JP2016200477A - Survey Meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a survey meter that can assure waterproofness by a simpler configuration.SOLUTION: A survey meter for measuring radiation comprises: a case including a lower case piece 31 and a battery cover 50 arranged so as to face the lower case piece 31; and a seal member 60 placed between the lower case piece 31 and the battery cover 50 for sealing fluid-tight between both. The seal member 60 has a substantially U-shaped cross section including a first leg part 61, a second leg part 62 situated outer side than the first leg part 61, and a coupling part 63 for coupling ends of the first and second leg parts 61 and 62. The first leg part 61 and the second leg part 62 have length different from each other.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a survey meter which is a portable radiation measurement apparatus.

  Since the survey meter may be used even in an environment with a lot of moisture and dust, the case of the survey meter is required to be waterproof. Here, the case is usually configured by combining a plurality of case pieces. Conventionally, in order to ensure waterproofness, a configuration in which a seal member (packing) made of a flexible material such as rubber is disposed between the case pieces and the case pieces has been widely adopted.

  Among cases, in the case of a battery cover or the like that is opened and closed by a user, the sealing surface is often set to two points (two rounds) or more in order to ensure waterproofness while absorbing attachment errors and the like. When the sealing surface has two points (two rounds), the reaction force of the crushing force of the sealing member is greatly applied to the battery cover as compared with the case where the sealing surface has one point (one round). In the case of a battery cover having a thin-walled structure that pursues weight reduction, the reaction force of the sealing member may exceed the rigidity of the battery cover, and the battery cover may be bent. When the battery cover is thus bent, it has been difficult to stably ensure waterproofness.

JP 2011-239099 A JP 2014-194907 A

  Therefore, in some cases, a technique of changing the hardness of the seal member for each seal surface has been proposed (for example, Patent Document 1). However, in this case, it is necessary to prepare two or more seal members made of different materials, which causes problems such as an increase in the number of parts and an increase in labor for assembling. Of course, it is possible to reduce the number of parts by making the hardness different for each part in one seal member, but such a seal member requires a complicated manufacturing process, which causes an increase in cost.

  In addition, in some cases, a technique for suppressing the reaction force applied from the seal member to the case piece by devising the shape of the seal member is also known (for example, Patent Document 2). However, in such a technique, the shape of the seal member is extremely complicated, which causes another problem of deterioration of assembling property and deterioration of workability.

  Therefore, an object of the present invention is to provide a survey meter that can ensure waterproofness with a simpler configuration.

  The survey meter of the present invention is a survey meter for measuring radiation, and includes a case having a first case piece and a second case piece arranged to face the first case piece, the first case piece and the first case piece. A seal member that is disposed between the two case pieces and seals between the two in a liquid-tight manner, and the seal member includes a first leg and a second leg located outside the first leg. And a connecting portion for connecting the end portions of the first and second leg portions, and a substantially U-shaped cross section, wherein the first leg portion and the second leg portion have different lengths from each other. And

  In a preferred aspect, the second leg is longer than the first leg. In another preferred aspect, the first and second leg portions protrude from the second case piece side toward the first case piece, and the first leg portion of the one case piece contacts the first case piece. The one abutment surface is an inclined surface that increases in distance from the first case piece as it approaches the outside, and the second abutment surface on which the second leg abuts is the first case piece. It is a flat surface with a constant distance from the piece. In this case, it is desirable that the first leg portion abuts on the inclined surface in a state where the tip is bent outward.

  According to the present invention, since there are two types of leg portions having different lengths in one seal member, different seal pressures can be obtained without using two different types of materials. That is, according to the present invention, it is possible to obtain different sealing pressures for each sealing surface with only a simple U-shaped sealing member. As a result, waterproofness can be secured with a simpler configuration.

It is a perspective view of the survey meter which is an embodiment of the present invention. It is a top view of a main body unit. It is the partial exploded perspective view which looked at the main body unit from the back side. It is a disassembled perspective view of a battery cover and a sealing member. It is sectional drawing of a sealing member. It is the X section enlarged view in FIG. It is AA sectional drawing of FIG. It is the Y section enlarged view of FIG. It is a figure which shows another seal structure. It is a figure which shows another seal structure. It is a figure which shows another seal structure.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a survey meter 10 according to an embodiment of the present invention. 2 is a plan view of the main unit 12, and FIG. 3 is a partially exploded perspective view of the main unit viewed from the back side.

  The survey meter 10 is a portable radiation measurement device, and is roughly classified into a substantially flat plate-shaped main body unit 12 and a detection unit 14 that can be attached to and detached from the main body unit 12. The main unit 12 and the detection unit 14 are connected by a wired communication method. Of course, instead of the wired communication system, the units 12 and 14 may be connected by a wireless communication system.

  The main unit 12 has a box-shaped case 11. The case 11 has a substantially rectangular shape in which the length in the front-rear direction (Y-axis direction length in the drawing) is longer than the width direction length (length in the X-axis direction in the drawing) in plan view. The thickness of the case 11 (the length in the Z-axis direction in the figure) is sufficiently smaller than the length in the front-rear direction and the length in the width direction, and the case 11 as a whole has a thin flat plate shape.

  As shown in FIG. 3, the case 11 of the present embodiment includes a case body 30 and a battery cover 50 that is detachable from the case body 30. The case main body 30 is further composed of an upper case piece 32 and a lower case piece 31 that are shaped like a substantially box-shaped body divided into two in the thickness direction. In an internal space configured by combining the upper case piece 32 and the lower case piece 31, a communication unit, a control unit, a memory, various electric wirings, and the like that constitute the main unit 12 are accommodated. The battery cover 50 is detachable from the lower case piece 31, and the dry battery 100 is accommodated in a space formed between the battery cover 50 and the lower case piece 31. The dry battery 100 is an electric energy source for driving the main unit 12 and is appropriately replaced by the user.

  On the surface of the case 11, a touch panel monitor 16, operation buttons 18, and a connection unit 20 are provided. The touch panel monitor 16 includes a liquid crystal display and a touch panel (touch sensor), and functions as a user interface that also serves as an input unit and a display unit. The touch panel monitor 16 displays measured values of radiation and the like. In addition, an icon group for instructing various processes is displayed on the touch panel monitor 16, and the measurer may perform various inputs using the icon group.

  The connection unit 20 is a cable jack into which the connector of the cable 46 drawn from the detection unit 14 is inserted. The detection unit 14 and the main unit 12 are connected by inserting the connector of the cable 46 drawn from the detection unit 14 into the cable jack (connection portion 20) of the main unit 12, and the connector is connected to the cable jack (connection portion 20). The connection is canceled by removing it from). In the present embodiment, a plurality of types of detection units 14 are prepared for one main unit 12, and the detection units 14 connected to the main unit 12 can be exchanged as necessary.

  A handle 22 is erected from the upper surface of the case 11. The handle 22 has a bridge shape with one end attached to the vicinity of the rear end of the main unit 12 and the other end attached to a position adjacent to the touch panel monitor 16. The handle 22 is located at the center in the width direction of the main unit 12 and extends in the front-rear direction. During radiation measurement, the user holds the handle 22 with one hand and the detection unit 14 with the other hand, and directs the detection surface 44 of the detection unit 14 toward the measurement target.

  A slide rail 23 is attached to the upper surface of the handle 22. The slider fixed to the detection unit 14 can slide along the slide rail 23. Then, the detection unit 14 is mounted on the main unit 12 by moving the detection unit 14 rearward with respect to the main unit 12 and inserting a slider into the slide rail 23.

  The main unit 12 includes a communication unit that receives measurement value data sent from the detection unit 14, a control unit that controls the operation of the main unit 12, a memory that stores measurement value data, and power. A battery to be supplied is built in. The measured value is displayed on the touch panel monitor 16 in a predetermined display format under the control of the control unit. The main unit 12 has a CPU, for example, and the function of the control unit is realized by the CPU executing a program, for example.

  The detection unit 14 is a unit that detects radiation. Inside the detection unit 14, a radiation detector such as a scintillation detector or a GM tube is incorporated. When a scintillation detector is employed, a scintillator for detecting radiation and a photomultiplier tube are built in the detection unit 14. The detection unit 14 includes an amplifier, a waveform shaping circuit, a pulse height discrimination circuit, a counter that counts the number of times of detection of radiation, a calculation unit that calculates a coefficient factor and a dose rate of radiation, and a measurement value that is a result of the calculation. A communication unit for sending the data to the main unit 12 is incorporated. The detection unit 14 includes, for example, a CPU and a memory, and the functions of the counter and the calculation unit are realized by the CPU executing a program, for example.

  Each of the detection units 14 includes a round bar-shaped gripping unit 40 and a head unit 42 connected to the front end of the gripping unit 40. On the peripheral surface of the grip portion 40, a slider that is slid and inserted into the slide rail 23 described above and an operation button 49 are provided. Further, a cable 46 for exchanging electrical signals with the main body unit 12 is drawn from the rear end of the grip portion 40.

  By the way, since such survey meter 10 is often used in an environment with a lot of dust and moisture, a sufficient waterproof function is required. In order to ensure waterproofness, it is necessary that a plurality of case pieces are assembled in a liquid-tight manner. In the case of the survey meter 10, the upper case piece 32 and the lower case piece 31 are assembled with accuracy in advance by the manufacturer, and are hardly disassembled thereafter. Therefore, the waterproofness of the upper case piece 32 and the lower case piece 31 is relatively easily secured.

  On the other hand, the battery cover 50 is attached to and detached from the lower case piece 31 by the user every time the battery is replaced. For this reason, it has been difficult to maintain high assembly accuracy. Therefore, in this embodiment, a special seal structure is provided between the lower case piece 31 and the battery cover 50 in order to absorb assembling errors and the like and to ensure stable waterproofness. Hereinafter, this seal structure will be described with reference to FIGS. FIG. 4 is an exploded perspective view of the battery cover 50 and the seal member 60, and FIG. 5 is a cross-sectional view of the seal member 60. FIG. 6 is an enlarged view of a portion X in FIG.

  As shown in FIG. 4, the seal member 60 is an endless seal member assembled to the periphery of the battery cover 50. A substantially rectangular accommodation groove 52 corresponding to the shape of the seal member 60 is formed on the inner surface of the battery cover 50. The seal member 60 is inserted and accommodated in the accommodation groove 52.

  The seal member 60 is made of a flexible material such as rubber and has moderate elasticity. As shown in FIG. 5, the seal member 60 has a first leg portion 61, a second leg portion 62, and a connecting portion 63 that connects the end portions of the first leg portion 61 and the second leg portion 62. The cross section is substantially U-shaped. The seal member 60 has a substantially rectangular endless shape, but the first leg portion 61 is located on the inner side of the second leg portion 62 and is shorter than the second leg portion 62. The difference in length between the leg portions 61 and 62 is determined according to the required sealing pressure, the shape of the sealing surface of the lower case piece 31 described later, and the like. However, in any case, by making the lengths of the two leg portions 61 and 62 different, different sealing pressures can be obtained for the leg portions 61 and 62.

  The battery cover 50 is a case piece made of resin, metal, or the like and disposed to face the lower case piece 31. On the inner surface of the battery cover 50, there are formed a claw 51 that engages with the lower case piece 31, a lock hole 53 in which a lock member is inserted and removed, a storage groove 52 in which the above-described seal member 60 is stored. The housing groove 52 has a substantially rectangular shape in which the periphery of the battery cover 50 is offset inward, and the bottom surface (bottom surface of the groove) is a flat surface.

  The lower case piece 31 is a case piece constituting the case main body 30 in cooperation with the upper case piece 32. On the bottom surface of the lower case piece 31, a locking hole 34 for locking the claw 51 of the battery cover 50, a locking member 38, and the like are provided. The lock member 38 allows / restricts the battery cover 50 from being removed, and a part (not shown) of the lock member 38 is inserted into and removed from the lock hole 53. When the battery cover 50 is attached to the lower case piece 31, the first and second leg portions 61 and 62 of the seal member 60 are in contact with and closely contact the bottom surface of the lower case piece 31 to ensure a liquid-tight seal. . Hereinafter, of the bottom surface of the lower case piece 31, the surface with which the first leg portion 61 abuts is referred to as the first seal surface 35, and the surface with which the second leg portion 62 abuts is referred to as the second seal surface 36 (see FIG. 6). . As described above, since the first leg portion 61 is located on the inner side of the second leg portion 62, the first seal surface 35 in contact with the first leg portion 61 is more than the second seal surface 36. It will be located inside. In the present embodiment, the second seal surface 36 is a flat surface substantially parallel to the inner surface of the battery cover 50. On the other hand, the 1st seal surface 35 is an inclined surface where the space | interval with the inner surface of the battery cover 50 spreads as it approaches an outer side.

  Next, the operation of the seal structure having the above configuration will be described with reference to FIGS. 7 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 8 is an enlarged view of a Y portion in FIG. As shown in FIG. 7 and as described above, the battery cover 50 is disposed to face the lower case piece 31. At this time, the seal member 60 is housed in the housing groove 52 of the battery cover 50. At this time, as shown in FIG. 7, the seal member 60 is such that the connecting portion 63 is positioned on the battery cover 50 side, and the first and second leg portions 61 and 62 protrude toward the lower case piece 31. It is an arrangement. And the front-end | tip of the 2nd leg part 62 contact | abuts and closely_contact | adheres to the 2nd seal surface 36 which is a flat surface. At this time, the tip end of the second leg portion 62 is pressed against the second seal surface 36 as shown by a two-dot chain line in FIG. Then, due to this crushing, the second leg portion 62 and the second seal surface 36 are securely adhered and sealed.

  The first leg portion 61 located on the inner side of the second leg portion 62 is located on the inner side of the second seal surface 36 and is in contact with and in close contact with the inclined first seal surface 35. At this time, the tip of the first leg portion 61 bends along the inclination of the first seal surface 35 as shown by a two-dot chain line in FIG. And by this bending, the 1st leg part 61 and the 1st seal surface 35 contact | adhere reliably, and are sealed.

  That is, in the present embodiment, there are two types of seal structures, that is, a seal structure including the first seal surface 35 and the first leg portion 61, and a seal structure including the second seal surface 36 and the second leg portion 62. become. These two types of seal structures have different seal pressures by making the lengths of the leg portions 61 and 62 and the shapes of the seal surfaces 35 and 36 different. In the present embodiment, since the second leg portion 62 located on the outer side is longer than the first leg portion 61, the outer seal structure exhibits a higher sealing pressure than the inner seal structure. However, this outer seal structure has a problem that it is relatively weak against intrusion of liquids such as water.

  That is, consider a case where a liquid such as water enters from the outside and the second leg 62 is subjected to water pressure in the direction of the broken line arrow in FIG. In this case, the second leg portion 62 is easily bent inward due to water pressure, and as a result, there is a risk of allowing intrusion of water or the like. In order to avoid such a problem, the length of the second leg portion 62 is made longer, or the second leg portion 62 is made of a harder material, and the seal between the second leg portion 62 and the second seal surface 36 is formed. It is also possible to increase the pressure. However, when the sealing pressure is excessively increased, the case pieces such as the battery cover 50 and the lower case piece 31 may bend due to the reaction force from the sealing member 60. The bending of the case piece not only makes the appearance worse, but also makes it difficult to ensure the sealing performance. Such a problem of bending of the case piece is particularly likely to occur when the case piece is thinned for weight reduction.

  In the present embodiment, in order to prevent liquid such as water reliably while preventing such bending of the case piece, the first leg 61 and the first leg 61 are disposed inside the second leg 62 and the second seal surface 36. A sealing surface 35 is provided. Since the first leg portion 61 is shorter than the second leg portion 62, its sealing pressure is lower than that of the second leg portion 62. However, the first leg portion 61 is bent along the first seal surface 35 that is an inclined surface. In this case, the higher the water pressure applied to the first leg portion 61, the higher the sealing pressure between the first leg portion 61 and the first seal surface 35. That is, when the liquid enters, the first leg 61 is applied with a force in the direction as indicated by the solid arrow in FIG. 8 due to the water pressure. Since the direction of this force is the direction in which the first leg 61 is pressed against the first seal surface 35, the higher the water pressure, the higher the seal pressure. As a result, by providing the first leg portion 61 and the first seal surface 35, intrusion of liquid such as water can be effectively prevented, and the waterproofness of the survey meter can be further improved.

  Here, although the first leg portion 61 and the first seal surface 35 effectively prevent the intrusion of the liquid, in the state before the liquid intrusion (the state where the force in the direction of the solid line arrow is not generated), the seal pressure is It is small. Therefore, excessive reaction force does not occur in the battery cover 50 and the lower case piece 31, and deformation of these case pieces can be effectively prevented.

  Further, as is apparent from the above description, in the present embodiment, the first leg portion 61 and the second leg portion 62 are the same part integrally molded of the same material. Moreover, the shape is a very simple shape with a substantially U-shaped cross section. Therefore, the seal structure of the present embodiment can be obtained relatively easily and inexpensively, and an increase in the number of parts can be prevented. That is, according to this embodiment, waterproofness can be secured with a simpler configuration.

  In addition, the structure demonstrated so far is an example, and if a sealing member has two leg parts from which length mutually differs, another structure may be changed suitably. For example, in this embodiment, an inclined surface (first seal surface 35) is arranged on the inner side, and a flat surface (second seal surface 36) is arranged on the outer side, but this may be reversed as shown in FIG. Good. In the present embodiment, the seal member 60 is attached to the battery cover 50, but the seal member 60 may be attached to the lower case piece 31 and the battery cover 50 may be provided with a seal surface. Further, not only between the lower case piece 31 and the battery cover 50 but also between other case pieces, for example, between the lower case piece 31 and the upper case piece 32, a similar seal structure may be arranged.

  In the present embodiment, the seal surface that contacts the first leg 61 (inner leg) is an inclined surface, and the seal surface that contacts the second leg 62 (outer leg) is a flat surface. If different seal pressures can be obtained, the first and second seal surfaces 35 and 36 are both inclined surfaces as shown in FIG. 10, or the first and second seal surfaces 35 as shown in FIG. , 36 may be flat surfaces.

10 Survey Meter, 11 Case, 12 Main Unit, 14 Detection Unit, 16 Touch Panel Monitor, 18 Operation Button, 20 Connection, 22 Handle, 23 Slide Rail, 30 Case Main Body, 31 Lower Case Piece, 32 Upper Case Piece, 34 Locking Hole, 35 First seal surface, 36 Second seal surface, 38 Lock member, 40 Grip part, 42 Head part, 44 Detection surface, 46 Cable, 49 Operation button, 50 Battery cover, 51 Claw, 52 Housing groove, 53 Lock Hole, 60 Seal member, 61 First leg, 62 Second leg, 63 Connecting part, 100 Dry cell.

Claims (4)

A survey meter for measuring radiation,
A case having a first case piece and a second case piece disposed opposite to the first case piece;
A seal member that is disposed between the first case piece and the second case piece and seals between the two in a liquid-tight manner;
With
The seal member has a substantially U-shaped cross section having a first leg, a second leg located outside the first leg, and a connecting part that connects ends of the first and second legs. Shape,
The first leg and the second leg have different lengths from each other,
Survey meter characterized by that. The survey meter according to claim 1,
The survey meter, wherein the second leg is longer than the first leg. The survey meter according to claim 1 or 2,
The first and second leg portions protrude from the second case piece side toward the first case piece,
Of the one case piece, the first abutment surface with which the first leg abuts is an inclined surface that increases in distance from the first case piece as it approaches the outside.
Of the one case piece, the second contact surface with which the second leg abuts is a flat surface having a constant distance from the first case piece.
Survey meter characterized by that. The survey meter according to claim 3, wherein
The survey meter according to claim 1, wherein the first leg portion is in contact with the inclined surface in a state in which a tip thereof is bent outward.