JP5219498B2 - Handling machine and control method thereof - Google Patents

Description

  The present invention relates to a cargo handling machine for raising and lowering a cargo handling object, and more particularly to a cargo handling machine that drives a lifting mechanism by an air-type drive source.

  In a factory production line or a warehouse, a wide variety of conveyances are performed such as conveyance associated with the removal and attachment of relatively heavy equipment, conveyance of semi-finished workpieces to the next process, and conveyance of shipped products. In such various load carrying work, a load handling machine that reduces labor and is safe, has a small turn and has mobility and simplicity is used.

FIG. 9 is a block diagram showing a configuration of an air control system of a conventional cargo handling machine.
As shown in FIG. 9, a pneumatic cylinder 120 is disposed inside a main body 103 of the cargo handling machine 101, and an arm 104 of an elevating mechanism 105 is connected to a tip portion of a piston rod 120 a of the pneumatic cylinder 120 by a link mechanism. Yes.

This link mechanism serves as a power point when the arm 104 moves up and down, and the arm 104 is supported inside the main body 103, and this support portion serves as a fulcrum of the arm 104.
Further, an operation box 109 having an operation grip 109a and a clamp mechanism 108 are provided at the tip of the arm 104, so that the cargo handling article 107 can be held and moved. Note that the operation box 109 is provided with a load balance button 111 and a no-load balance button 112.

  An air source 122 is connected to the pneumatic cylinder 120 via a pressure proportional control valve 121, and air is supplied to and exhausted from the air source 122 to the pneumatic cylinder 120 in response to an ascent / descent command from the operation box 109 by the operator 110. It is configured to perform processing. A silencer 123 is connected to the pressure proportional control valve 121.

  In such a configuration, for example, when the operator 110 operates the operation grip 109 a upward, air is supplied to the pneumatic cylinder 120 via the pressure proportional control valve 121, thereby causing the piston rod 120 a of the pneumatic cylinder 120 to move. The cargo handling object 107 that moves downward in the figure and is gripped by the clamp mechanism 108 at the tip of the arm 104 moves upward in the lever principle.

  By the way, the cargo handling machine 101 has a control mode called a balance mode in which the worker 110 can directly grab the cargo handling article 107 and freely move and transfer it with a sense of weightlessness. The operation of the control circuit in this balance mode will be described with reference to the control circuit block diagram of the conventional cargo handling machine shown in FIG.

  In this balance mode, the cargo handling machine 101 is supported by the piston rod 120a of the pneumatic cylinder 120 and the counterclockwise moment due to the weight of the arm 104 and the weight of the clamped cargo handling object 107 as shown in FIG. By making the clockwise moments coincided with each other, a stopped state (balance state) is obtained.

When the operator 110 applies a force to the cargo handling object 107 in this balanced state, a slight balance between these two moments is lost and the cargo handling object 107 can be moved freely.
It is the pressure proportional control valve 121 that plays an important role in this balance mode. The pressure proportional control valve 121 controls the air pressure in the cylinder so that the air pressure in the pneumatic cylinder 120 becomes constant.

  For example, when the load balance button 111 provided on the operation box 109 is pressed, the air control circuit 124 loads the load balance pressure set by the load / no-load balance pressure setting circuit 125 (balance when the cargo handling object is lifted). The value of the air pressure in the cylinder that maintains the state) is set in the input setting port of the pressure proportional control valve 121.

Thus, the pressure proportional control valve 121 sets the air pressure (load balance pressure) set at the input port to the output port, and sets the air pressure in the pneumatic cylinder 120 to an air pressure balanced with the load weight.
In this state, when a force is applied to the cargo handling object 107 lifted by the worker 110, the piston rod 120a of the pneumatic cylinder 120 is moved by the applied force, and the air pressure in the cylinder is slightly changed.

  However, the pressure proportional control valve 121 absorbs the air pressure slightly increased / decreased from the balance pressure by the supply / exhaust process, and controls so that the air pressure in the pneumatic cylinder 120 is maintained at the constantly set balance pressure. By controlling in this way, in the balance mode, even if the piston in the pneumatic cylinder 120 is moved by the operation of the operator 110, no force repelling this operating force is generated in the pneumatic cylinder 120. The person 110 moves in a direction in which a force is applied to the cargo handling object 107.

In such a balance mode, the operation when the cargo handling object 107 that has been clamped falls will be described.
In a state where the cargo handling object 107 is clamped, a counterclockwise moment due to the weight of the arm 104 with respect to the fulcrum and the weight of the clamped cargo handling object 107, and a clockwise moment supported by the piston rod 120a of the pneumatic cylinder 120, Although the balance state was maintained because the sizes of the cylinders coincided with each other, the moment in the counterclockwise direction with respect to the fulcrum becomes small when the cargo handling object 107 falls, so that the relative pressure due to the air pressure in the pneumatic cylinder 120 decreases. The moment in the clockwise direction becomes larger, and the arm 104 of the cargo handling machine 101 rises rapidly.

  When this phenomenon (hereinafter referred to as a jumping operation) occurs, the arm 104 of the cargo handling machine 101 rises rapidly regardless of the operation of the worker 110, so it is very difficult for the worker 110 who is operating the cargo handling machine 101. It becomes dangerous.

  In order to suppress this jumping operation, usually, as shown in FIG. 9, the cargo handling machine 101 is provided with a jumping countermeasure unit 130 inside the main body 103. This jumping countermeasure unit 130 monitors the movement of the piston rod 120a of the pneumatic cylinder 120 when ascending, and when the piston rod 120a operates exceeding the ascending speed (or acceleration) due to the operating force of the operator 110. The piston rod 120a is immediately locked to stop the raising operation of the arm 104.

  This type of cargo handling machine includes a belt (rope) type in addition to the arm type cargo handling machine described above, but also in the case of a belt type cargo handling machine, the high speed of the belt that is generated when the cargo handling material falls. A lock mechanism is provided that detects the ascending operation by mechanical means and stops the ascending operation of the belt when a predetermined speed (acceleration) is exceeded.

Conventionally, various proposals have been made for a mechanism for preventing jumping of a cargo handling machine (see, for example, Patent Documents 1 to 3). However, these conventional techniques have the following problems.
(1) In the case of a jumping prevention mechanism in which an oil damper is attached to the cylinder, there is a problem that the operating force by the oil damper becomes a resistance, and the operability during the up-and-down operation is deteriorated.
(2) The conventional mechanical jumping prevention mechanism cannot be installed depending on the structure of the cargo handling machine (eg, arm type, belt type, etc.), or it can be installed well due to physical restrictions such as empty space. There are cases where it is not possible. For example, a jumping prevention mechanism using a seat belt can be applied to a belt-type cargo handling machine, but cannot be applied to an arm-type cargo handling machine as it is.
(3) In the conventional mechanical overspeed / overacceleration detection mechanism, when changing the overspeed / overacceleration to be detected, it is necessary to change some of the components of the detection unit. It is extremely difficult to change the detection value according to the work content.
Japanese Patent No. 3787065 Japanese Patent Laid-Open No. 5-147892 Japanese Unexamined Patent Publication No. 2000-7287

  The present invention has been made to solve the above-described problems of the conventional technology, and the object of the present invention is to provide a low-cost, high-accuracy detection of jumping motion and to be flexibly attached to various cargo handling machines. The purpose is to provide technology for preventing jumping.

In order to achieve the above object, the invention according to claim 1 is configured to be movable in the vertical direction, and has a lifting mechanism having an arm that lifts and lowers a predetermined cargo by holding it with a clamp mechanism, and a predetermined air source. An air-type drive unit that drives the lifting mechanism by the pressure of air supplied from the air, and the flow rate and pressure of air supplied to and exhausted from the air-type drive unit are determined based on a command from a predetermined operation unit. A cargo handling machine that controls using a proportional control valve, an acceleration sensor that detects an operation acceleration of the elevating mechanism, an electromagnetic valve provided between the pressure proportional control valve and the pneumatic drive unit, and an electronic control circuit for controlling the operation of the pressure proportional control valve and the solenoid valve, said electronic control circuit, based on the results obtained and the acceleration cumulatively added by the acceleration sensor, before Ki圧 By operating the proportional control valve to control the air flow rate and pressure to the pneumatic drive unit, or one that is configured to cut off the supply of air to said pneumatic drive unit by operating the solenoid valve It is.
The invention according to claim 2 is configured to be movable in the vertical direction, and includes an elevating mechanism having an arm for moving up and down by holding a predetermined cargo item by a clamp mechanism, and the pressure of air supplied from a predetermined air source. Cargo handling that has an air-type drive unit that drives an elevating mechanism, and that controls the flow rate and pressure of air supplied to and exhausted from the air-type drive unit using a pressure proportional control valve based on a command from a predetermined operation unit An acceleration sensor for detecting an operation acceleration of the lifting mechanism, an electromagnetic valve provided between the pressure proportional control valve and the air driving unit, and an air type for stopping the air driving unit The brake unit for controlling the on / off of the brake unit, the pressure proportional control valve, the solenoid valve, and the brake solenoid valve. An electronic control circuit, and the electronic control circuit operates the electromagnetic valve based on the result obtained by the acceleration sensor to cut off the supply of air to the air-type drive unit, and the brake electromagnetic The valve is operated to stop the pneumatic drive unit .
According to a third aspect of the present invention, in the first or second aspect of the present invention, the acceleration sensor comprises a sensor based on MEMS technology.
According to a fourth aspect of the present invention, there is provided a method for controlling a cargo handling machine according to the first aspect, wherein when the acceleration obtained by the acceleration sensor exceeds a preset value, a cumulative addition process of the acceleration is performed. When the speed obtained by the cumulative addition process is greater than 0, the air is rapidly exhausted from the air-type drive unit according to a command from the electronic control circuit to the pressure proportional control valve. The control method for a cargo handling machine includes a step of shutting off the supply of air to the pneumatic drive unit according to a command from the electronic control circuit to the electromagnetic valve when the speed is 0 or less .

  In the case of the present invention, an acceleration sensor for detecting the operation acceleration of the elevating mechanism and an electronic control circuit for controlling the operation of the pressure proportional control valve are provided. Based on the result obtained by this acceleration sensor, the pressure from the electronic control circuit is Since the flow rate and pressure of air to the pneumatic drive unit are controlled by a command to the proportional control valve, over-acceleration can be detected with higher accuracy than the conventional mechanical jumping means. It is possible to quickly and accurately detect the falling of the cargo handling object and to quickly execute the jumping countermeasure process.

  In addition, the conventional mechanical jumping prevention mechanism cannot be installed depending on the structure of the cargo handling machine (for example, arm type, belt type, etc.), or may be installed due to physical restrictions such as empty mounting space. In some cases, the present invention can employ a small acceleration sensor, so that any loading machine can easily mount the sensor and detect over-acceleration.

  Furthermore, depending on the device equipped with the sensor, it is necessary to change the overacceleration to be detected depending on the load capacity of the cargo handling machine and the work content. However, the conventional mechanical overspeed / overacceleration detection mechanism detects it. When changing the overspeed / overacceleration, it is not possible to change or even if it can be changed, it is necessary to replace some of the components of the detection unit. On the other hand, according to the present invention, data can be stored as an over-acceleration detection set value in the memory as an environmental parameter. Therefore, when changing the over-acceleration detection value, it is easy to change only the environmental parameter. It is possible to respond.

  Furthermore, in the case of a conventional anti-jumping mechanism using an oil damper, there is a problem that the operating force of the oil damper becomes a resistance and deteriorates the operability during vertical movement. Since the over-acceleration detection is performed, there is an effect that the operability during the vertical movement is not affected at all.

In the present invention, between the pressure proportional control valve and pneumatic drive unit, said electronic control circuit solenoid valve controlled is provided by an electronic control circuit, and the acceleration obtained by the acceleration sensor by cumulatively adding Based on the result, that is, based on the current speed of the lifting mechanism, the pressure proportional control valve is operated to control the air flow rate and pressure to the pneumatic drive unit, or the electromagnetic valve is operated to supply air to the pneumatic drive unit. Since it is configured to shut off, in addition to being able to perform the jumping countermeasure processing quickly by operating the pressure proportional control valve and, for example, performing high-speed exhaust of air from the air-type drive unit, the air-type drive unit Elevator by operating the solenoid valve to shut off the air supply to the air drive unit even when the air exhaust processing time from It is possible to prevent the descent.

  In the present invention, when the acceleration sensor is composed of a sensor based on MEMS technology, a small-sized and low-priced acceleration sensor can be adopted. A cargo handling machine having functions can be provided.

The present invention further includes an air brake unit for stopping the air drive unit and a brake solenoid valve for controlling on / off of the brake unit, and an electronic control circuit is obtained by the acceleration sensor. based on the obtained results, as well as cutting off the supply of air for the pneumatic drive unit by operating the solenoid valve, because it is configured to stop the air drive part by operating a solenoid valve for brake, brake The load by the unit can be applied to the air-type drive unit , whereby the lifting mechanism can be stopped more reliably when the jumping operation is detected.

  ADVANTAGE OF THE INVENTION According to this invention, the detection accuracy of a jumping operation | movement is high at low cost, Furthermore, the cargo handling machine provided with the jump countermeasure function which can be flexibly attached to various cargo handling machines can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an external configuration of an embodiment of a cargo handling machine according to the present invention, and FIG. 2 is a block diagram showing a configuration of an air control system of the cargo handling machine.

As shown in FIG. 1, the cargo handling machine 1 according to the present embodiment includes a support column 2 that is erected vertically, and a main body 3 is provided above the support column 2.
As shown in FIG. 2, a pneumatic cylinder (pneumatic drive unit) 20 similar to the prior art is provided in the main body 3. The pneumatic cylinder 20 (hereinafter referred to as the cylinder 20) is connected to an air source 22 via a pressure proportional control valve 21 with a silencer 23.

  Here, an electromagnetic valve 24, which will be described later, is provided between the pressure proportional control valve 21 and the cylinder 20, and is configured to shut off air supply and exhaust from the pressure proportional control valve 21 to the cylinder 20 at a predetermined timing. ing.

The cargo handling machine 1 includes an elevating mechanism 5 having an arm 4 composed of first to third arms 4a to 4c. Here, the first arm 4a is supported so as to form a fulcrum and a power point of the lever 20 and is driven by the piston rod 20a of the cylinder 20 while being capable of rotating by a predetermined angle in the vertical direction.
Further, the first arm 4 a is supported so as to turn in the horizontal direction around the central axis of the support column 2.

  The second arm 4b is connected to the distal end of the first arm 4a in a state that always maintains a horizontal state via the joint portion 6, and is further connected to the distal end (lower end) of the second arm 4b. The third arm 4c extending in the vertical direction is connected in a state in which the third arm 4c can rotate in the horizontal direction around the joint 6.

  A clamp mechanism 8 that holds the cargo handling material 7 by gripping, for example, is attached to the lower end of the third arm 4c. An operation box (operation unit) 9 having an operation grip 9a is attached to the lower part of the third arm 4c.

As shown in FIG. 2, the operation box 9 is provided with a load balance pressure setting button 11 and a no-load balance pressure setting button 12. The load balance pressure setting button 11 and the no-load balance pressure setting button 12 are It is connected to an electronic control circuit 25 having a computer, a semiconductor memory and the like.
In the present embodiment, the operation box 9 is provided with a control box configured to incorporate an acceleration sensor 30 based on MEMS (Micro Electro Mechanical Systems) technology.

  Here, the acceleration sensor 30 is connected to the electronic control circuit 25 via the A / D converter 26, and the acceleration output signal detected by the acceleration sensor 30 is analog / digital converted and digitally converted to the electronic control circuit 25. It is read as data.

The electronic control circuit 25 is connected to the pressure proportional control valve 21 via a D / A converter 27. The air pressure of the input port of the pressure proportional control valve 21 is set by digital / analog converting the air pressure setting data output from the electronic control circuit 25 by the D / A converter 27.
Further, the electronic control circuit 25 is connected to an over acceleration detection value setting circuit 28 and a load / no load balance pressure data storage / setting circuit 29.

  The over-acceleration detection value setting circuit 28 stores over-acceleration threshold data detected when the cargo handling object 7 is dropped, for example, in a semiconductor memory. This over-acceleration threshold data can be changed by connecting a data input device to the electronic control circuit 25.

  And when the acceleration at the time of a raise of a clamp function operate | moves exceeding the preset over-acceleration, the electronic control circuit 25 will judge that it is a jumping operation | movement by cargo handling fall, and performs a jumping countermeasure process, and suppresses a jumping operation | movement To control. This process will be described later.

  The load / no-load balance pressure data storage / setting circuit 29 stores the respective values by operating the load balance pressure setting button 11 and the no-load balance pressure setting button 12 provided in the operation box 9 and Settings can be changed.

Hereinafter, a method for detecting the jumping motion (overacceleration) in the present embodiment and a countermeasure for the same will be described with reference to FIGS. 2, 3, and 4.
FIG. 3 is a flowchart showing an example of the jump countermeasure processing method according to the present embodiment, and FIG. 4 is a diagram for explaining the jump countermeasure processing method.

First, the electronic control circuit 25 shown in FIG. 2 determines whether or not the jump countermeasure process is being executed (step S1). If it is determined that the jump countermeasure process is not being executed, the process proceeds to step S2. Based on the acceleration output signal output from the acceleration sensor 30, it is determined whether or not the acceleration of the operation box 9, that is, the cargo handling object 7, exceeds the overacceleration set value.
In this case, the acceleration output signal output from the acceleration sensor 30 is analog / digital converted by the A / D converter 26 and is read by the electronic control circuit 25 at a predetermined sampling period.

  It is detected that the acceleration data read by the electronic control circuit 25 exceeds a preset over-acceleration detection threshold (step S2), and that the state has passed a predetermined duration Δta (see FIG. 4). In the case of (Step S3), it is determined that a jumping motion has occurred (a cargo item falls). Here, when the clamped cargo handling object 7 falls, the arm 4 of the cargo handling machine 1 rises rapidly by the air pressure in the cylinder 20.

The method for detecting the falling of a cargo item will be described in more detail with reference to FIG.
In FIG. 4, the acceleration data a from the acceleration sensor 30 is sampled at a sampling period ΔT, and the sampling result is integrated by the following equation (1) to obtain the velocity v of the arm 4 tip.
v = Σ (a × ΔT) (1)
Before the jumping motion is detected, if acceleration = 0 (stop state), v = 0 is set.

In addition, when the overacceleration detected in this state exceeds the set overacceleration threshold (step S2) and a predetermined time has passed (step S3), it is determined that the jumping action is present (loading object falling), and the current acceleration The current speed is calculated (step S4).
Further, it is determined whether or not the result of the cumulative addition of acceleration, that is, the speed is 0 or less (step S5), and the following processing is executed according to the result.

First, when the result of accumulative acceleration is greater than 0, the output of the pressure proportional control valve 21 is set to the lowest pressure (atmospheric pressure) according to a command from the electronic control circuit 25, and the air in the cylinder 20 is quickly exhausted. Processing is executed (step S6).
When this exhaust process is executed, the air pressure in the cylinder 20 decreases rapidly, so that the force that pushes up the arm 4 in the upward direction decreases rapidly.

  Thereafter, when the output of the pressure proportional control valve 21 is set to atmospheric pressure and the air exhaust process in the cylinder 20 is continued, the air pressure in the cylinder 20 further decreases. The pulling-down force due to the arm weight or the like is stronger than the lifting force, and the ascending speed of the arm 4 becomes zero.

The change in acceleration at this time is as shown in FIG. 4, and in the stopped state before the jumping operation occurs, the output of the acceleration sensor 30 shows 1 G (= 9.8 m / s ² ). During operation, the acceleration increases rapidly.

  In this state, when it is determined that there is a jumping operation and the air in the cylinder 20 is rapidly exhausted using the pressure proportional control valve 21, the acceleration detected by the acceleration sensor 30 rises and decelerates from the ascending acceleration region. -The acceleration detected when the arm 4 is stopped when the arm 4 stops is changed to the descending acceleration region, and becomes 1G at the time of stopping.

  In the acceleration waveform shown in FIG. 4, the area of the ascending acceleration region indicates the state in which the arm 4 is accelerated upward with respect to the acceleration 1G at the time of stop, and the ascending / decelerating / descending acceleration region is ascending / decreasing upward → It shows a state where the vehicle is descending and accelerating downward.

  As described above, during the jump countermeasure process, the speed v (= acceleration integrated value) of the tip of the arm 4 is controlled to be 0, but the time of the air exhaust process in the cylinder 20 is controlled. If it is too long, the area of the ascending / decelerating / descending acceleration area becomes larger than the area of the ascending acceleration area, and as a result, it moves greatly downward, so it is necessary to control so as not to descend more than necessary.

Further, in step S5 shown in FIG. 3, when the result of the cumulative addition of acceleration described above becomes 0 or less (t3), the electromagnetic valve 24 is operated by a command from the electronic control circuit 25, and the pressure proportional control valve 21 is operated. The air supply / exhaust processing to the cylinder 20 is stopped and the air supply circuit is shut off (step S7).
Thereby, the operation of the arm 4 is stopped.

  If it is determined in step S2 in FIG. 3 that the acceleration data read by the electronic control circuit 25 does not exceed the preset over-acceleration detection threshold, the current acceleration is accumulated and processed. Calculate the speed of. If the acceleration is “0” (stop state), the cumulative addition result is cleared (step S8).

Next, the effect of the jumping countermeasure process of the present embodiment will be described with reference to FIGS.
FIG. 5 is a graph showing changes in acceleration and speed when the cargo handling object is dropped from the balance mode in the case where the cargo handling machine has no jumping prevention mechanism.

  Here, when the cargo handling object 7 is dropped, the arm 4 rises while rapidly accelerating, and shows the acceleration and velocity waveforms when it collides with a mechanical stopper (not shown) of the cargo handling machine 1 and stops. ing.

On the other hand, FIG. 6 is a graph showing changes in acceleration and speed when the jumping countermeasure process of the present embodiment is executed.
As shown in FIG. 6, after the cargo handling object 7 falls, when the over-acceleration due to the fall is detected by the above method and the jumping countermeasure processing is executed, the detected acceleration changes from the ascending acceleration state to the ascending deceleration → descending acceleration state. Then stop.

  Here, since the area of the velocity waveform in the velocity waveform diagram corresponds to the amount of increase of the arm 4 during the jumping operation, in order to minimize the amount of increase of the arm 4, the area should be controlled to be minimized. That is, it is necessary to detect the fall of the cargo item as soon as possible, and to quickly perform the jumping countermeasure process after the fall of the cargo item is detected.

  The conventional jumping countermeasure means detects the jumping action by a mechanical mechanism using inertial force or the like. In the present embodiment described above, the jumping action is detected using the acceleration sensor 30 based on the MEMS technology. By doing so, it is possible to detect the overacceleration with high accuracy, so that it is possible to quickly and accurately detect the fall of the cargo handling material and to quickly execute the jumping countermeasure process.

  In addition, the acceleration sensor 30 based on the MEMS technology employed in the present embodiment has a shape of about 5 mm square and is small in size and low in price. Therefore, it realizes a jumping countermeasure function with low cost and high detection accuracy. Can do.

  Furthermore, the conventional mechanical jumping prevention mechanism cannot be installed depending on the structure of the cargo handling machine (for example, arm type, belt type, etc.), or may be installed due to physical restrictions such as empty mounting space. In some cases, the acceleration sensor 30 is very small in the present embodiment. Therefore, the sensor can be easily mounted on any cargo handling machine and the overacceleration can be detected.

  Furthermore, depending on the device equipped with the sensor, it is necessary to change the overacceleration to be detected according to the load capacity of the cargo handling machine and the work content. However, the conventional mechanical overspeed / overacceleration detection mechanism detects it. When changing the overspeed / overacceleration to be performed, it is not possible to change or even if it can be changed, it is necessary to replace some of the components of the detection unit. On the other hand, according to the present embodiment, since the overacceleration detection set value is stored as an environmental parameter in the semiconductor memory, for example, when changing the overacceleration detection value, only the environmental parameter is changed. It is possible to respond easily.

  Further, in the case of a conventional anti-jumping mechanism using an oil damper, there has been a problem that the operating force by this oil damper becomes resistance and deteriorates the operability during vertical movement, but according to this embodiment, the MEMS technology Since the acceleration sensor 30 detects overacceleration, there is also an effect that the operability during the vertical movement is not affected at all.

  FIG. 7 is a block diagram showing a configuration of an air control system of a cargo handling machine according to another embodiment of the present invention, and FIG. 8 is a flowchart showing a main part of the jumping countermeasure processing method according to the embodiment. In the following, parts corresponding to those in the above embodiment are given the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 7, in the cargo handling machine 1A of the present embodiment, in addition to the air control circuit of the above embodiment, the brake unit 40 attached to the piston rod 20a of the cylinder 20 and the brake unit 40 are turned on. Brake solenoid valve 41 for controlling off / off.
Here, the brake solenoid valve 41 is connected to the air source 22 described above, and is controlled to be turned on / off by a command from the electronic control circuit 25 described above.

  When performing the jump countermeasure process in the present embodiment having such a configuration, first, as in the case of the above-described embodiment, it is determined whether or not the jump countermeasure process is being executed (step S11). If it is determined that the jump prevention process has not been executed, the process proceeds to step S12, and the acceleration of the operation box 9, that is, the cargo handling object 7, is excessive based on the acceleration output signal output from the acceleration sensor 30, as described above. It is determined whether or not an acceleration set value (threshold value) is exceeded.

When it is further detected that the predetermined time has passed (step S13), it is determined that a jumping action has occurred (loading material falling), and the solenoid valve 24 is operated to operate the cylinder 20 from the pressure proportional control valve 21. The air supply / exhaust process is stopped and the air circuit is shut off (step S14), and the brake solenoid valve 41 is operated to turn on the brake unit 40 and lock the piston rod 20a (step S15).
Thereby, the rapid rise of the arm 4 is stopped.

  If it is determined in step S12 in FIG. 8 that the acceleration data read by the electronic control circuit 25 does not exceed a preset over-acceleration detection threshold, the current acceleration is accumulated and processed. Calculate the speed of. If the acceleration is “0” (stop state), the cumulative addition result is cleared (step S18).

According to the present embodiment having such a configuration, in addition to the same effects as in the above embodiment, a load by the brake unit 40 can be applied to the piston rod 20a. There is an advantage that the arm 4 can be surely stopped.
Since other configurations and operational effects are the same as those of the above-described embodiment, detailed description thereof is omitted.

The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, in the above-described embodiment, the acceleration sensor 30 is provided in the operation box 9 at the distal end portion of the arm 4, but the present invention is not limited to this, for example, the middle part of the arm 4 or the cylinder 20. The acceleration sensor 30 can also be provided on the piston rod 20a.
However, from the viewpoint of detecting the jumping state with high sensitivity, it is preferable to provide the tip of the arm 4 as in the above embodiment.

  Further, in the above-described embodiment, when the detection result of the overacceleration exceeds a predetermined threshold, the jump countermeasure processing is started. However, the present invention is not limited to this, and is an integral value of the overacceleration. It is also possible to configure to detect the arm speed and start the jump countermeasure process when the detection result exceeds a predetermined threshold.

  The process of starting the jump prevention process when the detection result of the arm speed exceeds a predetermined threshold is effective particularly when the arm is accelerated and reaches an overspeed state without exceeding the overacceleration detection threshold. Is.

Schematic which shows the external appearance structure of embodiment of the cargo handling machine which concerns on this invention. Block diagram showing the configuration of the air control system of the cargo handling machine Flow chart showing an example of a jumping countermeasure processing method in the cargo handling machine The figure for explaining the same bounce countermeasure processing method A graph showing changes in acceleration and speed when a cargo handling object is dropped from the balance mode when the cargo handling machine does not have any jumping prevention mechanism The graph which shows the change of the acceleration and speed when performing the jump countermeasure processing of this Embodiment The block diagram which shows the structure of the air control system of the cargo handling machine of other embodiment of this invention. The flowchart which shows the principal part of the jumping countermeasure processing method in the same embodiment Block diagram showing the configuration of the air control system of a conventional cargo handling machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cargo handling machine, 3 ... Main body, 4 ... Arm, 7 ... Cargo handling thing, 9 ... Operation box (operation part), 20 ... Pneumatic cylinder (pneumatic drive part), 20a ... Piston rod, 21 ... Pressure proportional control valve, 22 ... Air source, 24 ... Solenoid valve, 25 ... Electronic control circuit, 28 ... Over acceleration detection value setting circuit, 30 ... Acceleration sensor

Claims (4)

An elevating mechanism that is configured to be movable in the vertical direction, and has an arm that elevates while holding a predetermined cargo item by a clamp mechanism;
An air-type drive unit that drives the lifting mechanism by the pressure of air supplied from a predetermined air source;
A cargo handling machine that controls a flow rate and pressure of air supplied to and exhausted from the air-type drive unit using a pressure proportional control valve based on a command from a predetermined operation unit,
An acceleration sensor for detecting an operation acceleration of the lifting mechanism;
An electromagnetic valve provided between the pressure proportional control valve and the pneumatic drive unit;
An electronic control circuit for controlling the operation of the pressure proportional control valve and the solenoid valve ,
Said electronic control circuit, wherein based on the acceleration obtained by the acceleration sensor of the result of the cumulative addition, by operating the front Ki圧 force proportional control valve to control the air flow rate and pressure to the pneumatic drive unit or A cargo handling machine configured to operate the electromagnetic valve to shut off the supply of air to the pneumatic drive unit . An elevating mechanism that is configured to be movable in the vertical direction, and has an arm that elevates while holding a predetermined cargo item by a clamp mechanism;
An air-type drive unit that drives the lifting mechanism by the pressure of air supplied from a predetermined air source;
A cargo handling machine that controls a flow rate and pressure of air supplied to and exhausted from the air-type drive unit using a pressure proportional control valve based on a command from a predetermined operation unit,
An acceleration sensor for detecting an operation acceleration of the lifting mechanism;
An electromagnetic valve provided between the pressure proportional control valve and the pneumatic drive unit;
An air brake unit for stopping the air drive unit;
A brake solenoid valve for controlling on / off of the brake unit;
An electronic control circuit for controlling the operation of the pressure proportional control valve, the solenoid valve and the brake solenoid valve;
Based on the result obtained by the acceleration sensor, the electronic control circuit operates the electromagnetic valve to cut off the supply of air to the pneumatic drive unit, and operates the brake electromagnetic valve to operate the air Cargo handling machine configured to stop the traction drive.   The cargo handling machine according to claim 1, wherein the acceleration sensor is configured by a sensor based on MEMS technology. A method for controlling a cargo handling machine according to claim 1, comprising:
When the acceleration obtained by the acceleration sensor exceeds a preset value, the accumulative addition process of the acceleration is performed. When the speed obtained by the accumulative addition process is greater than 0, the pressure proportional from the electronic control circuit When the speed obtained by the cumulative addition process is 0 or less while the air-type drive unit performs rapid exhaust of air in response to a command to the control valve, the air-type is driven by a command from the electronic control circuit to the electromagnetic valve. A control method for a cargo handling machine, comprising a step of shutting off air supply to a drive unit.

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