JP5660805B2 - Weight sorter - Google Patents

Description

  The present invention relates to a weight sorter configured to measure a weight value of an object to be weighed by sliding the object to be weighed on at least a weighing table.

  2. Description of the Related Art Conventionally, as a weight sorter that slides an object to be weighed on a weighing table and measures the weight value of the object to be weighed, an object conveying surface of the weighing table has an inclination (for example, Patent Document 1, 2), and a configuration in which the article conveyance surface of the weighing platform is horizontal (for example, see Patent Document 3).

JP 57-158523 A JP 2003-214933 A JP 58-61878 A

Regarding the weight sorter exemplified in Patent Documents 1 to 3, the following (a) and (b) are given as reasons for sliding and weighing an object to be weighed on a weighing table.
(A) High-precision weight measurement can be performed at high speed.
(B) Since no conveying force is required, the configuration as a weight sorter can be simplified.

In order to transport the object to be weighed on the weighing platform, an endless traveling body such as a conveyor belt or chain is mounted on the weighing platform, and a motor that drives this endless traveling body is mounted on the weighing platform, and the motor is operated. In this case, vibration due to the eccentric load of the rotating body of the motor and vibration due to the difference in distributed load of the endless traveling body itself are mixed in the load signal as a noise signal, and the frequency of these noise signals is the natural vibration of the scale system. Since it is slower than the number, if it is attempted to process with a filter, there is a problem that a delay occurs in the load signal, resulting in a weight measurement error.
Further, when the motor is mounted on the weighing platform, there is a problem that the mass of the weighing platform is increased, the natural frequency of the weighing system is lowered, and the transient response of the load signal is delayed, so that it is not suitable for high-speed weighing. In order to reduce the mass of the weighing table, it is also possible to adopt a configuration in which a motor that drives an endless traveling body such as a conveyor belt or chain that transports the object to be weighed on the weighing table is installed on a fixed table outside the weighing table. However, in this case, tension is generated between the endless traveling body and the fixed base due to the driving force from the motor and the load of the conveyed article, and the force acting between the weighing base and the outside of the weighing base measures the weight. There may be a problem of error.

  Therefore, the weighing platform is not provided with the above-mentioned forced conveying means, and the weighing section is composed only of the weighing table, the load sensor that supports the weighing table, and the mounting bracket, and the driving of the feeding conveyor arranged at the front stage of the weighing table. Glide the object to be weighed on the weighing table with the inertial force applied by the force, or at least place the weighing table in an inclined position and cause the object to be weighed by generating a force along the inclined surface of the weighing table. A weight sorter with a configuration has been proposed and put into practical use.

However, in the case of a sliding type weight sorter, there is no forced conveying force on the weighing platform, so if the friction coefficient between the sliding surface of the weighing platform and the sliding surface of the object to be weighed is large or the friction coefficient changes, the friction force Due to the change in the weight, the residence time of the object to be weighed becomes longer or changes, and even if the object having the same weight is measured due to the change in the sliding state, the weight measurement value varies.
In addition, in a weight sorter having a weighing table with an inclined surface, it is arranged in front of the weighing table to send an object to be weighed to the weighing table, and the feeding table having an inclined surface also has a sliding surface. If the friction coefficient of the sliding surface is large or the friction coefficient changes, the staying time of the object to be weighed on the weighing platform will increase or change due to the change in friction force, and the same weight will be applied as the sliding state changes. Even when measuring a weighing object, the weight measurement value varies.

  In order to reduce the frictional force, in the device according to Patent Document 2, in order to reduce the frictional resistance of the sliding surface of the weighing platform, a contact between the sliding surface and the bottom surface of the object to be weighed is provided by providing a plurality of grooves on the sliding surface. By reducing the area, the frictional force acting on the sliding surface is reduced. Thereby, the change in speed at the time of sliding on the weighing table sliding surface of the object to be measured is reduced to increase the measurement accuracy.

  Moreover, in the apparatus which concerns on patent document 3, at the time of the transfer of the to-be-measured object horizontally conveyed from an infeed conveyor to the measuring stand, the deceleration by the frictional force of the to-be-measured object horizontally conveyed also on a measuring stand is carried out. In order to avoid this, a screw-type constant interval transport device is installed in front of the weighing table to keep the object to be weighed at a certain interval, and a claw-shaped pushing device that moves at a certain interval is provided to allow the object to be weighed to The pushing force is not lowered until most of the object is placed on the top, and the deceleration due to the frictional force until the object to be weighed is completely placed on the weighing table is prevented. However, when such a configuration is adopted, there is a problem that the apparatus is large and the cost is high.

By the way, if the objects to be weighed are heavy, such as cans, glass bottles, metal lumps, etc., if these objects repeatedly pass through the sliding surface of the weighing platform, the part including the sliding surface of the weighing platform will be removed. Even if it is made of a metal such as stainless steel (SUS), the sliding surface on the weighing platform is damaged and the friction coefficient increases, and the degree of deceleration gradually increases and stable weight measurement cannot be performed.
In addition, when the sliding surface portion of the weighing platform is made of SUS, since the specific gravity of the material is large in the case of SUS, the weighing platform cannot be made light. However, if the sliding surface portion of the weighing platform is made of, for example, resin or aluminum, the sliding surface has a large coefficient of friction, is easily damaged, and stable weight measurement accuracy cannot be obtained.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a weight sorter capable of performing highly accurate weight measurement stably over a long period of time.

In order to achieve the above object, a weight sorter according to the present invention comprises:
In a weight sorter comprising a weighing platform having a sliding surface for sliding an object to be weighed and configured to measure the weight of the object to be weighed by sliding the object to be weighed on the sliding surface,
The weighing platform is supported by a weighing platform support fixed to one end of the load sensor, and includes a plurality of single rails having a sliding contact surface portion having an upward convex curved surface that is in sliding contact with an object to be weighed. A hard film made of DLC is formed on the sliding contact surface portion of the single rail (first invention).

In the present invention, the plurality of single rails can be arranged in the shape of a U-shaped groove whose upper part is open , and the portion can be appropriately fixed with a fixing bracket (second invention).

According to the present invention, since the hard film is formed on at least the contact surface with the object to be weighed on the sliding surface on which the object to be weighed on the weighing platform is slid, it is possible to extremely increase the hardness of the sliding surface and The coefficient of friction of the surface can be lowered. In addition, since the hard film is made of DCL, the film can be easily formed on a metal or resin base material, and the film is not easily peeled off. Moreover, it is excellent in smoothness. Therefore, even when the object to be weighed is conveyed a large number of times, the degree of decrease in the conveyance speed can be reduced and stable and highly accurate weight measurement can be performed over a long period of time .

BRIEF DESCRIPTION OF THE DRAWINGS It is structure explanatory drawing of the weight sorter | selector which concerns on the 1st Embodiment of this invention, Plan view (a), X arrow directional view (a), YY sectional view (c) of (a) (C ') The figure for explaining the relation of the transient response signal by the state of rail friction Structure explanatory drawing of the weight sorter based on the 2nd Embodiment of this invention Structural explanatory diagram of a sliding feed base etc. according to the shape of the object to be weighed

  Next, specific embodiments of the weight sorter according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a structural explanatory view of a weight sorter according to a first embodiment of the present invention, and is a plan view (a), a view taken along arrow X in (a) (b) and a YY line in (a). Cross-sectional views (c) and (c ′) are respectively shown.

<Description of schematic configuration of weight sorter>
A weight sorter 1 shown in FIGS. 1 (a) and 1 (b) includes a pair of carry-in side transport chains 2 and 2, which are arranged in order from the upstream side to the downstream side along the transport path of the object to be weighed M, A stand 3 and a pair of carry-out side transfer chains 4 and 4 are provided.

<Description of the carry-in side transport chain>
The carry-in side conveyance chain 2 is wound around and mounted on a carry-in side chain guide 5 installed along the carry-in path of the object to be weighed M to the weighing table 3, and the object to be weighed M is driven by driving a motor (not shown). Carry into the weighing platform 3.

<Description of carry-out side transport chain>
The unloading-side transport chain 4 is wound around and mounted on an unloading-side chain guide 6 installed along the unloading path of the object to be weighed from the weighing table 3, and the object to be weighed M is driven by driving a motor (not shown). It is unloaded from the weighing platform 3 and further conveyed to the subsequent stage.

<Description of weighing platform>
The weighing table 3 is a sliding weighing table that slides the object to be weighed M without using a conveying means having a driving force, and has two rails 8 and 8 installed on the weighing table body 7. ing.

<Description of rail>
The two rails 8 and 8 extend horizontally straight along the transport path and are arranged in parallel to each other. The surface that forms the top of each rail 8 is a sliding surface having a sliding contact surface portion 8a that is in sliding contact with the object M.

<Description of support structure for weighing platform>
A load sensor support 9 is fixed on an installation base G on which the weight sorter 1 is installed. One end of a load sensor 10 such as a load cell or force balance is fixed to the load sensor support 9. The other end of the load sensor 10 and the weighing table body 7 are connected via a weighing table support 11. Thus, the weighing table 3 is supported on the installation base G via the weighing table support tool 11, the load sensor 10 and the load sensor support tool 9.

<Description of weighing platform attachment / detachment structure>
Between the weighing platform main body 7 and the weighing platform support 11, the weighing platform 3 can be easily detached from the weighing platform support 11 when the weighing platform 3 is cleaned or maintained. The weighing table attaching / detaching bracket 12 is interposed.

<Description of the operation to transport the object to be weighed>
The objects to be weighed M are transported from the left direction in FIGS. 1A and 1B by the power of the carry-in transport chain 2 and gradually move from the position indicated by the arrow A in the figure to the two rails 8 on the weighing platform 3. Move up 8
Here, m is the mass of the object to be weighed M, v _{0 is} the speed of the carry-in side conveyance chain 2, μ is the friction coefficient of the rail 8, and g is the acceleration of gravity. Assume that the speed changes to vx in the _meantime .
The frictional force acting on the workpiece M can be expressed by the following formula (1).
f = μF = μ · mg (1)
Further, since the change in momentum is equal to the impulse, the following formula (2) is established.
f · t = m · (v ₀ −v _x ) (2)
From the above equations (1) and (2), the friction coefficient μ of the rail 8 can be obtained as shown in the following equation (3).
μ · mg · t = m · (v ₀ −v _x )
μ = (v ₀ −v _x ) / (g · t) (3)
As apparent from the above equation (3), the larger the friction coefficient μ at a given elapsed time t v the value of _x is small, i.e. the degree of speed reduction increases.

<Exemplary description of objects to be weighed>
As the objects to be weighed M of the weight sorter 1, for example, many of them are enclosed in an iron can, a glass container, or a hard plastic container.

<Description of weight measurement method>
As a weight measurement method, when the object M reaches the vicinity of the weighing table 3, for example, the article sensor 13 is placed at a position indicated by a symbol A in FIG. 1B (hereinafter referred to as “A position”). When the article sensor 13 detects that the object M has reached the position A, a timer (not shown) is activated, and the position immediately before the object M is unloaded from the weighing table 3, that is, FIG. A weight measurement value is obtained based on a load signal from the load sensor 10 with a time point slightly before the position indicated by the middle symbol B (hereinafter referred to as “B position”) as a weight measurement time. There is also a method in which the article sensor 13 is arranged at the B position, and the weight measurement value is obtained by detecting that the object M has reached the B position.
Here, a fixed value is set for the operation time T of the timer.

<Description of weight measurement method>
However, when the friction coefficient μ is large as described above, the speed reduction amount also increases. When the speed decrease amount is large, the variation in the speed decrease amount itself becomes large, and the variation in the speed change amount on the weighing table 3 of the object M is also large. That is, the variation in the staying time on the weighing table 3 is increased.

<Description of weight measurement method>
In general, the weight sorter 1 is required to perform high-speed weighing, that is, to measure the weight of many objects to be weighed M in a short time. For this reason, the transient response of the load signal including the response of the filter in the measurement circuit or measurement calculation after the object M is placed on the weighing table 3 is the final value, that is, the load representing the true weight value of the object M. It is customary to set the weight measurement conditions in a state where the object M is unloaded from the weighing table 3 without responding to the signal.

<Description of weight measurement method>
The article sensor 13 detects that the object to be weighed M has reached the position A, and the weight is measured after a certain time T by operating the timer. In this case, the speed change is increased as the friction coefficient of the rail 8 is increased. Since the measurement object M slides on the two rails 8 and 8 on the weighing platform 3 most rapidly, the time immediately before reaching the B position is set as T.

<Explanation of relationship between rail friction coefficient and transient response signal>
FIG. 2 is a diagram for explaining the relationship of transient response signals depending on the state of rail friction.
FIG. 2A shows a conveyance state when the friction coefficient of the rail is relatively smallest. FIG. 2 (a) ′ shows a line (1) indicating a change in the load applied to the load sensor of an object to be weighed into the weighing platform, and a line (2) indicating a transient response signal that has passed through the filter. It is a thing.
Here, the time axis 0 is set at a position P immediately before the object M is placed on the weighing table 3. The position P ′ is a position at which the object M is completely placed on the weighing table 3, and requires time t ₁ (<t ₂ ) from the position P. Theoretically, the load W of the object M is completely applied to the load sensor 10 at the position of P ′. Then, as shown in FIG. 2A, the timer reaches time T immediately before the object M reaches the B position.

<Explanation of relationship between rail friction coefficient and transient response signal>
FIG. 2B shows a conveyance state when the friction coefficient of the rail is relatively largest. FIG. 2 (b) ′ shows a line (3) indicating a change in the load applied to the load sensor of an object to be weighed into the weighing platform, and a line (4) indicating a transient response signal that has passed through the filter. It is a thing.
Here, the time axis 0 is set at a position P immediately before the object M is placed on the weighing table 3. The position P ′ is a position P at which the object M is completely placed on the weighing table 3, and requires time t ₂ (> t ₁ ) from the position P. Theoretically, the load W of the object M is completely applied to the load sensor 10 at this position. Then, as shown in FIG. 2B, the timer reaches time T slightly before the object M of FIG. 2A where the object M reaches the B position.

<Explanation of relationship between rail friction coefficient and transient response signal>
As shown in FIGS. 2 (a ′) and 2 (b ′), when the rising time of the load load varies from t ₁ to t ₂ , the transient response signal of the load signal that passes through the filter according to each time is also obtained. As shown by lines (2) and (4) in FIGS.
Assuming that the weight measurement values by the respective transient response signals when the timer reaches the time T are W ₁ (T) and W ₂ (T), the magnitude relationship between them is expressed by the following equation (4).
W ₁ (T)> W ₂ (T) (4)
As shown in the above formula (4), even if the weight of the object M is the same, the weight measurement value varies depending on the friction coefficient. In this case, when the article sensor 13 is placed at the position P ′ and the timer M is operated at the operation time T ′ when the object M reaches the position P ′, the state shown in FIG. In this case, the weight measurement value is W ₃ (T) as shown in FIG. 5B ′. However, since the transient response load signal at the position of P ′ is w ₁ > w ₂ , W ₃ (T )> W ₂ (T), but the relationship expressed by the following formula (5) is maintained, which is also a problem.
W ₁ (T)> W ₃ (T)> W ₂ (T) (5)
Even if the article sensor 13 is arranged at the B position and the weight value is measured, if the time until the object M reaches the B position varies, the filter response will differ. Even if the weight is the same, the weight measurement value varies.

<Explanation of relationship between rail friction coefficient and transient response signal>
In addition, the article sensor 13 is installed at the position P ″, the timer is not set, and the weight is measured when the object to be weighed M reaches the position just before the unloading end (position B) of the weighing table 3. In any case, the rise time corresponding to the loading time of the object M to be loaded depending on the friction coefficient, and the length of time that the object M stays on the weighing table 3 completely. However, the transient response of the load signal differs according to the difference in the friction coefficient from time to time, and the weight measurement value varies even with the object M having the same weight.

<Explanation regarding conventional rail materials>
In order to avoid such a state, a stainless steel material (SUS material) is generally used as a material of the rail 8 that can maintain a friction coefficient as small as possible even if many objects M are repeatedly slid. Selected.
However, even if SUS material is used, the friction coefficient of SUS material is about 0.2, and when the object M is an iron can or glass bottle, these hard materials are repeatedly placed on the rail 8. As the object passes, it becomes scratched and the coefficient of friction increases. Furthermore, since the SUS material has a high density, it is heavy and the entire weighing table 3 is heavy, lowering the natural frequency of the weighing system and not suitable for high-speed weighing.

<Description of conventional measures to reduce the effect of friction coefficient>
As a conventional measure for reducing the influence of the coefficient of friction, Patent Document 3 discloses that the object to be weighed with a feed claw that moves at the same speed as the conveyor chain until just before the object to be weighed M is completely placed on the sliding weighing platform from the conveyor chain. A device has been proposed for feeding onto the weighing table so as not to decelerate due to the frictional force of the object M. To that end, it is necessary to keep the objects to be weighed from the previous stage of the weighing table, so a screw-type feeding device is also used. It must be attached and constitute a large-scale device.

<Explanation of measures of the present invention for reducing the weight of the apparatus and the influence of the friction coefficient>
In the weight sorter 1 of the present embodiment, aluminum, magnesium alloy or resin having a small specific gravity (specific gravity 3 or less) is selected as the material of the rail 8.
The top portion of the rail 8 may be a flat surface, but as shown in FIG. 1C, the contact area with the bottom surface of the object to be measured M is reduced as an upwardly convex curved shape. In addition, as shown in FIG. 1C ′, a round bar having a circular cross section may be used as the rail 8.
However, aluminum, magnesium alloy, or resin has a large coefficient of friction and is soft and scratches. Therefore, in the rail 8 made of these materials, a hard film is formed at least on the contact surface (sliding contact surface portion 8a) with the object M.

<Description of hard coating>
Examples of the material for forming the hard film on the sliding contact surface portion 8a of the rail 8 include ceramics, BCN-based superhard material, a mixture of metal and ceramics, and metal alloy.
Here, typical ceramic films include Ti element-containing hard films such as TiN and TiC, Ti-Al element-containing composite hard films such as composite nitrides containing Ti and Al, and Al ₂ O ₃ hard films. It is mentioned as a typical thing.
Typical examples of the high-hardness film made of a BCN-based superhard material include diamond, DLC (Diamond Like Carbon), cBN (cubic boron nitride), and the like.
A cermet is a typical example of a mixture of metal and ceramics.
Moreover, as a metal alloy, a Ni-Cl alloy etc. are mentioned as a representative example.
In addition, as a technique for coating the sliding contact surface portion 8a with a hard film, for example, dry methods such as wet methods such as electroplating, electroless plating, chemical conversion, chemical vapor deposition, physical vapor deposition, hot dipping, and thermal spraying. There is a law.

<Description of suitable hard coating>
As a material for forming a hard film on the sliding contact surface portion 8a of the rail 8, DLC is mentioned as an optimum material from the above list.
DLC has the characteristics that a film can be easily formed on a metal or resin substrate, and the film is not easily peeled off. It is extremely hard and not easily scratched, and has high wear resistance and excellent smoothness. Since the coefficient of friction is small (a coefficient of friction of 0.05 is also possible), excellent smoothness can be obtained stably over a long period of time even if the object M is repeatedly conveyed for a long time.

<Description of the operational effects of the weight sorter of the present embodiment>
According to the weight sorter 1 of the present embodiment, since a hard coating such as DLC is formed on the sliding contact surface portion 8a of the rail 8 on which the object M is slid, as disclosed in Patent Document 3 Even if a special feeding device such as a feeding claw or a constant interval device for that purpose is not provided, the object to be weighed M is fed onto the weighing table 3 with a small deceleration from the carry-on side transfer chains 2 and 2, and the weighing table 3 is also decelerated It can slide and move to the transport side carry-out chains 4 and 4. As a result, the influence on the variation of the transient response signal characteristics due to the frictional force can be made extremely small, so that highly accurate weight measurement can be performed stably over a long period. Also, the rail 8 is made of SUS or iron. Since a metal or a resin having a specific gravity of 3 or less, such as aluminum, an aluminum alloy, or a magnesium alloy, is not limited to a metal having a high density, the weighing table 3 can be lightened. Thereby, since the natural frequency of the scale system can be increased, there is an effect that the transient response as the measuring instrument is improved.
As described above, the weighing platform 3 on which the DLC film is formed has a low friction coefficient and maintains a low coefficient of friction for a long time due to the hard film, and improves the measurement accuracy and reduces the weight of the weighing unit. It plays a big role in simplifying the configuration.

[Second Embodiment]
FIG. 3 is an explanatory diagram of the structure of the weight sorter according to the second embodiment of the present invention.

<Description of schematic configuration of weight sorter>
The weight sorter 21 shown in FIG. 3 includes a sliding feed base 23 that is arranged in order from the upstream side to the downstream side along the conveyance path of the measurement object M from the supply device 22 that supplies the measurement object M. A weighing table 24 and a sliding delivery table 25 are provided.
In this weight sorter 21, a sliding feed table 23, a weighing table 24, and a sliding delivery table 25 are respectively inclined from a supply device 22 arranged at a predetermined height, and a sliding weighing table 25 is provided. As a tilt type weight sorter having 24, it has been widely used conventionally.
In addition, as the supply apparatus 22, a belt conveyor, a parts feeder, a vibration feeder, etc. are used.

<Description of the sliding feed base>
The sliding feed base 23 has a sliding surface for sliding the workpiece M supplied from the supply device 22. The sliding surface is inclined downward with respect to the conveyance direction of the object to be weighed M. In this sliding-type feeding base 23, an object to be weighed M from the supply device 22 is fed into the weighing stage 24 by a gravity force acting along a sloped sliding surface. Then, the weighing object M can be individually weighed on the weighing table 24 while the weighing object M from the supply device 22 is opened to an interval at which the weighing object M can be weighed.

<Description of the sliding delivery base>
The sliding feed table 25 has a sliding surface on which the object M from the weighing table 24 slides. The sliding surface is inclined downward with respect to the conveyance direction of the object to be weighed M. In this sliding-type delivery base 25, the object M to be weighed from the weighing stage 24 is further conveyed to the subsequent stage by the gravity force acting along the inclined sliding surface.
In addition, although the sorting apparatus by weight selection is arrange | positioned in the back | latter stage of the sliding delivery stand 25, illustration is abbreviate | omitted.

<Description of weighing platform>
The weighing table 24 is a sliding type weighing table that slides the object M without using a conveying means having a driving force. The weighing table 24 is configured by installing a sliding table 27 on the weighing table main body 26.

<Description of support structure for weighing platform>
A load sensor support 28 is fixed on the installation base G on which the weight sorter 21 is installed. One end of a load sensor 29 such as a load cell or force balance is fixed to the load sensor support 28. The other end of the load sensor 29 and the weighing table body 26 are connected via a weighing table support 30. Thus, the weighing table 24 is supported on the installation base G via the weighing table support 30, the load sensor 29, and the load sensor support 28.

<Description of weighing platform attachment / detachment structure>
Between the weighing platform body 26 and the weighing platform support 30, the weighing platform 24 can be easily detached from the weighing platform support 30 when the weighing platform 24 is cleaned or maintained. The weighing table attaching / detaching bracket 31 is interposed.

<Explaining how to load the object to be weighed>
In the weight sorter 21 of this embodiment, the object to be weighed M is sent to the weighing platform 3 by the driving force of the carry-in side transport chains 2 and 2 as in the weight sorter 1 of the first embodiment (see FIG. 1). Therefore, a constant speed and acceleration must be given to the weighing object M that repeatedly slides from the stage where the weighing object M slides on the sliding feed table 23 as well as the weighing table 24.

<Description of the shape of the sliding feed base when the object to be weighed has a cylindrical shape>
For this purpose, as shown in FIG. 4A, if the object to be weighed M has a columnar shape or a cylindrical shape, the sliding feed base 23 is at least larger than the column (cylindrical) radius of the object to be weighed M. A curved surface with a curved surface is used. A hard film represented by the above-mentioned DLC is formed on at least the sliding contact surface portion 23a in sliding contact with the object M on the sliding surface.

<Description of the shape of the slide when the object to be weighed has a cylindrical shape>
The same applies to the slide table 27 in the weighing table 24, and a slide table having a curved surface having a curvature larger than at least the cylindrical (cylindrical) radius of the object M is used. A hard film as represented by the aforementioned DLC is formed on at least the sliding contact surface portion 27a that is in sliding contact with the object M on the sliding surface.
In addition, since it is preferable that the measurement stand 24 is lightweight, as a material of the material which comprises the slide stand 27, aluminum, a magnesium alloy, resin, etc. are suitable.

<Description of the shape of the sliding delivery base when the object to be weighed has a cylindrical shape>
The same applies to the sliding-type delivery base 25, and one having a curved sliding surface having a curvature larger than at least the columnar (cylindrical) radius of the object M is used. The sliding delivery table 25 also needs to quickly carry the object M from the weighing table 24. Therefore, at least the sliding contact surface portion 25a in sliding contact with the object M on the sliding surface is represented by the aforementioned DLC. It is preferred that such a hard film is formed.

<Description of the shape, etc. of the sliding feed base when the object to be weighed is a rectangular parallelepiped>
In some cases, the object to be weighed M is a rectangular parallelepiped. In this case, each of the sliding feed base 23, the sliding base 27, and the sliding delivery base 25 has a concave portion having a curved surface large enough to accommodate the object to be weighed M, as shown in FIG. And a rail 32, 33, 33 comprising a required number (three in this example) of round bars or cylindrical pipes that extend straight along the transport path and are arranged in parallel with each other. Use. As shown in FIG. 4 (b ′), it is preferable to maintain the shape of the U-shaped groove by fixing appropriate portions of the rails 33, 33 adjacent to each other with a fixing bracket 34.
A hard film as represented by the above-mentioned DLC is formed on at least the sliding contact surface portion 33a that is in sliding contact with the workpiece M in each rail 33.

<Description of the shape, etc. of the sliding feed base when the object to be weighed is a rectangular parallelepiped>
As another example of the sliding feed base 23, the sliding base 27, and the sliding delivery base 25 in the case where the object M is a rectangular parallelepiped, the one shown in FIG. 4C may be employed.
In FIG. 4 (c), the sliding feed base 23, the sliding base 27, and the sliding delivery base 25 are all large enough to accommodate the object to be measured M in a generally U-shaped cross section opened upward. The flange 35 having a recess and the bottom surface of the flange 35 and the two inner side surfaces provided on both sides of the bottom surface are fixed to each other, and extend straight along the conveyance path so that the contact surface with the object to be weighed M It is comprised by the sliding board 36 which has the multiple groove | channel which is a curved surface.
A hard film represented by the aforementioned DLC is formed on at least the sliding contact surface portion 36a in sliding contact with the workpiece M on the sliding plate 36.
In addition, since it is preferable that the weighing platform 24 is lightweight, as a material of the material which comprises the sliding board 36, aluminum, a magnesium alloy, resin, etc. are suitable.

  As described above, the weight sorter of the present invention has been described based on a plurality of embodiments. However, the present invention is not limited to the configurations described in the above embodiments, and the configurations described in the embodiments are appropriately combined. The configuration can be changed as appropriate without departing from the spirit of the invention.

  The weight sorter of the present invention has a characteristic that the weighing platform is lightweight and can stably measure the weight with high accuracy over a long period of time. It can be suitably used for sorting applications.

1 Weight sorter (first embodiment)
3 Weighing table 8 Rail (guide member)
8a Sliding contact surface portion 21 Weight sorter (second embodiment)
23 Sliding feed base 23a Sliding contact surface portion 24 Weighing base 27 Slide base (guide member)
27a Sliding contact surface portion 33 Rail (guide member)
33a Sliding contact surface 36 Sliding plate (guide member)
36a Sliding contact surface

Claims (2)

In a weight sorter comprising a weighing platform having a sliding surface for sliding an object to be weighed and configured to measure the weight of the object to be weighed by sliding the object to be weighed on the sliding surface,
The weighing platform is supported by a weighing platform support fixed to one end of the load sensor, and includes a plurality of single rails having a sliding contact surface portion having an upward convex curved surface that is in sliding contact with an object to be weighed. A weight sorter characterized in that a hard film made of DLC is formed on the sliding contact surface portion of a single rail . 2. The weight sorter according to claim 1, wherein the plurality of single rails are arranged in a U-shaped groove having an open top, and are appropriately fixed with a fixing bracket .

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