JP2007033188A - Weighing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weighing apparatus which reduces the cost of introducing equipment and maintenance, and improves working efficiency. <P>SOLUTION: The weighing apparatus 10 comprises: a supply section 20 for supplying an object under measurement; a storage section 32 for storing the object under measurement supplied from the supply section 20; a substrate 34 on which the storage section 32 is mounted; an elastic section 36 which supports the substrate 34 from below and falls down by the weight of the object under measurement supplied to the storage section 32; a switch section 38 which is provided below a lower surface 34b of the substrate 34 with a predetermined distance therefrom and is switched to the on state when it is pressed from above when the object under measurement having a predetermined weight is stored in the storage section 32; and a control section 40 which operates, when the switch section 38 is pressed and switched to the on state, and controls the supply section 20 so that the supply of the object under measurement is stopped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a weighing device for weighing an object to be measured having a predetermined weight.

  As a conventional weighing device, for example, there is one described in Patent Document 1. FIG. 2 shows a weighing apparatus described in the document. The weighing apparatus 100 includes a liquid supply unit 102 for supplying a liquid to the storage unit 104, a storage unit 104 for storing the liquid, a weight sensor 106 for measuring the weight of the storage unit 104, and a weight sensor 106 for measuring. The first controller 108 that acquires the change in the weight of the storage unit 104 and the second controller 110 that acts on the on-off valve 114 based on the output of the first controller 108 to control the liquid supply amount. The liquid supply unit 102 is a chemical tank that stores liquid. The liquid supply unit 102 includes a pipe 116 that feeds liquid from the chemical tank 112 to the storage unit 104, and an on-off valve 114 that is provided in the middle of the pipe 116 and opens and closes the flow path.

In the weighing apparatus 100, the first controller 108 acquires the weight of the storage unit 104 that is measured at any time by the weight sensor 106 and compares it with the weight stored in advance. Then, the first controller 108 transmits a command related to the control of the on-off valve 114 to the second controller 110 based on the comparison result. The second controller 110 receives the command and executes control of the on-off valve 114.
JP-A-6-132268

  However, the weighing apparatus 100 described in the above document requires a weight sensor 106 and two controllers 108 and 110, and has a complicated configuration. Further, the first controller 108 constantly monitors the weight of the object to be measured, while the second controller 110 controls the supply amount based on a command from the first controller 108. Thus, in the conventional weighing apparatus 100, a complicated control process is required. Therefore, not only the cost for introducing the equipment is high, but also the maintenance cost is high. Furthermore, the conventional weighing device 100 has a complicated configuration, and the frequency of failure is high and the work efficiency is poor.

According to the present invention, a supply unit for supplying an object to be measured;
An accommodating portion for accommodating an object to be measured supplied from the supply portion;
A substrate on which the housing portion is placed;
An elastic part that supports the substrate from below and sinks downward due to the weight of the object to be measured supplied to the housing part;
A switch part which is provided at a predetermined distance below the lower surface of the substrate and is turned on when pressed from above when a measured object of a predetermined weight is accommodated in the accommodating part;
There is provided a weighing device including a control unit that operates when the switch unit is pressed to be turned on and controls the supply unit so as to stop the supply of the object to be measured.

  In such a weighing apparatus of the present invention, the supply unit is controlled by the switch unit and the control unit so as to stop the supply of the object to be measured. As described above, since the weighing apparatus has a simple configuration, the cost for introducing equipment and the cost for maintenance are reduced. Furthermore, the weight of the object to be measured can be detected by a simple control process. Therefore, the frequency of failure is reduced and work efficiency is improved.

  According to the weighing device of the present invention, the cost for introducing equipment and the cost for maintenance are reduced, and the work efficiency is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

  As shown in FIG. 1, the weighing apparatus 10 according to the present embodiment detects a supply unit 20 for supplying an object to be measured and that the weight of the object to be measured supplied from the supply unit 20 has reached a predetermined value. And a control unit 40 that controls the supply unit 20 to stop the supply of the object to be measured to the weight detection unit 30. In this embodiment, an example using a chemical solution as a measurement object will be described.

  The supply unit 20 includes a chemical solution tank 22 that stores a chemical solution, a pipe 24 that supplies liquid from the chemical solution tank 22 to the storage unit 32, and an on-off valve 26 that is provided in the middle of the pipe 24 and opens and closes the flow path.

  The weight detection unit 30 includes a storage unit 32 for holding a chemical solution supplied from the supply unit 20 and a detection unit 33 provided on the bottom plate 31.

  The detection unit 33 includes a substrate 34, an elastic unit 36 that supports the substrate 34 from the lower surface 34b side, and a switch unit 38 that is provided on the lower surface 34b side of the substrate 34 at a predetermined distance.

  On the upper surface 34 a of the substrate 34, a storage unit 32 for storing the chemical solution supplied from the supply unit 20 is placed. The shape of the upper surface of the substrate 34 is not particularly limited as long as the weight of the chemical solution can be measured, and may be substantially circular on the upper surface, square on the upper surface, or the like. A pair of guide members 35 are provided on the upper surface 34a of the substrate 34, and are configured to be able to contact and separate. By this guide member 35, the accommodating part 32 can be positioned in the substantially center part of the board | substrate 34, and a weight measurement can be performed accurately. A plurality of the pair of guide members 35 may be provided.

  Furthermore, the board | substrate 34 has the cover member 34c in the edge part. When the substrate 34 is viewed from above, the cover member 34 c is formed on the peripheral edge of the substrate 34. Thereby, even if the chemical liquid spills on the surface of the substrate 34, it does not wrap around the lower surface 34b. Therefore, failure due to corrosion or the like of the switch unit 38 can be prevented.

  The elastic portion 36 is erected on the surface of the bottom plate 31, and supports the substrate 34 from the lower surface 34b side at the upper end. The number of the elastic portions 36 can be three or more from the viewpoint of reliably measuring the weight of the chemical solution. A guide pin 36 a passes through the center of the elastic portion 36. Further, the elastic portion 36 and the guide pin 36 a are accommodated in the bearing member 37 at the upper end portion thereof. Thereby, while suppressing the inclination of the board | substrate 34, the position shift of the elastic part 36 can be suppressed. The elastic portion 36 is formed from an elastic member such as a spring.

  The switch part 38 has a contact part 38a at the upper end part. The contact part 38a is normally separated from the switch part 38, and contacts the switch part 38 body when pressed from above. Thereby, the switch part 38 will be in an ON state. Specifically, a micro switch or the like can be used as the switch unit 38.

  The switch unit 38 is fixed to a rod-shaped fixing member 39. The fixing member 39 is configured such that the height position can be changed in the vertical direction, and the position of the switch unit 38 can be changed as appropriate according to the weight of the chemical solution to be weighed.

  Such a fixing member 39 is not particularly limited as long as the height position can be changed, but the following configuration can be exemplified. For example, the fixing member 39 can be composed of two slide members, and these can be slid. Further, these slide members are provided with a plurality of positioning holes penetrating in the lateral direction. The slide members can be fixed by aligning the holes between the slide members and inserting a rod-shaped fixing tool at a predetermined position. With such a configuration, the fixing member 39 can be adjusted to a predetermined height position.

  The control unit 40 is configured by incorporating a control circuit therein. The control circuit operates when the switch unit 38 is turned on, and transmits a control signal to the on-off valve 26 of the supply unit 20. When receiving the control signal, the on-off valve 26 closes the on-off valve 26 and stops the supply of the chemical solution to the storage unit 32.

Specifically, the weight control of the chemical solution by the weighing device 10 is performed as follows.
First, the user positions the switch unit 38. Specifically, the position of the lower surface 34b of the substrate 34 corresponding to the desired weight is determined by the following method.

The substrate 34 tends to sink in proportion to the weight Pa (kgf) of the chemical solution supplied to the chemical solution tank 22. At this time, the elastic portion (spring) 36 disposed on the lower surface side of the substrate 34 repels due to the spring characteristic represented by the following formula (1).
Formula (1): P = kδ
(P: load kgf), k: spring constant (kgf / mm), δ: spring deflection (mm))
If it is supported by four springs, the load P related to one spring is expressed by the following formula (2).
Formula (2): P = Pa / 4
From these formulas (1) and (2), the following formula (3) is derived.
Formula (3): δ = Pa / (4k)

  The amount by which the substrate 34 sinks (spring deflection δ) is calculated by the above equation (3). The user confirms this value to fix the switch unit 38 at a predetermined position. In addition, the user may be configured to position the switch unit 38 by inputting a predetermined condition to the control unit 40.

  Next, the switch unit 38 is positioned so that the switch unit 38 is disposed at that position. For example, the height position of the fixing member 39 is changed in the vertical direction, and is fixed at a predetermined position by a fixing member (not shown).

  Next, the on-off valve 26 is opened, and the supply of the chemical solution from the supply unit 20 to the storage unit 32 is started.

  When the chemical solution is supplied to the storage portion 32, the substrate 34 gradually sinks downward. When the weight of the chemical solution reaches a predetermined weight, the contact portion 38a of the switch portion 38 is pressed downward by the lower surface 34b of the substrate 34. Thereby, the contact part 38a contacts the switch part 38 main body, and will be in an ON state. The contact portion 38a may be pressed by a protrusion formed on the surface of the lower surface 34b, or may be pressed by another member or the like fixed to the surface of the lower surface 34b.

  When the switch unit 38 is turned on, the control circuit of the control unit 40 transmits a control signal to the on-off valve 26 of the supply unit 20. When receiving the control signal, the on-off valve 26 closes the on-off valve 26 and stops the supply of the chemical solution to the storage unit 32. In this way, the weight control of the chemical solution by the weighing device 10 is performed.

  The weighing device 10 may be connected to a cleaning unit for a semiconductor substrate. In this case, a cleaning liquid is used as the chemical liquid, and the liquid can be fed from the storage section 32 to the cleaning section. Further, a plurality of weighing devices 10 may be provided, and a plurality of chemical solutions may be weighed and mixed in the cleaning unit.

The effect of such a weighing device will be described.
In the weighing apparatus 10 according to the present embodiment, the part for controlling the weight of the object to be measured has a simple configuration including only the switch unit 38 and the control unit 40. Furthermore, no complicated control is performed. Therefore, there is provided a weighing device in which costs for introducing equipment, maintenance costs, and manufacturing costs are reduced, and work efficiency is further improved.

  On the other hand, the conventional weighing device as shown in Patent Document 1 requires a weight sensor 106 and two controllers 108 and 110, and has a complicated configuration. Further, the first controller 108 constantly monitors the weight of the object to be measured, while the second controller 110 needs to control the supply amount based on the command of the first controller 108 and requires a complicated control process. . Therefore, not only the cost for introducing the equipment is high, but also the maintenance cost is high. Furthermore, since the conventional weighing device has a complicated configuration, the frequency of failure is high and the work efficiency is poor.

  On the other hand, in the weighing device 10 of the present embodiment, the weight of the chemical solution supplied into the storage unit 32 is set in advance, the amount of sinking of the substrate 34 corresponding to the weight is calculated, and the weight is set at that position. A switch unit 38 is provided. Further, when a predetermined amount of the object to be measured is accommodated in the accommodating portion 32 and the switch portion 38 is turned on, the control circuit of the control portion 40 is operated to close the on-off valve 26. Thus, the weighing device 10 has a simple configuration, and the cost for introducing the equipment and the cost for maintenance are reduced. Furthermore, the weight of the object to be measured can be detected by a simple control process. Therefore, the frequency of failure is reduced and work efficiency is improved.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  For example, although an example using a chemical as the object to be measured has been described, other liquid materials, semi-solid materials, solid materials, and the like can be applied.

  Moreover, although demonstrated by the example which provided one supply part 20, two or more may be arrange | positioned.

It is the schematic side view which showed typically the weighing apparatus which concerns on this embodiment. It is the schematic side view which showed the conventional weighing apparatus typically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Weighing device 20 Supply part 22 Chemical solution tank 24 Pipe 26 On-off valve 30 Weight detection part 31 Bottom plate 32 Storage part 33 Detection part 34 Substrate 34a Upper surface 34b Lower surface 34c Cover member 35 Guide member 36 Elastic part 36a Guide pin 37 Bearing member 38 Switch part 38a Contact unit 39 Fixing member 40 Control unit 100 Weighing device 102 Liquid supply unit 104 Storage unit 106 Weight sensor 108 First controller 110 Second controller 112 Chemical liquid tank 114 On-off valve 116 Piping

Claims (4)

A supply unit for supplying the object to be measured;
An accommodating portion for accommodating an object to be measured supplied from the supply portion;
A substrate on which the housing portion is placed;
An elastic part that supports the substrate from below and sinks downward due to the weight of the object to be measured supplied to the housing part;
A switch part which is provided at a predetermined distance below the lower surface of the substrate and is turned on when pressed from above when a measured object of a predetermined weight is accommodated in the accommodating part;
A control unit that operates when the switch unit is pressed and is turned on, and controls the supply unit to stop the supply of the object to be measured;
A weighing device. The weighing device according to claim 1,
The weighing device is configured such that the switch unit is pressed by the lower surface of the substrate to be turned on. The weighing apparatus according to claim 1 or 2,
The weighing device is configured to act on the on-off valve of the supply unit to stop the supply of the object to be measured. The weighing device according to any one of claims 1 to 3,
The weighing device is configured such that the switch unit is fixed to a fixing member whose height position can be changed in the vertical direction, and the separation distance from the lower surface of the substrate can be changed.

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