Radiation inspection system

Disclosed is an inspection system for inspecting a cargo by using radiation, comprising: a main plate conveyor; a radiation scanning unit that spans said main plate conveyor and is provided above said main plate conveyor, for scanning the cargo provided on the main plate conveyor; auxiliary conveyors that are provided at the front end and rear end of said main plate conveyor, respectively, so as to load the cargo to be inspected onto said main plate conveyor and to unload the inspected cargo from said main plate conveyor; and lifting devices for lifting said auxiliary conveyors. The inspection system according to the present invention occupies less area, has simple corollary equipments, a lower operating cost, and excellent compatibility, and can be widely applied.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a Section 371 National Stage Application of International Application No. PCT/CN2007/000066, filed Jan. 8, 2007, published as WO 2007/079675, not in English, the content of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention generally relates to an inspection system for inspecting cargo by means of radiation (rays). In particular, the present invention relates to an X-ray inspection system adapted to inspect pallet cargo, air containerized cargo or other larger cargo.

BACKGROUND OF THE INVENTION

A large-scale air containerized cargo inspection system is an inspection system urgently required by air customs. Currently, larger air cargo is inspected by opening a cargo container containing the larger air cargo or by using an X-ray machine.

However, the inspection operation of opening the cargo container is time-consuming and has a low efficiency and a high inspection cost. The inspection using the X-ray machine is implemented by reflecting the cargo to form an image. However, since the rays from the X-ray machine has low energy and poor penetrability, and only the portion of the cargo that is within a certain extent close to the ray source can be clearly imaged, and image quality and range of application of the machine can not meet requirement.

Accordingly, a cargo inspection system is disclosed in CN1405555A, entitled as “air containerized cargo/pallet cargo inspection system”, filed by the applicant of the present application. The cargo inspection system comprises an inverted-U shaped scanning frame composed of a radiation source, a detector array, a collimator, a subtense device arm, and an upright detector arm; a combined transporting system composed of a main plate conveyor and an auxiliary roller conveyor; a radiation shielding system, a device compartment, an operation room, and so on.

During loading the air containerized cargo/pallet cargo, when the bottom surface of the air containerized cargo/pallet cargo is brought into contact with the rollers provided on the outermost side of the loading roll table, the auxiliary roller conveyor is actuated, and then the rollers carry and transport the cargo onto the main plate conveyor. The main plate conveyor carries the cargo to pass through the region under the scanning frame.

However, in the above conventional inspection system, the heights of the auxiliary roller conveyor and the main plate conveyor are constant. Thus, an additional transport trailer, such as a fork truck or a full trailer, must be employed to transport the cargo between a truck and the auxiliary roller conveyor before and after the cargo is inspected. Therefore, when the above conventional inspection system is installed, a space for running and steering the transport trailer should be provided at the two ends of the system, and thus a larger installation area is required.

Therefore, the above conventional radiation inspection system has the following technical problems. The system occupies a larger region, the corollary equipments for it are complicated, and has a poor compatibility and a higher operation cost, and is not adapted for a freight yard with a limited space.

SUMMARY OF THE INVENTION

The embodiment of the present invention provides an inspection system for inspecting a cargo that occupies less area without requiring a transport trailer, has excellent compatibility and lower operating cost, and can be widely applied, or that has at least one of the above-mentioned advantages.

Accordingly, according to one aspect of the present invention, an inspection system for inspecting a cargo by using radiation, comprising: a main plate conveyor; a radiation scanning unit that spans said main plate conveyor and is provided above said main plate conveyor, for scanning the cargo provided on the main plate conveyor; auxiliary conveyors that are provided at a front end and a rear end of said main plate conveyor, respectively, so as to load the cargo to be inspected onto said main plate conveyor and to unload the inspected cargo from said main plate conveyor; and lifting devices for lifting said auxiliary conveyors.

Preferably, said auxiliary conveyors are roller conveyors.

Further, each of said lifting devices comprises: an upper platform that supports said roller conveyor on an upper surface of the upper platform and is provided along a longitudinal direction thereof with an upper sliding groove; a low platform that is provided along the longitudinal direction thereof with a lower sliding groove corresponding to the upper sliding groove; a link mechanism including a first link and a second link, in which said first link and said second link are pivotally connected with each other at respective substantial centers in longitudinal directions thereof, and an upper end of the first link and a low end of the second link are pivotally connected to the upper platform and the low platform, respectively, and a low end of the first link and an upper end of the second link are slidably engaged in said low sliding groove and said upper sliding groove, respectively; and an actuator for driving said first link and said second link to pivot with respect to each other, so that the upper platform is lifted and lowered.

Further, guiding wheels are provided at the low end of the first link and at the upper end of the second link, respectively, and the guiding wheels are slidably engaged in the upper sliding groove and the low sliding groove.

Further, said upper sliding groove is formed on a longitudinal side face of the upper platform, and said low sliding groove is formed on a longitudinal side face of the low platform which is on the same side as the longitudinal side face of the upper platform, and the upper end of the first link and the low end of the second link are hinged to the longitudinal side faces of the upper platform and the low platform, respectively.

Preferably, one end of said actuator is pivotally connected near the low end of the second link, and the other end thereof is pivotally connected between the upper end of the first link and the longitudinal center of the first link.

Further, said actuator comprises a hydraulic cylinder or an air cylinder. Alternatively, said actuator comprises: a lead screw; a threaded sleeve that is engaged with the lead screw, so that the threaded sleeve can longitudinally move with respect to the lead screw by rotation of the lead screw; and a motor for driving the lead screw to rotate. Further, said actuator comprises a telescopic bar.

Preferably, said radiation scanning unit comprises: a radiation source that is provided at a first side of the maim plate conveyor and emits rays; a collimator that is provided between the radiation source and the first side of the main plate conveyor and is adapted to collimate the rays emitted from the radiation source; an upright arm frame that is provided at a second side of said main plate conveyor opposite to the first side of the main plate conveyor, and is provided with a first detector array that receives the rays emitted from the radiation source and collimated by the collimator, and a horizontal or transverse arm frame, one end of which is connected with an upper end of the upright arm frame, and the other end of which spans said main plate conveyor so as to be connected with the collimator, so that the upright arm frame, the horizontal arm frame, and the collimator constitute an inverted-U shaped frame, and the horizontal arm frame is provided with a second detector array that receives the rays emitted from the radiation source and collimated by the collimator.

Furthermore, the inspection system according to the present invention further comprises a radiation shielding wall that is provided on an outside of the inverted-U shaped frame at the second side of the main plate conveyor to shield the rays.

Further, protection frames may be provided at the ends of said auxiliary conveyors apart from said main plate conveyor, respectively.

Preferably, the inspection system according to the present invention further comprises traction devices that are provided on ends of said upper platforms close to said main plate conveyor, respectively, each of the traction devices comprises: a drum; a motor for driving the drum to rotate; and a traction rope, one end of which is wound on said drum, and the other end of which drags the cargo to be inspected, so that the cargo is dragged onto the auxiliary conveyors.

According to the embodiment of the present invention, said radiation source may be an X-ray tube or an isotope radiation source.

Alternatively, each of said lifting devices comprises: a platform for supporting said auxiliary conveyor; and a hydraulic cylinder provided under the platform and used to support and lift said platform.

Alternatively, each of said lifting devices comprises: a platform for supporting said auxiliary conveyor; and a leading screw transmission device, comprising a leading screw, a motor for driving the leading screw, and a nut engaged with the leading screw and fixed to the bottom surface of said platform, so that said nut moves along the leading screw, thereby lifting said platform and said auxiliary conveyor, when the motor is actuated to drive the leading screw to rotate.

In accordance with the embodiment of the present invention, since the auxiliary conveyors capable of being lifted are employed, no transport trailer is needed. Furthermore, the inspection system has advantages that it occupies less region, has lower operating cost and excellent compatibility, and can be widely applied, and is adapted to inspect air containerized cargo, pallet cargo, or other cargo transported through road, train, seaport, and so on, which is inspected without opening cargo containers

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiment of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

Referring toFIG. 1toFIG. 4, an inspection system100according to the present invention, that inspects air containerized cargo, pallet cargo, and other larger cargo by using radiation of, for example, X rays, comprises a main plate conveyor8, a radiation scanning unit, auxiliary conveyors7, and lifting devices10.

Specifically, as shown inFIG. 1, the radiation scanning unit spans above the main plate conveyor8to scan a cargo provided on the main plate conveyor8. For instance, the main plate conveyor8carries and moves the cargo along the direction D indicated by an arrow inFIG. 4to pass through the radiation scanning unit so as to scan and image the cargo, thereby implementing inspection. Alternatively, the main plate conveyor8can carry and move the cargo along an opposite direction to the direction D to pass through the radiation scanning unit, or reciprocate the cargo along the direction D and the opposite direction thereto to pass through the radiation scanning unit, so that the cargo is repeatedly inspected.

As shown inFIGS. 2-4, the auxiliary conveyors7are provided in front of (the left side inFIGS. 2-4) and behind (the right side inFIGS. 2-4) the main plate conveyor8, respectively, to load the cargo to be inspected onto the main plate conveyor8and to unload the inspected cargo from the main plate conveyor8.

In the embodiment of the present invention, as shown inFIGS. 2-4, for the propose of facilitating description, the auxiliary conveyor provided at the left side of the main plate conveyor8is referred to as an auxiliary loading conveyor for loading the cargo onto the main plate conveyor8; and the auxiliary conveyor provided at the right side of the main plate conveyor8is referred to as an auxiliary unloading conveyor for unloading the cargo from the main plate conveyor8. However, since the main plate conveyor8can carry the cargo provided thereon to reciprocatively pass through the radiation scanning unit so as to repeatedly inspect the cargo, the terminologies “loading” and “unloading” are only illustrative, and are not for limiting the present invention. Alternatively, for example, inFIGS. 2-4, the auxiliary conveyor provided at the left side of the main plate conveyor8is used to unload the cargo from the main plate conveyor8, and the auxiliary conveyor provided at the right side of the main plate conveyor8is used to load the cargo onto the main plate conveyor8.

More specifically, as shownFIGS. 3 and 4, the auxiliary conveyors are roller conveyors. However, the auxiliary conveyors7are not limited to roller conveyors, and can be, for example, plate conveyors or any other suitable conveyors.

The lifting devices10are used for lifting the auxiliary conveyors7, respectively, so that a height of the auxiliary conveyors7can be adjusted to be in the same level as that of the main plate conveyor8so as to load the cargo onto the main plate conveyor8from the auxiliary conveyors7or unload the cargo to the auxiliary conveyors7from the main plate conveyor8, or the height of the auxiliary conveyors7can be adjusted to be lower or higher than that of the main plate conveyor8. It should be noted that the height of the auxiliary conveyors provided at the two sides of the main plate conveyor8are separately adjusted.

Specifically, shown inFIGS. 3 and 4, each of the lifting devices10comprises an upper platform10-2, a low platform10-6, a link mechanism10-3, and an actuator10-7.

The upper platform10-2is used for supporting the auxiliary roller conveyor7on an upper surface thereof and is provided along a longitudinal direction thereof with an upper sliding groove10-10. More specifically, rollers7aand other component parts of the auxiliary conveyor7are provided on the upper platform10-2. The low platform10-6is provided along a longitudinal direction thereof with a low sliding groove10-11corresponding to the upper sliding groove10-10.

The link mechanism10-3comprises a first link10-3-1and a second link10-3-2. The first link10-3-1and the second link10-3-2are pivotally connected with each other at substantial centers A along longitudinal directions thereof via, for example, a pin10-12. An upper end of the first link10-3-1(i.e., the end apart from the main plate conveyor8) is pivotally connected to the upper platform10-2via, for example, a pin10-9, and a low end of the second link10-3-2(i.e., the end apart from the main plate conveyor8) is pivotally connected (hinged, in this embodiment,) to the low platform10-6via, for example, a pin10-8, while a low end of the first link10-3-1(i.e., the end close to the main plate conveyor8) and an upper end of the second link10-3-2(i.e., the end close to the main plate conveyor8) are slidably engaged in the low sliding groove10-10and the upper sliding groove10-11, respectively.

Preferably, guiding wheels10-4and10-5are provided at the low end of the first link10-3-1and at the upper end of the second link10-3-2, respectively. The guiding wheels10-4and10-5are engaged into the upper sliding groove10-10and the low sliding groove10-11, so that the low end of the first link10-3-1and the upper end of the second link10-3-2can slide within the upper sliding groove10-10and the low sliding groove10-1.

More specifically, the upper sliding groove10-10is formed on a first side face of the upper platform10-2(i.e., the low side face shown inFIG. 2), and the low sliding groove10-11is formed on a first side face of the low platform10-6(i.e., the low side face shown inFIG. 2). Meanwhile, the upper end of the first link10-3-1and the low end of the second link10-3-2are pivotally hinged to the firs side faces of the upper platform10-2and the low platform10-6via the pins10-9and10-8, respectively. However, one skilled in the art can understand that the formation positions of the upper sliding groove and the low sliding groove are not limited to be on the side faces of the upper platform and the low platform, and the upper sliding groove and the low sliding groove can be formed, for example, lower surfaces of the upper platform and the low platform, respectively. Furthermore, a number of the sliding grooves may be any appropriate number.

It should be noted that the lifting devices for lifting the auxiliary conveyors7are not limited to the above-mentioned embodiment, and one skilled in the art can achieve lifting of the auxiliary conveyors in any suitable way. For instance, the upper platform10-2can be supported by a hydraulic cylinder or a lead screw, and be lifted by actuating the hydraulic cylinder or driving the lead screw to rotate, so that the auxiliary conveyors7can be lifted.

The actuator10-7drives the first link10-3-1and the second link10-3-2to rotate about the pin10-12with respect to each other, so that the upper platform10-2is lifted and lowered with respect to the low platform10-6.

Specifically, as shown inFIG. 3andFIG. 4, one end of the actuator10-7(the low end inFIG. 3) is pivotally connected near the low end of the second link10-3-2, and the other end thereof is pivotally connected between the upper end of the first link10-3-1and the longitudinal center A of the first link.

As shown in the left part ofFIG. 3, when the cylinder bar of the hydraulic cylinder is extended out, the first link10-3-1and the second link10-3-2are pivoted about the pin10-12with respect to each other, so that a distance between the upper end of the first link10-3-1and the low end of the second link10-3-2and a distance between the low end of the first link10-3-1and the upper end of the second link10-3-2are increased, and at the same time the low end of the first link10-3-1and the upper end of the second link10-3-2slide within the low sliding groove10-11and the upper sliding groove10-10to leave apart from the main plate conveyor8, so that the upper platform10-2is lifted with respect to the low platform10-6.

In contrast, as shown in the right part ofFIG. 3, when the cylinder bar of the hydraulic cylinder is drawn back, the upper platform10-2is lowered with respect to the low platform10-6. Thus, a height of the auxiliary conveyors7can be adjusted to be in the same level as that of the main plate conveyor8(as shown inFIG. 4), or be lower or higher than that of the main plate conveyor8(as shown inFIG. 3).

In the embodiment shown inFIGS. 3 and 4, the actuator10-7is a hydraulic cylinder or an air cylinder, but is not limited to this. The actuator10-7may be a telescopic bar. Alternatively, the actuator10-7comprises a lead screw; a threaded sleeve that is engaged with the lead screw, so that the threaded sleeve can longitudinally move with respect to the lead screw by rotation of the lead screw; and a motor for driving the lead screw to rotate. In this case, the operation of the actuator10-7is similar to that of the above-mentioned hydraulic cylinder or air cylinder, and the detailed description for it is omitted.

The lifting device for lifting the auxiliary conveyor7is not limited to the above-mentioned link mechanism. Alternatively, the lifting device may comprise a platform (no shown), similar to the upper platform10-2, for supporting the auxiliary conveyor7, and a hydraulic cylinder provided under the platform and used to support and lift the platform. A number of the hydraulic cylinders may be determined according to practical requirement. Furthermore, instead of the above-mentioned hydraulic cylinder, a leading screw transmission device can be used. The leading screw transmission device may comprises a leading screw, a motor for driving the leading screw, and a nut engaged with the leading screw and fixed to a bottom surface of the platform for supporting the auxiliary conveyor7. When the motor is actuated, the leading screw is rotated, so that the nut moves along the leading screw, thereby driving the platform and the auxiliary conveyor7to lift. The above contents can be easily understood by one skilled in the art, and accordingly, the detailed description thereof is omitted.

In accordance with the embodiment of the present invention, as shown inFIG. 1andFIG. 2, the radiation scanning unit comprises a radiation source1, such as an X-ray tube and an isotope radiation source, a collimator2, an upright arm frame4, and a horizontal or transverse arm frame3. Preferably, the radiation scanning unit further comprises a radiation shielding wall5.

Specifically, the radiation source1is provided at a first side of the main plate conveyor8(the left side inFIG. 1, i.e., the low side inFIG. 2) and emits rays R. It should be noted that although two straight lines are used to indicate rays R inFIG. 1, a ray beam emitted from the radiation source1is collimated by the collimator2to form a sector-shaped ray beam plane.

The collimator2is provided between the radiation source1and the first side of the main plate conveyor8and is adapted to collimate the rays R emitted from the radiation source1.

The upright arm frame4is provided at a second side of the main plate conveyor8(the left side inFIG. 1, i.e., the upper side inFIG. 2) opposite to the first side of the main plate conveyor8, and the upright arm frame is provided with a first detector array (not shown) that receives the rays R emitted from the radiation source1and collimated by the collimator2.

One end of the horizontal arm frame3(the right end inFIG. 1) is connected with an upper end of the upright arm frame4, and the other end thereof spans the main plate conveyor8so as to be connected with the collimator2, that is, the collimator2is supported on the other end of the horizontal arm frame3, so that the upright arm frame4, the horizontal arm frame3, and the collimator2constitute an inverted-U shaped frame. The horizontal arm frame3is provided with a second detector array (not shown) that receives the rays R emitted from the radiation source1and collimated by the collimator2.

The radiation shielding wall5is provided at the second side of the main plate conveyor8and on an outside of the inverted-U shaped frame to shield the rays R (including rays generated due to diffusing, refracting and the like).

Alternatively, the inspection system100according to the embodiment of the present invention further comprises protection frames6that are provided at ends of the auxiliary conveyors7apart from the main plate conveyor8, respectively, so that the cargo is prevented from dropping from the auxiliary conveyors7.

Alternatively, the inspection system100according to the embodiment of the present invention further comprises traction devices9that are provided on ends of the upper platform2close to the main plate conveyor8, respectively, for dragging (loading) the cargo onto the auxiliary conveyors7.

Specifically, each of the traction devices9comprises a drum9-1, a motor (not shown) for driving the drum9-1to rotate, and a traction rope9-2. One end of the traction rope9-2is wound on the drum9-1, and the other end thereof drags the cargo to be inspected, so that the cargo is dragged onto the auxiliary convey or is dragged down from the auxiliary conveyor.

It should be noted that the inspection system according to the present invention further comprises a scan controlling module, an image capturing module, an operation inspecting device, a data processing unit, and a controlling unit. These component parts are similar to those in the prior art, and the detailed description thereof is omitted.

Next, the operation of inspecting the cargo using the radiation inspection system in accordance with the embodiment of the present invention will be explained.(1) Firstly, the inspection system is started up for warming up and then becomes in a standby condition.(2) The auxiliary loading roller conveyor7(for example, the auxiliary conveyor7at the left side inFIGS. 2-4) is adjusted to an appropriate height by the lifting device10, so that the cargo can be loaded onto the auxiliary conveyor7.(3) The containerized cargo is dragged onto the auxiliary loading roller conveyor7by the traction device9or by manual work.(4) The auxiliary loading roller conveyor7is adjusted to flush with the main plate conveyor8, as shown inFIG. 4.(5) The auxiliary loading roller conveyor7is stated up to transport the cargo onto the main plate conveyor8, and then the main plate conveyor8carries the cargo provided thereon to move along the direction D to pass through the radiation scanning unit; when the cargo passes through a ray beam plane, scanning data is generated and transmitted to the data processing center to form a real-time cargo image.(6) When the cargo has passed through the ray beam plane, displaying the image is stopped; and the inspected cargo is transported to the auxiliary unloading roller conveyor7(the auxiliary conveyor at the right side inFIGS. 2-4) from the main plate conveyor8, and at this point, the height of the auxiliary unloading roller conveyor7is the same as that of the main plate conveyor8.(7) The height of the auxiliary unloading roller conveyor7is adjusted to be in an appropriate level, and then the cargo is removed.

If the inspector judges by observing the cargo image that the cargo should be re-inspected, the cargo on the auxiliary unloading roller conveyor7is transported onto the main plate conveyor8by the controlling unit, and then the main plate conveyor8carries the cargo to move along the opposite direction to the direction D to pass through the radiation scanning unit, so that the cargo is re-inspected, or the cargo can be unloaded, and then the cargo container is opened so as to re-inspect the cargo. Also, the cargo can be repeatedly inspected by changing arrangement or angle of the cargo, so that accuracy of inspection is improved, as shownFIG. 4.