JP3728365B2 - Work equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a working device that is mounted on a vehicle and performs work while the vehicle is moving , and more particularly , to a working device that includes a buffer mechanism for preventing damage to the device such as when it collides with an obstacle.
[0002]
[Prior art]
A general rotary snowplow is composed of a vehicle body and a snow removal device, and the snow removal device is attached to the front of the vehicle body. The snow removal device has an auger, a blower, and a chute, collects snow on the road with the auger, and throws it to an appropriate place outside the road through the chute with the blower.
[0003]
By the way, it is during the snowfall season in winter that the snow removal work is performed by the rotary snowplow, and it becomes an idle facility during periods when there is no snow. Therefore, in order to utilize the snowplow other than in winter, various work devices can be mounted on the front portion of the vehicle from which the snowplow is removed. For example, there is a mowing device attached to the front of a snowplow (the front of the vehicle body from which the snow removal device is removed). FIGS. 6 and 7 show an example of a mowing apparatus used by being mounted on a snow removal vehicle. This is a mowing apparatus for mowing grass that grows on a roadside portion (for example, a roadside slope of an expressway). Of course, it can be used outside the road or outside the road.
[0004]
As shown in FIG. 6, this mowing apparatus mainly includes a mowing apparatus main body 1, a support arm 2, and a base frame 3. The mowing apparatus is attached to the front portion of the snow removal vehicle via the attachment arm 4 provided on the base frame 3. The power of the mowing device is based on the hydraulic pressure of a hydraulic motor 5 driven from a snow removal vehicle by a transmission mechanism (not shown). Note that an arrow S in FIG. 6 indicates the vehicle traveling direction.
[0005]
FIG. 7 is a front view of the mowing apparatus. As shown by the solid line in this figure, the mowing device main body 1 is held in front of the snow removal vehicle by folding the support arm 2. This state is a non-working state such as storage or forwarding, and the vehicle balance can be kept good by folding the support arm 2. Further, as shown by a two-dot chain line in the figure, by extending the support arm 2, the mowing apparatus main body 1 is projected to the side of the vehicle and becomes ready for work.
[0006]
By the way, the mowing apparatus main body 1 may collide with an obstacle during the operation in the state where the support arm 2 is extended as shown by a two-dot chain line in FIG. An unexpected obstacle may exist in the grassland beside the road, and when the grass is stretched, the vehicle driver may not be able to confirm the obstacle and may hit the mowing device. In order to prevent the mowing apparatus from being damaged in such a case, there is one provided with a safety device. In the mowing apparatus shown in FIGS. 6 and 7, the safety device 6 is provided in the middle portion of the second arm 12.
[0007]
As for the 2nd arm 12, the substantially center part is comprised with two plate-shaped members, and the two plate-shaped members are pivotally attached so that rotation is possible. The safety device 6 is fixed on one plate-like member. A spring is built in the safety device, and a rod urged by the spring so as to protrude outside the safety device is built in. The plate-like member where the rod protrudes is provided with a hole, and the tip of the rod fitted into the hole protrudes from the plate-like member and comes into contact with the end of the other plate-like member. The rotation of the plate-like member is restricted.
[0008]
When the mowing apparatus collides with an obstacle during mowing, the mowing apparatus main body 1 is moved forward by the obstacle, while the vehicle itself cannot be stopped immediately and continues moving forward. Therefore, a load is applied to the support arm 2. When the load becomes larger than a predetermined value, the two plate-like members of the second arm 12 try to rotate, and the rod is pushed into the device against the force of the spring of the safety device 6. When the rod is pushed in, the two plate-like members rotate, the second arm 12 is bent in the middle thereof, and the mowing apparatus main body 1 moves rearward, so that the load at the time of collision is released.
[0009]
[Problems to be solved by the invention]
However, in the case of the buffer mechanism configured as described above (hereinafter, the entire part that acts as a safety device including the support arm 12 of the part to which the safety device 6 is mounted is referred to as a buffer mechanism). The second arm 12 has to be extended by human power and returned to the original state, and there is a problem that it takes time for the driver (operator) to get out of the vehicle and perform the return operation.
[0010]
In addition, in this shock absorbing mechanism, the safety device can operate at any position between the non-working state and the working state (the state shown by the solid line and the state shown by the two-dot chain line in FIG. 6). When the safety device is activated for some reason, there is a problem that the portion beyond the safety device 6 moves without permission.
[0011]
The present invention solves the above-described problems in a conventional shock absorber provided in a working device that is mounted on a snowplowing vehicle or the like and that works by projecting the working device body to the side of the vehicle by a support arm. Another object of the present invention is to provide a shock absorber for a working device that can be automatically reset to the initial state (safety device inactive state) after the safety device is activated.
[0012]
[Means for Solving the Problems]
According to the present invention, there is provided a shock absorbing mechanism provided on the support arm of the working device configured to hold the working device main body portion at the working position by the support arm, wherein two constituent members are pivotally attached. In the working device having a buffer mechanism provided with a safety device that operates to restrict the refraction of the arm at a normal time and to allow the refraction of the arm by a load greater than or equal to the refraction fulcrum portion of the support arm that is provided so as to be able to refract. A hydraulic cylinder is juxtaposed to a support arm provided with the safety device, both ends of the cylinder are pivotally attached to the two constituent members, and the cylinder is extended to release the bending state of the support arm. the safety device was capable reset inoperative, said the extension-side oil chamber of the hydraulic cylinder and the communication pipe line connecting the contraction side oil chamber, distribution to the communication pipe line along with the And a switching valve that switches between a circulating state and a shut-off state of the hydraulic oil, and when the working device is working, the switching valve is switched to a circulating state so that the communication line is a free line, and the switching valve This is solved by controlling the extension and contraction of the hydraulic cylinder by switching the direction of the hydraulic pressure supplied to the hydraulic cylinder in the shut-off state .
[0013]
Furthermore, in order to solve the above-described problems, the present invention releases the bending state of the support arm by extending the hydraulic cylinder when the working device main body is retracted from the working position to the non-working position. In addition, it is proposed to reset the safety device to an inactive state .
[0014]
Further, in order to solve the above-described problem, the present invention switches the switching valve to the flow state only when the working device main body is within a predetermined working range, and the working device main body is outside the working range. In some cases, it is proposed to switch the switching valve to the shut-off state .
[0015]
Furthermore, in order to solve the above-described problems, the present invention proposes that the working device is a mowing device .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a mowing apparatus to which an embodiment of the present invention is attached. The basic configuration of the mowing apparatus shown in this figure is the same as that shown in FIGS. That is, the mowing apparatus main body 1 is supported on the base frame 3 via the support arm 2. A first cylinder 13 is installed between the base frame 3 and the first arm 11, and a second cylinder 14 is installed between the first arm 11 and the second arm 12. Further, a third cylinder 15 is installed between the second arm 12 and the mowing apparatus main body 1. By these three hydraulic cylinders, the support arm 2 is bent and extended and the mowing apparatus main body 1 is tilted left and right.
[0017]
In the mowing apparatus according to the present embodiment, an operation restriction cylinder 7 is mounted at a lower position of the safety device 6. FIG. 2 is an enlarged view showing in detail the buffer mechanism composed of the safety device 6, the second arm 12, the operation restricting cylinder 7 and the like in this part, and FIG. 3 illustrates the operation of the buffer mechanism. 2 is a side view of the buffer mechanism, and FIG. 3 is a plan view of the buffer mechanism as viewed from above. However, in FIG. 2 and FIG. 3, the left-right positional relationship is shown in reverse.
[0018]
As shown in these drawings, a safety device (shear pinless safety device) 6 is fixed to the plate-like member 12a of the second arm. A spring 8 is built in the safety device 6 and urges a rod 9 built in the central portion of the device downward. The plate-like member 12a is provided with a hole into which the lower portion of the rod 9 is fitted, and the lower end portion 9a of the rod 9 protrudes below the plate-like member 12a at normal times (when the safety device is not operated). The plate-like members 12a and 12b are pivotally attached to each other so as to be rotatable. When the two plate-like members 12a and 12b are positioned in a straight line, the lower end portion 9a of the rod 9 comes into contact with the end of the plate-like member 12b, and thereby the rotation of the two plate-like members 12a and 12b is achieved. Is restricted. By this restriction, the second arm 12 is kept linear.
[0019]
Now, when performing mowing work, a mowing apparatus, ie, a vehicle, advances in the direction shown by the arrow S in FIG. When the mowing apparatus main body 1 collides with an obstacle or the like during work, a force acts to rotate the mowing apparatus main body 1 counterclockwise in FIG. When this load exceeds a predetermined value, the end of the plate-like member 12b pushes up the rod lower end 9a and retracts the rod 9 in the safety device 6 against the urging force of the spring 8 (the rod lower end 9a is To a position where it does not protrude from the lower surface of the plate member 12a). As a result, the plate-like members 12a and 12b can rotate, and the second arm 12 is refracted to release the load.
[0020]
By the way, in the buffer mechanism of the present embodiment, the operation restriction cylinder 7 is disposed below the safety device 6 (see FIG. 2). The cylinder 7 is installed between the support portion of the plate-like member 12a of the second arm 12 and the support portion of the plate-like member 12b. Both end portions of the cylinder 7 are pivotally attached (rotatably mounted) to the respective support portions. Further, as shown in FIG. 3, the extension side oil chamber and the contraction side oil chamber of the cylinder 7 are connected to each other by a pipe line 16 via a switching valve 15. This valve 15 is a spring-offset solenoid valve, and is set to a distribution position when the mowing apparatus is operated. Therefore, the cylinder 7 acts as an absorber when the mowing apparatus is working. Since the switching valve 15 and the pipe line 16 become free pipe lines at the time of work and both ends of the cylinder 7 are pivotally attached to the second arm 12, the second arm is caused by collision with an obstacle or the like. When 12 is refracted, the cylinder 7 can be freely expanded and contracted and rotated in the erection support portion, and can respond to the arm refraction (extension).
[0021]
Further, the cylinder 7 is connected to a hydraulic pump and a reserve tank via pipe lines 17 and 18. The hydraulic circuit including the hydraulic pump, the reserve tank, and the cylinder 7 will be described later, but the expansion and contraction of the cylinder 7 are controlled by switching the direction of the hydraulic pressure supplied to the cylinder 7 with the switching valve 15 closed. be able to. That is, when the second arm 12 is refracted due to a collision with an obstacle or the like, the cylinder 7 is extended by closing the switching valve 15 and supplying hydraulic pressure to the extension side oil chamber of the cylinder 7 to be refracted. It becomes possible to return the two arms 12 to the initial position (extend linearly). Then, when the second arm 12 returns to the initial position, the safety device 6 is reset to the original state, and the refraction of the second arm 12 is restricted again. Control of the hydraulic pressure supply for resetting the buffer mechanism can be performed from the vehicle driver's seat.
[0022]
As a result, even when the buffer mechanism is activated by collision with an obstacle or the like during work (when the safety device 6 is activated and the second arm 12 is bent), the driver (operator) gets out of the driver's seat. The mowing device main body 1 can be returned to the working position by easily resetting the buffer mechanism.
[0023]
FIG. 4 is a hydraulic circuit diagram of the mowing apparatus. As shown in this figure, hydraulic pressure is supplied from the hydraulic pump 22 to the first, second, and third cylinders 13, 14, and 15 that control the behavior of the mowing device via control valves 21a, b, and c. Is done. In the present embodiment, a hydraulic circuit for the operation control cylinder 7 is connected in parallel in the hydraulic circuit to the first cylinder 13, and the control valve 21a is shared to operate the switching lever 24 for controlling the first cylinder. The control cylinder 7 is configured to be interlocked.
[0024]
As described above, the extension side oil chamber and the contraction side oil chamber of the cylinder 7 are connected to each other by the pipe line 16 via the solenoid valve 15 having a spring offset. This switching valve 15 is in a flow state when energized and is shut off when not energized. The electric power to the switching valve 15 is supplied via the switch 19 and the relay 20. That is, when the relay 19 is switched in conjunction with the switching lever 24 with the switch 19 turned on, the power ON / OFF to the solenoid of the switching valve 15 is switched, and the flow and shut-off state of the valve are switched. However, when the switch 19 is OFF, power is not supplied to the switching valve 15 regardless of the state of the relay 20, and the switching valve 15 is cut off.
[0025]
Further, the operation regulating cylinder 7 is connected to the hydraulic pump 22 and the reserve tank 23 via the control valves 21 a by the pipe lines 17 and 18. The hydraulic pump 22 is driven by a vehicle engine equipped with a mowing device. The control valve 21 is a spring offset type manual switching valve, and is a 4-port 3-position switching valve. The valve position is switched by a switching lever 24.
[0026]
When the control valve 21 a is in the neutral position, the hydraulic pressure from the pump 22 is not supplied to the operation control cylinder 7 and the first cylinder 13. At this time, the relay 20 interlocked with the lever 24 is turned on, and if the switch 19 is turned on, the switching valve 15 is in the flow position. Therefore, the pipe line 16 becomes a free pipe line, and the buffer mechanism including the cylinder 7 exhibits a buffering action as described above.
[0027]
When the control valve 21a is switched to the right (R) position by the lever 24, the hydraulic pressure of the pump 22 flows into the contraction side oil chamber of the first cylinder 13, and the first arm 11 rotates counterclockwise (counterclockwise) in FIG. Turn to. At this time, the relay 20 linked to the lever 24 is turned OFF, the switching valve 15 is shut off, and the pipe line 16 is shut off. The hydraulic pressure from the pump 22 is also supplied to the extension side oil chamber of the operation control cylinder 7 to extend the cylinder 7. Therefore, when the buffer mechanism is operating (the second arm 12 is bent), it is reset.
[0028]
When the control valve 21a is switched to the left (L) position by the lever 24, the hydraulic pressure of the pump 22 flows into the extension side oil chamber of the first cylinder 13, and the first arm 11 is rotated clockwise (clockwise) in FIG. Rotate. At this time, the relay 20 interlocked with the lever 24 is turned ON, the switching valve 15 flows, and the pipe line 16 becomes a free pipe line.
[0029]
When the mowing apparatus is in the retracted state, the arm 2 is folded, so the first cylinder 13 is contracted. That is, the control valve 21a is switched to the R position. At this time, since the cylinder 7 is extended as described above, the buffer mechanism is always reset when the arm 2 of the mowing apparatus is retracted.
[0030]
In order to carry out the mowing work, it is necessary to extend the arm 2 to a predetermined position. For this purpose, the control valve 21a is switched to the L position. At this time, since the check valve 25 is provided, the oil discharged from the control valve 21a does not flow to the operation control cylinder 7 side, flows into the first cylinder 13 and extends it. When the first arm 11, the second arm 12, and the mowing apparatus main body 1 are set to appropriate positions (angles), the control valves 21a, b, and c are switched to the neutral positions, so that the arms and the mowing apparatus main body 1 are moved to their positions. Retained. In this workable state, the relay 20 is in the ON state, and since the pipe line 16 is a free pipe line, the cylinder 7 acts as an absorber, and when the mowing apparatus main body 1 collides with an obstacle or the like, a buffer mechanism Is activated, the safety device 6 is activated, the second arm 12 is bent, and the external force applied to the device is released. Therefore, damage to the mowing apparatus can be prevented, and damage to the attachment portion with the vehicle body can be prevented. Further, the buffer mechanism can be easily reset by operating the lever 24 provided in the vehicle driver's seat and switching the control valve 21a to the R position.
[0031]
By the way, in this embodiment, as shown in FIG. 5, the switching valve 15 can be in the flow state only within the buffer mechanism operating range (safety device operating range), and the other buffer mechanism lock range (safety) In the device lock range), the switching valve 15 is cut off. When the switching valve 15 is shut off, the cylinder 7 is fixed, so that the buffer mechanism cannot be operated and the second arm 12 cannot be refracted. The method for enabling the shock absorber mechanism to operate only within this predetermined range is, for example, such that the switch 19 (FIG. 4) is turned ON only within the safety device operating range, and the switch 19 is turned OFF otherwise. That's fine.
[0032]
Here, the buffer mechanism operating range and the buffer mechanism lock range are represented by the angle of the first arm 11, and in this embodiment, when the device storage state is 0 degree, the lock range is from 0 to 68 degrees. The operating range is set to 68 degrees or more (the maximum rotation range of the first arm 11 is up to the position indicated by a two-dot chain line in FIG. 1). The angle of the first arm 11 can be easily detected by a mechanical switch, an optical sensor, or the like.
[0033]
In other words, in the present embodiment, the buffer mechanism is divided into an operation range and a non-operation range (lock range) according to the angle of the first arm 11, and the switch 19 is turned on within the operation range and the switch 19 is turned off within the lock range. It is configured. In this way, by not operating the buffer mechanism in the range close to the retracted state and retracted position of the mowing device, the mowing device main body 1 is prevented from moving freely when the mowing device is retracted or near the vehicle. it can.
[0034]
Here, the role of the check valve 15 provided between the hydraulic circuit of the first cylinder 13 and the pipe lines 17 and 18 will be supplemented. First, since the switch 19 can be turned on when the buffer mechanism is in the operating range and the switching valve 15 can be in a flow state, the pressure oil can be applied to the switching valve 15 when the control valve 21a is operated to the L position. This prevents the first cylinder 13 from becoming inoperable.
[0035]
Next, when the buffer mechanism is in the lock range, the switch 19 is turned OFF and the switching valve 15 is cut off. When the control valve 21a is operated to the L position in this state, the pressure oil reduces the operation control cylinder 7 if the check valve 25 is not provided. Therefore, the check valve 25 is provided so that the pressure oil does not flow to the operation control cylinder 7 and only the first cylinder 13 is operated.
[0036]
That is, in the process of extending the arm 2 (the control valve 21a is in the L position), the oil discharged from the control valve 21a always flows into the first cylinder 13 by the check valve 25 in any state of the buffer mechanism operating range and the lock range. Arm 2 is extended. When the arm 2 is folded (the control valve 21a is in the R position), a check valve 25 is provided so that the oil flows from the pipe line 17 to the operation control cylinder 7 to be extended and the safety device 6 can be reset. ing.
[0037]
【The invention's effect】
As described above, by the working device of the present invention lever, even when the working device during operation buffered mechanism actuated by the collision of the obstacle or the like, reset easily cushioning mechanism simply by extending the hydraulic cylinder Thus, it is possible to return to a workable state.
[0038]
In addition, by providing a conduit that communicates with the expansion / contraction oil chamber of the hydraulic cylinder and using this as a free conduit during work, the hydraulic cylinder can be operated as an absorber.
[0039]
In addition, when storing the work device, the buffer mechanism is always reset so that the work device does not move freely during storage.
In addition, since the buffer mechanism is configured to operate only within a predetermined range, the work device does not move arbitrarily in the storage position or in a range close thereto.
[Brief description of the drawings]
FIG. 1 is a front view showing a mowing apparatus equipped with an embodiment of the present invention.
FIG. 2 is an enlarged view showing in detail a buffer mechanism of the mowing apparatus.
FIG. 3 is a schematic diagram for explaining the operation of the buffer mechanism.
FIG. 4 is a hydraulic circuit diagram of the mowing device shown in FIG.
FIG. 5 is a schematic diagram showing an operation range and a lock range of the buffer mechanism.
FIG. 6 is a side view showing an example of a mowing apparatus.
FIG. 7 is a front view of the mowing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mowing apparatus main body 2 Support arm 6 Safety device 7 Operation control cylinder 11 1st arm 12 2nd arm 12a, b Plate-like member 15 Switching valve 16-18 Pipe line 20 Relay 21a, b, c Control valve 22 Hydraulic pump 24 Switching lever

Claims (4)

A shock absorbing mechanism provided on the support arm of the working device configured to hold the working device main body in the working position by the support arm, and the support arm provided with two components pivotally attached and capable of being bent. In the working device having a buffer mechanism provided with a safety device that operates to restrict the refraction of the arm at a normal time and to allow the refraction of the arm by a load greater than or equal to a predetermined load,
A hydraulic cylinder is juxtaposed to a support arm provided with the safety device, both ends of the cylinder are pivotally attached to the two constituent members, and the cylinder is extended to release the bending state of the support arm. And the safety device can be reset to a non-operating state ,
A connecting pipe that connects the expansion side oil chamber and the contraction side oil chamber of the hydraulic cylinder, and a switching valve that is arranged in the connecting pipe and switches between a flow state and a shutoff state of the hydraulic oil. At the time of work, the switching valve is switched to a flow state and the communication pipeline is a free pipeline,
An operation device characterized in that expansion and contraction of the hydraulic cylinder can be controlled by switching a direction of hydraulic pressure supplied to the hydraulic cylinder with the switching valve shut off . When the working device main body is stored from the working position to the non-working position, the hydraulic cylinder is extended to release the bending state of the support arm and to reset the safety device to a non-operating state. The working device according to claim 1. The switching valve is switched to a flow state only when the working device main body is within a predetermined working range, and the switching valve is switched to a shut-off state when the working device main body is outside the working range. The working device according to claim 1. The working device according to claim 1, wherein the working device is a mowing device.

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