JPH0260134B2 - - Google Patents
Info
- Publication number
- JPH0260134B2 JPH0260134B2 JP23098683A JP23098683A JPH0260134B2 JP H0260134 B2 JPH0260134 B2 JP H0260134B2 JP 23098683 A JP23098683 A JP 23098683A JP 23098683 A JP23098683 A JP 23098683A JP H0260134 B2 JPH0260134 B2 JP H0260134B2
- Authority
- JP
- Japan
- Prior art keywords
- load cell
- cell body
- cover
- end surface
- side end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 210000004027 cell Anatomy 0.000 claims description 29
- 210000005056 cell body Anatomy 0.000 claims description 23
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 125000006850 spacer group Chemical group 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims 1
- 238000005520 cutting process Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 239000003034 coal gas Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/26—Auxiliary measures taken, or devices used, in connection with the measurement of force, e.g. for preventing influence of transverse components of force, for preventing overload
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Force In General (AREA)
Description
【発明の詳細な説明】
本発明は耐圧防爆機能を有するロードセルの製
造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a load cell having a pressure-resistant and explosion-proof function.
爆発性ガス（たとえばアセトン、石炭ガス、水
素など）を取扱う設備に用いられるロードセル
は、そのストレンゲージの発熱や短絡事故等によ
つて爆発性ガスが爆発しても、その爆発エネルギ
ーがロードセル内にとどめられ、またロードセル
外に火炎逸走が生じないよう耐圧防爆構造とする
ことが義務づけられている。たとえば従来、耐圧
防爆機能を有するロードセルの例として第１図に
示すものがある。１は基端が固定台２にボルト３
止めされたロードセル本体であつて、先端は着力
部Ａとされている。４はロードセル本体１の中央
部適所に形成されたストレンゲージ貼着部であつ
て、ロードセル本体１を削つて四角柱状に形成さ
れると共にその中央に互いに連通する３つの貫通
穴５を穿設されたロバーバル機構６と、該ロバー
バル機構６の上面と下面の薄肉部７に貼着された
ストレンゲージ８とから構成されている。９はス
トレンゲージ貼着部４を覆うベローズである。 Load cells used in equipment that handle explosive gases (e.g. acetone, coal gas, hydrogen, etc.) do not allow the explosion energy to be absorbed into the load cell even if the explosive gas explodes due to heat generation or a short circuit accident in the strain gauge. It is also required to have a flameproof and explosion-proof structure to prevent flames from escaping outside the load cell. For example, there is a conventional load cell shown in FIG. 1 as an example of a load cell having a pressure-resistant and explosion-proof function. 1 has the base end attached to the fixed base 2 with bolt 3
It is a stopped load cell main body, and the tip is made into a force application part A. Reference numeral 4 denotes a strain gauge attachment part formed at a suitable location in the center of the load cell body 1, which is formed by cutting the load cell body 1 into a rectangular prism shape, and has three through holes 5 in the center thereof that communicate with each other. It consists of a Roberval mechanism 6 and strain gauges 8 attached to thin-walled portions 7 on the upper and lower surfaces of the Roberval mechanism 6. 9 is a bellows that covers the strain gauge attachment part 4.
上記構成において、ベローズ９はストレンゲー
ジ貼着部４に塵が付着しないようにするために用
いられており、もしもこのベローズ９に耐圧防爆
機能を持たせるべく、その肉厚を大きくして強度
を持たせると剛性が大きくなり過ぎて、着力部Ａ
に加わつた荷重Ｐの計量を正確におこなうことが
困難となる。特に小秤量のロードセルにおいては
計量精度を高めると、耐圧防爆構造が得にくいの
が現状である。 In the above configuration, the bellows 9 is used to prevent dust from adhering to the strain gauge attachment part 4. If the bellows 9 is to have a pressure-resistant and explosion-proof function, its thickness may be increased to increase its strength. If you hold it, the rigidity will become too large, and the force applied part A
It becomes difficult to accurately measure the load P applied to the Particularly in the case of load cells with small weights, it is currently difficult to obtain a pressure-resistant and explosion-proof structure when measuring accuracy is increased.
耐圧防爆構造でしかも小秤量でも使用できるも
のとして第２図のような新規な構造のロードセル
が考えられる。１０はロードセル本体で、その基
端部は固定台１１にボルト１２止めされている。
１３はロードセル本体１０の中央適所に形成され
たストレンゲージ貼着部であつて、ロードセル本
体１０を削つて四角柱状に形成されると共にその
中央に互いに連通する３つの貫通穴１４を穿設さ
れたロバーバル機構１５と、該ロバーバル機構１
５の上面と下面の薄肉部１６に貼着されたストレ
ンゲージ１７とから構成されている。１８はロー
ドセル本体１０に外嵌する円筒状カバーであつ
て、ボルト１９によりロードセル本体１０に固定
されている。２０はロードセル本体１０に外嵌す
ると共にカバー１８に所定の間隙α1をおいて接近
させられかつロードセル本体１０に溶接（または
ボルト止めでもよい）させられたリング状対向部
材である。なお、間隙α1の幅W1と奥行L1は耐圧
防爆を満足するように次のように設定されてい
る。すなわち、産業安全研究所技術指針（産業安
全研究所報告、RIIS−TR−79−１、昭和54年11
月15日発刊、著者労働省産業安全研究所）の
「3231接合面」に基づいてカバー１８内のロード
セル本体を除く空間２１が「２cm3を越え100cm3以
下」の場合には、奥行L1を10mm以上とし、幅W1
を0.1mm（爆発等級２の場合）以下としてある。
また、ロードセル本体１０とカバー１８との間か
ら火炎逸走が生じないようカバー１８の段部２２
からボルト１９の貫通穴との間の間隙L2を６mm
以上に設定してある。また、２３はゴム製防塵カ
バー、２４は計量受台であつて、ボルト２５およ
びナツト２６を介してロードセル本体１０の先端
に連結されている。２７はストレンゲージ接続コ
ードの挿通用貫通穴、２８はストレンゲージ接続
コードを覆う耐圧防爆端子箱である。 A load cell with a novel structure as shown in Fig. 2 can be considered as a load cell with a pressure-resistant and explosion-proof structure that can be used even with a small weight. Reference numeral 10 denotes a load cell main body, the base end of which is fixed to a fixing base 11 with bolts 12.
Reference numeral 13 denotes a strain gauge attachment part formed at a proper central location of the load cell body 10, which is formed into a square column shape by cutting the load cell body 10, and three through holes 14 that communicate with each other are bored in the center thereof. Roberval mechanism 15 and Roberval mechanism 1
The strain gauge 17 is affixed to a thin wall portion 16 on the upper and lower surfaces of the strain gauge 5. Reference numeral 18 denotes a cylindrical cover that fits onto the load cell main body 10 and is fixed to the load cell main body 10 with bolts 19. Reference numeral 20 denotes a ring-shaped opposing member that is fitted onto the load cell main body 10, is brought close to the cover 18 with a predetermined gap α1 , and is welded (or bolted) to the load cell main body 10. Note that the width W 1 and depth L 1 of the gap α 1 are set as follows to satisfy explosion-proof conditions. In other words, the Technical Guidelines of the Institute of Industrial Safety (Report of the Institute of Industrial Safety, RIIS-TR-79-1, November 1978)
Based on "3231 Joint Surface" published by the Ministry of Labor, Industrial Safety Research Institute) published on May 15th, if the space 21 inside the cover 18 excluding the load cell body is "more than 2 cm 3 and less than 100 cm 3 ", the depth L 1 should be 10mm or more, width W 1
0.1mm (for explosion class 2) or less.
In addition, the stepped portion 22 of the cover 18 is designed to prevent flames from escaping between the load cell body 10 and the cover 18.
The gap L2 between the hole and the through hole of the bolt 19 is 6 mm.
The above settings have been made. Further, 23 is a rubber dustproof cover, and 24 is a weighing pedestal, which is connected to the tip of the load cell main body 10 via a bolt 25 and a nut 26. 27 is a through hole for inserting the strain gauge connection cord, and 28 is a pressure-resistant and explosion-proof terminal box that covers the strain gauge connection cord.
しかし、第２図のような構成のロードセルの製
造に際し、リング状対向部材２０が取付けられた
ロードセル本体１０に、ロードセル本体１０の基
端部側から所定の形成に仕上げられたカバー１８
を外嵌させて、前記幅W1の間隙となるようにボ
ルト１９止めする作業は信頼性が悪く、また歩留
りの悪いものである。 However, when manufacturing a load cell having the configuration as shown in FIG.
The work of fitting the bolts onto the outside and fixing them with the bolts 19 so that there is a gap of the width W1 is unreliable and has a low yield.
本発明は歩留りが良く、しかも高信頼性で微少
の幅W1の間隙α1を作ることができる耐圧防爆ロ
ードセルの製造方法を提供することを目的とす
る。 An object of the present invention is to provide a method for manufacturing a pressure-resistant and explosion-proof load cell that can produce a gap α 1 with a small width W 1 with high yield and high reliability.
本発明の耐圧防爆ロードセルの製造方法は、仕
上り形状よりも長い筒状カバーでロードセル本体
のストレインゲージ貼着部を覆うと共にその基端
部を前記ロードセル本体の基端部に固定し、ロー
ドセル本体の着力側端面と前記筒状カバーの着力
側端面とを面一に切削し、ロードセル本体の着力
側端面に筒状カバーの着力側端面と対向する対向
部材をスペーサを介して接当させて、筒状カバー
と対向部材との間に火炎逸走防止用の間隙を形成
することを特徴とする。 The method for manufacturing a pressure-resistant and explosion-proof load cell of the present invention covers the strain gauge attachment part of the load cell body with a cylindrical cover that is longer than the finished shape, and fixes its base end to the base end of the load cell body. The force application side end face and the force application side end face of the cylindrical cover are cut flush, and an opposing member facing the force application side end face of the cylindrical cover is brought into contact with the force application side end face of the load cell main body via a spacer, thereby forming a cylinder. A gap for preventing flame escape is formed between the shaped cover and the opposing member.
以下、本発明の製造方法を具体的な実施例に基
づいて説明する。 Hereinafter, the manufacturing method of the present invention will be explained based on specific examples.
第３図と第４図は第１の実施例を示す。 3 and 4 show a first embodiment.
製造工程は、先ず第３図のようにロードセル本
体１０にカバー１８をボルト１９によつて固定し
て第３図に仮想線で示すカバー１８の着力側端面
２９をロードセル本体１０の着力点側端面３０と
面一になるよう精密フライス盤などで切削し、次
にロードセル本体１０の端面３０に、第４図のよ
うに前記カバー１８の端面２９と長さＬ以上にわ
たつて対向する円盤状対向部材３１を、均一な厚
みｔのスペーサ板３２を介在させてボルト３３に
よつて固定して、幅Ｗ、奥行Ｌの間隙α1が形成さ
れている。３４は対向部材３１にボルト３５によ
つて固定された着力部材で、ここでは第２図にお
けるボルト２５を挿通するための貫通孔３６が穿
設されている。 The manufacturing process begins by fixing the cover 18 to the load cell body 10 with bolts 19 as shown in FIG. 30, using a precision milling machine or the like, and then attach a disk-shaped opposing member to the end surface 30 of the load cell body 10, which faces the end surface 29 of the cover 18 over a length L or more, as shown in FIG. 31 are fixed by bolts 33 with a spacer plate 32 having a uniform thickness t interposed therebetween, thereby forming a gap α 1 having a width W and a depth L. Reference numeral 34 denotes a force-applying member fixed to the facing member 31 by a bolt 35, in which a through hole 36 for inserting the bolt 25 shown in FIG. 2 is bored.
このように第１の実施例では火炎逸走防止用の
間隙α1を切削と均一な厚みｔのスペーサ板３２と
によつて作製するため、カバー１８のロードセル
本体１０への固定の際にカバー１８とロードセル
本体１０との相対位置を調節する製造方法に比べ
て作業性が良好で、また間隙α1の信頼性も向上す
る。 In this way, in the first embodiment, the gap α 1 for preventing flame escape is created by cutting and the spacer plate 32 having a uniform thickness t, so when the cover 18 is fixed to the load cell body 10, the cover 18 is Compared to a manufacturing method in which the relative position between the load cell body 10 and the load cell body 10 is adjusted, the workability is better, and the reliability of the gap α 1 is also improved.
第５図は第２の実施例を示す。第１の実施例で
は厚みの均一なスペーサ板３２を使用したため、
間隙α1は端面２９の全周にわたつて幅Ｗと均一で
あつたが、この第２の実施例では下端側厚みt1と
上端側厚みt2がt1≠t2の不均一のスペーサ板３７
が使用されている。下端と上端の間の厚みはt1か
らt2に次第に減少する傾斜面に形成されており、
負荷が作用していない状態で間隙α1は、下側の幅
W11が上側の幅W12よりも大きくなる。 FIG. 5 shows a second embodiment. In the first embodiment, since the spacer plate 32 with a uniform thickness is used,
The gap α 1 was uniform in width W over the entire circumference of the end face 29, but in this second embodiment, the spacer has an uneven lower end thickness t 1 and upper end thickness t 2 such that t 1 ≠ t 2 Board 37
is used. The thickness between the lower end and the upper end is formed into an inclined surface that gradually decreases from t 1 to t 2 ,
In the unloaded state, the gap α 1 is the width of the lower side
W 11 is larger than the upper width W 12 .
この第５図のように構成すると次のような効果
が得られる。すなわち、ロードセル本体１０の着
力点側端部は荷重Ｐが作用すると理想的には基端
部に対して下方へ平行移動する。しかし実際には
回転モーメントによつて間隙α1の幅は下側で減少
して上側で増加する。そのため、火炎逸走を防止
するためには幅Ｗを小さくする必要があるが、あ
まりに小さくすると下側で対向部材３１がカバー
１８の端面２９に衝突して正確な計重ができなく
なると云う相反した関係にある。これに対して第
２の実施例では無負荷時にW11＞W12で、荷重が
作用するに従つてW11が減少してW12が増加して
最大荷重時にW12≦Ｗにしておくことによつて上
記のような相反する問題を解決することができ、
また厚みがt1＞t2のスペーサ板３７を使用するこ
とによつて容易にW11＞W12のロードセルを製造
できる。 When configured as shown in FIG. 5, the following effects can be obtained. That is, when the load P is applied to the end portion of the load cell body 10 on the force application point side, ideally the end portion moves downward parallel to the base end portion. However, in reality, the width of the gap α 1 decreases on the lower side and increases on the upper side due to the rotational moment. Therefore, in order to prevent the flame from escaping, it is necessary to make the width W small, but if it is made too small, the opposing member 31 collides with the end surface 29 of the cover 18 on the lower side, making accurate weighing impossible. In a relationship. On the other hand, in the second embodiment, W 11 > W 12 when no load is applied, and as the load acts, W 11 decreases and W 12 increases, so that W 12 ≦W at maximum load. The conflicting problems mentioned above can be resolved by
Furthermore, by using the spacer plate 37 with a thickness of t 1 >t 2 , a load cell with a thickness of W 11 >W 12 can be easily manufactured.
以上説明のように本発明の耐圧防爆ロードセル
の製造方法によると、ロードセル本体の着力点側
端面とカバーの端面とを面一に切削し、次いでロ
ードセル本体の着力点側端面に対向部材をスペー
サ板を介して固定して火炎逸走防止用の間隙を作
成するため、ロードセル本体への筒状カバー取付
時にロードセル本体と筒状カバーとの相対位置を
調節して間隙の幅Ｗを決定する製造方法に比べ
て、容易にしかも高信頼性の火炎逸走防止用の間
隙を高い歩留りで得ることができるものである。 As explained above, according to the method of manufacturing a pressure-resistant and explosion-proof load cell of the present invention, the end face of the load cell body on the force point side and the end face of the cover are cut flush, and then the opposing member is attached to the end face of the load cell body on the force point side with a spacer plate. In order to create a gap to prevent flame escape by fixing the load cell through the load cell, the manufacturing method involves adjusting the relative position between the load cell body and the cylindrical cover to determine the width W of the gap when attaching the cylindrical cover to the load cell body. In comparison, a gap for preventing flame escape that is easy and highly reliable can be obtained at a high yield.
第１図は従来のベンデイング形ロードセルの一
部切欠き正面図、第２図は耐圧防爆ロードセルの
一部切欠き正面図、第３図と第４図は本発明の具
体的な一実施例の製造過程のロードセル要部詳細
図、第５図は本発明の他の実施例の要部詳細図で
ある。
１０……ロードセル本体、１１……固定台、１
８……筒状カバー、１９……ボルト、２９……筒
状カバーの着力側端面、３０……ロードセル本体
の着力側端面、３１……対向部材、３２，３７…
…スペーサ板、α……火炎逸走防止用間隙。
FIG. 1 is a partially cutaway front view of a conventional bending type load cell, FIG. 2 is a partially cutaway front view of a flameproof explosion-proof load cell, and FIGS. 3 and 4 are of a specific embodiment of the present invention. FIG. 5 is a detailed view of the main parts of the load cell in the manufacturing process. FIG. 5 is a detailed view of the main parts of another embodiment of the present invention. 10...Load cell body, 11...Fixing stand, 1
8... Cylindrical cover, 19... Bolt, 29... End face on the force application side of the cylindrical cover, 30... End face on the force application side of the load cell main body, 31... Opposing member, 32, 37...
...Spacer plate, α... Gap for preventing flame escape.
Claims (1)
ル本体のストレインゲージ貼着部を覆うと共にそ
の基端部を前記ロードセル本体の基端部に固定
し、ロードセル本体の着力側端面と前記筒状カバ
ーの着力側端面とを面一に切削し、ロードセル本
体の着力側端面に筒状カバーの着力側端面と対向
する対向部材をスペーサを介して接当させて筒状
カバーと対向部材との間に火炎逸走防止用の間隙
を形成する耐圧防爆ロードセルの製造方法。1 Cover the strain gauge attachment part of the load cell body with a cylindrical cover that is longer than the finished shape, and fix its base end to the base end of the load cell body, so that the force applied between the force application side end surface of the load cell body and the cylindrical cover The side end surface is cut flush with the side end surface, and the opposing member facing the force applying side end surface of the cylindrical cover is brought into contact with the force applying side end surface of the load cell body via a spacer to prevent flame escape between the cylindrical cover and the opposing member. A method for manufacturing a pressure-resistant explosion-proof load cell that forms a protective gap.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23098683A JPS60122339A (en) | 1983-12-06 | 1983-12-06 | Manufacture of explosion-proof load cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23098683A JPS60122339A (en) | 1983-12-06 | 1983-12-06 | Manufacture of explosion-proof load cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60122339A JPS60122339A (en) | 1985-06-29 |
| JPH0260134B2 true JPH0260134B2 (en) | 1990-12-14 |
Family
ID=16916434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23098683A Granted JPS60122339A (en) | 1983-12-06 | 1983-12-06 | Manufacture of explosion-proof load cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60122339A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0710269Y2 (en) * | 1989-01-31 | 1995-03-08 | 株式会社寺岡精工 | Mounting structure of load cell in load cell type balance |
-
1983
- 1983-12-06 JP JP23098683A patent/JPS60122339A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60122339A (en) | 1985-06-29 |
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