which are similar judgments, and the results of the second rotation speed comparison and the third rotation speed comparison are The drive device 56 can be placed in a standby state by repeating the second rotation speed comparison and the third rotation speed comparison until the result is different from the result of the first rotation speed comparison. If the results of the second rotation speed comparison and the third rotation speed comparison are different from the results of the first rotation speed comparison, the first rotation speed comparison is performed again and the drive device 56 is operated.

By performing the second rotation speed comparison and the third rotation speed comparison, it is possible to prevent the drive device 56 from operating again immediately after the operation and stop of the drive device 56 due to the first rotation speed comparison. That is, after the opening/closing cover 54 is rotated to the open position side based on the result of the first rotation speed comparison, the rotational load on the working part 4 due to the deposits T etc. is eliminated, and the rotating shaft 41 of the working part 4 is rotated. The control step for operating the drive device 56 cannot be proceeded to unless the rotational speed shifts to a maintained state or an increased state. Therefore, the opening/closing cover 54 rotates to the open position side, the deposit T is discharged from the inside of the cover part 5 while the gap H is secured, and unless the rotational load on the working part 4 due to the deposit T is released, the drive The device 56 remains in a standby state. Furthermore, during this standby state, the immediate opening/closing cover 54 can be operated whenever the rotational speed of the rotating shaft 41 of the working section 4 changes.

Further, even after the opening/closing cover 54 is rotated to the shielding position side based on the result of the first rotation speed comparison, the rotational load on the working part 4 increases due to deposits T, etc., so that the working part 4 The control step for operating the drive device 56 cannot proceed unless the rotation speed of the rotating shaft 41 continues to decrease. Therefore, in a state where the opening/closing cover 54 is rotated toward the shielding position, the drive device 56 maintains the standby state unless the deposit T remains in the cover part 5 and the rotational load on the rotating shaft 4 increases. Furthermore, during this standby state, the immediate opening/closing cover 54 can be operated whenever the rotational speed of the rotating shaft 41 of the working section 4 changes.

Since the drive device 56 is kept in a standby state until the calculation results of the second rotation speed comparison and the third rotation speed comparison are different from the calculation results of the first rotation speed comparison, the drive device 56 continues to operate repeatedly. This can be prevented.

The operation of the drive device 56 using the rotation sensor 74 is extremely simplified so that it operates only for a preset operating time. By setting the operating time of the drive device 56 to an arbitrary time, it is possible to change the angle of the opening position of the opening/closing cover 54. Devices and members related to the operation of the drive device 56 can be omitted as much as possible, and the risk of malfunctions occurring in peripheral parts of the drive device 56 can be suppressed as much as possible.

As described above, the control section 7 controls the rotation of the opening/closing cover 54 located at the rear of the working section 4 using the load sensor 72 or the rotation sensor 74. As a result, the pressing state inside the cover part 5 and the state of the load on the working part 4 can be detected, and the opening/closing cover 54 can be opened or closed based on the judgment of the control part 7, without increasing the required power and the power transmission member. Operate. Therefore, by smoothly discharging the cut grass from the enlarged gap H, the mowing work can be continued without any inconvenience caused by the deposits T inside the cover part 5.

Furthermore, although the explanation has been made assuming that the support member 57 and the gauge section 6 are provided, the opening/closing cover 54 can be operated by the load sensor 72 or the rotation sensor 74 even without these members. In addition, in the explanation, in order to make it easier to understand, the operations using the load sensor 72 and the rotation sensor 74 were explained as separate operation flows, but the control using the load sensor 72 and the rotation sensor 74 at the same time The opening/closing cover 54 may be operated.

1 Mowing machine 2 Frame section 24 Side plate 3 Transmission section 33 First pulley 34 Second pulley 35 Transmission belt 4 Working section 41 Rotating shaft 42 Cutting blade 5 Cover section 51 Cutting blade cover 54 Opening/closing cover 55 Hinge 56 Drive device 57 Support member 71 Control part 72 Load sensor 74 Rotation sensor G Ground H Gap Ha Gap T Deposit

Claims (4)

a working part that has a cutting blade around a rotating shaft and performs work by rotating;
an opening/closing cover that is provided rearward of the working section so that the other end is rotatable about one end, and that is rotatable between a shielding position where the working section is shielded and an open position where the working section is opened; and,
a drive device for rotationally driving the opening/closing cover;
a rotation sensor configured to be able to detect the rotational speed of the rotating shaft and capable of transmitting a signal detected by the rotational speed as a rotational signal;
It is possible to perform a comparison operation while receiving the rotation signal, and to control the drive device according to the result of the comparison operation between a first rotation signal that is a past rotation signal and a second rotation signal that is a current rotation signal. A control unit that can be driven;
The control unit rotates the opening/closing cover toward the open position when the value indicated by the first rotation signal is larger than the value indicated by the second rotation signal, and the control unit rotates the opening/closing cover toward the open position when the value indicated by the first rotation signal is larger than the value indicated by the second rotation signal. rotating the opening/closing cover toward a shielding position when the rotation signal is less than or equal to a value indicated by the rotation signal;
This is a grass cutting machine that is characterized by: The control unit performs a first rotation speed comparison for performing a comparison calculation between the second rotation signal and the first rotation signal , and the first rotation signal is larger than the second rotation signal in the first rotation speed comparison. If it is determined that If it is determined that the signal is not greater than the signal, a third rotation speed comparison is performed again in which a comparison calculation is made between the second rotation signal and the first rotation signal, and the second rotation speed comparison or the third rotation speed comparison is performed. placing the drive device in a standby state until the calculation result of is different from the calculation result of the first rotation speed comparison;
The mowing machine according to claim 1, characterized in that: The control unit performs a comparison operation between the second rotation signal and the first rotation signal after rotating the opening/closing cover to the shielding position at the time of starting control.
The mowing machine according to claim 1 or 2, characterized in that: The rotation sensor detects the rotation speed by a protrusion piece that rotates together with the rotation shaft.
The mowing machine according to any one of claims 1 to 3 , characterized in that:

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