JP2011174534A - Hydraulic motor driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic motor driving device which prevents a hydraulic motor from being broken due to an excessive increase in the pressure in a drain pipe while the hydraulic motor remains rotatable when the pressure in the drain pipe is increased. <P>SOLUTION: The hydraulic motor driving device driving a hydraulic motor 23 by a pressure oil supplied through a direction switching valve 36 from a hydraulic pump 33 driven by an engine 32 includes a pressure switch 27 whose contact is switched when the pressure of the drain in the drain pipe 26 of the hydraulic motor 23 exceeds a specified value, a relay 42 whose drive is switched according to the switching of the contact of the pressure switch, and contacts for switching an electrical control circuit (signal line 37) which controls a switching operation of a direction switching valve according to the switching of the drive of the relay. The direction switching valve is switched to the position in which the supply of the pressure oil to the hydraulic motor is stopped depending on the each switching of the pressure switch, the relay, and the electrical control circuit when the pressure of the drain exceeds the specified value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydraulic motor drive device, and more particularly, to a hydraulic motor drive device that drives a hydraulic motor with pressure oil supplied from a hydraulic pump via a direction switching valve.

  As a hydraulic motor drive device that drives a hydraulic motor with pressure oil discharged from a hydraulic pump, a hydraulic switching valve provided in a hydraulic circuit for driving the hydraulic motor when the pressure of the drain pipe rises due to poor connection of the drain pipe There is known a hydraulic motor drive device provided with a protection circuit that stops the hydraulic motor by switching and blocking the hydraulic path on the hydraulic motor side (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-5122

  However, since the hydraulic motor driving device described in Patent Document 1 is mainly intended to protect the hydraulic motor that drives the hoisting drum of the winch around which the hoisting rope of the crane is wound, the pressure of the drain pipe has increased. When an abnormality occurs, the hydraulic path of the hydraulic motor is shut off, and the hoisting drum of the winch is prevented from rotating by locking the hydraulic motor to prevent the article lifted by the hoisting rope from falling.

  On the other hand, in the hydraulic motor for driving the casing tube of the full-rotation tubing device that performs foundation work and the auger driving hydraulic motor in the auger driving device of the pile driving machine, when the hydraulic motor is suddenly stopped when an abnormality occurs, Since the reaction force and inertial force from the casing tube and auger that are driven to rotate with a large force are applied to the equipment of the hydraulic motor and drive unit, there is a risk of adverse effects on these equipment. .

  The full-rotation tubing device includes a tubing device main body having a hydraulic motor, and a hydraulic unit having an engine and a hydraulic pump. The hydraulic motor side hydraulic circuit of the tubing device main body and the hydraulic pump side hydraulic pressure of the hydraulic unit. The circuit is connected with a hydraulic hose equipped with a self-sealing coupling (quick coupling). For this reason, it is necessary to attach and detach the hydraulic hose more frequently than cranes and pile driving machines, and in the case where various sensors are provided on the main body of the tubing device, the battery provided in the hydraulic unit is supplied with power. It was necessary to connect the wiring, and it took time and effort to check the condition of the hydraulic hose and wiring.

  Accordingly, the present invention provides a hydraulic motor drive device capable of preventing damage to the hydraulic motor due to excessive rise of the pressure of the drain pipe while keeping the hydraulic motor in a rotatable state when the pressure of the drain pipe rises. The purpose is that.

  In order to achieve the above object, a hydraulic motor drive apparatus according to the present invention includes a hydraulic circuit that drives a hydraulic motor with pressure oil supplied from a hydraulic pump driven by an engine via a direction switching valve. , A pressure switch that switches a contact when the drain pressure of the hydraulic motor exceeds a preset specified value, a relay that switches driving when the contact of the pressure switch switches, and a switching of the driving of the relay And a contact for switching an electric control circuit that performs switching operation of the direction switching valve. The direction switching valve, when the drain pressure exceeds the specified value, the pressure switch, the relay, and the electric control. Switching to a position where supply of pressure oil to the hydraulic motor is stopped by each switching of the circuit It is.

  Furthermore, the hydraulic motor drive device of the present invention is a hydraulic motor in which the hydraulic motor is provided in a full-rotation tubing device, and the hydraulic pump is provided in a hydraulic unit that drives a hydraulic pump by an engine, The hydraulic piping of the full rotation tubing device and the hydraulic piping of the hydraulic unit are characterized in that they are detachably connected by a hydraulic hose provided with a self-sealing coupling.

  The drain pressure for switching the contacts of the hydraulic switch is the pressure of the drain that flows in via the pilot pipe branched from the drain pipe of the hydraulic motor, and the drain pipe between the hydraulic motor and the pilot pipe In the vicinity of the hydraulic motor, there is provided a check valve that allows only a flow that is discharged from the hydraulic motor, passes through the drain pipe, and returns to the hydraulic unit.

  Furthermore, the contact of the pressure switch is turned off when the drain pressure of the hydraulic motor exceeds a preset specified value, and the relay is driven when the contact of the pressure switch is turned off. When the contact of the electric control circuit is switched off, the direction switching valve returns to the neutral position where all the flow paths of the direction control valve are communicated when the contact of the electric control circuit is switched off. It is characterized by.

  In addition, it is provided with alarm means for operating when the contact is turned on by driving by the relay when the drain pressure of the hydraulic motor exceeds a preset specified value and the contact of the pressure switch is switched. It is said.

  According to the hydraulic motor driving device of the present invention, when the drain pressure rises, the pressure switch is switched, and the switching of the pressure switch causes the relay to switch the electric control circuit of the directional switching valve so that the directional switching valve is switched to the hydraulic motor. By switching to the position where the supply of pressure oil is stopped, it is possible to prevent the supply of pressure oil to the hydraulic motor from stopping and the drain pressure of the hydraulic motor from rising excessively.

  Also, by providing a check valve in the drain piping, it is possible to maintain the state in which the drain pressure increases and the pressure switch is switched, so it can be restored until the cause of the increase in drain pressure is resolved. Therefore, even if the drain pressure moves up and down, the pressure switch is not switched, and the directional switching valve is switched and pressure oil is prevented from being intermittently supplied to the hydraulic motor.

  Furthermore, by connecting all the flow paths of the direction switching valve when the supply of pressure oil is stopped, the hydraulic motor can be stopped in a rotatable state, and the hydraulic motor does not stop suddenly. Since it automatically stops when the reaction force or inertial force decreases, it does not adversely affect the hydraulic motor and the equipment driven by the hydraulic motor.

1 is a hydraulic circuit diagram showing an embodiment of a hydraulic motor driving device of the present invention.

  FIG. 1 shows an embodiment in which the hydraulic motor drive device of the present invention is applied to a hydraulic motor for rotationally driving a casing tube in a full-rotation tubing device. The full-rotation tubing device 11 includes a lifting frame 14 that moves up and down by expansion and contraction of a lifting cylinder 13 that is erected on a base frame 12 that is installed on the ground, and a chuck that is moved up and down by a chuck cylinder 15 that is erected on the lifting frame 14. A frame 16, a ring-shaped lower rotating body 18 that is rotatably provided inside the elevating frame 14 via a bearing 17, and a ring-shaped ring that is rotatably provided inside the chuck frame 16 via a bearing 19. An upper rotating body 20, a chuck 21 suspended from the upper rotating body 20, and a hydraulic motor 23 provided on the elevating frame 14 and rotating the lower rotating body 18 via a speed reducer 22 are provided.

  The hydraulic circuit of the hydraulic motor 23 in the full-rotation tubing device 11 includes a normal rotation side pipe 24 connected to the normal rotation side port of the hydraulic motor 23, a reverse rotation side pipe 25 connected to the reverse rotation side port of the hydraulic motor 23, and the hydraulic motor. A drain pipe 26 connected to the drain port 23, a pressure switch 27, a pilot pipe 28 branched from the drain pipe 26 toward the pressure switch 27, and a drain port and a pilot pipe 28 of the hydraulic motor 23. A check valve 29 that is provided in the drain pipe 26 near the drain port and passes only through the drain pipe 26 from the hydraulic motor 23 and returns to the hydraulic unit 31 is provided.

  The pressure switch 27 is provided with a normally closed contact whose contact is switched ON or OFF by the pressure from the pilot pipe 28, and the pressure of the drain flowing through the pilot pipe 28 is equal to or less than a preset specified value. Is maintained in the ON state, and when the drain pressure in the drain pipe 26 exceeds the specified value, the drain pressure flowing through the pilot pipe 28 is switched to the OFF state.

  The hydraulic motor 23 is driven by pressure oil supplied from a hydraulic unit 31 formed separately from the full-rotation tubing device 11. The hydraulic unit 31 includes an engine 32, a hydraulic pump 33 driven by the engine 32, and a flow path of pressure oil boosted by the hydraulic pump 33 through a normal rotation side flow path 34 and a reverse rotation side flow path of the hydraulic motor 23. A direction switching valve 36 for switching to 35, a signal line 37 for operating the direction switching valve 36, a drain recovery pipe 39 for recovering drain from the hydraulic motor 23 to the tank 38, and a discharge pressure of the hydraulic pump 33. And a relief valve 33a for preventing excessive rise, and a relay circuit 41 for switching ON / OFF of the signal line 37 and ON / OFF of the alarm means 40. Further, at the neutral position N of the direction switching valve 36, the forward rotation side flow path 34, the reverse rotation side flow path 35, the pump side flow path P, and the tank side flow path T are all in communication.

  The relay circuit 41 includes a relay 42 whose driving is switched by switching the ON / OFF state of the pressure switch 27, contacts 37a and 37b of the signal line 37 driven by the relay 42, and a contact 40a of the alarm means 40. When the pressure switch 27 is ON, the contacts 37a and 37b of the signal line 37 are both ON by the relay 42, the signal line 37 is energized to the solenoid of the direction switching valve 36, and the alarm means 40 The contact 40a is OFF, and the alarm means 40 is configured to be driven in a stopped state.

  When construction is performed by the full-rotation tubing device 11, in the rotational drive system, the hydraulic circuit of the full-rotation tubing device 11 and the hydraulic circuit of the hydraulic unit 31 are the three hydraulic hoses of the forward rotation side, the reverse rotation side, and the drain. The wiring 45 from the battery 44 serving as a power source is connected to the pressure switch 27. Self-sealing couplings (quick joints) 46 are respectively provided at both ends of each hydraulic hose 43 and the hose connection port of each hydraulic circuit, and the hydraulic hose 43 when the full-rotation tubing device 11 and the hydraulic unit 31 are moved. Can be easily attached and detached.

  In the all casing method using the full-rotation tubing device 11, the chuck frame 16 is lowered by the chuck cylinder 15 with the casing tube 47 inserted inside the lower rotating body 18, the upper rotating body 20 and the chuck 21, and the lower rotating body. The chuck 21 is fitted between the body 18 and the casing tube 47 so that the casing tube 47 is gripped inside the lower rotary body 18, the upper rotary body 20 and the chuck 21. 13 is operated to lower the elevating frame 14, and an operation signal is sent from the signal line 37 to the solenoid of the direction switching valve 36 by operating the operation lever, etc., and the direction switching valve 36 is switched to the normal rotation position A to The hydraulic oil is supplied from 31 to the forward rotation side piping 24 of the hydraulic motor 23 to provide a hydraulic mode. 23 is rotated forward and continue to press fit the casing tube 47 into the ground while rotating the casing tube 47 via the lower rotary member 18. When the direction switching valve 36 is returned from the normal rotation position A to the neutral position N after the construction is completed, the normal rotation side flow path 34, the reverse rotation side flow path 35, the pump side flow path P, and the tank side flow path T are all in communication. Therefore, the hydraulic motor 23 is in a freely rotatable state, and the hydraulic motor 23 is stopped at a position where the reaction force from the casing tube 47 is eliminated.

  During construction of the casing tube 47, pressure oil is supplied from the hydraulic unit 31 to the hydraulic motor 23 from the normal rotation side flow path 34 through the normal rotation side hydraulic hose 43 a to the normal rotation side pipe 24. After the oil is rotated in the forward direction, the return oil passes through the reverse-side hydraulic hose 43b from the reverse-side pipe 25 and is collected in the tank 38 via the tank-side channel T. Further, the drain from the hydraulic motor 23 is recovered from the drain pipe 26 through the drain recovery hydraulic hose 43 c to the tank 38 by the drain recovery pipe 39. The pressure in the drain pipe 26 in the normal construction state is such that the end on the tank 38 side is opened to the atmospheric pressure, so that the pressure is about atmospheric pressure (about 100 kPa) or slightly higher than the atmospheric pressure. It has become.

  Accordingly, the pressure acting on the pressure switch 27 via the pilot pipe 28 is also a predetermined value set according to conditions such as the pressure resistance of the hydraulic motor 23, for example, a pressure of 150 kPa or less. The battery 44 as a power source and the relay 42 of the relay circuit 41 are energized through the pressure switch 27. Since the relay 42 is energized, as shown in FIG. 1, both the contacts 37a and 37b of the signal line 37 in the relay circuit 41 are turned on, and the solenoid of the direction switching valve 36 is activated by the signal from the signal line 37. By switching and opening / closing the flow path of the direction switching valve 36, the hydraulic oil is supplied to the hydraulic motor 23 and the hydraulic motor 23 rotates. Further, since the contact point 40a of the alarm unit 40 is OFF, the alarm unit 40 is in a stopped state.

  On the other hand, when the connection of the drain recovery hydraulic hose 43c is forgotten or the connection is insufficient, the drain that has flowed from the hydraulic motor 23 through the check valve 29 into the drain pipe 26 is released to the tank 38. The drain pressure of the drain pipe 26, that is, the drain pressure increases, and the pressure of the pilot pipe 28 also increases at the same time. In this way, when the pressure of the pilot pipe 28 rises to a pressure exceeding the preset specified value, the pressure switch 27 is switched to the OFF state, and the energization to the relay 42 is cut off. When the relay 42 is deenergized, the contacts 37a and 37b of the signal line 37 in the relay circuit 41 are both turned OFF, the operation signal from the signal line 37 to the solenoid is cut off, and the direction switching valve 36 is urged to the urging means. Returning to the neutral position N, as described above, the forward rotation side flow path 34, the reverse rotation side flow path 35, the pump side flow path P, and the tank side flow path T are all in communication with each other. The supply of pressure oil is interrupted, and the drain pressure of the hydraulic motor 23 is prevented from rising. Further, since the contact point 40a of the alarm means 40 is switched ON by the relay 42, the battery 44 and the alarm means 40 are connected, and the alarm means 40 is activated to cause an abnormality to the worker due to a warning light or a warning sound. Report outbreaks.

  At this time, the forward and reverse ports of the hydraulic motor 23 communicate with the hydraulic hoses 43a and 43b through the direction switching valve 36 at the neutral position N. Similarly to when 36 is returned from the normal rotation position A to the neutral position N, the hydraulic motor 23 is in a freely rotatable state, and the hydraulic motor 23 is stopped at a position where the reaction force from the casing tube 47 is lost. Therefore, the hydraulic motor 23 does not stop when receiving a large reaction force, and not only the hydraulic motor 23 and the speed reducer 22 but also devices such as the chuck 21 can be protected.

  In addition, by providing a check valve 29 on the drain pipe 26 near the hydraulic motor 23 to prevent the flow to the hydraulic motor 23 side, the pilot pipe 28 even if the hydraulic motor 23 stops rotating and the drain pressure decreases. The pressure switch 27 in the OFF state can be maintained in the OFF state, so that the pressure in the pilot pipe 28 increases or decreases due to the change in the drain pressure due to the operation / stop of the hydraulic motor 23. The pressure switch 27 does not repeat ON / OFF, and chatter vibrations of the hydraulic motor 23 caused by the operation signal intermittently switching the direction switching valve 36 can be prevented.

  When the pressure switch 27 is turned OFF and the hydraulic motor 23 is stopped, the operation lever and the like are returned to the stop position to neutralize the operation signal to the solenoid, and the connection state of the drain recovery hydraulic hose 43c is confirmed. By connecting the hydraulic hose 43c securely, the drain whose pressure has increased in the drain pipe 26 can be discharged from the hydraulic hose 43c to the tank 38, and as the pressure in the drain pipe 26 decreases, the pilot pipe Since the pressure 28 also decreases, the pressure switch 27 returns to the normal ON state, and the normal operation state is obtained.

  In addition, when the connection of the wiring 45 is forgotten, the relay 42 is not energized from the battery 44 via the pressure switch 27, so that the contacts 37a and 37b of the signal line 37 in the relay circuit 41 are both OFF. Since the contact 40a of the alarm means 40 is ON, an operation signal cannot be sent to the solenoid even if the operation lever or the like is operated. Therefore, the direction switching valve 36 maintains the neutral position N and supplies the hydraulic oil 23 with pressure oil. In addition, since the contact 40a of the alarm means 40 is ON, the alarm means 40 is activated to notify that there is an abnormal situation. Therefore, it is possible to perform construction by securely connecting the three hydraulic hoses 43 and the wiring 45, and construction is performed in a state where power is supplied to various sensors and various electrical components provided in the full rotation tubing device 11. Therefore, safety and the like can be improved as compared with a pressure switch that is turned on when the drain pressure increases.

  The same applies not only when the hydraulic motor is rotated forward but also when the hydraulic motor is rotated backward, and the same applies when a plurality of hydraulic motors are driven. Further, the hydraulic motor driving device of the present invention is not limited to a full-rotation tubing device, but may be a free rotating state when stopping the hydraulic motor when drain pressure rises, such as an auger driving device of a pile driving machine. It can be utilized for driving a hydraulic motor of various preferred devices.

  Further, since the pressure switch 27 and the relay 42 are always energized in a normal construction state, the power is supplied to the engine 32 as a power source from a battery 44 that is charged while the engine 32 is rotating. This makes it possible to reliably supply power to the relay 42 during construction.

  DESCRIPTION OF SYMBOLS 11 ... Full rotation tubing device, 12 ... Base frame, 13 ... Elevating cylinder, 14 ... Elevating frame, 15 ... Chuck cylinder, 16 ... Chuck frame, 17 ... Bearing, 18 ... Lower rotating body, 19 ... Bearing, 20 ... Upper rotation Body, 21 ... chuck, 22 ... speed reducer, 23 ... hydraulic motor, 24 ... forward side piping, 25 ... reverse side piping, 26 ... drain piping, 27 ... pressure switch, 28 ... pilot piping, 29 ... check valve, 31 DESCRIPTION OF SYMBOLS ... Hydraulic unit, 32 ... Engine, 33 ... Hydraulic pump, 33a ... Relief valve, 34 ... Forward rotation flow path, 35 ... Reverse rotation flow path, 36 ... Direction switching valve, 37 ... Signal line, 37a, 37b ... Contact, 38 ... Tank, 39 ... Drain recovery piping, 40 ... Alarm means, 40a ... Contact, 41 ... Relay circuit, 42 ... Relay, 43 ... Hydraulic hose, 44 Battery, 45 ... wire, 46 ... self-sealing coupling, 47 ... casing tube

Claims (5)

  In a hydraulic motor driving device having a hydraulic circuit for driving a hydraulic motor by pressure oil supplied from a hydraulic pump driven by an engine via a direction switching valve, a drain pressure of the hydraulic motor is set to a predetermined value set in advance. Switching between a pressure switch whose contact is switched when exceeded, a relay whose driving is switched by switching of the contact of the pressure switch, and an electric control circuit which performs switching operation of the direction switching valve by switching of driving of the relay The directional control valve is configured to supply pressure oil to the hydraulic motor by switching each of the pressure switch, the relay, and the electric control circuit when the drain pressure exceeds the specified value. The hydraulic motor drive device is characterized in that it is switched to a position where it stops.   The hydraulic motor is a hydraulic motor provided in a full-rotation tubing device, and the hydraulic pump is a hydraulic pump provided in a hydraulic unit that drives a hydraulic pump by an engine. 2. The hydraulic motor driving device according to claim 1, wherein the hydraulic piping is detachably connected by a hydraulic hose provided with a self-sealing coupling.   The drain pressure for switching the contacts of the hydraulic switch is the pressure of the drain that flows in via the pilot pipe branched from the drain pipe of the hydraulic motor, and the hydraulic pressure of the drain pipe between the hydraulic motor and the pilot pipe 3. A check valve is provided near the motor, wherein the check valve allows only a flow that is discharged from the hydraulic motor and returns to the hydraulic unit through the drain pipe. Hydraulic motor drive device.   The contact of the pressure switch is switched off when the drain pressure of the hydraulic motor exceeds a preset specified value, and the driving of the relay is performed when the contact of the pressure switch is switched off. The contact of the electric control circuit is switched to OFF, and the direction switching valve returns to a neutral position where all the flow paths of the direction switching valve are communicated when the contact of the electric control circuit is switched to OFF. The hydraulic motor drive device according to any one of claims 1 to 3.   It is provided with alarm means for operating when the contact is turned on by driving by the relay when the drain pressure of the hydraulic motor exceeds a preset specified value and the contact of the pressure switch is switched. The hydraulic motor drive device according to any one of claims 1 to 4.

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