JP2021188387A - Pile-driving machine - Google Patents

Abstract

To provide a pile-driving machine that can monitor the inclination of a reader and safely return from the automatically stopped state when an alarm is activated.SOLUTION: A pile-driving machine is capable of adjusting the tilt of a leader in the front-back and right-left directions by means of a pair of right and left backstays equipped with stay cylinders 27 and 28 that can be extended and retracted. The pile-driving machine comprises a leader tilt limit switch that emits an alarm signal when the right-left tilt from the upright state in the leader exceeds a preset threshold (set tilt angle). A hydraulic circuit that supplies and discharges hydraulic fluid to the pair of right and left stay cylinders is provided with oil flow direction control switching valves 38, 39 that prohibit the flow of hydraulic fluid in the direction of increasing the right-left tilt of the leader upon receiving an alarm signal and allow the flow of hydraulic fluid in the direction of decreasing the right-left tilt of the leader.SELECTED DRAWING: Figure 10

Description

The present invention relates to a pile driver, and more particularly to a three-point support type pile driver provided with a pair of left and right backstays that support a leader erected at the front of a base machine.

The three-point support type pile driver supports the leader standing in the front part of the base machine from the rear with a pair of left and right back stays, and tilts the leader in the front-back and left-right directions by the expansion and contraction operation of the stay cylinder provided in the back stays. Is adjusted. The stay cylinder has a long stroke that exceeds the amount required for tilt adjustment (vertical extension) of the leader in consideration of the assemblability of the back stay. For this reason, if the stay cylinder continues to expand (shrink) due to an operator's erroneous operation or a malfunction of the hydraulic system, the leader will swing significantly in the left-right direction and the moving parts will be damaged, and in the worst case, it may fall. .. For this reason, the three-point support type pile driver is provided with a safety device that issues an alarm when the tilt of the leader exceeds a permissible angle (see, for example, Patent Document 1).

JP-A-2007-31977

The tilt adjustment of the reader is usually performed by tilting the two left and right operating levers provided in the driver's seat from the neutral position to either the front or the back. That is, when the operator operates both operation levers individually or in combination, the back stay that has received the expansion / contraction operation of the stay cylinder pushes and pulls the leader, and the leader is adjusted perpendicularly to the ground. However, in the safety device described in Patent Document 1, it is not easy for the operator to properly perform such a lever operation in a situation where the reader is tilted and an alarm (sound or light) is issued. In addition, it is conceivable to install an automatic stop device that stops the expansion and contraction operation of the stay cylinder together with the alarm, but it is safe to restore the stopped control function on the spot because the operation must be careful. It was not enough as a device.

Therefore, an object of the present invention is to provide a pile driver capable of safely returning from an automatically stopped state when an alarm is activated while monitoring the tilt of the reader.

In order to achieve the above object, in the pile driving machine of the present invention, a leader swingably supported in the front-back and left-right directions with respect to the base machine is erected by a pair of left and right back stays equipped with a telescopic stay cylinder. In a pile driving machine capable of adjusting the tilt of the leader in the front-back and left-right directions by expanding and contracting the stay cylinder, an alarm is given when the tilt of the leader in the left-right direction from the standing state exceeds a preset threshold value. A hydraulic circuit equipped with a detecting means for emitting a signal and supplying and discharging hydraulic oil to a pair of left and right stay cylinders prohibits the flow of hydraulic oil in a direction in which the reader receives the alarm signal and the tilt in the left-right direction increases. At the same time, it is characterized in that an oil flow control means is provided that allows the flow of hydraulic oil in a direction in which the tilt of the reader in the left-right direction is reduced.

According to the pile driving machine of the present invention, a detection means for issuing an alarm signal when a threshold value set corresponding to the left-right tilt of the reader is exceeded is provided, and an alarm signal is sent to a hydraulic circuit connected to a pair of left and right stay cylinders. In response to this, an oil flow control means is provided to prohibit the flow of hydraulic oil in the direction in which the tilt in the left-right direction of the reader increases, and to allow the flow in the direction in which the tilt in the left-right direction of the reader decreases, which is the flow in the opposite direction. Therefore, when the reader tilts to the left or right and automatically stops, it is possible to hydraulically control the lever so that the lever can be operated only in the direction to return the tilt of the leader, and it is possible to easily and safely return from the tilted state of the leader. can.

It is a side view of the pile driver which shows one embodiment of this invention. It is also a plan view. It is also a front view. It is also a side view of the main part. FIG. 6 is a sectional view taken along line VV of FIG. It is operation explanatory drawing of a leader tilt limit switch. It is an electric circuit diagram of the non-energized state in which the contact of a leader tilt limit switch is open. It is also a hydraulic circuit diagram. It is an electric circuit diagram of the energized state in which the contact of a leader tilt limit switch is closed. It is also a hydraulic circuit diagram.

1 to 10 show an example of a form of the pile driver of the present invention. As shown in FIGS. 1 to 3, the base machine 12 of the pile driver 11 is provided with the upper swivel body 14 swivelably provided on the upper part of the lower traveling body 13 provided with the crawler via a swivel bearing. A leader bracket 17 to which a leader 15 and front jacks 16 and 16 are attached is provided at the front portion of the upper swing body 14, and an out trigger box 19 to which rear jacks 18 and 18 are attached is provided at a rear end portion of the upper swing body 14. And a counter weight 20 mounted on the out trigger box 19. Further, the upper swivel body 14 is provided with a driver's cab 21 and a power unit 22 on which a hydraulic pump or the like is mounted on the machine frame, and an undulating gantry 23 is provided above the rear portion of the upper swivel body 14. ing.

The reader 15 is formed by connecting a plurality of leader members 15b to the upper portion of a leader base member 15a that is pivotally supported in the front-back and left-right directions with respect to the leader bracket 17, and a holder 24 is provided in the middle portion. The tips of a pair of left and right back stays 25 and 26 erected on the upper surface of the arm tip of the rear jack 18 are connected to the rear of the holder 24. The back stays 25 and 26 are provided with stay cylinders (hydraulic cylinders) 27 and 28 on the lower end side thereof, and the leader 15 is moved in the front-rear direction by the expansion and contraction operation of the stay cylinders 27 and 28 while the leader 15 is supported from the rear. Alternatively, it is possible to adjust the tilt in the left-right direction (vehicle width direction). The reader 15 whose inclination has been adjusted is in an upright state, and its verticality is ensured.

As shown in FIGS. 4 and 5, the leader bracket 17 has a pair of left and right reader holding portions 17a, 17a for holding the leader base member 15a at the front end portions, and the leader holding portions 17a, 17a and the reader are provided by the support pins 29. The support pins 29 are prevented from coming off by the adapters 30 and 30 in a state of penetrating the pin hole blocks 15c and 15c of the base member 15a. Further, the pin hole 15d of the pin hole block 15c is formed in a long hole shape extending in the axial direction (vertical direction) of the leader base member 15a. As a result, the reader 15 is provided so as to be swingable in the front-rear direction around the support pin 29, and further, due to the vertical gap provided between the support pin 29 and the pin hole 15d, only the amount of play is provided. Tilt in the left-right direction is allowed. The allowable tilt angle θ is, for example, about 2 degrees in each of the left-right directions from the vertical line L, and represents the mechanical limit of the tilt angle.

The tilt adjustment of the reader 15 is performed by tilting the two left and right operating levers provided in the driver's seat from the neutral position to either the front or the back. When the operator operates both operation levers individually or in combination, the back stays 25 and 26 that have received the expansion and contraction operation of the stay cylinders 27 and 28 push and pull the leader 15 to stand upright, that is, the leader 15 is perpendicular to the ground. It will be adjusted.

Specifically, when the leader 15 is tilted in the front-rear direction with respect to the vertical line L, both the left and right stay cylinders 27 and 28 are simultaneously expanded and contracted by the same stroke. As a result, the leader 15 swings around the support pin 29 that pivotally supports the leader base member 15a at the lower end, and the inclination in the front-rear direction is adjusted. On the other hand, when the leader 15 is tilted in the left-right direction with respect to the vertical line L, the left and right stay cylinders 27 and 28 are expanded and contracted by a predetermined amount of stroke, respectively. More specifically, when the reader 15 is tilted to the left (right side in FIG. 5), either or both of the extension operation of the left stay cylinder 27 and the contraction operation of the right stay cylinder 28 are executed. On the contrary, when the reader 15 is tilted to the right (left side in FIG. 5), either or both of the contraction operation of the left stay cylinder 27 and the extension operation of the right stay cylinder 28 are executed.

Here, when the stroke difference between the left and right stay cylinders 27 and 28 becomes large and the left and right tilt of the reader 15 reaches the allowable tilt angle θ, the stay cylinders 27 and 28 still try to expand (shrink) in that state. Then, an unreasonable load is applied to the leader shaft support portion, which may lead to damage. Therefore, the pile driver 11 is provided with a safety device capable of safely returning from the automatically stopped state when the alarm is activated while monitoring the inclination of the leader 15.

The safety device is for a detection means that issues an alarm signal when the tilt of the reader 15 in the left-right direction from the standing state exceeds a preset threshold value (set tilt angle), and for a pair of left and right stay cylinders 27, 28. It is provided in the hydraulic circuit that supplies and discharges hydraulic oil, and in response to the alarm signal, the flow of hydraulic oil in the direction in which the tilt of the reader 15 in the left-right direction increases (dangerous side) is prohibited, and the tilt of the reader 15 in the left-right direction is increased. It is equipped with an oil flow control means that allows the flow of hydraulic oil in the decreasing direction (safety side).

The detection means includes a pair of left and right leader tilt limit switches 31 and 32, and is provided on both left and right sides of the leader base member 15a via mounting brackets 33 and 33, respectively. Further, on the upper surface of the leader bracket 17, a pair of left and right dog plates 34, 34 are provided at positions corresponding to the leader tilt limit switches 31, 32, and the arms 31a, 32a for operating the limit switches are dog plates 34. , 34 can be contacted with the plate surface.

The arms 31a and 32a are adjusted to a set angle corresponding to the left-right tilt of the reader 15 at the initial position before abutting on the dog plate 34, and as shown in FIG. 6A, the dog plate is in the standing state of the leader 15. It has a certain gap S between it and the plate surface of 34. Here, when the reader 15 begins to tilt to the left (right side in FIG. 6) from the standing state and tilts beyond, for example, 1.5 degrees set as a threshold value, as shown in FIG. 6 (B), The arm 31a in contact with the dog plate 34 rotates from the initial position by a predetermined angle to reach the operating position.

Here, as shown in FIG. 7, the electric circuit provided with the reader tilt limit switches 31 and 32 branches two wirings 36 and 37 from the fuse 35 connected to the power supply, and the reader is on the wiring 36 side. There are two solenoids (drive circuits) 38a and 38a of the oil flow direction regulation switching valve (electromagnetic valve) 38 for left inclination which is an oil flow control means via the left inclination limit switch 31 which detects the inclination in the left direction of 15. They are connected in parallel in pairs. On the other hand, on the wiring 37 side, a solenoid (drive) of an oil flow direction regulation switching valve (solenoid valve) 39 for right inclination, which is an oil flow control means, is passed through a right inclination limit switch 32 for detecting the inclination of the reader 15 in the right direction. Circuit) 39a and 39a are paired and connected in parallel.

The tilt limit switches 31 and 32 are limit switches that are always open (normally open), and the contacts are maintained in an open state when the reader 15 is upright, and the tilt of the reader 15 in the left-right direction exceeds the threshold value. The contacts are closed and energized during operation. The alarm signal generated by this energization becomes a drive signal of each oil flow direction regulation switching valve 38, 39. Further, although not shown, the electric circuit incorporates a warning light made of a lighting member such as a buzzer or an LED that sounds in response to the warning signal.

The oil flow control means selectively selects two of the four electromagnetic two-position switching valves constituting the oil flow direction regulation switching valves 38 and 39 for left / right tilting, which correspond to the tilting direction of the reader 15. As shown in the hydraulic circuit of FIG. 8, the four pipes 42, 43, 44, 45 between the left and right stay cylinder operation valves (manual operation valves) 40, 41 and the left and right stay cylinders 27, 28 are driven. The oil passages are bidirectionally communicated in a non-excited state where the spool is in the neutral position (FIG. 8), and the oil goes to and returns to the left and right stay cylinders 27 and 28 in each of the pipes 42, 43, 44 and 45. Allows the flow of.

In this communication state, for example, when the left operation lever 40a is tilted forward, the spool of the left stay cylinder operation valve 40 switches from the neutral position (FIG. 8) to the switching position moved to the right, and the hydraulic pressure rotated by the drive of the engine. The discharge oil of the pump is supplied to the bottom side of the left stay cylinder 27 through the pipe 42, and the left stay cylinder 27 extends. At this time, the oil discharged from the rod side of the left stay cylinder 27 is returned to the tank through the pipe 43.

As the reverse operation, when the left operation lever 40a is tilted backward, the spool of the left stay cylinder operation valve 40 switches from the neutral position to the switching position moved to the left, and the oil discharged from the hydraulic pump passes through the pipe 43 to the left stay cylinder 27. It is supplied to the rod side of the left stay cylinder 27, and the left stay cylinder 27 contracts. At this time, the oil discharged from the bottom side of the left stay cylinder 27 is returned to the tank through the pipe 42. The same applies to the right operating lever 41a, and when the lever is operated, the discharge oil of the hydraulic pump is supplied to the bottom side or the rod side of the right stay cylinder 28, whereby the right stay cylinder 28 can be expanded and contracted.

Further, when the reader 15 is tilted in the left-right direction beyond the threshold value, the solenoids 38a and 39a corresponding to the tilting direction are energized and excited. For example, in a state where the reader 15 is tilted to the left, the left tilt limit switch 31 is turned on when the arm 31a reaches an operating position rotated by a predetermined angle and emits an alarm signal, as shown in FIG. As a result, both the left tilt oil flow direction regulation switching valves 38 are excited, and as shown in FIG. 10, only the two left tilt oil flow direction regulation switching valves 38 and 38 are moved to the right from the neutral position. Then, due to the closing action of the check valve (check valve), the flow of hydraulic oil toward the rod side of the left stay cylinder 27 and the flow of hydraulic oil toward the bottom side of the right stay cylinder 28 are prohibited. Can be switched.

On the other hand, at the refueling restricted position, the check valve is opened by the reverse flow returning to the tank, and the hydraulic oil flow from the rod side of the left stay cylinder 27 and the hydraulic oil from the bottom side of the right stay cylinder 28. Flows are allowed respectively. Here, the other two right-inclining oil flow direction regulation switching valves 39 and 39 are in the non-excited state, respectively, and the spool is in the neutral position to maintain the communication state of the oil passage. As a result, the flow of hydraulic oil in the direction in which the tilt of the leader 15 in the left direction increases, that is, the contraction operation of the left stay cylinder 27 and the extension operation of the right stay cylinder 28 are prohibited, but the tilt of the leader 15 in the left direction is prohibited. The flow of the hydraulic oil in the direction of decreasing, that is, the extension operation of the left stay cylinder 27 and the contraction operation of the right stay cylinder 28 are allowed.

The left and right stay cylinder operation valves 40 and 41 secure a constant flow rate proportional to the operation amount of the left and right operation levers 40a and 41a, that is, the spool switching amount, and when the levers 40a and 41a are released during operation, the valves 40, The spring inside 41 acts to return to the neutral position. In this neutral position, the oil discharged from the hydraulic pump is released to the tank side, and the internal pressures of the pipes 42, 43, 44, 45 are maintained. As a result, the pressure oil in the stay cylinders 27 and 28 is sealed by the attached pilot check valves 27a and 28a, and the expansion and contraction operation of the stay cylinders 27 and 28 is stopped (hydraulic lock).

When the leader 15 is tilted using the pile driver 11 formed in this way, when the leader 15 is tilted to the left from the upright state, for example, exceeding 1.5 degrees set as a threshold value, The left tilt limit switch 31 turns ON when the arm 31a reaches an operating position rotated by a predetermined angle, and emits an alarm signal. As a result, the buzzer and the warning light notify the left tilt state of the reader 15, and both of the left tilt oil flow direction regulation switching valves 38 are excited, so that the spool is switched from the neutral position to the refueling regulation position.

In this way, the swing of the leader 15 is automatically stopped, and only the lever operation in the left tilt direction (dangerous side) where the tilt of the leader 15 increases from this state is invalidated, while the return direction in which the tilt of the leader 15 decreases. Only (safety side) lever operation is allowed. Here, when the lever is operated in the return direction, the arm 31a of the left tilt limit switch 31 is rotated to the initial position and turned off, and both of the left tilt oil flow direction regulation switching valves 38 are degaussed. As a result, the oil passages of the four oil flow direction regulation switching valves 38 and 39 are all communicated in both directions, and the reader 15 can be swung in an arbitrary direction.

As described above, according to the pile driving machine 11 of the present invention, a detection means for issuing an alarm signal when the threshold value set corresponding to the left-right tilt of the reader 15 is exceeded is provided, and a pair of left and right stay cylinders 27, 28 are provided. In response to an alarm signal, the flow of hydraulic oil in the direction in which the lateral tilt of the reader 15 increases is prohibited in the hydraulic circuit connected to the above, and the flow in the opposite direction, in the direction in which the horizontal tilt of the reader 15 decreases. Since an oil flow control means that allows the flow is provided, when the reader 15 tilts in the left-right direction and automatically stops, hydraulic control can be performed so that only the lever operation in the direction of returning the tilt of the leader 15 is effective. , The reader 15 can easily and safely recover from the tilted state.

The present invention is not limited to the above-mentioned embodiment, and the detection means includes an existing leader tilt angle sensor conventionally provided in a pile driver, a stay stroke sensor described in Patent Document 1, and the like. The detectors can be diverted, and when the left / right tilt of the reader exceeds the threshold value, the safety device can be activated by receiving the alarm signals issued by these. Further, the oil flow control means is composed of four electromagnetic two-position switching valves in the embodiment, but the circuit configuration can be appropriately changed as long as the oil flow control means has the same effect. Further, the stay cylinder operation valve may be a hydraulic control valve whose spool movement can be finely adjusted, and in addition to the manual operation valve that is directly manually operated, the operation is controlled by an electric control signal from the controller. A control valve may be adopted.

11 ... Pile driving machine, 12 ... Base machine, 13 ... Lower traveling body, 14 ... Upper rotating body, 15 ... Leader, 15a ... Leader base member, 15b ... Leader member, 15c ... Pin hole block, 15d ... Pin hole, 16 ... front jack, 17 ... leader bracket, 17a ... leader holding part, 18 ... rear jack, 19 ... out trigger box, 20 ... counter weight, 21 ... cab, 22 ... power unit, 23 ... gantry, 24 ... holder, 25, 26 ... back stay, 27, 28 ... stay cylinder, 27a, 28a ... pilot check valve, 29 ... support pin, 30 ... adapter, 31, 32 ... leader tilt limit switch, 31a, 32a ... arm, 33 ... mounting bracket, 34 ... dog plate, 35 ... fuse, 36, 37 ... wiring, 38 ... left tilt oil flow direction regulation switching valve, 38a ... solenoid, 39 ... right tilt oil flow direction regulation switching valve, 39a ... solenoid, 40, 41 ... Stay cylinder operation valve, 40a, 41b ... Operation lever, 42, 43, 44, 45 ... Piping

Claims (1)

A leader swingably supported in the front-back and left-right directions with respect to the base machine is erected by a pair of left and right back stays equipped with a stretchable stay cylinder, and the leader is moved in the front-back and left-right directions by the expansion and contraction operation of the stay cylinder. In a pile driver that can adjust the tilt to
A detection means for issuing an alarm signal when the tilt of the reader in the left-right direction from the standing state exceeds a preset threshold value is provided.
In the hydraulic circuit that supplies and discharges hydraulic oil to the pair of left and right stay cylinders, the flow of hydraulic oil in the direction in which the tilt in the left-right direction of the reader increases in response to the alarm signal is prohibited, and the flow in the left-right direction of the reader is prohibited. A pile driving machine characterized in that an oil flow control means for allowing the flow of hydraulic oil in a direction in which the inclination of the oil pressure is reduced is provided.

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