JP2019156602A - Earth drill - Google Patents

Abstract

To provide an earth drill having control means capable of performing suspended work safely in the state that two auxiliary hoist ropes hung are changed from one auxiliary hoist ropes hung.SOLUTION: An earth drill capable of changing an auxiliary hoist rope in the state of one rope hung to two ropes hung comprises a coupling position detection limit switch 34 for detecting a position in a height direction of a swivel in the state of two auxiliary hoist ropes hung and control means 41 for restricting a hoisting of the auxiliary rope when a position of the swivel is situated below than a predetermined coupling position detection height.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an earth drill, and more particularly, an earth that can be switched from a one-hung state in which a supplementary winding rope is connected to a tail to a two-hung state that is wound around a sheave of a supplementary winding hook with a sheave. Regarding drills.

  In general, an earth drill uses a supplementary hook connected to a supplementary rope to lift various materials used during work. When lifting a relatively heavy object, replace the supplementary hook with a supplementary hook with a sheave. The tip of the auxiliary winding rope via the auxiliary hook with sheave is fixed to the boom. Thereby, since the lifting operation can be performed in a state where the auxiliary winding rope is changed from one to two, the lifting ability can be increased. As one of the methods of changing the auxiliary winding rope, there is a rope changing method in which the main winding rope and the auxiliary winding rope are lowered to the ground and connected to each other in a loop shape so that the boom can be safely changed without lowering the boom. It is known (for example, refer to Patent Document 1).

JP 2015-145307 A

  However, in the rope switching method described in Patent Document 1 described above, the swivel as a connecting member is provided at the connecting portion between the main winding rope and the auxiliary winding rope because of the structure. The position of the direction changed with the lifting operation or the boom raising / lowering operation, and the swivel might be caught in the sheave of the auxiliary winding hook with the sheave.

  Accordingly, an object of the present invention is to provide an earth drill provided with a control means capable of safely performing a lifting operation in a state where the auxiliary winding rope is changed from one to two.

  In order to achieve the above object, an earth drill according to the present invention includes a main winding sheave on which a main winding rope having a connecting member connected to a tip is wound around a sheave shaft disposed at a tip of a boom provided in a base machine. An auxiliary winding sheave with an auxiliary winding rope connected to the tip of the auxiliary winding sheave is rotatably attached, and the auxiliary winding with the sheave from the single hook connection with the auxiliary winding hook on the tail of the auxiliary winding rope. In the earth drill which can be switched to a two-hanging state by wrapping the auxiliary winding rope around the sheave of the hook and connecting the tail of the auxiliary winding rope to the connecting member, Connecting position detecting means for detecting the position of the connecting member in the height direction, and winding of the auxiliary winding rope when the position of the connecting member is below a preset connecting position detecting height; It is characterized in that a control means for regulating the lower.

  Further, the control means includes a main overwinding position detecting means for detecting a position in the height direction of the connecting member, and an overwinding position for detecting a position in the height direction of the auxiliary winding hook or the auxiliary winding hook with sheave. The main winding when the position of the connecting member is higher than the connecting position detection height and is at a preset main overwinding detection height in the state where the two hooks are provided. Restricting the hoisting of the rope, and restricting the hoisting of the auxiliary winding rope when the position of the auxiliary winding hook with sheave is below the connecting member and at a preset overwinding detection height. It is characterized by being composed.

  Further, the control means includes a switching means for switching between valid / invalid of the connection position detection means, and in the state where the connection position detection means is enabled by the switching means and the switching means is effective, In the state where the winding of the auxiliary winding rope is restricted when the position is lower than the connection position detection height, the one is hooked and the connection position detection means is invalidated by the switching means, the connection position Regardless of the state of the detection means, it is characterized in that the winding of the auxiliary winding rope is restricted only when the position of the auxiliary winding hook is at the detection height of the extra winding.

  According to the ground drill of the present invention, since the control means for restricting the winding of the auxiliary winding rope is provided when the position of the connecting member is below the detection position of the connecting position, it is caused by the winding operation of the auxiliary winding rope. Thus, the connecting portion can be prevented from being caught in the sheave of the auxiliary winding hook with the sheave, and the lifting work by two hooks can be performed safely. Further, since the excessive winding of the main winding rope and the auxiliary winding rope is restricted according to the detection states of the main overwinding position detection means and the auxiliary overwinding position detection means, the connecting portion is the main winding sheave and the auxiliary winding hook with sheave. It is not caught in either sheave, and the lifting work can be performed more safely. Furthermore, since the valid / invalid of the connection position detecting means is switched by operating the switching means, safety control suitable for the number of hooks can be performed with a simple circuit configuration.

It is a side view which shows one example of the earth drill to which this invention is applied (the state of 2 hooks wound around the sheave of the auxiliary winding hook with a sheave). It is a side view similarly (a state where the auxiliary winding hook with sheave is wound up to a predetermined height). It is a circuit diagram which shows the example of one form of the control circuit similarly provided in the earth drill.

  FIGS. 1 to 3 show an embodiment of the earth drill according to the present invention. The earth drill 11 shown in this embodiment is self-propelled in which an upper swing body 13 is provided on the upper portion of the lower travel body 12 so as to be rotatable. And a boom 16 provided in a front portion of the upper swing body 13 via a parallel link mechanism 15 so as to be able to rise and fall.

  A counterweight 17 is mounted on the rear portion of the upper swing body 13. Further, an operation room 13a and an equipment room (not shown) are provided on the right side of the upper swing body 13, and an engine room 13b in which an engine and a hydraulic pump are housed is provided on the left side.

  In the parallel link mechanism 15, one end of each of the upper frame 15a and the lower frame 15b is pivotally supported with respect to the upper swing body 13, and a boom support 15c is pivotally supported at the other end. The upper frame 15a and the lower frame 15b are pivotally supported at both ends so that they are parallel to each other to form a parallel link, and the boom is generated by the expansion and contraction operation of the link cylinder 18 provided between the upper frame 15a and the upper swing body 13. The upper surface of the support 15c is formed to be swingable in the front-rear direction while maintaining the level.

  The boom 16 is formed by connecting a plurality of boom members having a box-shaped cross section. A top sheave block 19 is provided at the top, and a lower part is pivotally supported by a bracket protruding forward from the boom support 15c. The undulation cylinder 20 provided between the support 15c and the support 15c is formed so as to be undulated by expansion and contraction. A kelly bar rotation drive device 21 (kelly drive) is mounted on the front portion of the boom 16 so as to be movable up and down.

  A main winding sheave 24 and an auxiliary winding sheave 25 are rotatably provided on the sheave shafts 22 and 23 of the top sheave block 19. The main winding rope 28 fed out from the main winding winch 26 through the guide sheave 27 is wound around the main winding sheave 24, and a swivel 29 as a connecting member is attached to the tip.

  When performing excavation work, the main winding rope 28 is configured to suspend a kelly bar (not shown) via a swivel 29 so that the main winding winch 26 can be raised and lowered, and the kelly bar is driven to rotate. An expanded bottom bucket (not shown) and an excavating bucket (not shown) that rotate integrally with the kelly bar and move up and down are attached to the lower end of the kelly bar that protrudes downward from the device 21.

  When carrying out crane work together with this excavation work, the auxiliary winding rope 31 fed out from the auxiliary winding winch 30 is wound around the auxiliary winding sheave 25 via the guide sheave 27 and the auxiliary winding 31 is wound around the tail of the auxiliary winding rope 31. Various materials are lifted with a hook (not shown) connected.

  On the other hand, when carrying out a crane work for lifting a heavy object without performing an excavation work, the auxiliary winding 31 with the sheave 29 removed from the swivel 29 and the auxiliary winding hook 31 is removed from the auxiliary winding hook 32 with the sheave. By winding the sheave 33 on the sheave 33 and connecting the tail of the auxiliary winding rope 31 to the swivel 29 to hang it twice, heavy crane work is possible.

  In the ground drill 11 formed in this way, in the state where the two auxiliary winding ropes 31 are hung, the lifting ability can be enhanced, but the position of the swivel 29 in the height direction is the lifting operation or boom in terms of its structure. The swivel 29 may be caught in the sheave 33 of the auxiliary winding hook 32 with sheave. In particular, immediately after the change (FIG. 1), the swivel 29 is located in the vicinity of the auxiliary winding hook 32 with the sheave, so when the auxiliary winding rope 31 is wound up, the swivel 29 is caught in the sheave 33 and the auxiliary winding rope 31 or The swivel 29 is damaged. Therefore, it is necessary to restrict the winding of the auxiliary winding rope 31.

  For this reason, in the earth drill 11 shown in this embodiment, as shown in FIG. 3, the top sheave block 19 is connected to the connection position detection limit switch 34 serving as connection position detection means for detecting the position of the swivel 29 in the height direction. A main overwinding position detection limit switch 35 serving as a main overwinding position detection means and an overwinding position detection limit switch serving as an overwinding position detection means for detecting the height direction position of the auxiliary winding hook or the auxiliary winding hook 32 with sheave. 36, and a hook number changeover switch 37 serving as a switching means for switching between valid / invalid of the connection position detection limit switch 34 and a hydraulic circuit of the main winding winch 26 for winding the main winding rope 28 in the cab 13a. The main winding up stop solenoid 38 for shutting off and stopping, and the auxiliary winding winch 30 hydraulic circuit for winding up the auxiliary winding rope 31 A control means 41 comprising an electric circuit having an auxiliary winding upper stop solenoid 39 for shutting off and stopping, and an overturn stop solenoid 40 for shutting down the boom 16 by shutting off the hydraulic circuit of the hoisting cylinder 20 is provided. ing.

  The contact point drive unit of the connection position detection limit switch 34 is connected to a suspension rope in which a ring-shaped weight 34 a that passes through the main winding rope 28 is suspended. The weight 34a can move up and down with respect to the main winding rope 28, and is suspended from the top sheave block 19 at a connection position detection height positioned below a preset distance L1. In this state (FIG. 1), the connection position detection limit switch 34 is OFF with its contact open. On the other hand, as shown in FIG. 2, when the ring member 42 at the upper end of the swivel 29 comes into contact with the weight 34a by the winding of the main winding rope 28, the tension of the suspension rope that has been acting on the connection position detection limit switch 34 until now is increased. Since it does not act, the connection position detection limit switch 34 is turned on with its contact closed.

  To the contact drive part of the main overwinding position detection limit switch 35, a suspension rope is connected to which a ring-shaped weight 35a that passes through the main winding rope 28 is suspended. The weight 35a can move up and down with respect to the main winding rope 28, and is above the connection position detection height, that is, above the weight 34a and below the top sheave block 19 by a preset distance L2. It is suspended at the position where the main overwind detection is located. In this state (FIGS. 1 and 2), the main overwinding position detection limit switch 35 is ON with its contact closed. On the other hand, when the weight 34a pushed up by the winding of the main winding rope 28 comes into contact with the weight 35a, the tension of the suspension rope that has been applied to the main overwinding position detection limit switch 35 does not work. The overwinding position detection limit switch 35 is turned OFF with its contact open.

  To the contact drive portion of the overwinding position detection limit switch 36, a hanging rope is connected to which a ring-shaped weight 36a that passes through the auxiliary winding rope 31 is suspended. The weight 36a can move up and down with respect to the auxiliary winding rope 31, and the swivel 29 is caught in the sheave 33 of the auxiliary winding hook 32 with the sheave while the upper portion of the auxiliary winding hook 32 with the sheave contacts the lower end thereof. It is hung at the overwinding detection height that is located below the top sheave block 19 by a preset distance L3. In this state (FIGS. 1 and 2), the overwinding position detection limit switch 36 is ON with its contact closed. On the other hand, when the upper part of the auxiliary winding hook 32 with sheave comes into contact with the weight 36a due to the winding of the auxiliary winding rope 31, the tension of the suspension rope that has been applied to the overwinding position detection limit switch 36 does not work. The overwinding position detection limit switch 36 is turned OFF with its contact open.

  The main hoisting stop solenoid 38 is set to shut off the main winding rope 28 by shutting off the hydraulic circuit of the main winding winch 26 when the main winding winch 26 is turned off. The auxiliary winding up stop solenoid 39 is set so as to stop the winding of the auxiliary winding rope 31 by interrupting the hydraulic circuit of the auxiliary winding winch 30 when it is in a non-energized state. The fall stop solenoid 40 is set so as to stop the fall of the boom 16 by shutting off the hydraulic circuit of the hoisting cylinder 20 when it is not energized.

  A line 43 to which the main overwinding position detection limit switch 35 and the auxiliary overwinding position detection limit switch 36 are connected in series is connected to the main winding up stop solenoid 38, the auxiliary winding up stop solenoid 39, and the overturn stop solenoid 40, respectively. Lines 38a, 39a, and 40a to be branched are provided. In addition, a connection position detection limit switch 34 is provided in the line 39a, and a line 37a in which a hook number changeover switch 37 is connected in parallel to the connection position detection limit switch 34 is provided by branching from the line 39a. Yes.

  The hook number changeover switch 37 is an ON / OFF switch that allows the operator to set either a single hook or double hook state. When the contact is closed, it corresponds to the single hook state. When OFF is set, the setting is made corresponding to the state of two hooks. When the hook number changeover switch 37 is turned ON, the line 39a is electrically connected via the line 37a regardless of whether the connection position detection limit switch 34 is ON or OFF, and the switching function of the connection position detection limit switch 34 is set. Becomes invalid. On the other hand, when the hook number switching switch 37 is turned OFF, the line 37a is electrically cut off, and the switching function of the connection position detection limit switch 34 is enabled.

  As shown in FIG. 1, after the earth drill 11 having such a control means 41 is switched to two hooks near the ground, the hook number changeover switch 37 is turned OFF corresponding to the two hook state, that is, When the switching function of the coupling position detection limit switch 34 is enabled, the electric circuit is in an energized state in which the main overwinding position detection limit switch 35 and the overwinding position detection limit switch 36 are respectively ON as shown in FIG. Since the connection position detection limit switch 34 and the hook number changeover switch 37 are in the non-energized state, the auxiliary winding upper stop solenoid 39 is not excited and the hydraulic circuit of the auxiliary winding winch 30 is cut off. The winding of the auxiliary winding rope 31 is restricted.

  Accordingly, when the main winding rope 28 capable of being wound up is wound up, as shown in FIG. 2, the ring member 42 comes into contact with the weight 34a, and the connection position detection limit switch 34 is turned on to be in the energized state. Become. As a result, the auxiliary winding upper stop solenoid 39 is excited, the hydraulic circuit of the auxiliary winding winch 30 is opened, and the auxiliary winding rope 31 can be wound up.

  Thus, since the control means 41 regulates the winding of the auxiliary winding rope 31 when the position of the swivel 29 is below the connection position detection height, the swivel 29 is caused by the winding operation of the auxiliary winding rope 31. The state where the sheave 33 of the auxiliary winding hook 32 with the sheave is prevented from being caught is prevented, and the lifting work by two hooks can be performed safely.

  By the way, even if the auxiliary winding 31 can be wound up, the main winding rope 28 can continue to be wound. However, when the pushed weight 34a comes into contact with the weight 35a, the main overwinding position detection limit switch. 35 is turned off and is in a non-energized state. As a result, the excitation of the main winding stop solenoid 38 is released, the hydraulic circuit of the main winding winch 26 is cut off, and the winding of the main winding rope 28 is restricted. Here, since the main overwinding position detection limit switch 35 is OFF and is in a non-energized state, the winding of the auxiliary winding rope 31 and the falling of the boom 16 are also restricted at the same time. Therefore, the operator can confirm that the main winding rope 28 is in an excessively wound state by restricting various operations.

  Further, the auxiliary winding rope 31 can be wound up, that is, the ring member 42 is positioned between the connection position detection height (the position of the weight 34a) and the main overwinding detection height (the position of the weight 35a). When the auxiliary winding rope 31 is wound up, the upper part of the auxiliary winding hook 32 with sheave comes into contact with the weight 36a, and the overwinding position detection limit switch 36 is turned off to be in a non-energized state. Thereby, the excitation of the auxiliary winding upper stop solenoid 39 is released, the hydraulic circuit of the auxiliary winding winch 30 is cut off, and the winding of the auxiliary winding rope 31 is restricted. Here, since the overwinding position detection limit switch 36 is OFF and is in a non-energized state, the winding of the main winding rope 28 and the overturning of the boom 16 are also restricted at the same time. In this state, the swivel 29 and the sheave 33 of the auxiliary winding hook 32 with sheave approach each other but do not come into contact with each other.

  As described above, the excessive winding of the main winding rope 28 and the auxiliary winding rope 31 is restricted according to the respective detection states of the main overwinding position detection limit switch 35 and the auxiliary overwinding position detection limit switch 36. It is not caught in either the winding sheave 24 or the sheave 33 of the auxiliary winding hook 32 with sheave, and the lifting operation can be performed more safely. Further, since the fall of the boom 16 is also restricted at the same time as these restrictions, further safety is ensured.

  When the crane work with two hooks is completed and the crane is replaced again with one hook, the connection between the auxiliary winding rope 31 and the swivel 29 is released and the auxiliary winding hook 31 is connected to the tail of the auxiliary winding rope 31. The hook number changeover switch 37 is turned ON corresponding to the state of one hook, that is, the switching function of the connection position detection limit switch 34 is invalidated. As a result, the main overwinding position detection limit switch 35 and the auxiliary overwinding position detection limit switch 36 are in the ON energized state and the hook number changeover switch 37 is in the ON energized state. The auxiliary winding winch 30 is excited and the hydraulic circuit of the auxiliary winding winch 30 is opened, and the auxiliary winding rope 31 can be wound up.

  In this way, since the valid / invalid of the connection position detection limit switch 34 is switched by operating the hook number changeover switch 37, safety control suitable for the state of the hook number can be performed with a simple circuit configuration. In addition, when switching to the two-hanging, the main winding rope 28 is lowered to the ground with the boom 16 raised, so that no special measures are required for regulating the lowering during crane work. It is.

  The present invention is not limited to the above-described embodiment, and each weight may be provided at a height position that can prevent overwinding of the main winding rope and the auxiliary winding rope. The hanging position can be changed as appropriate according to the shape of the winding hook. Further, the connection position detecting means is not limited to the limit switch, and for example, the connection position may be detected using a non-contact type sensor or the like. Furthermore, the control means may be configured to restrict the overturning of the boom and to restrict the forward tilt of the parallel link mechanism, and can be changed as appropriate within the scope of the present invention.

  DESCRIPTION OF SYMBOLS 11 ... Earth drill, 12 ... Lower traveling body, 13 ... Upper turning body, 13a ... Driver's cab, 13b ... Engine room, 14 ... Base machine, 15 ... Parallel link mechanism, 15a ... Upper frame, 15b ... Lower frame, 15c ... Boom support, 16 ... Boom, 17 ... Counter weight, 18 ... Link cylinder, 19 ... Top sheave block, 20 ... Elevating cylinder, 21 ... Keriba rotary drive, 22,23 ... Sheave shaft, 24 ... Main winding sheave, 25 ... Auxiliary sheave, 26 ... main winding winch, 27 ... guide sheave, 28 ... main winding rope, 29 ... swivel, 30 ... auxiliary winding winch, 31 ... auxiliary winding rope, 32 ... auxiliary winding hook with sheave, 33 ... sheave, 34 ... Connection position detection limit switch, 34a ... Weight, 35 ... Main overwind position detection limit switch, 35a ... Weight, 36 ... Overwinding Position detection limit switch, 36a ... weight, 37 ... hanging number changeover switch, 37a ... line, 38 ... main winding stop solenoid, 38a ... line, 39 ... supplementary winding stop solenoid, 39a ... line, 40 ... fall stop solenoid , 41 ... control means, 42 ... ring member, 43 ... line

Claims (3)

  A main winding sheave around which a main winding rope having a connecting member connected to the tip is wound around a sheave shaft arranged at the tip of a boom provided in the base machine, and an auxiliary winding rope having an auxiliary winding hook connected to the tip are wound. The auxiliary winding sheave to be hung is rotatably attached, and the auxiliary winding rope is wound around the sheave of the auxiliary winding hook with sheave from the single hook state in which the auxiliary winding hook is connected to the tail of the auxiliary winding rope. In a ground drill that can be switched to a two-hanging state by connecting the tail of the auxiliary winding rope to the connecting member, a connection position detection that detects the position of the connecting member in the two-hanging state in the height direction And a control means for restricting the winding of the auxiliary winding rope when the position of the connecting member is below a preset connection position detection height. Sudoriru.   The control means includes a main overwinding position detecting means for detecting a position in the height direction of the connecting member, and an overwinding position detecting means for detecting a position in the height direction of the auxiliary winding hook or the auxiliary winding hook with sheave. And when the position of the connecting member is above the connection position detection height and is at a preset main overwinding detection height, the main winding rope is The hoisting is restricted, and when the position of the auxiliary winding hook with sheave is below the connecting member and is at a preset overwinding detection height, the hoisting of the auxiliary winding rope is restricted. The earth drill according to claim 1, wherein:   The control means includes a switching means for switching between valid / invalid of the connection position detection means, and when the connection position detection means is enabled by the switching means and the switching position is enabled, the position of the connection member is In the state where the winding of the auxiliary winding rope is restricted when the position is lower than the connection position detection height, the one is hooked, and the connection position detection means is disabled by the switching means, the connection position detection means 3. The ground drill according to claim 2, wherein the winding of the auxiliary winding rope is restricted only when the position of the auxiliary winding hook is at the detected height of the extra winding regardless of the state of the above. .

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