Weighing device

Abstract

To provide a weighing device that can effectively suppress weighing errors. [Solution] The weighing device 1 comprises a weighing pan 2 on which an object to be weighed is placed, a pan support portion 3 that supports the weighing pan 2, a weighing mechanism 4 connected to the pan support portion 3 for weighing the mass of the object placed on the weighing pan 2, an inner housing 5 that houses the weighing mechanism 4, an outer housing 6 connected to the inner housing 5 and covering the periphery of the inner housing 5, and an elastic member 7 interposed between the inner housing 5 and the outer housing 6 at the connection point between the inner housing 5 and the outer housing 6.

Description

Technical Field

[0001] The present disclosure relates to a weighing device.

Background Art

[0002] Patent Document 1 discloses an electronic scale that allows a user to recognize the magnitude of disturbances such as vibrations from the outside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As disclosed in the above Patent Document 1, when a disturbance such as vibration from the outside is applied to an electronic scale, the weighing mechanism for weighing the mass of the object to be weighed is affected by the disturbance, and as a result, a weighing error may occur. The mechanism disclosed in the above Patent Document 1 only allows the user to recognize the magnitude of the disturbance, and there is room for improvement from the perspective of reducing the influence of the disturbance on the weighing mechanism and suppressing the weighing error.

[0005] An object of the present disclosure is to provide a weighing device that can effectively suppress weighing errors.

Means for Solving the Problems

[0006] The present disclosure includes the weighing devices of the following [1] to [6].

[0007] [1] A weighing pan on which an object to be weighed is placed, A pan receiver that supports the weighing pan, A weighing mechanism that is connected to the pan receiver and weighs the mass of the object to be weighed placed on the weighing pan, An inner housing that houses the weighing mechanism, An outer housing connected to the inner housing and covering the periphery of the inner housing, A weighing device comprising an elastic member interposed between the inner housing and the outer housing at the connection point between the inner housing and the outer housing.

[0008] In the weighing device described in [1] above, the weighing mechanism is housed inside the inner housing, and the outer housing is provided so as to cover the outside of the inner housing. As a result, the outer housing is susceptible to external disturbances such as vibrations. If such vibrations are applied to the outer housing, and the contact state between the outer housing and the inner housing changes, the characteristics of the outer housing (e.g., natural frequency) may change in accordance with the change in the contact state. Such changes in the characteristics of the outer housing can affect the weighing mechanism, potentially causing weighing errors. In contrast, in the weighing device described above, an elastic member is interposed at the connection point between the inner housing and the outer housing, thereby stabilizing the contact state between the outer housing and the inner housing. This suppresses changes in the characteristics of the outer housing as described above, and effectively suppresses weighing errors.

[0009] [2] Further comprising a support portion connected to the outer housing and for supporting the outer housing with respect to a predetermined mounting surface, The weighing device [1] wherein the inner housing is supported by the outer housing via the elastic member at the connection point and is not in contact with the mounting surface.

[0010] According to the configuration described in [2] above, the effects of external vibrations are mainly applied to the outer housing, which is in contact with the mounting surface via the support. Furthermore, since the inner housing is supported by the outer housing via an elastic member so as not to come into contact with the mounting surface, the elastic member is appropriately compressed by the load of the inner housing on the outer housing, thereby effectively enhancing the stability of the contact between the outer housing and the inner housing via the elastic member. As a result, the influence of vibrations of the outer housing on the weighing mechanism can be more effectively suppressed.

[0011] [3] No electrical components are placed in the space between the inner housing and the outer housing. The aforementioned weighing mechanism includes a sensor having a predetermined natural frequency. The weighing device [1] or [2], wherein the outer housing has a natural frequency different from the natural frequency of the sensor.

[0012] In the configuration described in [3] above, since no electrical components are placed between the inner and outer housings, it is not necessary to seal the connection between the inner and outer housings for waterproofing. However, by providing an elastic member, the contact state of the outer housing with respect to the inner housing can be stabilized, and the natural frequency of the outer housing can be maintained at a level different from that of the sensor. In other words, it is possible to suppress changes in the contact state of the outer housing with respect to the inner housing due to disturbances such as vibrations applied to the outer housing, and consequently, changes in the characteristics of the outer housing, such as its natural frequency (for example, becoming close to the natural frequency of the sensor). As a result, the influence of vibrations of the outer housing on the sensor can be suppressed, and measurement errors can be effectively reduced.

[0013] [4] The elastic member is positioned in part of the connection point between the inner housing and the outer housing, according to any of the weighing devices [1] to [3].

[0014] According to the configuration described in [4] above, by placing an elastic member in part of the connection point, the amount of elastic member required can be reduced, and as described above, a configuration that can suppress weighing errors can be realized at a low cost.

[0015] [5] The elastic member is arranged over the entire connection point between the inner housing and the outer housing, any of the weighing devices [1] to [3].

[0016] According to the configuration described in [5] above, it is possible to eliminate any points where the inner housing and the outer housing directly contact each other, and to realize a configuration in which the inner housing and the outer housing contact each other via an elastic member at the entire connection point. This makes it possible to stabilize the contact state of the outer housing with respect to the inner housing even more effectively, thereby enhancing the effect of suppressing the weighing error described above.

[0017] [6] The outer housing has side walls extending in a substantially vertical direction so as to cover the periphery of the inner housing. The inner housing is connected to the upper end portion of the side wall. The elastic member is provided so as to cover the upper end portion of the side wall, and is a weighing device according to any one of [1] to [5].

[0018] According to the configuration of [6] above, while appropriately supporting (connecting) the inner housing by the upper end portion of the side wall of the outer housing, by providing an elastic member at the support portion, the contact state of the outer housing with respect to the inner housing can be effectively stabilized, so that the above-described effect of suppressing the weighing error can be enhanced.

Effects of the Invention

[0019] According to the present disclosure, it is possible to provide a weighing device capable of effectively suppressing a weighing error.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a perspective view of a weighing device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the weighing device. [Figure 3] FIG. 3 is a top view of the weighing device. [Figure 4] FIG. 4 is a perspective view showing the arrangement configuration inside the weighing device. [Figure 5] FIG. 5 is a cross-sectional view of the weighing device taken along the line V-V of FIG. 1. [Figure 6] FIG. 6 is a cross-sectional view of the weighing device taken along the line VI-VI of FIG. 1. [Figure 7] FIG. 7 is an enlarged cross-sectional view of the connection portion between the inner housing and the outer housing.

Modes for Carrying Out the Invention

[0021] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. In the following description, the same reference numerals will be used for the same or equivalent elements, and redundant explanations will be omitted. Furthermore, in the drawings, some parts are exaggerated in order to clearly illustrate the characteristic parts of the embodiment. For this reason, the dimensional ratios of each part in the drawings may differ from the actual dimensional ratios. [Overall configuration of the weighing device]

[0022] As shown in Figures 1 to 6, the weighing device 1 comprises a weighing pan 2, a pan support 3, a weighing mechanism 4, an inner housing 5, an outer housing 6, and an elastic member 7. Four support legs 8 are provided at the four corners of the bottom wall 61 of the outer housing 6 to support the outer housing 6. The weighing device 1 is an electronic scale configured to measure the weight of an item placed on the weighing pan 2. Note that the weighing pan 2 is not shown in Figures 2 and 3.

[0023] The weighing pan 2 has a weighing surface 2a on which the object to be weighed is placed. The weighing surface 2a extends along the horizontal direction and has, for example, a square or rectangular shape. In the following description, the direction perpendicular to the weighing surface 2a is called the Z-axis direction (vertical direction), one direction perpendicular to the Z-axis direction is called the Y-axis direction (in this embodiment, the direction along the straight line L (see Figure 4) where the fixed end 41a and the free end 41b of the weighing mechanism 4 are aligned), and the direction perpendicular to both the Z-axis direction and the Y-axis direction is called the X-axis direction. The X-axis direction and the Y-axis direction, respectively, are parallel to the horizontal direction.

[0024] The pan support portion 3 is a member (pan base) that supports the weighing pan 2 from below. As shown in Figures 2, 3, 5, and 6, the pan support portion 3 is positioned above the weighing mechanism 4, the inner housing 5, and the outer housing 6. The pan support portion 3 has a first portion 31 that occupies the central part of the pan support portion 3, four second portions 32 that protrude outward from the four corners of the first portion 31, and two third portions 33. Each of the two third portions 33 is positioned between two adjacent second portions 32 in the X-axis direction and protrudes outward from the first portion 31. The first portion 31 is fixed to the weighing mechanism 4 (the upper surface 41d of the free end 41b of the first strain-generating body 41, which will be described later) by a plurality (four, for example) of screws 21. As an example, one fixed end 31a of the first part 31 in the Y-axis direction (the lower side in Figure 3) is fixed to the free end 41b of the first strain body 41. A heat shield member 13, which will be described later, is placed between the first part 31 and the free end 41b of the first strain body 41. A through hole 31b is provided in the central part of the first part 31.

[0025] The dish receiving portion 3 further includes a plurality (four in this embodiment) of first protrusions 71, a plurality (two in this embodiment) of second protrusions 72, a plurality (six in this embodiment) of first elastic members 81, a plurality (four in this embodiment) of second elastic members 82, and a plurality (four in this embodiment) of third elastic members 83. The four first protrusions 71 are provided on each of the four second portions 32. The two second protrusions 72 are provided on each of the two third portions 33.

[0026] The weighing mechanism 4 is a mechanism for weighing the mass of an object placed on the weighing pan 2. As shown in Figures 4 to 6, the weighing mechanism 4 has a first strain body 41, a second strain body 42, and a weight placement section 43. Each of the first strain body 41 and the second strain body 42 has a roughly rectangular parallelepiped (rectangular block) shape. Each of the first strain body 41 and the second strain body 42 has a so-called Roberval mechanism. Each of the first strain body 41 and the second strain body 42 is an elastic body made of a metal such as aluminum alloy or stainless steel.

[0027] The first strain-generating body 41 extends along the Y-axis direction in the central part of the inner housing 5 in the X-axis direction when viewed from the Z-axis direction. The first strain-generating body 41 has a fixed end 41a and a free end 41b. The fixed end 41a is fixed to the bottom wall 51 of the inner housing 5, which will be described later, via a support member 9. In other words, the fixed end 41a is fixed to the inner housing 5. The free end 41b is positioned parallel to the fixed end 41a in the Y-axis direction. The free end 41b has a projection 41c that protrudes upward, and the upper surface 41d of the projection 41c is connected to the first part 31 via a heat shield member 13. In other words, the free end 41b is connected to the pan support part 3. The free end 41b is connected to the weighing pan 2 via the pan support part 3 and is the part to which the load from the weighing pan 2 is applied. The first strain-generating body 41 has a lever mechanism (not shown) for reducing the load from the weighing pan 2.

[0028] The weighing mechanism 4 further includes a tuning fork sensor 40 (vibration-type load sensor) incorporated (fixed) into the first strain body 41. For example, when an object to be weighed is placed on the weighing pan 2, a load corresponding to the weight of the object is applied to the free end 41b of the first strain body 41, causing the first strain body 41 to deform. Then, a load corresponding to the deformation of the first strain body 41 is applied to the tuning fork sensor 40, and the vibration frequency of the tuning fork vibrator in the tuning fork sensor 40 changes according to the magnitude of the load. A weight sensor (not shown) is connected to the tuning fork sensor 40, which is configured to measure the weight of the object to be weighed based on the vibration (vibration frequency) of the tuning fork vibrator. The configuration of the weighing mechanism 4 is not limited to the tuning fork type described above, and other configurations such as a strain gauge type may be used.

[0029] The second strain body 42 is fixed to the first strain body 41. For example, the second strain body 42 is smaller than the first strain body 41. The weight placement section 43 is fixed to the second strain body 42. The weight W is placed on the weight placement section 43 by a weight moving mechanism (not shown) configured to grip and move the weight W. When the weight W is placed on the weight placement section 43, the second strain body 42 deforms. Then, a load corresponding to the deformation of the second strain body 42 is applied to the tuning fork sensor 40. This allows the weighing mechanism 4 (tuning fork sensor 40) to be calibrated. Note that when weighing an object, the weight W is not placed on the weight placement section 43, but is held, for example, by the weight moving mechanism.

[0030] The inner housing 5 is a component that houses the weighing mechanism 4. As shown in Figures 2 to 6, the inner housing 5 is located below the pan holder 3. The inner housing 5 has a bottom wall 51, side walls 52, a top wall 53, and a lid 54. The bottom wall 51, side walls 52, and lid 54 define the housing space V in which the weighing mechanism 4 is housed. The bottom wall 51 is located below the weighing mechanism 4. The fixed end 41a of the first strain-generating body 41 is fixed to the bottom wall 51 via a support member 9. The side wall 52 is positioned to cover the sides of the weighing mechanism 4. The side wall 52 is formed in a rectangular cylindrical shape that extends upward, connected to the edge of the bottom wall 51, so as to surround the weighing mechanism 4 (housing space V) when viewed from the Z-axis direction.

[0031] The top wall 53 is connected to the upper end 52a of the side wall 52 (the end opposite to the end of the side wall 52 that is connected to the bottom wall 51). The top wall 53 extends horizontally so as to project outward from the upper end 52a and is formed in a substantially rectangular ring shape when viewed from the Z-axis direction. The lid 54 is fixed to the upper end 52a of the side wall 52, for example by screws (not shown), so as to close the opening defined by the upper end 52a of the side wall 52 (close the storage space V). The lid 54 is located below the pan head 3 and extends horizontally. The lid 54 is provided with a through hole 54a for the projection 41c of the first strain body 41 to pass through. In other words, the free end 41b is connected to the pan head 3 located above the lid 54 by passing through the lid 54 via the through hole 54a.

[0032] The inner housing 5 has an upper surface 5a facing the dish receiving portion 3. For example, the upper surface 5a is composed of the upper surface of the side wall 52, the upper surface of the top wall 53, and the upper surface of the lid portion 54. The upper surface 5a is formed in a substantially rectangular shape when viewed from the Z-axis direction. The inner housing 5 has four corners 55 when viewed from the Z-axis direction. For example, the four corners 55 are the parts that correspond to the four corners of the upper surface 5a when viewed from the Z-axis direction (parts included in the vicinity of the four corners). The inner housing 5 has four edges 56 when viewed from the Z-axis direction. Each of the four edges 56 is the part that connects two adjacent corners 55 and is the part that corresponds to the four sides of the upper surface 5a when viewed from the Z-axis direction (parts included in the vicinity of the four sides). The upper surface 5a is provided with a plurality of first opposing portions 91 that face the plurality of first protrusions 71 described above, and a plurality of second opposing portions 92 that face the plurality of second protrusions 72.

[0033] The outer housing 6 is a component that houses the inner housing 5. The outer housing 6 is connected to the inner housing 5 and is provided to cover the perimeter of the inner housing 5. As shown in Figures 1 to 6, the outer housing 6 is positioned below the pan head 3. The outer housing 6 has a bottom wall 61 and side walls 62. The bottom wall 61 is positioned below the bottom wall 51 of the inner housing 5. The bottom wall 61 is fixed to the bottom wall 51, for example, by screws (not shown). The side walls 62 are positioned to cover the sides of the side walls 52 of the inner housing 5. The side walls 62 are formed in a rectangular tubular shape that extends upward, connected to the edge of the bottom wall 61, so as to surround the side wall 52 when viewed from the Z-axis direction.

[0034] The elastic member 7 is an elastic member interposed between the inner housing 5 and the outer housing 6 at the connection point between the inner housing 5 and the outer housing 6. The elastic member 7 is, for example, a rubber member having a hardness of 60° or less. As shown in Figure 2, as an example, the elastic member 7 is formed in a substantially rectangular ring shape. The elastic member 7 is positioned between the top wall 53 of the inner housing 5 and the side wall 62 of the outer housing 6. As an example, the elastic member 7 is positioned in a groove 53a formed on the lower surface of the top wall 53 and is in contact with the upper end 62a of the side wall 62 (the end opposite to the end of the side wall 62 connected to the bottom wall 61) (see Figure 7). In other words, the top wall 53 of the inner housing 5 and the side wall 62 of the outer housing 6 are connected to each other via the elastic member 7. Note that the elastic member 7 is not shown in Figures 5 and 6.

[0035] As shown in Figures 3 to 6, the weighing device 1 includes a porous membrane 10 positioned to cover the through-hole 51a provided in the bottom wall 51, a diaphragm 11 positioned along the outer edge of the through-hole 54a in the lid 54, and a retaining plate 12 for fixing the diaphragm 11 to the lid 54, as a configuration for waterproofing and dustproofing. [Details of the connection configuration between the inner and outer enclosures and their effects]

[0036] As shown in Figures 2, 5, and 6, in the weighing device 1, the weighing mechanism 4 is housed inside the inner housing 5, and the outer housing 6 is provided so as to cover the outside of the inner housing 5. Therefore, the outer housing 6 is susceptible to external disturbances such as vibrations. If such vibrations are applied to the outer housing 6, and the contact state between the outer housing 6 and the inner housing 5 changes, the characteristics of the outer housing 6 (e.g., natural frequency) may change in accordance with the change in the contact state. Such a change in the characteristics of the outer housing 6 can affect the weighing mechanism 4, potentially causing weighing errors. In contrast, in the weighing device 1, an elastic member 7 is interposed at the connection point between the inner housing 5 and the outer housing 6, thereby stabilizing the contact state between the outer housing 6 and the inner housing 5. For example, when an external force is applied to the outer housing 6 and the outer housing 6 attempts to move toward the inner housing 5 at the contact point between the outer housing 6 and the inner housing 5, the elastic member 7 is appropriately compressed, so that the external force applied to the outer housing 6 is appropriately absorbed by the elastic member 7. As a result, the contact between the outer housing 6 and the inner housing 5 via the elastic member 7 can be stabilized. This suppresses changes in the characteristics of the outer housing 6 as described above, and effectively reduces weighing errors.

[0037] As shown in Figure 2, the weighing device 1 is connected to the outer housing 6 and is equipped with support legs 8 (support parts) for supporting the outer housing 6 against a predetermined mounting surface (horizontal plane). The inner housing 5 is supported by the outer housing 6 via an elastic member 7 at the connection point with the outer housing 6 and does not come into contact with the mounting surface (the surface to which the bottom surfaces of the support legs 8 make contact). With the above configuration, the effects of external vibrations are mainly applied to the outer housing 6, which is in contact with the mounting surface via the support legs 8. Furthermore, because the inner housing 5 is supported by the outer housing 6 via the elastic member 7 so as not to come into contact with the mounting surface, the elastic member 7 is appropriately compressed by the load of the inner housing 5 on the outer housing 6, thereby effectively increasing the stability of the contact between the outer housing 6 and the inner housing 5 via the elastic member 7. As a result, the influence of vibrations of the outer housing 6 on the weighing mechanism 4 can be more effectively suppressed. In other words, when vibration (disturbance) is applied to the outer casing 6 from the outside, the outer casing 6 and the inner casing 5 are stabilized to move together via the elastic member 7, and the outer casing 6 does not vibrate excessively relative to the inner casing 5 (i.e., the natural frequency of the outer casing 6 does not change).

[0038] As shown in Figures 2, 5, and 6, no electrical components are placed in the space between the inner housing 5 and the outer housing 6. Electrical components refer to electrical components such as wiring and electrical circuits. The weighing mechanism 4 includes a tuning fork sensor 40 (see Figure 5) having a predetermined natural frequency. The outer housing 6 has a natural frequency different from that of the tuning fork sensor 40. That is, the mass and rigidity of the outer housing 6 are designed such that, when the inner housing 5 is stably supported by the outer housing 6 as described above, it has a natural frequency different from that of the tuning fork sensor 40. In the above configuration, since no electrical components are placed between the inner housing 5 and the outer housing 6, it is not necessary to seal the connection between the inner housing 5 and the outer housing 6 for waterproofing. However, by providing the elastic member 7, the contact state of the outer housing 6 with respect to the inner housing 5 can be stabilized, and the state in which the natural frequency of the outer housing 6 is different from that of the tuning fork sensor 40 can be maintained. In other words, disturbances such as vibrations applied to the outer housing 6 can suppress changes in the contact state of the outer housing 6 with respect to the inner housing 5, and consequently, changes in the characteristics of the outer housing 6, such as its natural frequency (for example, becoming close to the natural frequency of the tuning fork sensor 40). As a result, the influence of vibrations of the outer housing 6 on the tuning fork sensor 40 can be suppressed, and weighing errors can be effectively suppressed. The weighing device 1 may also be equipped with a sensor of a different type than the tuning fork type (for example, an electromagnetic force balance type) instead of the tuning fork sensor 40. Since the above-mentioned natural frequency problem can also occur with such a sensor, the configuration of this embodiment is effective. In other words, by stabilizing the contact state of the outer housing 6 with respect to the inner housing 5, the natural frequency of the outer housing 6 (a natural frequency different from the natural frequency of the sensor) can be stabilized. This suppresses the influence of vibrations of the outer housing 6 on the sensor, which would increase if the natural frequency of the outer housing 6 and the natural frequency of the sensor were close, and effectively suppresses weighing errors in the sensor.

[0039] As shown in Figure 2, the elastic member 7 is positioned over the entire connection point between the inner housing 5 and the outer housing 6. With this configuration, it is possible to eliminate any points where the inner housing 5 and the outer housing 6 directly contact each other, and to realize a configuration in which the inner housing 5 and the outer housing 6 contact each other via the elastic member 7 over the entire connection point. This makes it possible to stabilize the contact state of the outer housing 6 with respect to the inner housing 5 even more effectively, thereby enhancing the effect of suppressing the weighing error mentioned above.

[0040] As shown in Figures 2 and 5 to 7, the outer housing 6 has a side wall 62 that extends substantially vertically to cover the periphery of the inner housing 5. The inner housing 5 is connected to the upper end 62a of the side wall 62. The elastic member 7 is provided to cover the upper end 62a of the side wall 62. In this embodiment, a groove 53a formed on the lower surface of the top wall 53 of the inner housing 5 is connected to the side wall 62 (upper end 62a) of the inner housing 5 via an elastic member 7 that is provided with a U-shaped cross-section to cover the upper end 62a. With the above configuration, the inner housing 5 is appropriately supported (connected) by the upper end 62a of the side wall 62 of the outer housing 6, and by providing the elastic member 7 in the support portion, the contact state of the outer housing 6 with the inner housing 5 can be effectively stabilized, thereby enhancing the effect of suppressing the weighing error described above. [Differentiation]

[0041] This disclosure is not limited to the embodiments described above. The materials and shapes of each of the above-described components are not limited to those described above, and various materials and shapes can be used. Furthermore, some of the components included in the above embodiments may be omitted or modified as appropriate. For example, although some characteristic components included in the above embodiments and some effects exhibited by each component have been described, the weighing device according to this disclosure does not necessarily have to be configured to exhibit all of the effects described in the above embodiments, and may be configured to exhibit only some of the effects described in the above embodiments. In the latter case, the weighing device only needs to have components that are essential to exhibit at least those components, and components that are not essential to exhibit those components may be omitted or modified as appropriate.

[0042] For example, in the above embodiment, the elastic member 7 is arranged over the entire connection point between the inner housing 5 and the outer housing 6 (the upper end portion 62a of the side wall 62), but the elastic member 7 may be arranged over a portion of the connection point between the inner housing 5 and the outer housing 6. In other words, there may be areas at the connection point between the inner housing 5 and the outer housing 6 where the elastic member 7 is not present. For example, in the above embodiment, as shown in Figure 2, the elastic member 7 is provided continuously to cover the entire upper end portion 62a of the side wall 62, but the elastic member 7 may be provided to cover a portion of the upper end portion 62a of the side wall 62. Alternatively, the elastic member 7 may be composed of multiple elastic members provided fragmentarily to cover a portion of the upper end portion 62a of the side wall 62. According to the above configuration, by arranging the elastic member 7 in a portion of the connection point, the amount of elastic member 7 required can be reduced, and a configuration that can suppress weighing errors as described above can be realized at low cost.

[0043] Furthermore, although the weighing device 1 in the above embodiment is configured to include a tuning fork sensor 40, the weighing device 1 may be a weighing device that does not include a tuning fork sensor 40. Also, although the weighing device 1 is configured as a load cell type weighing device having a strain-generating body, it may be a weighing device of a different type. In other words, the configuration in which the inner housing 5 and the outer housing 6 are connected via an elastic member 7 as described above may be applied to a weighing device of a different type than that of the above embodiment (for example, an electromagnetic force balance type). In that case as well, the same effects as in the above embodiment can be obtained. [Explanation of Symbols]

[0044] 1...Weighing device, 2...Weighing pan, 3...Pan holder, 4...Weighing mechanism, 5...Inner housing, 6...Outer housing, 7...Elastic member, 40...Tuning fork sensor, 62...Side wall.

Claims

1. A weighing pan on which the object to be weighed is placed, A plate support portion that supports the aforementioned measuring pan, A weighing mechanism connected to the pan holder, which weighs the mass of the object to be weighed placed on the weighing pan, An inner housing that houses the aforementioned weighing mechanism, An outer housing connected to the inner housing and covering the periphery of the inner housing, A weighing device comprising an elastic member interposed between the inner housing and the outer housing at the connection point between the inner housing and the outer housing.

2. The outer housing is connected to a support portion for supporting the outer housing with respect to a predetermined mounting surface, The weighing device according to claim 1, wherein the inner housing is supported by the outer housing via the elastic member at the connection point and is not in contact with the mounting surface.

3. No electrical components are placed in the space between the inner housing and the outer housing. The aforementioned weighing mechanism includes a sensor having a predetermined natural frequency. The weighing device according to claim 1, wherein the outer housing has a natural frequency different from the natural frequency of the sensor.

4. The weighing device according to claim 1, wherein the elastic member is disposed at a part of the connection point between the inner housing and the outer housing.

5. The weighing device according to claim 1, wherein the elastic member is arranged over the entire connection point between the inner housing and the outer housing.

6. The outer housing has side walls that extend substantially vertically so as to cover the periphery of the inner housing, The inner housing is connected to the upper end of the side wall, The weighing device according to claim 1, wherein the elastic member is provided so as to cover the upper end of the side wall.

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