JP2011209155A - X-ray inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray inspection device capable of improving the lifetime by effectively protecting an X-ray sensor with a sure operation, despite its simple structure with low production cost.SOLUTION: The X-ray inspection device includes an X-ray source 6 above a transport surface 5 of a conveying means 4, a sensor 9 under the transport surface 5, and a shutter device 10 consisting of an operation member 11 and a shield member 12 in front of an irradiation position 7. In a state that a work W is not in contact with the operation member, the shield member shields the sensor from the X-ray, and in a state that the work W pushes the operation member, the shield member moves and the X-ray transmitted through the work reaches the sensor 9. Even if X-ray beam is always irradiated during the inspection, X-rays reaching the sensor remains being a minimum dose required for the inspection. There is no need of the risk that the sensor is overly damaged by the X-rays and of acceleration of deterioration of the lifetime.

Description

  The present invention relates to an X-ray inspection apparatus that performs X-ray irradiation while irradiating X-rays while being transported to an inspected product, and detecting X-rays transmitted through the inspected product with a sensor. The present invention relates to an X-ray inspection apparatus in which a sensor is not easily damaged even if irradiation is continued.

  Patent Document 1 listed below discloses an automatic X-ray inspection apparatus aimed at extending the life of an X-ray sensor unit by minimum X-ray irradiation. The apparatus includes a transport mechanism 5 that transports the target article 4, an X-ray generation mechanism 1 that irradiates the target article 4 with X-rays, and a TV from an X-ray sensor unit 6 that detects an X-ray transmission image of the target article 4. An image processing unit 7 that performs image processing on the video signal, a control unit 9 that receives a signal from the image processing unit 7 and a signal from the transport mechanism 5, and a shutter 2 that opens and closes by driving means 3 that operates according to the output. have.

Japanese Patent Laid-Open No. 10-132761

  According to the X-ray automatic inspection apparatus described in Patent Document 1, some detection means is used to detect the target article, and the X-ray shielding control is performed by opening and closing the shutter by the driving means using the output. ing. Therefore, the detecting means and the driving means are indispensable, and there is a problem that the structure is complicated, the number of parts is large, and the manufacturing cost is high. In addition, there is a problem that the reliability of the components for controlling the driving of the shutters is not sufficient because there is a possibility of failure.

  The present invention has been made in view of the above-described problems, and is an X-ray capable of effectively protecting an X-ray sensor and improving the lifetime with a reliable operation while having a simple structure with a low manufacturing cost. The object is to provide an inspection device.

The X-ray inspection apparatuses 1a, 1b, 1c described in claim 1 are:
A transport unit 4 that transports the article W to be inspected along a predetermined transport direction, and an X-ray source 6 that is disposed above the transport unit 4 and emits X-rays toward an irradiation position 7 on the transport unit 4. A sensor 9 for detecting X-rays emitted from the X-ray source, and irradiating the product to be inspected W transported by the transport means 4 with X-rays from the X-ray source 6. In the X-ray inspection apparatuses 1a, 1b, and 1c that inspect the inspected product W by detecting the X-rays transmitted through W by the sensor 9,
Operation members 11, 21, 31 that are disposed above the transport unit 4 and upstream of the irradiation position 7 in the transport direction and are operated in contact with the article W to be inspected transported by the transport unit 4,
The sensor 9 is configured integrally with the operation members 11, 21, 31 and shields the sensor 9 from X-rays at least in a state in which the product to be inspected W does not contact the operation members 11, 21, 31. Shielding members 12, 22, 32 that release the shielding of the sensor 9 so that X-rays that have moved through the inspected product W and reached the sensor 9 when the members 11, 21, 31 are operated;
It has the shutter apparatus 10,20,30 which consists of.

The X-ray inspection apparatus 1a according to claim 2 is the X-ray inspection apparatus according to claim 1,
The operation member 11 of the shutter device 10 is made of an X-ray transmissive material, and is supported at the upper part by a support portion 13 above the conveying means 4 so as to be swingable, so that the article to be inspected W contacts the operation member 11. In the state where it is not, the lower part is lower than the top part of the article W to be inspected and is not in contact with the conveying means 4,
The shielding member 12 of the shutter device 10 is made of an X-ray shielding material, and is configured integrally with the operation member 11 in the lower portion.
When the article W to be inspected is at the irradiation position 7, X-rays are transmitted through the operation member 11 and irradiated to the article W to be inspected.

The X-ray inspection apparatus 1b, 1c according to claim 3 is the X-ray inspection apparatus according to claim 1,
The operation members 21 and 31 of the shutter devices 20 and 30 are made of an X-ray transmissive material, and are supported at the upper part by a support portion 13 above the conveying means 4 so as to be swingable. In a state where the members 21 and 31 are not in contact with each other, the lower portion is lower than the top of the article to be inspected W and is not in contact with the transport means 4.
The shielding members 22 and 32 of the shutter devices 20 and 30 are made of an X-ray shielding material, and are configured integrally with the operation members 21 and 31 in the upper part.
When the product to be inspected W is at the irradiation position 7, the X-rays pass through the operation members 21 and 31 and are irradiated to the product to be inspected W.

The X-ray inspection apparatus 1b, 1c according to claim 4 is the X-ray inspection apparatus according to claim 3,
The shutter devices 20 and 30 are plate-like members in which the operation members 21 and 31 and the shielding members 22 and 32 are integrated with each other at a predetermined angle and are rotatably supported by the support portion 13. In a state where the inspected product W is not in contact, the operation members 21 and 31 are in a state parallel to the vertical direction,
Said shielding said length for pivoting radius of the support portion 13 around the member 22 and 32 is D _S, wherein a predetermined angle is a right angle + theta _0, the operating member inspection object W 21 and 31 When the X-rays from the X-ray source 6 start to reach the sensor 9 by rotating the shutter devices 20 and 30 by operating the rotation angle of the shutter devices 20 and 30 is θ _c . When the distance that the lower ends of the operation members 21 and 31 are moved in the horizontal direction is D, the following equation (1) is satisfied, and the minimum height of the product W to be inspected is h, and the operation member 21 is , 31 is characterized in that the following equation (2) is established, where H _{S is} the length of the turning radius around the support portion 13 and H is the height of the support portion 13.
D _S cos (θ ₀ + θ _c ) <D <D _S cos θ ₀ ≦ D _S (1)
h = H−H _S cos θ _c (2)

  According to the X-ray inspection apparatus recited in claim 1, when X-rays are irradiated from the X-ray source while the product to be inspected is transported by the transport means, the sensor is in a state where the product to be inspected is not in contact with the operation member. Is shielded from X-rays, but when the article to be inspected operates the operating member of the shutter device, the shielding member moves and releases the shielding of the sensor. The inspection object passing therethrough can be transmitted and reach the sensor for inspection. If the product to be inspected passes the shutter device, the shutter device returns to the original position and shields the sensor from the X-rays again. Therefore, even if X-rays are always irradiated from the X-ray source during the inspection, the X-rays only reach the sensor in the minimum range necessary for the inspection of the inspected product. There is little risk of excessive damage and accelerated life.

  According to the X-ray inspection apparatus described in claim 2, in the X-ray inspection apparatus according to claim 1, the shutter device is an X-ray transmissive member suspended from the support portion above the transport unit so as to be swingable. Since the operation member and the shielding member that is integrally attached to the lower portion of the operation member and shields the sensor are configured, when the article to be inspected that has been transported presses the operation member, the shielding member moves to disengage from the sensor. The X-ray from the radiation source passes through the operation member and is irradiated onto the product to be inspected, so that the above effect can be obtained.

  According to the X-ray inspection apparatus described in claim 3, in the X-ray inspection apparatus according to claim 1, the X-ray transmission apparatus is configured such that the shutter device is swingably supported by the support portion above the conveying means. Since the operation member and the shielding member that is integrally attached to the upper portion of the operation member and covers the irradiation port of the X-ray source and shields the sensor, the shielding member is pressed when the conveyed inspection object presses the operation member. Move away from the irradiation port of the X-ray source, and the X-ray from the X-ray source passes through the operation member and is irradiated onto the product to be inspected.

  According to a fourth aspect of the present invention, in the X-ray inspection apparatus according to the third aspect, the shutter device is made rotatable at the support portion by integrating the operation member and the shielding member at a predetermined angle. Since it is composed of a plate-like member, its condition is set as in the above equation (1), and the condition for the inspected item is also set as in the above equation (2), the inspected item passes through the shutter device. Sometimes the operating member can be operated by touching the operating member to move the shielding member, and when the lower end of the operating member comes to the irradiation position, the shielding member releases the X-ray shielding so that the X-ray Since it is in an irradiation state, the above-mentioned effect can be surely obtained.

(A) is a front view of the X-ray inspection apparatus which concerns on 1st Embodiment, (b) is the same right view. In 1st Embodiment, it is a schematic diagram explaining the relationship between the shutter apparatus and angle which change an angle with the approach of a workpiece | work. In 1st Embodiment, it is a figure which shows the graph showing the relationship between the angle of a shutter apparatus, and X-ray intensity. In 1st Embodiment, it is a schematic diagram explaining the relationship between the angle and X-ray | X_line when a shutter apparatus returns from an open state. (A) is a front view of the X-ray inspection apparatus which concerns on 2nd Embodiment, (b) is the same right view. (A) is a schematic diagram which shows the steady state of the shutter device in 2nd Embodiment, (b) is a schematic diagram explaining a state when the shutter device returns from an open state. In 2nd Embodiment, it is a schematic diagram explaining the relationship between the shutter apparatus and angle which change an angle with the approach of a workpiece | work. In 2nd Embodiment, it is a schematic diagram for demonstrating the setting of the shutter apparatus according to a workpiece | work size (height). (A) is a front view of the X-ray inspection apparatus which concerns on 3rd Embodiment, (b) is the same right view.

1. 1st Embodiment (FIGS. 1-4)
(1) Structure FIG. 1 shows an X-ray inspection apparatus 1a according to this embodiment. This X-ray inspection apparatus 1a includes a housing 2 having an X-ray shielding structure as a main body of the apparatus. The housing 2 is provided with an opening 3 in which both the front surface and the left and right sides are opened. A door (not shown) having a shielding performance is provided at the front opening so as to be openable and closable. Shielding members 15 and 15 are provided. At the bottom of the opening 3 of the housing, conveying means 4 for conveying an article to be inspected (hereinafter referred to as a workpiece W) along a predetermined conveying direction (left-right direction in FIG. 1A) is provided on the casing 2. Each end is protruded from the left and right openings of the opening 3. The conveying means 4 of the present embodiment is a belt conveyor formed by winding an endless belt around a plurality of rollers, and the upper side of the belt is a horizontal conveying surface 5, and the work W is placed and conveyed. After being sent into the housing 2 through the shielding member 15 from the opening on one side surface of the housing 2 and inspected in the housing 2, the housing 2 is opened from the opening on the other side surface of the housing 2 through the shielding member 15. It can be moved out of the body 2.

  As shown in FIG. 1, an X-ray source 6 is provided above the transport unit 4 inside the housing 2. The X-ray source 6 emits X-rays from the irradiation port 8 toward an irradiation position 7 (inspection position) that is a position directly below the transport unit 4. The X-ray source 6 shown in FIGS. 1A and 1B schematically shows the X-ray generation position. As shown in FIG. 1B, the X-ray is irradiated downward from this point. It irradiates in the state which expanded toward the position 7 toward the downward direction in the vertical plane in the triangle shape.

  As shown in FIG. 1, a sensor 9 for detecting X-rays is provided on the lower side of the conveying means 4 on the opposite side of the X-ray irradiation position 7. Although not shown in detail, the sensor 9 includes a large number of detection elements arranged at predetermined intervals in a direction orthogonal to the conveyance direction of the conveyance means 4 and a scintillator disposed above the detection elements. The detecting element is configured to detect light emitted from the light.

  The entire apparatus 1a including the transport unit 4, the X-ray source 6 and the sensor 9 is controlled by a control unit (not shown). During the inspection, X-rays are continuously emitted from the X-ray source 6. The workpiece W conveyed by the conveying means 4 is irradiated with X-rays from the X-ray source 6 at the irradiation position 7. Then, X-rays that have passed through the workpiece W are detected by the sensor 9, and inspections such as detection of foreign substances contained in the workpiece W are performed based on the result.

  As shown in FIG. 1, the X-ray inspection apparatus 1a according to the present embodiment includes a shutter device 10 in order to protect the sensor 9 from X-rays constantly irradiated from the X-ray source 6 during inspection. The shutter device 10 includes an operating member 11 that swings in contact with the workpiece W transported by the transporting unit 4 and a shielding member 12 that integrally shields the sensor 9 from X-rays.

  The operation member 11 is a plate-like member made of an X-ray transmissive hard material, and as shown in FIG. 1B, the overall outer shape is a table along a substantially triangular irradiation surface of X-rays. It is a shape, and is divided into three substantially along the X-ray irradiation direction so as to have substantially the same dimension in the width direction. As shown in FIG. 1 (a), each of these operation members 11 rotates its upper end portion on a support portion 13 provided at a predetermined position above the conveying means 4 and slightly upstream of the irradiation position 7 in the conveying direction. It is provided to be movably supported. The dimensions of the operation member 11 are set so that the lower end of the work member 11 is lower than the top of the work W and is not in contact with the transport surface 5 of the transport means 4 when the work W is not in contact with the control member 11. Yes. In this example, the lower end portion of the operation member 11 does not contact the transport surface 5 of the transport unit 4 but is set at a position directly above the transport surface 5 with a small gap. When the workpiece W is conveyed by the conveying means 4 and comes into contact with the operation member 11, the operation member 11 rotates around the support portion 13 and is lifted toward the downstream in the conveyance direction. Go over and return to the original position. In addition, the hard material which comprises the operation member 11 should just be a material which has the intensity | strength of the grade which is not bent or bent by the contact of the workpiece | work W conveyed.

  The shielding member 12 is made of an X-ray shielding material, and is attached to the lower end portion of the operation member 11 so as to face the downstream in the transport direction in a posture perpendicular to the operation member 11. Therefore, when the workpiece W is not in contact with the operation member 11 and the operation member 11 hangs vertically downward, the shielding member 12 is in a position immediately above the portion where the detection elements of the sensor 9 are arranged, The sensor 9 can be shielded from the X-rays irradiated from the irradiation port 8 of the X-ray source 6 to the irradiation position 7 below. When the workpiece W is conveyed by the conveying means 4 and comes into contact with the operation member 11, and the operation member 11 rotates around the support portion 13, the shielding member 12 moves together with the operation member 11 and moves away from the sensor 9. Then, X-rays are irradiated to the workpiece W that has come to the irradiation position 7.

(2) Operation of Shutter Device 10 Next, the operation of the shutter device 10 described above will be described.
FIG. 2 is a diagram for explaining the relationship between the angle of the shutter device 10 (shutter angle) and the X-ray transmission intensity (X-ray intensity) reaching the sensor 9, from the same figure (a) to the same figure (e). The workpiece W is transported by the transport means 4 and the angle at which the operation member 11 of the shutter device 10 in contact with the workpiece W rotates and the state in which the X-rays reach (or do not reach) the sensor 9 in each state are schematically shown. It is a thing. Further, FIG. 3 is a diagram illustrating the rotational angle θ of the position, that the operating member 11 of the work is W, the relationship between the X-ray transmission intensity I _s reaching the sensor 9.

As shown in FIG. 2 (a), before the workpiece W conveyed by the conveying means 4 reaches the shutter device 10, the operation member 11 of the shutter device 10 hangs vertically downward, and the shielding member 12 is The sensor 9 is covered. Accordingly, as shown in FIG. 3, the strength of X-rays emitted from the X-ray source 6 is a I _0, X-ray transmission intensity I _s reaching the sensor 9 is 0, the sensor 9 from the X-ray Protected.

As shown in FIG. 2B, when the workpiece W conveyed by the conveying means 4 comes into contact with the operation member 11 of the shutter device 10 and swings and the angle exceeds θ _c , the shielding member 12 is moved to the sensor. The X-ray from the X-ray source 6 starts to reach the sensor 9. At this time, the work W has not reached the irradiation position 7, but the operation member 11 is on the irradiation position 7, so that the intensity I _s of the X-ray reaching the sensor 9 is as shown in FIG. The intensity I _e transmitted through the operation member 11 is obtained. The intensity I _e is smaller than the intensity I _{0 of} X-rays irradiated from the X-ray source 6 by the amount that has passed through the operation member 11.

As shown in FIG. 2 (c), when the workpiece W that pushes open the operating member 11 of the shutter device 10 while being transported by the transport means 4 begins to enter the X-ray irradiation position 7, the angle at the operating portion becomes θ. _{Pass m} . X-rays from the X-ray source 6 pass through the operation member 11 and then pass through the workpiece W to reach the sensor 9. Therefore, as shown in FIG. 3, the intensity I _s of the X-rays reaching the sensor 9 is an intensity transmitted through the operation member 11 and the workpiece W. In FIG. 3, X-ray absorption by the work W is indicated by a hatched area. The shape of the absorbed portion of X-rays depends on the shape of the workpiece W or the like, but if it is a rectangular parallelepiped shape as shown in FIG. 2, the shape of the absorption region as shown in FIG. also becomes substantially rectangular parallelepiped shape, while the workpiece W as shown in FIG. 2 (c) ~ (d) passing through the irradiation position 7, the intensity I _s of X-rays reaching the sensor 9, the graph of FIG. 3 Are represented by line segments corresponding to the bottom side of the hatched region parallel to the horizontal axis. Since this intensity is the intensity of the X-ray transmitted through the operation member 11 and the workpiece W, it is naturally smaller than the intensity I _{0 of the} X-ray irradiated from the X-ray source 6 and smaller than the intensity I _e .

When the workpiece W has passed through the X-ray irradiation position 7 but the operating member 11 is still caught by the workpiece W and the angle θ is increasing, the X-ray from the X-ray source 6 passes through the operating member 11, Since it reaches the sensor 9 without being applied to the workpiece W, the intensity I _s of the X-ray that reaches the sensor 9 is the intensity I transmitted through the operation member 11 as shown by an angle θ after the hatching region in FIG. _e .

As shown in FIG. 2 (e), the workpiece W eventually passes through the operation member 11. The angle θ _n of the operation member 11 at this time is the maximum angle θ _max of the operation member 11. When the workpiece W passes through the operation member 11, the operation member 11 returns to its original position by its own weight, and the shielding member 12 again shields the sensor 9 from the X-rays. Therefore, the intensity of X-rays emitted from the X-ray source 6 is is a I _0, X-ray transmission intensity I _s reaching the sensor 9 is 0, the sensor 9 is protected from X-ray.

In addition, since it takes some time for the work W to pass through the operation member 11 and the operation member 11 separated from the work W to return to its original position due to its own weight, the angle of the operation member 11 does not necessarily exceed the angle θ _n . However X-ray transmission intensity I _s immediately reaching the sensor 9 does not become zero. As shown in FIG. 4, when the operating member 11 separated from the workpiece W returns to its original position by its own weight, the operating member 11 moves to the original position shown in FIG. It is possible to go too far. FIG. 4 shows a state in which the operating member 11 has gone too far when returning to the original position, and the operating member 11 is lifted by an angle θ _r toward the upstream in the transport direction. In this case, if the length of the shielding member 12 in the transport direction is appropriately set, the state where the shielding member 12 covers the range of the sensor 9 can be maintained. Although not shown, a stopper member is provided next to the operation member 11 and upstream in the transport direction so that the operation member 11 that is not in contact with the workpiece W comes into contact with the stopper member and has a vertical posture. By doing so, it is possible to prevent the operation member 11 away from the workpiece W from going too far in the vertical position when returning to the original position by its own weight.

As described above, when the angle θ of the operation member 11 is 0 ≦ θ <θ _c , the X-ray is blocked by the shielding member 12 and is not irradiated to the sensor 9. When θ ≧ θ _c , the irradiation position 7 (inspection position) is irradiated with X-rays having intensity I _e , and the workpiece W can be inspected. While the workpiece W passes through the irradiation position 7 (inspection position), θ> θ _{c is} satisfied, and the X-ray transmitted through the workpiece W can be detected by the sensor 9.

  As described above, according to the X-ray inspection apparatus 1a of the present embodiment, when X-rays are irradiated from the X-ray source 6 while the work W is being transported by the transport means 4, the work W comes into contact with the operation member 11. The sensor 9 is shielded from X-rays in a state where it is not, but when the work W operates the operation member 11 of the shutter device 10, the shielding member 12 moves to release the shield of the sensor 9. X-rays from the source 6 pass through the workpiece W passing through the irradiation position 7 and reach the sensor 9 for inspection. If the workpiece W passes the shutter device 10, the shutter device 10 returns to the original position and shields the sensor 9 from the X-rays again. Accordingly, even if X-rays are always irradiated from the X-ray source 6 during the inspection, the X-rays only reach the sensor 9 within the minimum range necessary for the inspection of the inspected product. X-rays do not cause excessive damage and there is little risk of accelerated lifespan.

2. Second Embodiment (FIGS. 5 to 8)
(1) Structure Since the X-ray inspection apparatus 1b according to the embodiment shown in FIG. 5 is the same as that of the first embodiment except for the structure of the shutter apparatus, the following description will be made focusing on the shutter apparatus 20.
As in the first embodiment, the operation member 21 is a plate-like member made of an X-ray transparent hard material. As shown in FIG. 5B, the outer shape of the operation member 21 is a substantially triangular X-ray shape. Are trapezoidal along the irradiation surface, and are roughly divided into three along the X-ray irradiation direction so as to be approximately equal in the width direction. As shown in FIG. 5 (a), these operation members 21 rotate their upper end portions to a support portion 13 provided at a predetermined position above the conveying means 4 and slightly upstream of the irradiation position 7 in the conveying direction. It is provided to be movably supported. The dimensions of the operating member 21 are set so that the lower end of the work member 21 is lower than the top of the work W and is not in contact with the transport surface 5 of the transport means 4 when the work W is not in contact with the control member 21. Yes. In this example, the lower end portion of the operation member 21 is set at a position directly above the conveyance surface 5 with a small gap therebetween, although it does not contact the conveyance surface 5 of the conveyance unit 4. When the workpiece W is conveyed by the conveying means 4 and contacts the operation member 21, the operation member 21 is rotated about the support portion 13 and lifted toward the downstream in the conveyance direction, and rides on the workpiece W. Go over and return to the original position.

The shielding member 22 is made of an X-ray shielding material, and is integrally attached to the upper end portion of the operation member 21 so as to be disposed downstream of the operation member 21 in the transport direction. The angle of the shielding member 22 with respect to the operation member 21 is a predetermined angle (90 degrees + θ _{0 in} this example) that is greater than 90 degrees. Therefore, when the workpiece W is not in contact with the operation member 21 and the operation member 21 is hung vertically downward, the shielding member 22 is in a position immediately below the irradiation port 8 of the X-ray source 6, and the X-ray The sensor 9 can be shielded from X-rays by covering the irradiation port 8 of the source 6. When the work W is transported by the transport means 4 and comes into contact with the operation member 21 and the operation member 21 rotates around the support portion 13, the shielding member 22 rotates together with the operation member 21 and moves away from the irradiation port 8. The workpiece W that has come to the irradiation position 7 is irradiated with X-rays.

(2) Setting of the shutter device 20 according to the height of the workpiece W The shutter device 20 in the present embodiment shields the sensor 9 from X-rays when the workpiece W is not in contact with the workpiece W and has been conveyed. When the workpiece W passes through the X-ray irradiation position 7 (inspection position), the workpiece W is irradiated with X-rays so that the workpiece W can be inspected. After passing through the (inspection position), the sensor 9 is again shielded from X-rays. In the basic structure of the shutter device 20 described above, in order to reliably perform such operations / actions, it is necessary to set the dimensions, angles, and the like of each part of the shutter device 20 according to the size of the workpiece W under appropriate conditions. is there. Therefore, the conditions for the shutter device 20 and the conditions for the height of the workpiece W in the present embodiment will be described with reference to FIGS.

FIG. 6A shows an initial state of the shutter device 20, that is, a state where the workpiece W is not in contact. The angle between the operation member 21 and the shielding member 22 is 90 degrees + θ ₀ , and the operation member 21 is in a state parallel to the vertical direction. FIG. 6B shows a state in which, after the workpiece W has passed through the shutter device 20, the shutter device 20 is lifted upstream by an angle θ _r when returning to the initial state by its own weight. That is, since the shutter device 20 is rotatable about the support portion 13, the shutter device 20 is pushed by the moving workpiece W and lifted from the initial state shown in FIG. After the workpiece W is removed, the workpiece W returns to its upstream side by its own weight, and can pass through the initial state and turn to the position shown in FIG.

FIG. 7 is a schematic diagram for explaining the relationship between the shutter device 20 whose angle changes as the work W enters and the X-ray. The reference sign in the figure indicates the angle θ that the operation member 21 forms with the vertical line, θ = 0 which is the initial state, and the angle θ at which the workpiece W presses the operation member 21 and X-rays are emitted to the sensor 9. = Θ _c , the angle θ = θ _m when the workpiece W enters the irradiation position 7 (inspection position), and the maximum angle θ _max = θ _n after the workpiece W passes through the irradiation position 7 (inspection position). That is, when θ ≧ θ _c , X-rays are irradiated to the irradiation position 7 (inspection position), and then the workpiece W is moved to X until the workpiece W passes through the irradiation position 7 (inspection position). The sensor 9 is covered with the shielding member 22 and shielded from the X-rays before the workpiece W comes into contact with and after the workpiece W passes. In order to operate the shutter device 20 in this way, the following conditions must be satisfied.

In FIG. 8, the shutter device 20 is pushed by the workpiece W and rotates, the angle θ of the operation member 21 with respect to the vertical line becomes θ _c , and the shielding member 22 opens the irradiation port 8 of the X-ray source 6 to perform X-rays. Shows a state in which the irradiation position 7 (inspection position) starts to be irradiated.
As shown in the figure, the length of the turning radius around the support portion 13 of the shielding member 22 is D _S , and the length of the operation member 21 around the support portion 13 is H. _When the height of the support portion 13 from the conveying surface 5 is H and the distance that the lower end of the operation member 21 is moved in the horizontal direction is D, the following equation (1) needs to be satisfied.
D _S cos (θ ₀ + θ _c ) <D <D _S cos θ ₀ ≦ D _S (1)

In particular, when θ ₀ = 0, the condition to be satisfied is as shown in the following formula (1 ′).
D _S cos θ _c <D <D _S (1 ′)

In addition, the size (height H _w ) of the workpiece W needs to satisfy a necessary condition. That is, if the workpiece W is too low, the operation member 21 cannot be touched and the shutter device 20 does not operate, so X-rays are not irradiated, and even if the shutter device 20 operates, it is sufficient until X-rays are irradiated. Since the shielding member 22 may not move at the same time, in order to set θ = θ _c as a critical angle and an angle at which X-rays start to be irradiated, assuming that the minimum height of the workpiece W is h, the following formula ( 2) must be established.
h = H−H _S cos θ _c (2)
However, cos θ _c = (H _S ² −D ² ) ^1/2 / H _S
∵sinθ _c = D / H _S

At this time, if the workpiece W passes through the irradiation position 7 (inspection position), θ _m ≧ θ _c , and the intensity of X-rays transmitted through the operation member 21 of the shutter device 20 (intensity I _{e in} the first embodiment). Work W is inspected.

Having thus the lower limit of the range of height Hw of the workpiece W is required to be h in the formula (2), when the H _wmin <h by the height H _w <h or variation, the workpiece W is It is necessary to lower the mounting height of the shutter device 20, that is, the height H of the support portion 13. However, the lowest mounting position H _min = H _S.

If the height of the workpiece W is H _w >> h, X-ray shielding is released long before the workpiece W reaches the irradiation position 7. If the height of the workpiece W is stable under such conditions, H may be increased. However, the H <H _w. Further, when the height of the workpiece W is unstable under such conditions, D may be reduced. However, the D> D _S.

  As described above, the shutter device 20 is configured to be able to turn to the position in the reverse direction shown in FIG. If the operation member 21 that is separated from the workpiece W returns to the original position by its own weight, it can be prevented that the vertical position is excessively passed by striking the member and taking a posture along the vertical direction.

3. Third Embodiment (FIG. 9)
The X-ray inspection apparatus 1c according to the embodiment shown in FIG. 9 is basically the same as the second embodiment except for the structure of the shutter device 30, and the same reference numerals as those in FIG. The description will be used with reference. This embodiment is characterized in that the operation member 31 is slightly shorter, the shielding member 32 is slightly longer, and the angle between the operation member 31 and the shielding member 32 is a right angle when compared to the second embodiment. As in the second embodiment, the setting conditions indicated by the expressions (1) and (2) relating to the shutter device 20 and the workpiece W are also necessary in this embodiment. According to the present embodiment, the same effects as those of the second embodiment can be obtained. In addition, when the fixed workpiece W having an appropriate height is applied to the shutter device 30 having the short operation member 31 as described above, the operation member 21 is Compared to the relatively long second embodiment, when the workpiece W passes, X-rays are shielded by the shielding member 32 at an early stage, so that the time during which the sensor 9 is irradiated with X-rays is further shortened. There is an effect that deterioration is difficult to proceed.

Further, according to the present embodiment, the rotation angle of the shutter device 30 when the workpiece W passes completely can be reduced, and the moment when the shutter device 30 returns to the initial state is weakened. You can reduce the impact. Furthermore, while the workpiece W passes the inspection position, the operation member 31 is not positioned on the X-ray irradiation path, and the X-ray is not absorbed by the operation member 31, so that I _e in FIG. 3 can be made equal to I _o. The workpiece W can be efficiently irradiated with the attenuation by the operation member 31 without being attenuated. Furthermore, since the operation member 31 does not need to be made of an X-ray transmissive material, the same material as that of the shielding member 32 can be used to easily manufacture a single metal plate by bending, and also improve durability. be able to.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c ... X-ray inspection apparatus 4 ... Conveyance means 5 ... Conveyance surface 6 ... X-ray source 7 ... Irradiation position (inspection position)
DESCRIPTION OF SYMBOLS 9 ... Sensor 10, 20, 30 ... Shutter apparatus 11, 21, 31 ... Operation member 12, 22, 32 ... Shielding member 13 ... Supporting part W ... Inspected goods (workpiece)

Claims (4)

A transport means (4) for transporting the product to be inspected (W) along a predetermined transport direction, and X for irradiating X-rays toward an irradiation position (7) on the transport means arranged above the transport means. A radiation source (6) and a sensor (9) for detecting X-rays emitted from the X-ray source are provided, and an X-ray is emitted from the X-ray source to the inspected product conveyed by the conveying means. In the X-ray inspection apparatus (1a, 1b, 1c) for inspecting the inspected product by detecting the X-rays transmitted through the inspected product by the sensor,
An operation member (11, 21, 31) disposed above the transport means and upstream of the irradiation position in the transport direction and operated in contact with an inspected product transported by the transport means;
The sensor is configured integrally with the operation member, and at least in a state where the inspected product does not contact the operation member, the sensor is shielded from X-rays, and moves when the inspected product operates the operating member to move the inspected product. A shielding member (12, 22, 32) for releasing shielding of the sensor so that transmitted X-rays reach the sensor;
An X-ray inspection apparatus (1a, 1b, 1c) characterized by comprising a shutter device comprising: The operating member (11) of the shutter device (10) is made of an X-ray transmissive material, and is supported on the upper support portion (13) above the conveying means (4) so as to be swingable. In a state where (W) does not contact the operation member, the lower part is lower than the top of the inspected product and is not in contact with the conveying means,
The shielding member (12) of the shutter device is made of an X-ray shielding material, and is configured integrally with the operation member at the lower part,
The X-ray inspection apparatus (1a) according to claim 1, wherein when the product to be inspected is at the irradiation position, X-rays are transmitted to the product to be inspected through the operation member. The operating members (21, 31) of the shutter device (20, 30) are made of an X-ray transmissive material, and are supported at the upper part by a support part (13) above the conveying means (4) so as to be swingable. In the state where the product to be inspected (W) does not contact the operation member, the lower part is lower than the top of the product to be inspected and is not in contact with the conveying means,
The shielding members (22, 32) of the shutter device are made of an X-ray shielding material, and are configured integrally with the operation member at the upper part,
The X-ray inspection apparatus (1b, 1c) according to claim 1, wherein when the product to be inspected is at the irradiation position, X-rays pass through the operation member and are applied to the product to be inspected. In the shutter device (20, 30), the operation member (21, 31) and the shielding member (22, 32) are integrated with each other at a predetermined angle, and are rotatably supported by the support portion (13). In a state where the plate-shaped member is not in contact with the product to be inspected (W), the operation member is in a state parallel to the vertical direction,
The length of the rotation radius around the support portion of the shielding member is a D _S, wherein a predetermined angle is a right angle + theta _0, the shutter device object to be inspected by operating the operating member When the X-ray from the X-ray source starts to reach the sensor (9) by rotating, the rotation angle of the shutter device is θ _c and the lower end of the operation member has moved in the horizontal direction. When the distance is D, the following equation (1) holds,
When the minimum height of the product to be inspected is h, the length of the operation member with respect to the turning radius around the support portion is H _S , and the height of the support portion is H, the following equation (2) is obtained. The X-ray inspection apparatus according to claim 3, wherein the X-ray inspection apparatus is established. D _S cos (θ ₀ + θ _c ) <D <D _S cos θ ₀ ≦ D _S (1)
h = H−H _S cos θ _c (2)

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