JP2018188298A - Non-load lowering safety circuit of pneumatic cargo transporting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the safety by softly landing a hand part with an operator's will in the case of emergency stop of an air source caused by power failure, disconnection of an air hose, or the like at a no-load time.SOLUTION: The non-load lowering safety circuit includes: an air discharge pipe for emergency stop and a moderately lowering valve. After an air source is brought to an emergency stop and a cylinder is positionally held at the no-load time, the cylinder internal pressure of the cylinder is increased by the movement for lowering a hand part by an operator. The increased cylinder internal pressure switches the moderately lowering valve through the air discharge pipe for emergency stop. Thereby the air inside the cylinder is discharged from the moderately lowering valve so as to lower the hand part.SELECTED DRAWING: Figure 6

Description

  The present invention is a cargo handling equipment that uses an air cylinder for the actuator, ensuring the safety of workers during an emergency stop of the air source such as a power failure or disconnection of the air hose during unloaded work that does not grip the load. It relates to a descending safety circuit.

  There are two types of cargo handling equipment using an air cylinder as an actuator: a method for controlling air only, and a method for controlling air electrically. In recent years, a microcomputer is installed and the method of making the raising / lowering operation more comfortable increases, and the air cylinder is electrically controlled. Conventionally, there has been an air-type cargo handling machine equipped with a microcomputer (Cited document 1). The throttle valve shown in FIG. 6 of the cited document 1 uses the control valve to mechanically control the sudden drop and to land slowly during energization and power outage.

  In addition, the cargo handling machine of the cited document 1 using the microcomputer suddenly locks the air cylinder when the air hose from the air supply source is disconnected. The lock is a state in which air is sealed in an air cylinder, which is a characteristic of the air cylinder, that is, a state where the glove unit moves up and down to bounce when trying to move up and down. The globe unit stops at the same height as during a power failure. And since the hand is inserted in the glove unit, when the cylinder is locked, there are times when the hand stops from the glove unit where it is difficult to remove. Suddenly stopping at the highest position where the hand could reach, there was a problem that the posture was bad and the hand could not be removed from the glove unit.

  Further, in Cited Document 2, the working chamber of the fluid pressure prime mover is connected to the throttle mechanism via an operation switching valve that operates by cutting off the current or decreasing the vacuum, and the working fluid is discharged little by little so that the load is lowered and landed at a low speed. It is stated that it was done. And land slowly even when there is no load and no load. This is forcibly landing at the same time as the power failure regardless of the operator's intention. (The “slow landing” will be described in the following “soft landing”.) Forced soft landing is contrary to the will of the operator and should not be lowered even when there is no load and no load. There was also a scene. During a power failure, the soft landing operations of Cited Document 1 and Cited Document 2 are the same.

JP 2008-247488 A JP 09-175799 A

  The problem to be solved is that the cylinder is locked when the air hose is suddenly detached as in the cited document 1. In addition, in the case of a sudden power failure as in the cited documents 1 and 2, it is a problem to forcibly perform soft landing separately from the operator's intention. In other words, the soft landing timing cannot be selected by the operator's intention.

  In the present invention, after the cylinder is held in position at the time of an emergency stop of the air source such as a power failure at no load or when the air hose is disconnected, the movement to try to lower the hand part slightly at the timing intended by the operator is The main feature is that the cylinder internal pressure is increased, the increased cylinder internal pressure operates the slow-down valve, and the air in the cylinder is exhausted from the throttle valve of the slow-down valve to cause soft landing.

  The no load lowering safety circuit of the pneumatic cargo handling machine of the present invention is intended to lower a little at the timing intended by the operator without special switch operation at the time of emergency stop of the air source at no load. There is an advantage that the hand portion can be soft-landed by the operation. Further, when it is not desired to lower the hand part, there is an advantage that the position can be maintained as it is even during an air source emergency stop or during soft landing.

FIG. 1 is a general view of a material handling machine. (Example 1) FIG. 2 is a diagram of a hand unit, an operator, and a connector (Example 1). Drawing 3 is a figure of a hand part, an operator, and a connecting implement (example 1). FIG. 4 shows the state of the circuit before the power failure. (Example 1) FIG. 5 shows a circuit state immediately after a power failure. (Example 1) FIG. 6 shows a state of the circuit during the soft landing operation after the power failure. (Example 1) FIG. 7 shows the state of the circuit immediately after the air hose disconnection. (Example 2)

  A slowly descending valve is provided, and after the air cylinder holds the position during an air source emergency stop, the cylinder internal pressure of the cylinder is increased by a movement of an operator trying to lower the hand portion, and the increased cylinder internal pressure is Was activated, and the air in the cylinder was exhausted from the throttle valve, realizing safe soft landing.

  FIG. 1 is a general view of a material handling machine. In the cargo handling machine 1, a swivel base 3 is attached to a pedestal 2, a lift mechanism 4 is attached to the swivel base 3, and a parallel link arm 5 is attached to the lift mechanism 4. The elevating mechanism 4 is driven up and down by an actuator (not shown), and the elevating unit 6 at the tip of the parallel link arm 5 moves up and down. The actuator is an air cylinder (not shown) using air. The hand unit 7 is suspended from the elevating unit 6 via a connector 8. The part shown with the dotted line of the coupling tool 8 is a rope or a sling belt. An operator's (not shown) hand (not shown) is attached to or inserted into the hand portion 7, and the hand portion 7 is positioned between the hand (not shown) and the cargo handling article 9. The cargo handling item 9 is a box. The operation of the present invention is in a state in which there is no cargo handling material 9, but the cargo handling material 9 is described as an explanation of the cargo handling material transporter.

  FIG. 2 is a diagram of a hand unit, an operator, and a connector. The hand portion 7 is suspended from the connector 8. The hand 11 of the operator 10 is attached to or inserted into the hand unit 7. The operator 10 can grip the cargo handling item 9 (not shown) using the hand unit 7. A pressure sensor (not shown) is disposed in the hand unit 7 and senses a part of the pressure gripping the cargo item 9 (not shown) to control the lifting speed and the lifting force according to the pressure. . In FIG. 2, the hand 11 is at the upper end, the posture of the worker 10 is bad, and the hand 11 cannot be removed from the hand portion 7.

  FIG. 3 is a diagram of a hand unit, an operator, and a connector. The reference numerals are the same as those in FIG. FIG. 3 shows a state in which the hand 11 is in front of the body and the hand 11 is removed from the hand unit 7. Also, the vertical position of the hand portion 7 in FIG. 3 is substantially the center position of the movable range of the cargo handling equipment 1, and the hand portion 7 is lowered when it is lowered from the position of the hand portion 7.

  FIG. 4 shows the state of the circuit before the power failure. Air cylinder 12, piston 13 and rod 14 of cylinder 12, position holding valve 15, balance control valve 16, energizing valve 17, slow descent valve 18, slow descent switching valve 19, emergency exhaust air discharge pipe 20, primary air A source 21 is provided. The slow descending valve 18 has a spring 22 and a throttle valve 23. The direction of the cylinder 12 is not shown in FIG. 1, but is not the same as FIG. In FIG. 4, for the purpose of explanation, when the rod 14 is lowered downward, the hand portion 7 of FIG. 1 is lowered. A dotted line connecting each device in the circuit diagram represents a state in which air pressure or air that does not affect the device connecting the dotted lines is shut off. This is the state of the circuit before the power failure, and the operator 10 (not shown) can raise and lower the hand unit 7 (not shown) without load. Although the cargo handling object 9 (not shown) can be held and raised / lowered, control for balancing the cargo handling article 9 (not shown) is omitted.

  FIG. 5 shows a circuit state immediately after a power failure. The configuration is the same as in FIG. A dotted line connecting each device in the circuit diagram represents a state in which air pressure or air that does not affect the device connecting the dotted lines is shut off. This is a circuit immediately after a power failure. When a sudden power failure occurs, the energizing valve 17 is activated, the position holding valve 15, the balance control valve 16, and the slowly descending switching valve 18 are switched, and the cylinder 12 is held in position. The position holding means that, for example, even if the hand 11 is pulled out from the hand unit 7 in the state of FIG. 3, the hand unit 7 holds the position as it is. When the position is maintained, the cylinder internal pressure of the cylinder 12 does not exceed the threshold value of the slowly descending valve 18, so the spring 22 does not contract and the slowly descending valve 18 is not switched to the exhaust side, so the hand portion 7 does not soft land. In other words, when the cylinder internal pressure exceeds the elastic force of the spring 22, the spring 22 contracts and the slow-down valve 18 is switched to the exhaust side to perform soft landing. When the cylinder internal pressure is lower than the elastic force of the spring 22, the spring 22 does not contract. The slowly descending valve 18 is kept in position without being switched to the exhaust side.

  FIG. 6 shows a state of the circuit during the soft landing operation after the power failure. The configuration is the same as in FIG. A dotted line connecting each device in the circuit diagram represents a state in which air pressure or air that does not affect the device connecting the dotted lines is shut off. This is a circuit during soft landing operation after a power failure. After the power failure, if the operator 10 intentionally lowers the hand portion 7, the piston 13 of the cylinder 12 moves, and the movement of the piston 13 increases the cylinder internal pressure. Then, the balance control valve 16, the energization valve 17, and the slow-down valve 18 are switched from the state shown in FIG. The slow-down valve 18 includes a spring 22 and a throttle valve 23. When the cylinder internal pressure exceeds a threshold value and the spring 22 contracts, the slow-down valve 18 is switched to the exhaust side, and the air in the cylinder 12 is switched through the throttle valve 23. Exhaust. When the air in the cylinder 12 is exhausted, the hand unit 7 is lowered. Due to the soft landing, the piston 13 and the piston rod 14 are lower than in FIG.

  The operation will be described with reference to FIGS. In the state of FIG. 2, when a sudden power failure occurs, it becomes FIG. 5, the energizing valve 17 operates, the position holding valve 15, the balance control valve 16, and the slowly descending switching valve 18 are switched, and the cylinder 12 holds the position. In the state of FIG. 2, the hand 11 cannot be removed from the hand portion 7, so when the operator 10 lowers the hand portion 7 a little to lower the hand portion 7, the piston 13 of the cylinder 12 (FIG. 5). ) Moves downward in the figure, and the piston 13 moves to increase the cylinder internal pressure. The slow-down valve 18 has a spring 22 and a throttle valve 23. When the cylinder internal pressure exceeds a threshold value, the spring 22 contracts and the slow-down valve 18 is switched to the exhaust side, and the cylinder 12 is switched via the throttle valve 23. Gently exhaust the air inside. Air in the cylinder 12 is gently discharged through the throttle valve 23, so that the hand unit 7 performs soft landing. FIG. 6 shows the state of the soft landing after exhausting. When the hand unit 7 is in the state shown in FIG. 3, the operator 10 removes the hand 11 from the hand unit 7. Thereby, the hand 11 can be pulled out from the hand part 7 at a safe place even in case of a sudden power failure. When the operator 10 stops lowering the hand portion 7, the position is held at that position. FIG. 5 shows when the hand 11 is pulled out or when the lowering of the hand portion 7 is stopped.

  FIG. 7 shows the state of the circuit immediately after the air hose disconnection. The configuration is the same as in FIG. A dotted line connecting each device in the circuit diagram represents a state in which air pressure or air that does not affect the device connecting the dotted lines is shut off. This is a circuit immediately after the air hose disconnection (not shown). When the air hose (not shown) is suddenly disconnected, the cylinder 12 holds the position. Next, when the operator 10 lowers the hand portion 7 slightly to lower the hand portion 7, the piston 13 of the cylinder 12 moves, and the internal pressure of the cylinder rises due to the movement of the piston 13, and the air discharge pipe at the time of emergency stop The cylinder internal pressure to the slowly descending valve 18 is increased via 20, and the balance control valve 16, the energizing valve 17, and the slowly descending valve 18 are switched. The slow-down valve 18 has a spring 22 and a throttle valve 23. When the cylinder internal pressure exceeds a threshold value, the spring 22 contracts and the slow-down valve 18 is switched to the exhaust side, and the cylinder 12 is switched via the throttle valve 23. Gently exhaust the air inside. The air in the cylinder 12 is gently discharged through the throttle valve 23 to perform soft landing.

  Although the material handling machine 1 using the hand unit 7 can be used in place of the hand unit 7, a material handling machine that holds the material handling object 9 with an attachment such as an adsorption type or a clamp type.

DESCRIPTION OF SYMBOLS 1 Load handling machine 2 Pedestal 3 Pivoting stand 4 Elevating mechanism 5 Parallel link arm 6 Elevating part 7 Hand part 8 Connecting tool 9 Cargo handling object 10 Worker 11 Hand 12 Cylinder 13 Piston 14 Rod 15 Position holding valve 16 Balance control valve 17 Energizing valve 18 Slowly descending valve 19 Slowly descending switching valve 20 Air discharge piping at emergency stop 21 Primary air source 22 Spring 23 Throttle valve

Claims (2)

  In the cargo handling equipment that uses a pneumatic cylinder for the actuator and grips the cargo handling material with the hand part to transport the cargo handling equipment, it is equipped with an air discharge pipe and a slowly descending valve at emergency stop, and the air source is emergency when there is no load The cylinder internal pressure of the cylinder is increased by the movement of the operator trying to lower the hand portion after the cylinder is stopped and the position is held, and the increased cylinder internal pressure is slowly lowered via the air discharge pipe at the time of emergency stop. A no-load lowering safety circuit for a pneumatic cargo handling machine, wherein the valve is switched, the air in the cylinder is discharged from the slow lowering valve, and the hand part is lowered.   The slow-down valve has a spring and a throttle valve. When the cylinder internal pressure exceeds a threshold value, the spring contracts and the slow-down valve is switched to the exhaust side to exhaust the air in the cylinder from the throttle valve. 2. A no-load descending safety circuit for a pneumatic cargo handling machine according to claim 1, wherein:

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