JP2016183451A - Work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically keep a grapple in a suspended posture, and to allow a worker to freely operate the grapple.SOLUTION: An operation determination section 52 determines whether a grapple 30 is in an operation state in which operation of the grapple 30 by an operation lever 43 is performed or in a non-operation state in which operation of the grapple 30 by the operation lever 43 is not performed. A hydraulic control section 51 performs posture control for expanding and contracting a cylinder rod 36 so that the grapple 30 takes a suspended posture in which an end of a gripping claw 32 is downwardly directed when the non-operation state is determined by the operation determination section 52, and releases the posture control of the grapple 30 when the operation state is determined.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a work machine.

  2. Description of the Related Art Conventionally, there is known a work machine including a lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and an attachment that is mounted to be raised on the front side of the upper revolving body (for example, , See Patent Document 1).

  In Patent Document 1, in order to prevent the bucket from interfering with the cab, the arm is automatically moved forward when the proximal boom is raised while detecting the elevation angle of the proximal boom and the swing angle of the arm. The structure which performed the arm avoidance operation | movement to push out is described.

  The bucket is automatically rotated in the excavating direction at the same time as the arm avoiding operation, so that the posture of the bucket is maintained almost horizontal even if the proximal boom is raised and the arm is pushed forward at the same time. ing. This prevents the soil stored inside the bucket from falling during the boom rise.

Japanese Patent No. 4446042

  By the way, in the attachment provided with a grapple having a plurality of gripping claws instead of the bucket, the grapple is placed in a suspended posture with the tip of the gripping claw facing downward when transporting scraps gripped by the grapple. It is preferable to maintain. Therefore, it is conceivable to apply the control described in Patent Document 1 even to an attachment provided with a grapple.

  However, in an actual work site, there is a case where an operator wants to operate the grapple while the grapple posture control is being performed, and the grapple is always maintained in the suspended posture as in the invention of Patent Document 1. In such a configuration that performs feedback control, there is a problem that operability is deteriorated.

  Specifically, the operator needs to perform a release operation to release the grapple posture control, and after performing the grapple operation, the worker needs to perform a start operation to start the grapple posture control. It was.

  The present invention has been made in view of this point, and an object of the present invention is to automatically maintain the grapple in a suspended posture and to allow the operator to freely operate the grapple.

  The present invention is provided with a lower traveling body, an upper revolving body that is turnably mounted on the lower traveling body, and a grapple having a plurality of gripping claws, and is mounted on the front side of the upper revolving body so as to be undulated. The following solution was taken for work machines equipped with attachments.

That is, the first invention is a front cylinder that adjusts the inclination angle of the grapple by swinging the grapple as the cylinder rod expands and contracts.
An angle detector for detecting the inclination angle of the grapple;
An operation lever for operating the grapple by switching the supply / discharge direction of the hydraulic oil with respect to the front cylinder;
An operation determination unit for determining whether the operation of the grapple by the operation lever is performed or a non-operation state in which the operation of the grapple by the operation lever is not performed;
When the operation determination unit determines that the non-operation state is established, the grapple has a hanging posture in which the tip of the gripping claw is directed downward based on the inclination angle detected by the angle detection unit. The hydraulic control unit is configured to perform posture control to extend and contract the cylinder rod, and to release the grapple posture control when it is determined to be in the operation state.

  In the first invention, when the grapple is not operated by the operation lever, the posture control of the grapple is performed. Accordingly, the grapple can be automatically maintained in the suspended posture without manually adjusting the posture of the grapple.

  On the other hand, when the grapple is operated by the operation lever, the posture control of the grapple is released. Thereby, the operator can operate the grapple freely.

According to a second invention, in the first invention,
The operation lever is configured to be switchable between a neutral position where hydraulic oil is not supplied to and discharged from the front cylinder and an operation position where hydraulic oil is supplied to and discharged from the front cylinder.
The operation determination unit determines that the operation lever is in the non-operation state when the operation lever is in the neutral position.

  In the second invention, since it is determined that the grapple is in the non-operating state only by performing a normal operation such as returning the operation lever to the neutral position when the grapple is not operated, the operator performs a special operation. The posture of the grapple can be controlled.

According to a third invention, in the second invention,
The operation determination unit determines that the operation lever is in the non-operation state when a predetermined time has elapsed since the operation lever was switched from the operation position to the neutral position.

  In the third invention, since the posture control of the grapple is not performed until a predetermined time elapses after the operation lever is returned to the neutral position, the operator freely operates the grapple during this period, The tilt angle can be adjusted with a margin.

  Specifically, it is necessary to repeat the adjustment of the inclination angle of the grapple and the gripping operation of the gripping object a plurality of times after the grapple is brought close to the gripping object and before the gripping object is lifted. For this reason, it is preferable to maintain the grapple in the operating state until a predetermined time has elapsed even after the object to be grasped is grasped by the grasping nail.

According to a fourth invention, in the first invention,
An opening and closing cylinder for opening and closing the gripping claws of the grapple;
A hydraulic pressure detection unit that detects the hydraulic pressure on the head side of the open / close cylinder;
The operation determining unit determines that the non-operating state is detected when the hydraulic pressure detecting unit detects that the hydraulic pressure in the open / close cylinder is greater than a predetermined pressure by closing the gripping claw. It is a feature.

  In the fourth aspect of the invention, when the oil pressure detecting unit detects that the object to be grasped is grasped by the grasping claws, the posture control of the grapple is performed. Accordingly, the grapple can be automatically adjusted to the suspended posture without special operation for the operator to control the posture of the grapple, and workability is improved.

A fifth invention is the fourth invention,
The operation determination unit closes the gripping claw and detects that the hydraulic pressure in the open / close cylinder is greater than a predetermined pressure when the predetermined time has elapsed after the hydraulic pressure detection unit detects that It is characterized by determining that there is.

  In the fifth aspect of the invention, since the posture control of the grapple is not performed until a predetermined time elapses after the oil pressure detection unit detects that the object to be grasped is grasped by the grasping claws, However, the grapple can be freely operated to adjust the inclination angle of the grapple with a margin.

A sixth invention is any one of the first to fifth inventions,
A position detection unit that detects the position of the grapple and outputs an interference avoidance signal to the hydraulic pressure control unit when the grapple reaches a predetermined interference area set in advance;
The hydraulic control unit is configured to control the operation of the attachment so that the grapple does not move to the upper swing body side of the interference area when the interference avoidance signal is output from the position detection unit. ,
The position detection unit outputs the interference avoidance signal when the grapple reaches the first interference area when the operation determination unit determines that the operation state is in the operation state, while in the non-operation state. When it is determined that there is a signal, the grapple is configured to output the interference avoidance signal when the grapple reaches a second interference zone set between the first interference zone and the upper swing body. It is characterized by that.

  In the sixth invention, when the grapple is in the operating state, the attachment is made so that the grapple does not move on the upper turning body side than the first interference area, and when the grapple is in the non-operating state, on the upper turning side than the second interference area. Is controlled. Here, the second interference zone is set between the first interference zone and the upper swing body.

  With such a configuration, when the grapple is in the non-operating state in which the posture is controlled, the arm of the attachment can be swung to the upper swinging body side, and the work range of the attachment is ensured wider than in the operating state. can do.

A seventh invention is the sixth invention, wherein
In the hydraulic control unit, the non-operated grapple located between the first interference area and the second interference area is operated by the operation lever to be in the operation state. The front cylinder so that the grapple does not swing toward the upper swinging body until the grapple is released from posture control and the grapple moves forward of the first interference area. It is characterized by controlling the operation of.

  In the seventh invention, when the grapple is in the operating state when the grapple is located between the first interference area and the second interference area, the posture control of the grapple is released. However, until the grapple moves to the front of the vehicle from the first interference zone, the grapple is controlled not to swing to the upper swing body side.

  With such a configuration, when the grapple is located between the first interference area and the second interference area, the grapple is erroneously swung to the upper swing body side, resulting in the upper swing body. The problem of interference can be prevented.

In an eighth aspect based on the sixth aspect,
In the hydraulic control unit, the non-operated grapple located between the first interference area and the second interference area is operated by the operation lever to be in the operation state. In this case, the posture control of the grapple is continued until the grapple moves forward of the vehicle from the first interference area.

  In the eighth aspect of the invention, when the grapple is positioned between the first interference area and the second interference area, the grapple is further forward of the vehicle than the first interference area even if the grapple is in the operating state. Until it moves to, the grapple posture control is continued.

  With such a configuration, when the grapple is located between the first interference area and the second interference area, the grapple is erroneously swung to the upper swing body side, resulting in the upper swing body. The problem of interference can be prevented.

According to a ninth invention, in any one of the first to eighth inventions,
There is provided a changeover switch that selectively switches whether to perform posture control of the grapple or to cancel the posture control.

  In the ninth aspect of the invention, the operator can determine the timing for performing the grapple posture control by selectively switching whether the grapple posture control is performed or canceled by the changeover switch. That is, even when the grapple is in a non-operation state, it is possible to prevent the grapple from being subjected to posture control.

According to a tenth aspect of the invention, in any one of the first to ninth aspects of the invention,
The center position of the arm top pin that supports the grapple so as to be swingable with respect to the arm of the attachment, and the gravity center position of the grapple are arranged so as to be aligned vertically.
When the angle detecting unit detects that the grapple is inclined more than a predetermined angle, the hydraulic control unit communicates the cylinder chamber on the head side and the rod side of the front cylinder with the tank, and The posture control is performed by swinging the grapple while allowing the cylinder rod to expand and contract by its own weight.

  In the tenth invention, the cylinder chamber on the head side and the rod side of the front cylinder are communicated with the tank when the boom or arm of the attachment is swung to tilt the grapple from a predetermined angle. Thus, the suspended posture can be automatically maintained by the weight of the grapple.

  According to the present invention, when the grapple is not operated by the operation lever, the posture of the grapple is controlled, so that the grapple is automatically suspended without manually adjusting the posture of the grapple. The posture can be maintained. On the other hand, when the grapple is operated by the operation lever, the posture control of the grapple is released, so that the operator can freely operate the grapple.

It is a side view which shows the structure of the working machine which concerns on this Embodiment 1. FIG. It is a hydraulic control circuit diagram for adjusting the inclination angle of the grapple. It is a side view explaining the relationship of the inclination angle of a boom, an arm, and a grapple. It is a timing chart figure which shows the timing which performs posture control of a grapple. It is a side view when the grapple of an operation state reaches the 1st interference zone. It is a side view when the grapple of a non-operation state reaches the 2nd interference zone. It is a timing chart figure which shows the timing which performs attitude control of the grapple which concerns on this Embodiment 2. FIG. It is a timing chart figure which shows the timing which performs posture control of the grapple which concerns on this Embodiment 3. FIG. It is a timing chart figure which shows the timing which performs attitude control of the grapple concerning this Embodiment 4. It is a hydraulic control circuit diagram for adjusting the inclination angle of the grapple according to the fifth embodiment. It is a side view which shows the structure of an angle detection part. It is a side view which shows the state which inclined the grapple. It is a side view when a grapple is made into a communication state.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

Embodiment 1
FIG. 1 is a side view showing the configuration of the work machine according to the first embodiment. As shown in FIG. 1, the work machine 10 includes a crawler-type lower traveling body 11 and an upper revolving body 12 that is turnably mounted on the lower traveling body 11. A cab 15 is disposed in front of the left side of the upper swing body 12. An attachment 20 is mounted in the center front of the upper swing body 12 so as to be raised and lowered.

  The attachment 20 has a base 21 pivotably attached to the upper swing body 12, an arm 25 pivotally attached to the distal end of the boom 21, and pivotable to the distal end of the arm 25. And a grapple 30 attached to the.

  The boom 21 is rotated in the vertical direction of the upper swing body 12 around the boom foot pin 23 by expanding and contracting the boom cylinder 22 (see FIG. 3). The arm 25 is rotated in the front-rear direction of the upper swing body 12 around the boom top pin 24 by expanding and contracting the arm cylinder 26. The grapple 30 is rotated in the front-rear direction of the arm 25 around the arm top pin 28 by expanding and contracting the front cylinder 35.

  The grapple 30 includes a main body 31, a plurality of gripping claws 32 that are suspended from the lower end of the main body 31, and an open / close cylinder 33 that opens and closes the gripping claws 32. In the present embodiment, four gripping claws 32 are provided, and four open / close cylinders 33 are provided corresponding to the number of gripping claws 32.

  The main body 31 is supported so as to be swingable around an arm top pin 28 provided at the tip of the arm 25. The main body 31 and the arm 25 are connected through a link 34. The link portion 34 is connected to the tip of the cylinder rod 36 of the front cylinder 35. The inclination angle of the grapple 30 is adjusted by swinging through the link portion 34 in accordance with the expansion and contraction of the cylinder rod 36.

  The gripping claws 32 can grip a gripping target object S such as scrap by expanding and contracting the open / close cylinder 33. The open / close cylinder 33 operates to close the gripping claws 32 by extending the cylinder rod and to open the gripping claws 32 by contracting the cylinder rod. The open / close cylinder 33 is provided with a pressure sensor 33a as a hydraulic pressure detection unit that detects the pressure in the cylinder chamber on the head side (see FIG. 3).

  The detected pressure detected by the pressure sensor 33a is transmitted to a mechatronics controller 50 described later (see FIG. 2). The mechatronics controller 50 determines that the grapple 30 is in the gripping state in which the grapple 30 has gripped the gripping object S and closed the gripping claws 32 when the detected pressure detected by the pressure sensor 33a is greater than the predetermined pressure. To do.

  FIG. 2 is a hydraulic control circuit diagram for adjusting the inclination angle of the grapple. A solid line shown in FIG. 2 indicates a hydraulic oil path, and a dotted line shown in FIG. 2 indicates a path of signals input to and output from the mechatronics controller 50.

  As shown in FIG. 2, the control valve 40 extends and contracts the front cylinder 35 by switching the supply / discharge direction of the hydraulic oil discharged from the main pump 41. Here, the control valve 40 is switched to the neutral position when not in operation, and the front cylinder 35 is not expanded or contracted.

  The pilot valve 42 switches the supply / discharge direction of the pilot oil discharged from the pilot pump 44 by operating the operation lever 43. A shuttle valve 46 is connected to a pilot line 45 that connects the pilot valve 42 and the control valve 40. The shuttle valve 46 is also connected to a first switching valve 47 and a second switching valve 48 for controlling the posture of the grapple 30 described later. The shuttle valve 46 is constituted by a check valve that communicates with the higher pressure side.

  The operation lever 43 is located in a neutral position when not in operation, and pilot oil is not supplied to or discharged from the control valve 40. That is, when the operation lever 43 is in the neutral position, hydraulic oil is not supplied to or discharged from the front cylinder 35. On the other hand, when the operation lever 43 in the neutral position is tilted, the pilot oil is supplied to and discharged from the control valve 40. Thereby, hydraulic oil is supplied / discharged to / from the front cylinder 35 and the grapple 30 can be operated.

  Specifically, when the operation lever 43 is tilted leftward in FIG. 2 and pilot oil is supplied from the left pilot line 45, the control valve 40 is a cylinder on the head side (right side in FIG. 2) of the front cylinder 35. The hydraulic oil is supplied to the chamber, and the hydraulic oil in the cylinder chamber on the rod side (left side in FIG. 2) is switched to a position where it returns to the tank 49. As a result, the cylinder rod 36 extends, and the grapple 30 swings so that the tip of the gripping claw 32 faces rearward.

  On the other hand, when the operation lever 43 is tilted rightward in FIG. 2 and pilot oil is supplied from the right pilot line 45, the control valve 40 supplies hydraulic oil to the cylinder chamber on the rod side of the front cylinder 35. At the same time, the hydraulic oil in the cylinder chamber on the head side is switched to a position where it returns to the tank 49. As a result, the cylinder rod 36 contracts, and the grapple 30 swings so that the tip of the gripping claw 32 faces forward.

  Here, the pilot oil discharged from the pilot pump 44 branches on the way to the pilot valve 42 and is also supplied to the first switching valve 47 and the second switching valve 48. The first switching valve 47 and the second switching valve 48 can be switched to a position where the circulation of the pilot oil is permitted or blocked in response to a control signal from the mechatronics controller 50.

  Here, when a control signal is output from the mechatronics controller 50 to the first switching valve 47 and the circulation of the pilot oil is permitted, the control valve 40 is moved to a position where the hydraulic oil is supplied to the cylinder chamber on the head side of the front cylinder 35. Are switched, and the cylinder rod 36 of the front cylinder 35 extends.

  On the other hand, when a control signal is output from the mechatronics controller 50 to the second switching valve 48 and the circulation of the pilot oil is permitted, the control valve 40 is placed at a position where hydraulic oil is supplied to the cylinder chamber on the rod side of the front cylinder 35. As a result, the cylinder rod 36 of the front cylinder 35 contracts.

  The automatic posture control of the grapple 30 associated with the switching of the first switching valve 47 and the second switching valve 48 will be described later.

  The mechatronic controller 50 includes a hydraulic control unit 51, an operation determination unit 52, and a position detection unit 53. The hydraulic control unit 51 controls the operation of the attachment 20 by controlling the supply and discharge of hydraulic oil to and from the boom cylinder 22, the arm cylinder 26, the front cylinder 35, and the opening / closing cylinder 33.

  The operation determination unit 52 determines whether the grapple 30 is operated by the operation lever 43 or a non-operation state where the grapple 30 is not operated by the operation lever 43.

  Specifically, the operation lever 43 can be switched between a neutral position where the front cylinder 35 is not supplied and discharged with hydraulic oil and an operation position where the front cylinder 35 is supplied and discharged with hydraulic oil. The operation determination unit 52 determines that the operation lever 43 is in a non-operation state when the operation lever 43 is in the neutral position. On the other hand, when the operation lever 43 is at the operation position, it is determined that the operation lever 43 is in the operation state.

  The position detection unit 53 detects the position of the grapple 30 based on the inclination angle of the attachment 20. Specifically, as shown in FIG. 3, in the vicinity of the boom foot pin 23, the boom top pin 24, and the arm top pin 28 that rotatably support the boom 21, the arm 25, and the grapple 30 of the attachment 20, Angle sensors 55a, 55b, and 55c are provided as the angle detector 55. A signal indicating the tilt angle detected by the angle sensors 55a, 55b, and 55c is transmitted to the mechatronics controller 50. The angle detector 55 may be composed of a stroke meter that measures the stroke of each cylinder that swings the boom 21, the arm 25, and the grapple 30.

  By the way, in the attachment 20 which has the grapple 30, when conveying the holding | grip target object S hold | gripped with the grapple 30, it is preferable to maintain the grapple 30 in the hanging attitude | position with the front-end | tip part of the holding claw 32 facing downward. Therefore, in the present embodiment, the grapple 30 can be automatically maintained in the suspended posture.

  In the mechatronics controller 50, the operation determination unit 52 determines whether the grapple 30 is in an operation state or a non-operation state. When it is determined that the grapple 30 is in the non-operating state, the hydraulic pressure control unit 51 controls the first switching valve 47 or the second switching valve 48 based on the inclination angle detected by the angle detection unit 55. Output a control signal.

  Specifically, when the grapple 30 is in a posture in which the tip of the gripping claw 32 is inclined forward, the cylinder rod 36 needs to be extended in order to place the grapple 30 in the suspended posture. The hydraulic control unit 51 of the controller 50 outputs a control signal to the first switching valve 47.

  On the other hand, when the grapple 30 has a posture in which the tip of the gripping claw 32 is inclined rearward, the cylinder rod 36 of the front cylinder 35 needs to be contracted in order to place the grapple 30 in a suspended posture. The hydraulic control unit 51 of the mechatronics controller 50 outputs a control signal to the second switching valve 48.

  Here, the posture control of the grapple 30 is performed, for example, by automatically performing feedback control so as to satisfy the following expression (1). As shown in FIG. 3, the angle between the first angle line L1 connecting the centers of the boom foot pin 23 and the boom top pin 24 and the horizontal line H extending horizontally from the boom foot pin 23 toward the front of the vehicle is θ1, The angle between the second angle line L2 connecting the centers of the boom top pin 24 and the arm top pin 28 and the first angle line L1 is θ2, and the second angle line L2 and the arm top pin 28 are directed forward of the vehicle. Thus, when the angle with the line GR extending in the inclination direction of the grapple 30 is θ3, control is performed so as to satisfy the following expression (1).

  θ3 = θ1 + θ2 (1)

  Thus, when the expansion / contraction operation of the front cylinder 35 is automatically controlled so as to satisfy the expression (1), the grapple 30 is automatically brought into the suspended posture without manually adjusting the posture of the grapple 30. Can be maintained.

  On the other hand, when the operation determination unit 52 determines that the grapple 30 is in the operating state, the hydraulic control unit 51 releases the posture control of the grapple 30. That is, the grapple 30 can be freely operated by the operator operating the operation lever 43.

  In the present embodiment, it is detected whether the grapple 30 is in the suspended posture based on the relationship between the inclination angles of the boom 21, the arm 25, and the grapple 30, but an electric inclinometer is attached to the grapple 30. It may be mounted and the inclination angle of the grapple 30 may be directly detected.

  FIG. 4 is a timing chart showing the timing at which the posture control of the grapple is performed. As shown in FIG. 4, when the operation lever 43 is in the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. In the non-operation state, the posture control of the grapple 30 is started, and the posture control is continued while the non-operation state is continued.

  Here, when the operation lever 43 is tilted to switch from the neutral position to the operation position, the pilot pressure is detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in the operation state. When in the operating state, the posture control of the grapple 30 is released.

  Further, when the operation lever 43 is switched from the operation position to the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35, and the operation determination unit 52 determines that the grapple 30 is in a non-operation state. Thereby, the posture control of the grapple 30 is resumed.

  Further, as shown in FIG. 2, a changeover switch 56 is connected to the mechatronics controller 50. The changeover switch 56 is for selectively switching whether to perform posture control of the grapple 30 or to cancel the posture control, and an operator can determine the timing for performing the posture control of the grapple 30. That is, even if the grapple 30 is in the non-operating state, it is possible to prevent the grapple 30 from being subjected to posture control.

  By the way, if the grapple 30 is brought too close to the upper swing body 12 side, the grapple 30 may interfere with the cab 15 of the upper swing body 12. Therefore, in the present embodiment, it is possible to detect that the grapple 30 has reached a predetermined interference area.

  Specifically, the position of the grapple 30 is detected by the position detection unit 53. The position detection unit 53 detects the position of the grapple 30 by calculating the position of the arm top pin 28 based on the inclination angle detected by the angle sensors 55a and 55b.

  A predetermined interference area indicating that it is dangerous if the grapple 30 approaches further is set in front of the cab 15 of the upper swing body 12 in advance. As shown in FIGS. 5 and 6, as the interference area, a first interference area A1 and a second interference area A2 between the first interference area A1 and the cab 15 of the upper swing body 12 are set. ing.

  The first interference zone A1 is set at a position where the grapple 30 does not interfere with the cab 15 even when the grapple 30 is in a posture in which the tip of the gripping claw 32 faces backward (see FIG. 5).

  The second interference zone A2 is set at a position where the grapple 30 does not interfere with the cab 15 when the grapple 30 is in a suspended posture with the tip of the gripping claw 32 facing downward (see FIG. 6). The first interference area A1 and the second interference area A2 are set based on the position of the arm top pin 28.

  By the way, the first interference zone A1 is set to be relatively wide so that the gripping claws 32 do not interfere with the cab 15 even when the tip of the gripping claws 32 of the grapple 30 is directed backward. Therefore, when the grapple 30 is in the suspended posture, if the grapple 30 is stopped in the first interference area A1, the movable range of the attachment 20 is narrowed.

  Therefore, in the present embodiment, the operation of the grapple 30 is changed depending on whether the grapple 30 is in the operating state or in the non-operating state.

  Specifically, when it is determined that the grapple 30 is in the operating state, the position detection unit 53 outputs an interference avoidance signal to the hydraulic pressure control unit 51 when the grapple 30 reaches the first interference area A1. To do. When the interference avoidance signal is output from the position detection unit 53, the hydraulic control unit 51 controls the operation of the grapple 30 so that the grapple 30 does not move to the upper swing body 12 side from the first interference area A1.

  On the other hand, when it is determined that the grapple 30 is in the non-operation state, the position detection unit 53 outputs an interference avoidance signal to the hydraulic pressure control unit 51 when the grapple 30 reaches the second interference zone A2. . When the interference avoidance signal is output from the position detection unit 53, the hydraulic control unit 51 controls the operation of the grapple 30 so that the grapple 30 does not move to the upper swing body 12 side from the second interference area A2.

  Thereby, when the grapple 30 is in the non-operating state in which the posture is controlled, the arm 25 of the attachment 20 can be swung to the upper swing body 12 side compared with the operation state, and the work range of the attachment 20 is widened. Can be secured.

  Further, as shown in FIG. 6, in the hydraulic control unit 51, the grapple 30 in a non-operating state located between the first interference area A <b> 1 and the second interference area A <b> 2 operates the operation lever 43. When the operation state is reached, the posture control of the grapple 30 is released. However, the operation of the front cylinder 35 is controlled so that the grapple 30 does not swing toward the upper swing body 12 until the grapple 30 moves forward of the vehicle from the first interference area A1.

  As a result, when the grapple 30 is located between the first interference area A1 and the second interference area A2, the grapple 30 is erroneously swung to the upper swing body 12 side and thus the upper swing body. 12 can be prevented from interfering with 12.

  Note that the hydraulic control unit 51 is configured so that when the grapple 30 in the non-operation state is located between the first interference area A1 and the second interference area A2, the grapple 30 is in the operation state. The posture control of the grapple 30 may be continuously performed until the grapple 30 moves forward of the vehicle from the first interference area A1.

<< Embodiment 2 >>
FIG. 7 is a timing chart showing the timing for performing posture control of the grapple according to the second embodiment. Hereinafter, the same portions as those in the first embodiment are denoted by the same reference numerals, and only differences will be described.

  As shown in FIG. 7, when the operation lever 43 is in the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. In the non-operation state, the posture control of the grapple 30 is started, and the posture control is continued while the non-operation state is continued.

  Here, when the operation lever 43 is tilted to switch from the neutral position to the operation position, the pilot pressure is detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in the operation state. When in the operating state, the posture control of the grapple 30 is released.

  Further, when the operation lever 43 is switched from the operation position to the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. Then, when a predetermined time has elapsed since the operation lever 43 was switched from the operation position to the neutral position, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. Thereby, the posture control of the grapple 30 is resumed. In addition, what is necessary is just to measure whether the predetermined time passed, for example with the timer etc. which were provided in the mechatronics controller 50.

  Thus, since the posture control of the grapple 30 is not performed until the predetermined time has elapsed after the operation lever 43 is returned to the neutral position, the operator freely operates the grapple 30 during this period, The adjustment work of the inclination angle of the grapple 30 can be performed with a margin.

<< Embodiment 3 >>
FIG. 8 is a timing chart showing the timing for performing posture control of the grapple according to the third embodiment. As shown in FIG. 8, when the operation lever 43 is in the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. In the non-operation state, the posture control of the grapple 30 is started, and the posture control is continued while the non-operation state is continued.

  Here, when the operation lever 43 is tilted to switch from the neutral position to the operation position, the pilot pressure is detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in the operation state. When in the operating state, the posture control of the grapple 30 is released.

  Further, when the operation lever 43 is switched from the operation position to the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. When the gripping object S is gripped, when the cylinder rod of the opening / closing cylinder 33 is extended and the gripping claw 32 is closed, the pressure detected by the pressure sensor 33a provided on the head side of the opening / closing cylinder 33 is larger than a predetermined pressure. It becomes a relief state. At this time, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. Thereby, the posture control of the grapple 30 is resumed.

  As described above, when the pressure sensor 33a detects that the gripping object S is gripped by the gripping claws 32, the posture control of the grapple 30 is performed. Accordingly, the grapple 30 can be automatically adjusted to the suspended posture without performing a special operation for the operator to control the posture of the grapple 30, and workability is improved.

<< Embodiment 4 >>
FIG. 9 is a timing chart showing the timing for performing posture control of the grapple according to the fourth embodiment. As shown in FIG. 9, when the operation lever 43 is in the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in a non-operation state. In the non-operation state, the posture control of the grapple 30 is started, and the posture control is continued while the non-operation state is continued.

  Here, when the operation lever 43 is tilted to switch from the neutral position to the operation position, the pilot pressure is detected in the pilot line of the front cylinder 35. At this time, the operation determination unit 52 determines that the grapple 30 is in the operation state. When in the operating state, the posture control of the grapple 30 is released.

  Further, when the operation lever 43 is switched from the operation position to the neutral position, the pilot pressure is not detected in the pilot line of the front cylinder 35. When the gripping object S is gripped, when the cylinder rod of the opening / closing cylinder 33 is extended and the gripping claw 32 is closed, the pressure detected by the pressure sensor 33a provided on the head side of the opening / closing cylinder 33 is larger than a predetermined pressure. It becomes a relief state.

  Then, when a predetermined time has elapsed after the pressure sensor 33a detects that the hydraulic pressure on the head side in the open / close cylinder 33 has become larger than the predetermined pressure, the operation determination unit 52 determines that the grapple 30 is in a non-operating state. Judge that there is. Thereby, the posture control of the grapple 30 is resumed. In addition, what is necessary is just to measure whether the predetermined time passed, for example with the timer etc. which were provided in the mechatronics controller 50.

  As described above, since the posture control of the grapple 30 is not performed until the predetermined time elapses after the pressure sensor 33a detects that the gripping object S is gripped by the gripping claws 32, A person can freely operate the grapple 30 to adjust the inclination angle of the grapple 30 with a margin.

<< Embodiment 5 >>
FIG. 10 is a hydraulic control circuit diagram for adjusting the inclination angle of the grapple according to the fifth embodiment. As shown in FIG. 10, the control valve 40 extends and contracts the front cylinder 35 by switching the supply / discharge direction of the hydraulic oil discharged from the main pump 41. Here, the control valve 40 is switched to the neutral position when not in operation, and the front cylinder 35 is not expanded or contracted.

  The pilot valve 42 switches the supply / discharge direction of the pilot oil discharged from the pilot pump 44 by operating the operation lever 43. The pilot valve 42 and the control valve 40 are connected by a pilot line 45.

  A hydraulic pipe 66 connecting the control valve 40 and the front cylinder 35 is branched in the middle of the pipe and connected to the switching valve 67. The switching valve 67 can be switched so as to permit or block the hydraulic oil in the front cylinder 35 and the hydraulic piping 66 from returning to the tank 49 in response to a control signal from the mechatronics controller 50.

  Specifically, when the control signal is not output from the mechatronics controller 50 to the switching valve 67, the switching valve 67 is in a position where the hydraulic oil in the front cylinder 35 and the hydraulic piping 66 is blocked from returning to the tank 49. Can be switched. Accordingly, the front cylinder 35 is in an operation state in which the tilt angle of the grapple 30 can be adjusted by expanding and contracting the cylinder rod 36 by hydraulic pressure.

  On the other hand, when a control signal is output from the mechatronics controller 50 to the switching valve 67, the switching valve 67 is switched to a position that allows the hydraulic oil in the front cylinder 35 and the hydraulic piping 66 to return to the tank 49. Accordingly, the front cylinder 35 is in a communication state that allows the cylinder rod 36 to expand and contract due to the weight of the grapple 30.

  Note that the switching timing of the operation state or the communication state of the grapple 30 associated with the switching of the switching valve 67 will be described later.

  As shown in FIG. 11, the center position of the arm top pin 28 and the gravity center position G of the grapple 30 are arranged so as to be aligned in the vertical direction. Thereby, when the front cylinder 35 is switched to the communication state, the grapple 30 can be swung by its own weight, and the grapple 30 can be automatically maintained in the suspended posture.

  The angle detection unit 55 includes a detection lever 61, a detection sensor 62, and a stopper 63.

  The upper end portion of the detection lever 61 is supported so as to be rotatable about a central shaft 61 a provided in the main body portion 31 of the grapple 30. Accordingly, the detection lever 61 is rotated so as to extend along the vertical direction from the upper end portion to the lower end portion, and is maintained in the vertical posture even when the grapple 30 swings. A notch 61 b is formed at the lower end of the detection lever 61.

  The detection sensor 62 is configured by a proximity sensor or the like embedded in the main body 31. The detection sensor 62 is located in the notch 61b of the detection lever 61 when the grapple 30 is in the suspended posture. Here, when the detection lever 61 rotates as the grapple 30 swings, the lower end of the detection lever 61 overlaps the detection sensor 62. At this time, the detection sensor 62 outputs a detection signal indicating that the grapple 30 is tilted to the mechatronics controller 50.

  The stoppers 63 are disposed on the front and rear sides of the detection lever 61 and attached to the main body 31. The rear stopper 63 contacts the detection lever 61 when the grapple 30 is tilted so that the tip of the gripping claw 32 faces forward, and is detected at a position where the lower end of the detection lever 61 and the detection sensor 62 overlap. The lever 61 is regulated (see FIG. 12).

  On the other hand, the front stopper 63 is in contact with the detection lever 61 when the grapple 30 is tilted so that the tip of the gripping claw 32 faces the rear side, and the lower end of the detection lever 61 and the detection sensor 62 overlap each other. The detection lever 61 is restricted.

  As shown in FIG. 10, in the mechatronics controller 50, the operation determination unit 52 determines whether the grapple 30 is in an operation state or a non-operation state.

  Then, as shown in FIG. 12, it is detected by the detection sensor 62 that the grapple 30 is inclined more than a predetermined angle by the angle detector 55, and the grapple 30 is determined to be in a non-operation state by the operation determination unit 52. In this case, the hydraulic control unit 51 of the mechatronics controller 50 outputs a control signal to the switching valve 67.

  When a control signal is output to the switching valve 67, the front cylinder 35 is switched to the communication state, and the grapple 30 can freely swing around the arm top pin 28 by its own weight (see FIG. 13).

  Thus, the suspended posture can be automatically maintained by the weight of the grapple 30. When the grapple 30 is maintained in the suspended posture, the detection lever 61 of the angle detector 55 returns to the vertical posture, so that no detection signal is output from the detection sensor 62. At this time, the hydraulic control unit 51 of the mechatronics controller 50 does not output a control signal to the switching valve 67. Thereby, the front cylinder 35 is switched to an operation state, and the operator can operate the grapple 30 freely.

  As described above, the present invention is extremely useful and industrial because the grapple can be automatically maintained in the suspended posture and the operator can freely operate the grapple with a highly practical effect. The availability is high.

DESCRIPTION OF SYMBOLS 10 Work machine 11 Lower traveling body 12 Upper revolving body 20 Attachment 28 Arm top pin 30 Grapples 32 Grip claw 33 Opening and closing cylinder 33a Pressure sensor (hydraulic pressure detection part)
35 Front cylinder 36 Cylinder rod 43 Operation lever 49 Tank 51 Hydraulic control section 52 Operation determination section 53 Position detection section 55 Angle detection section 56 Changeover switch A1 First interference area A2 Second interference area G Center of gravity position S Grasping object

Claims (10)

A lower traveling body, an upper revolving body mounted on the lower traveling body so as to be capable of swiveling, and an attachment provided with a grapple having a plurality of gripping claws and mounted on the front side of the upper revolving body so as to be able to undulate Working machine,
A front cylinder that adjusts the angle of inclination of the grapple by swinging the grapple as the cylinder rod expands and contracts;
An angle detector for detecting the inclination angle of the grapple;
An operation lever for operating the grapple by switching the supply / discharge direction of the hydraulic oil with respect to the front cylinder;
An operation determination unit for determining whether the operation of the grapple by the operation lever is performed or a non-operation state in which the operation of the grapple by the operation lever is not performed;
When the operation determination unit determines that the non-operation state is established, the grapple has a hanging posture in which the tip of the gripping claw is directed downward based on the inclination angle detected by the angle detection unit. A work machine comprising: a hydraulic control unit that performs posture control to extend and contract the cylinder rod so as to cancel the posture control of the grapple when it is determined to be in the operation state. In claim 1,
The operation lever is configured to be switchable between a neutral position where hydraulic oil is not supplied to and discharged from the front cylinder and an operation position where hydraulic oil is supplied to and discharged from the front cylinder.
The operation determining unit determines that the operation lever is in the non-operation state when the operation lever is in the neutral position. In claim 2,
The operation machine is characterized in that the operation determining unit determines that the operation lever is in the non-operation state when a predetermined time elapses after the operation lever is switched from the operation position to the neutral position. In claim 1,
An opening and closing cylinder for opening and closing the gripping claws of the grapple;
A hydraulic pressure detection unit that detects the hydraulic pressure on the head side of the open / close cylinder;
The operation determining unit determines that the non-operating state is detected when the hydraulic pressure detecting unit detects that the hydraulic pressure in the open / close cylinder is greater than a predetermined pressure by closing the gripping claw. Features a working machine. In claim 4,
The operation determination unit closes the gripping claw and detects that the hydraulic pressure in the open / close cylinder is greater than a predetermined pressure when the predetermined time has elapsed after the hydraulic pressure detection unit detects that A work machine characterized by being determined to be present. In any one of claims 1 to 5,
A position detection unit that detects the position of the grapple and outputs an interference avoidance signal to the hydraulic pressure control unit when the grapple reaches a predetermined interference area set in advance;
The hydraulic control unit is configured to control the operation of the attachment so that the grapple does not move to the upper swing body side of the interference area when the interference avoidance signal is output from the position detection unit. ,
The position detection unit outputs the interference avoidance signal when the grapple reaches the first interference area when the operation determination unit determines that the operation state is in the operation state, while in the non-operation state. When it is determined that there is a signal, the grapple is configured to output the interference avoidance signal when the grapple reaches a second interference zone set between the first interference zone and the upper swing body. A working machine characterized by In claim 6,
In the hydraulic control unit, the non-operated grapple located between the first interference area and the second interference area is operated by the operation lever to be in the operation state. The front cylinder so that the grapple does not swing toward the upper swinging body until the grapple is released from posture control and the grapple moves forward of the first interference area. A work machine characterized by controlling the operation of the machine. In claim 6,
In the hydraulic control unit, the non-operated grapple located between the first interference area and the second interference area is operated by the operation lever to be in the operation state. In such a case, the grapple attitude control is continued until the grapple moves forward of the first interference area. In any one of claims 1 to 8,
A work machine comprising a changeover switch that selectively switches whether to perform posture control of the grapple or to cancel posture control. In any one of claims 1 to 9,
The center position of the arm top pin that supports the grapple so as to be swingable with respect to the arm of the attachment, and the gravity center position of the grapple are arranged so as to be aligned vertically.
When the angle detecting unit detects that the grapple is inclined more than a predetermined angle, the hydraulic control unit communicates the cylinder chamber on the head side and the rod side of the front cylinder with the tank, and A work machine that performs the attitude control by allowing the cylinder rod to extend and contract by its own weight and swinging the grapple.

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