JP2013169964A - Cargo protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a cargo safe by adjusting a pressure of an air bag in accordance with vibration characteristics of the cargo.SOLUTION: A cargo protection device includes: an air bag 3 disposed in a cargo compartment of a cargo carrying device; a gas supply device 5 supplying a working gas to the air bag 3; a switching valve 8 switching between an operation of supplying or stopping the working gas supplied to the air bag 3 and an operation of discharging the gas to the outside; a cargo compartment acceleration sensor 11 for measuring vibration of the cargo compartment; a cargo acceleration sensor 12 for measuring vibration of the cargo; and a controller 14, which receives an input of a cargo compartment acceleration Gv and of a cargo acceleration Gc and controls switching of the switching valve 8. The controller 14 acquires an acceleration transmission ratio in a high frequency band and an acceleration transmission ratio in a low frequency band on the basis of the cargo compartment acceleration Gv and the cargo acceleration Gc, performs control to decrease the pressure in the air bag 3 if the acceleration transmission ratio in the high frequency band is larger than 1, and performs control to increase the pressure in the air bag 3 if the acceleration transmission ratio in the low frequency band is larger than 1.

Description

  The present invention relates to a load protection device.

  Conventionally, when cargo is transported by a cargo transport device such as a transport vehicle, a railway vehicle, a ship, an aircraft, etc., lashing using ropes, wires, chains, belts and lashing rails, etc. in the cargo compartment, or mats or bracing materials are used. By providing a load collapse prevention device composed of choking or the like, it is possible to prevent the movement of the load and the collapse of the load.

  However, in the above conventional load collapse prevention device, it is necessary for an operator to perform fixing work such as wrapping a rope around each load, which is troublesome and takes time, and the efficiency of the fixing work is poor. There was a problem. In addition, when unloading the load, it is necessary to perform an unlocking operation such as unfixing the rope, and there is a problem that the unlocking operation is troublesome and takes time, and the efficiency of the unlocking operation is poor. For this reason, it has a problem that it takes time to load and unload the load and the work efficiency is low.

  For this reason, there is a load collapse prevention device in which an inflatable / deflable airbag is disposed in the cargo compartment, and the airbag is inflated and pressed against the load to fix the load (Patent Documents 1 and 2). Etc.).

  According to the load collapse prevention device shown in Patent Documents 1 and 2, the load fixing operation and the unlocking operation are facilitated, and the efficiency of the load loading / unloading operation can be increased.

Japanese Patent Laid-Open No. 06-092472 Japanese Utility Model Publication No. 06-027321

  In the load collapse prevention device shown in Patent Documents 1 and 2, the airbag is inflated with a constant pressure to hold the load so that the load does not move.

  However, for example, the load loaded on the transport vehicle has a large weight (a large specific gravity), a small weight (a small specific gravity), a relatively hard package, a relatively soft package, etc. In addition, there are various types, and the transport vehicle may vibrate greatly due to road conditions, etc. Therefore, as described above, when supporting various types of loads with airbags adjusted to a constant pressure, There is a possibility that the load may move due to the vibration and collapse, or the package may be crushed to cause damage. For example, when the weight of the load loaded in the cargo compartment is large (the specific gravity is large), the airbag maintained at a constant pressure has a low rigidity, so the load collapses due to the collapse and movement of the load, or There is a possibility that the cargoes collide with each other and damage them, and when the weight of the cargo is small (specific gravity is small) and the packaging is soft, the rigidity strength of the airbag maintained at a constant pressure is too high. The package may be crushed and cause damage.

  The present invention has been made in view of the above-described conventional problems, and intends to provide a load protection device capable of ensuring the safety of a load by adjusting the pressure of an airbag in accordance with the vibration characteristics of the load. It is.

The load protection device according to the present invention includes an airbag that is disposed on at least a peripheral wall of a cargo compartment of a cargo carrying device and that can be inflated and contracted by a working gas, and a gas supply that supplies the working gas by connecting to the airbag via a pipe A switching valve that switches between supply / stop of working gas supplied from the gas supply device to the airbag and discharge to the outside, and a pressure sensor that detects the pressure of the airbag provided downstream of the switching valve , A load acceleration sensor for measuring the vibration of the cargo loaded in the cargo compartment, a cargo compartment acceleration sensor for measuring the vibration of the cargo compartment, and a controller for controlling the switching of the switching valve by inputting the load acceleration and the cargo compartment acceleration And
The controller has an acceleration transmissibility in a high frequency band obtained by dividing the cargo acceleration in the high frequency band from the cargo compartment acceleration and the cargo acceleration obtained by the cargo compartment acceleration sensor and the cargo acceleration sensor by the cargo compartment acceleration, and Obtaining the acceleration transmissibility of the low frequency band obtained by dividing the cargo acceleration in the low frequency band by the cargo compartment acceleration from the cargo compartment acceleration and the cargo acceleration obtained by the cargo compartment acceleration sensor and the cargo acceleration, When the acceleration transmission rate in the frequency band is greater than 1, the control valve is operated to reduce the pressure of the airbag, and when the acceleration transmission rate in the low frequency band is greater than 1, the switching valve is operated. Control is performed to increase the pressure of the airbag by operating.

  Thus, in the load protection device of the present invention, the cargo compartment acceleration and the cargo acceleration are measured and input to the controller. The controller calculates the acceleration transmissibility in the high frequency band from the integrated value of the measured load acceleration and the cargo compartment acceleration and the low acceleration. The acceleration transmission rate in the frequency band is obtained. When the acceleration transmission rate in the high frequency band is greater than 1, the control valve is operated to reduce the pressure of the airbag, and the acceleration transmission rate in the low frequency band is greater than 1. Is larger, the control of the airbag is performed to control the increase in the pressure of the airbag, thereby adjusting the pressure of the airbag in accordance with the vibration characteristics of the load.

  In the load protection device, the controller can control the pressure of the airbag by operating the switching valve so that the acceleration transmission rate in the high frequency band and the acceleration transmission rate in the low frequency band are 1 or less.

  In the load protection device, the controller may control the pressure of the airbag by operating the switching valve so that the pressure detected by the pressure sensor is maintained at an initial value at the start of inflation of the airbag. it can.

  In the load protection device, the gas supply device is preferably an air tank.

  In the load protection device of the present invention, the cargo carrier device is a refrigerated / refrigerated cargo carrier device, and the gas supply device takes in a part of the evaporator cooling gas and pressurizes the pressurized cooling working gas into the pipe. A cooling gas supply device is provided, wherein the airbag is an outflow type airbag having one end connected to the pipe and the other end having an exhaust port.

  In the above load protection device, it is preferable that the cooling gas supply device has a cooling gas tank for storing pressurized cooling working gas.

  In the load protection device, it is preferable that a guide for forming a cooling gas flow path is provided inside the outflow type airbag.

  In the load protection device, it is preferable that the guide is disposed so as to form a flow path in which the cooling working gas flows in a zigzag manner throughout the inside of the outflow type airbag.

  According to the present invention, the load acceleration and the cargo compartment acceleration are measured and input to the controller, and the controller obtains the high frequency band acceleration transmissibility and the low frequency band acceleration transmissibility from the measured load acceleration and the cargo compartment acceleration. When the acceleration transmission rate in the high frequency band is larger than 1, the control valve is operated to reduce the pressure of the airbag, and when the acceleration transmission rate in the low frequency band is larger than 1, the switching valve is operated. Control to increase the pressure of the airbag. Thereby, since the rigidity of the airbag is adjusted so as to adapt to the vibration characteristics of the load, an excellent effect that the load is safely held can be obtained.

It is a side view which shows one Example of the load protection apparatus of this invention applied to the cargo transportation vehicle. It is sectional drawing which looked at FIG. 1 from the II-II direction. It is a front view which shows the outline of an example of a controller. It is a side view which shows one Example of the load protection apparatus of this invention applied to the freezing / refrigeration conveyance vehicle. It is a front view which shows an example provided with the guide which forms the flow path of cooling working gas inside an outflow type airbag. It is a front view at the time of providing the guide of the shape different from FIG. 5 inside the outflow type airbag. It is a diagram which shows the vibration of a cargo compartment. It is the diagram which showed the vibration of the load at the time of hold | maintaining a load with an airbag compared with the vibration of a cargo compartment, and is explanatory drawing which shows the state which resonance generate | occur | produced in the high frequency band. It is the diagram which showed the vibration of the load at the time of hold | maintaining a load with an airbag compared with the vibration of a cargo compartment, and is explanatory drawing which shows the state which resonance generate | occur | produced in the low frequency band. It is a control flowchart of the calculation command part with which the controller was equipped.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show an embodiment of a load protection device of the present invention applied to a general cargo carrier vehicle 1 (truck) which is an example of a cargo carrier device. The airbag 3 that can be expanded and contracted by the working gas is disposed. In the example of illustration, the case where the airbag 3a, 3b, 3c, 3d, 3e is arrange | positioned at five places of the right-and-left side of the cargo compartment 2, front and rear peripheral walls, and a ceiling part is shown. One end of each airbag 3a, 3b, 3c, 3d, 3e is connected to a pipe 4 via a branch pipe 4a, and the pipe 4 is connected to a gas supply device 5. The airbag 3 has a strength capable of withstanding expansion at a required pressure by the working gas.

  The gas supply device 5 is connected to an air tank 6 such as an air suspension provided in the freight transport vehicle 1 and an outlet of the air tank 6 via a check valve 7 to supply / stop working gas from the air tank 6 and externally. And a pressure sensor 9 for detecting the pressure of the air bag 3 provided downstream of the switching valve 8. Although FIG. 3 shows the case of the switching valve 8 composed of a three-way valve provided with the opening 8a, the switching valve 8 may be configured by combining, for example, an on-off valve and an opening valve. The gas supply device 5 may include an air pump that compresses and supplies air instead of the air tank 6.

  As shown in FIG. 2, the cargo compartment 2 is provided with a cargo compartment acceleration sensor 11 that measures vibration (load acceleration Gv) of the cargo compartment 2 moving in the left-right direction of the cargo transport vehicle 1. A load acceleration sensor 12 that measures vibration (load acceleration Gc) of the load 10 moving in the left-right direction (left-right direction in FIG. 2) of the freight transport vehicle 1 is installed in the load 10 loaded on the load 2. The cargo compartment acceleration sensor 11 and the cargo acceleration sensor 12 are preferably installed at locations where the vibrations of the cargo compartment 2 and the cargo 10 appear remarkably, and may be provided for one or a plurality of each as shown in the figure. You may make it provide.

A controller 14 is installed in the cab 13 of the cab 1a of the cargo carrying vehicle 1, and the controller 14 includes a cargo compartment acceleration Gv from the cargo compartment acceleration sensor 11, as shown in FIG. A calculation command unit 15 to which the load acceleration Gc from the load acceleration sensor 12 is input is provided. Further, the calculation command unit 15 is input with the detected pressure P from the pressure sensor 9, the tank pressure P ₀ from the pressure sensor 16 that detects the pressure of the working gas in the air tank 6, and the cargo transport vehicle. 1 is input, and the calculation command unit 15 performs a calculation based on the cargo acceleration Gc and the cargo compartment acceleration Gv to create a control signal 17, and the control signal 17 is transmitted to the switching valve via a signal line 18. 8 to perform switching control of the switching valve 8.

  The controller 14 is provided with an operation button 19 for starting / stopping the operation of the load holding device of the present invention.

  FIG. 4 shows an embodiment of the load protection device of the present invention applied to a refrigeration / refrigeration transport vehicle 20 (refrigeration / refrigeration vehicle) which is another example of a cargo transport device. The apparatus 5 is different from the above-described embodiment in that the apparatus 5 is a cooling gas supply device 22 provided inside an evaporator 21 (cooler) provided at the front portion of the cargo compartment 2. The evaporator 21 produces cold air for keeping the load 10 in the cargo compartment 2 at a low temperature, and supplies the produced cold air to the cargo compartment 2 to cool the cargo 10.

  The cooling gas supply device 22 has a pump 23, and a part of the cooling gas of the evaporator 21 is taken in and pressurized by the pump 23, and the pressurized cooling working gas is supplied to the pipe 4.

  Each of the airbags 3a, 3b, 3c, 3d, and 3e is an outflow type airbag by forming an exhaust port 24 having a small opening at the end opposite to one end connected to the pipe 4. 3 '.

  Here, inside each outflow type airbag 3 ′, as shown in FIG. 5, there is provided a guide 26 for forming a plurality of flow paths 25 for the cooling working gas, and the cooling operation supplied from the pipe 4 at one end. It is preferable that the gas flows through the flow path 25 between the guides 26 and is guided to the exhaust port 24 at the other end, and as shown in FIG. 6, the entire inside of the outflow type airbag 3 ′. It is preferable that the parallel guides 26 are alternately arranged so as to form a flow path 25 in which the cooling working gas flows in a zigzag manner.

  In the refrigeration / refrigeration transport vehicle 20 of FIG. 4, the pump 23 of the cooling gas supply device 22 takes in a part of the cooling gas of the evaporator 21 and pressurizes it. When supplied to the mold airbag 3 ', each outflow airbag 3' is inflated.

  When the pressure of each outflow type airbag 3 ′ increases, a part of the cooling working gas is discharged from the exhaust port 24 that is a small opening provided at the other end of each outflow type airbag 3 ′. As described above, since a part of the cooling working gas is discharged from the exhaust port 24, the inside of each outflow type airbag 3 'is always kept at a predetermined low temperature by the flow of the cooling working gas. The inside is cooled uniformly.

  In the refrigerated / refrigerated transport vehicle 20 shown in FIG. 4 as well, the cargo compartment acceleration sensor 11 for measuring vibration in the left-right direction of the cargo compartment 2 and the cargo compartment 2 are loaded as in the embodiment of FIGS. A load acceleration sensor 12 that measures vibration in the left-right direction of the load 10 is installed, and a controller 14 is installed in the cab 13 of the cab 1a of the refrigeration / refrigeration transport vehicle 20.

In the embodiment shown in FIGS. 1, 2 and 4, when the time axis data of the cargo compartment acceleration Gv detected by the cargo compartment acceleration sensor 11 is replaced with frequency data as shown in FIG. The vibration 30 is low in the unsprung vibration eigenvalue f ₁ (around 10 Hz) in the high frequency band X below the suspension of tires, wheels, brakes, etc. and low in the body (cargo compartment 2) above the suspension. Two vibration peaks of the sprung vibration eigenvalue f ₂ (around 1 Hz) in the frequency band Y are generated, and it has been conventionally known that such vibration characteristics are generated in the cargo transportation device as shown in FIGS. Known from.

  FIGS. 8 and 9 compare the vibration 31 (solid line) of the load 10 with the vibration 30 (broken line) of the cargo chamber 2 when the cargo 10 is held by the airbags 3 and 3 ′ provided in the cargo chamber 2. In the case where the rigidity of the airbags 3 and 3 ′ is too high, the resonance 32 in which the acceleration of the load 10 is larger than the acceleration of the cargo compartment 2 in the high frequency band X as shown in FIG. If the rigidity of the airbag 3 is too low, a resonance 33 is generated in which the acceleration of the load 10 is larger than the acceleration of the cargo compartment 2 in the low frequency band Y as shown in FIG. Generation | occurrence | production of such resonance 32,33 causes the load collapse by the movement of the load 10, the damage by the collapse of a package, etc.

In order to prevent the occurrence of the resonances 32 and 33, the calculation command unit 15 uses the cargo compartment acceleration Gv from the cargo compartment acceleration sensor 11 and the cargo acceleration Gc from the cargo acceleration sensor 12 to use the high frequency band X The acceleration transmission rate POAH at the following equation (1)
POAH = Gc / Gv (1)
Calculated by

Further, using the cargo compartment acceleration Gv from the cargo compartment acceleration sensor 11 and the cargo acceleration Gc from the cargo acceleration sensor 12, the acceleration transmission rate POAL in the low frequency band Y is expressed by the following equation (2).
POAL = Gc / Gv (2)
Calculated by

  In the calculation command section 15 of the controller 14, when the acceleration transmission rate POAH in the high frequency band X is larger than 1 (the rigidity of the airbag 3 is too high, the load 10 moves greatly with respect to the cargo compartment 2). When the resonance 32 occurs), the control signal 17 for reducing the pressure of the airbag 3 is calculated and output to the switching valve 8, so that the switching valve 8 discharges the working gas from the opening 8a. The pressure of the airbag 3 is reduced. Thereby, the resonance 32 in the high frequency band X in FIG. 8 is reduced as indicated by an arrow.

  Further, when the acceleration transmission rate POAL in the low frequency band Y is larger than 1 (when the load 10 moves greatly with respect to the cargo compartment 2 due to the rigidity of the airbag 3 and the resonance 33 is generated). The control signal 17 for increasing the pressure of the airbag 3 is calculated and output to the switching valve 8, whereby the switching valve 8 is switched to supply the working gas to the airbag 3, and the pressure of the airbag 3 is To increase. Thereby, the resonance 33 in the low frequency band Y in FIG. 9 is reduced as shown by the arrow.

  At this time, the calculation command unit 15 sets the acceleration transmission rate POAH in the high frequency band X and the acceleration transmission rate POAL in the low frequency band Y to values of approximately 1 or less, that is, 8. Control is performed so that the vibration 31 of the load 10 in FIG. 9 is lower than the value of the vibration 30 of the cargo compartment 2.

  Next, the operation of the above embodiment will be described.

  When the loading of the load 10 into the cargo compartment 2 of FIGS. 1 and 4 is completed, the driver operates the operation button 19 provided on the controller 14 to start the operation of the load holding device.

  Then, the calculation command unit 15 of the controller 14 outputs a control signal 17 to the switching valve 8, and the switching valve 8 supplies the working gas from the gas supply device 5 or the cooling gas supply device 22 to the airbags 3, 3 ′. As a result, the air bags 3 and 3 ′ are inflated, so that the gap between the cargo 10 and the cargo compartment 2 is filled.

  Since the pressures of the air bags 3 and 3 ′ are detected by the pressure sensor 9 and the detected pressure P is input to the calculation command unit 15, if the detected pressure P of the pressure sensor 9 reaches a predetermined pressure (specified value), the air The supply of working gas to the bags 3, 3 ′ is stopped. The refrigeration / refrigeration transport vehicle 20 shown in FIG. 4 has a structure in which the cooling working gas flows out from the exhaust port 24 of the outflow type airbag 3 ′. When the pressure of the outflow type airbag 3 ′ reaches the upper limit of the set width, the supply of the cooling working gas is stopped, and when the cooling working gas flows out and the pressure of the outflow type airbag 3 ′ decreases to the lower limit of the set width. Control to restart the supply of the cooling working gas is performed. Thereby, the pressure of the outflow type airbag 3 ′ is always kept within the set width.

When the cargo transportation device starts traveling, the cargo compartment 2 and the load 10 are vibrated. At this time, as shown in the control flowchart of FIG. Since the chamber acceleration Gv and the cargo acceleration Gc detected by the cargo acceleration sensor 12 are input, in step S1, the following equation (1) is obtained from the cargo chamber acceleration Gv and the cargo acceleration Gc.
POAH = Gc / Gv (1)
The acceleration transmission rate POAH in the high frequency band X is calculated and calculated by the following equation (2).
POAL = Gc / Gv (2)
Thus, the acceleration transmission rate POAL in the low frequency band Y is calculated and obtained.

  In step S2, it is determined whether the conditions of POAL ≦ 1 and POAH ≦ 1 are satisfied. If these conditions are satisfied, control is performed to maintain the current pressure of the airbags 3, 3 ′. Do.

  In step S3, it is determined whether the conditions of POAL ≦ 1 and POAH> 1 are satisfied. If this condition is satisfied, the rigidity of the airbags 3 and 3 ′ is too high (too hard). 8, the resonance 32 in the high frequency band X is generated. Therefore, by switching the switching valve 8 in FIG. 3 to the opening 8a side and exhausting, the pressure of the airbags 3, 3 ′ is reduced ( Control to reduce rigidity).

  In step S4, it is determined whether the conditions of POAL> 1 and POAH ≦ 1 are satisfied. If this condition is satisfied, the rigidity of the airbags 3, 3 ′ is too low (too soft), 9, the resonance 33 in the low frequency band Y is generated. Therefore, by switching the switching valve 8 in FIG. 3 so as to supply the working gas to the airbags 3, 3 ′, the airbags 3, 3 are switched. Control to increase 'pressure (increase rigidity).

  As described above, since the airbags 3 and 3 ′ are automatically adjusted so as to have an appropriate pressure according to the vibration characteristics based on the volume weight of the load 10 and hold the load 10, the cargo 10 is loaded from the cargo chamber 2. The transmission of vibration to the vehicle is suppressed, and the vibration of the load is suppressed, so that the problem of collapse of goods and damage to the cargo can be reduced.

  In the above embodiment, the case where the present invention is applied to a freight transport vehicle (truck) and a refrigeration / refrigeration transport vehicle (refrigeration / refrigeration vehicle) has been described. Needless to say, various changes can be made without departing from the scope of the present invention.

1 Cargo Carrier (Cargo Carrier)
2 Cargo compartment 3 Air bag 3 'Outflow type air bag 3a, 3b, 3c, 3d, 3e Air bag 4 Piping 5 Gas supply device 6 Air tank 8 Switching valve (three-way valve)
DESCRIPTION OF SYMBOLS 9 Pressure sensor 10 Load 11 Cargo compartment acceleration sensor 12 Load acceleration sensor 14 Controller 15 Computation command part 20 Refrigeration / refrigeration conveyance vehicle (cargo conveyance device)
21 Evaporator 22 Cooling gas supply device 23 Pump 24 Exhaust port 30 Vibration 31 Vibration Gc Cargo acceleration Gv Cargo compartment acceleration P Detection pressure POAH Acceleration transmission rate POAL in high frequency band XAL Acceleration transmission rate X in low frequency band High frequency band Y Low frequency band

Claims (8)

An airbag that is disposed on at least a peripheral wall of a cargo compartment of a cargo transporter and that can be expanded and contracted by a working gas, a gas supply device that is connected to the airbag via a pipe and supplies the working gas, and the gas supply device A switching valve that switches between supply / stop of working gas supplied to the airbag and release to the outside, a pressure sensor that detects the pressure of the airbag provided downstream of the switching valve, and measures the vibration of the cargo compartment Cargo compartment acceleration sensor, cargo acceleration sensor that measures the vibration of the cargo loaded in the cargo compartment, cargo compartment acceleration from the cargo compartment acceleration sensor and cargo acceleration from the cargo acceleration sensor are input to switch the switching valve. A controller to control,
The controller has an acceleration transmissibility in a high frequency band obtained by dividing the cargo acceleration in the high frequency band from the cargo compartment acceleration and the cargo acceleration obtained by the cargo compartment acceleration sensor and the cargo acceleration sensor by the cargo compartment acceleration, and Obtaining the acceleration transmissibility of the low frequency band obtained by dividing the cargo acceleration in the low frequency band by the cargo compartment acceleration from the cargo compartment acceleration and the cargo acceleration obtained by the cargo compartment acceleration sensor and the cargo acceleration, When the acceleration transmission rate in the frequency band is greater than 1, the control valve is operated to reduce the pressure of the airbag, and when the acceleration transmission rate in the low frequency band is greater than 1, the switching valve is operated. A cargo protection device that is operated to increase pressure of an airbag.   The said controller controls the pressure of an airbag by operating the said switching valve so that the acceleration transmission rate of a high frequency band and the acceleration transmission rate of a low frequency band may be 1 or less. Load protection device.   The said controller controls the pressure of an airbag by operating the said switching valve so that the detection pressure of the said pressure sensor may be hold | maintained to the initial value at the time of the inflation start of an airbag. Load protection device as described in.   The cargo protection device according to any one of claims 1 to 3, wherein the gas supply device is an air tank.   The cargo transport device is a refrigerated / refrigerated cargo transport device, and the gas supply device is a cooling gas supply device that takes in a part of the evaporator cooling gas and pressurizes it, and supplies the pressurized cooling working gas to the piping. The load protection device according to any one of claims 1 to 4, wherein the airbag is an outflow type airbag having one end connected to the pipe and the other end having an exhaust port.   The cargo protection device according to claim 5, wherein the cooling gas supply device has a cooling gas tank for storing pressurized cooling working gas.   The load protection device according to claim 5 or 6, further comprising a guide that forms a flow path of a cooling working gas inside the outflow type airbag.   8. The load protection device according to claim 7, wherein the guide is disposed so as to form a flow path in which the cooling working gas flows in a zigzag manner throughout the inside of the outflow type airbag.

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