JPH0720539U - Differential pressure sensor - Google Patents
Differential pressure sensorInfo
- Publication number
- JPH0720539U JPH0720539U JP5613893U JP5613893U JPH0720539U JP H0720539 U JPH0720539 U JP H0720539U JP 5613893 U JP5613893 U JP 5613893U JP 5613893 U JP5613893 U JP 5613893U JP H0720539 U JPH0720539 U JP H0720539U
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- differential pressure
- medium
- pressure medium
- differential
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 abstract description 8
- 230000002159 abnormal effect Effects 0.000 abstract description 2
- 230000004043 responsiveness Effects 0.000 abstract description 2
- 239000010720 hydraulic oil Substances 0.000 description 38
- 239000003921 oil Substances 0.000 description 23
- 238000010276 construction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000011144 upstream manufacturing Methods 0.000 description 4
- 238000009530 blood pressure measurement Methods 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Measuring Fluid Pressure (AREA)
Abstract
(57)【要約】 （修正有）
【目的】 応答性に優れかつ安価であり、また異常な差
圧が発生してもダイヤフラムの差圧検出部分に過負荷を
与えない差圧センサを提供する。
【構成】 第１の圧力媒体Ｂが耐圧性の高い側の面に導
入されかつ第２の圧力媒体Ａが耐圧性の低い側の面に導
入される両面受圧式のダイヤフラム部材１を有し、ダイ
ヤフラム部材の受圧部での差圧による歪み状態をダイヤ
フラム部材上に設けられた差圧検出部で検出して圧力差
を測定し、圧力媒体Ａが導入される側の圧力が圧力媒体
Ｂが導入される側の圧力を越えないように、圧力媒体Ｂ
の通路と圧力媒体Ａの通路との間に圧力媒体Ａを圧力媒
体Ｂ側へバイパスさせるチェック弁１８を設ける。さら
に、圧力媒体Ａの圧力よりも大きな圧力状態に保持され
た圧力媒体Ｂの圧力と、圧力媒体Ａの圧力との差が、所
定値を越えないように、圧力媒体Ｂの通路と圧力媒体Ａ
の通路との間にリリーフ弁１７を設ける。
(57) [Summary] (Modified) [Purpose] To provide a differential pressure sensor that has excellent responsiveness and is inexpensive, and that does not overload the differential pressure detection portion of the diaphragm even if an abnormal differential pressure occurs. . A double-sided pressure-receiving diaphragm member 1 in which a first pressure medium B is introduced to a surface having a high pressure resistance and a second pressure medium A is introduced to a surface having a low pressure resistance, The pressure difference is measured by detecting the distorted state due to the differential pressure at the pressure receiving portion of the diaphragm member by the differential pressure detecting portion provided on the diaphragm member, and the pressure on the side where the pressure medium A is introduced is introduced by the pressure medium B. Pressure medium B so as not to exceed the pressure of the side
A check valve 18 for bypassing the pressure medium A to the pressure medium B side is provided between the passage of the pressure medium A and the passage of the pressure medium A. Further, the passage of the pressure medium B and the pressure medium A are kept so that the difference between the pressure of the pressure medium B held at a pressure state higher than the pressure of the pressure medium A and the pressure of the pressure medium A does not exceed a predetermined value.
A relief valve 17 is provided between the relief valve 17 and the passage.
Description
【０００１】[0001]
本考案は差圧センサ関し、特に、土木機械や建設機械等の駆動装置として利用 される油圧系の作動油の差圧状態を測定するのに好適であり、差圧検出機構部を 保護する油圧回路構造を備えた差圧センサに関する。 The present invention relates to a differential pressure sensor, and in particular, is suitable for measuring the differential pressure state of hydraulic oil in a hydraulic system used as a drive device for civil engineering machines, construction machinery, etc. The present invention relates to a differential pressure sensor having a circuit structure.
【０００２】[0002]
歪みゲージを利用して構成される両面受圧式ダイヤフラムを含む差圧センサは 、例えば金属製の板状ダイヤフラムの一方の面に、半導体成膜技術等を用いて歪 みゲージを含む差圧検出部（または圧力検出部）を設けた構造を有し、ダイヤフ ラムの両面のそれぞれに異なる圧力の作動油を導入して印加させ、この作動油の 圧力差に基づきダイヤフラムの受圧部（または起歪部）に歪みを生じさせ、この 歪みを、上記差圧検出部によって、作動油の差圧として検出する作用を有する。 この差圧センサにおいて、上記ダイヤフラムは、ハウジングを形成するセンサ本 体の内部に取り付けられる。センサ本体は、前記異なる圧力の作動油のそれぞれ を導入するための２つの作動油通路を有しており、ダイヤフラムは、通常、２つ の作動油通路のうちの一方の作動油通路の出口開口部を塞ぐように、接着剤等を 用いて取り付けられる。 A differential pressure sensor that includes a double-sided pressure-sensitive diaphragm configured using a strain gauge is a differential pressure detection unit that includes a strain gauge on one surface of a metal plate diaphragm, for example, using semiconductor film formation technology. (Or pressure detection part) is provided, hydraulic oil of different pressure is introduced and applied to both sides of the diaphragm, and the pressure receiving part (or strain generating part) of the diaphragm is based on the pressure difference of this hydraulic oil. ) Is generated, and the strain is detected as the differential pressure of the hydraulic oil by the differential pressure detection unit. In this differential pressure sensor, the diaphragm is attached inside the sensor body forming a housing. The sensor body has two hydraulic oil passages for introducing the hydraulic oils of different pressures, and the diaphragm is usually provided with an outlet opening of one of the two hydraulic oil passages. It is attached using an adhesive or the like so as to close the part.
【０００３】 また、差圧検出部が設けられたダイヤフラムの受圧部の強度については、検出 対象となる油圧回路で発生する差圧値の最大値を想定し、破壊されるおそれのな い強度を有するようにダイヤフラムを設計する。ある程度の大きな差圧が発生し てもダイヤフラムが破壊しないように、余裕をもってダイヤフラムの強度を設計 している。Further, regarding the strength of the pressure receiving portion of the diaphragm provided with the differential pressure detecting portion, the maximum value of the differential pressure value generated in the hydraulic circuit to be detected is assumed, and the strength that is not likely to be destroyed is set. Design the diaphragm to have. The strength of the diaphragm is designed with a margin so that the diaphragm does not break even if a large differential pressure is generated.
【０００４】[0004]
従来の両面受圧式差圧センサでは、差圧を検出するためのダイヤフラム部分の 強度を高めに設計して作っている。そのため、反面、圧力に対する感度が低くな り、実際の差圧測定では分解能の悪い状態で検出していることとなり、精度が低 減した差圧センサとなっている。差圧センサとしての精度を高めるためには、ダ イヤフラムの差圧を検出する部分の強度を弱くして感圧性を高める必要があるが 、そのようにすると、測定すべき差圧において予期した値以上の大きな差圧がダ イヤフラムの検出部に印加したときには、ダイヤフラムが塑性変形したりもしく は破壊されるという不具合が生じる。 The conventional double-sided pressure-sensitive differential pressure sensor is designed and manufactured with a higher strength of the diaphragm part for detecting the differential pressure. As a result, the sensitivity to pressure is low, and the actual differential pressure measurement is performed with poor resolution, resulting in a low-precision differential pressure sensor. In order to improve the accuracy of the differential pressure sensor, it is necessary to weaken the strength of the part that detects the differential pressure of the diaphragm to improve the pressure sensitivity. When the above large differential pressure is applied to the detection part of the diaphragm, the problem that the diaphragm is plastically deformed or destroyed occurs.
【０００５】 また、センサ本体に対するダイヤフラムの取付け構造上、接着剤等で固定され た面側（取付け側）への作動油圧力の印加に対してダイヤフラムの耐圧性は弱く 、その反対側（非取付け側）への作動油圧力の印加に対してダイヤフラムの耐圧 性は高いという特性を有している。このようなダイヤフラム取付け構造を有した 差圧センサでは、一般的に、耐圧性の高い側の圧力が高く、耐圧性が低い側の圧 力が低くなるようにして、異なる圧力の作動油がダイヤフラムに導入・印加され ることを前提としている。この反対の状態、すなわち、耐圧性の高い側の圧力が 弱く、耐圧性が低い側の圧力が高くなるような逆圧状態は、予め測定することを 前提としていないので、このような圧力状態が発生する場合には、差圧センサの 破損防止上の観点から、これを避けることが望ましい。Further, due to the mounting structure of the diaphragm to the sensor body, the pressure resistance of the diaphragm is weak against the application of hydraulic fluid pressure to the surface side (mounting side) fixed with an adhesive or the like, and the opposite side (non-mounting). The pressure resistance of the diaphragm is high against the application of hydraulic oil pressure to the side). In a differential pressure sensor having such a diaphragm mounting structure, generally, the pressure on the side with high pressure resistance is high and the pressure on the side with low pressure resistance is low, so that hydraulic oil of different pressures is It is assumed that it will be introduced and applied to the. This opposite state, that is, the back pressure state in which the pressure on the high pressure side is weak and the pressure on the low pressure side is high, is not premised on pre-measurement. If it occurs, it is desirable to avoid it from the viewpoint of preventing damage to the differential pressure sensor.
【０００６】 本考案の目的は、直接に接液する構造で、ダイヤフラム受圧部に形成された歪 みゲージを利用して受圧部両面に導入された異なる圧力の圧力媒体の差圧を測定 でき、応答性に優れ、かつ安価であり、また異常な差圧が発生してもダイヤフラ ムの差圧検出部分に過負荷を与えない構造を有する差圧センサを提供することに ある。The object of the present invention is to directly contact the liquid, and it is possible to measure the differential pressure of the pressure medium of different pressures introduced on both sides of the pressure receiving portion by using the strain gauge formed in the diaphragm pressure receiving portion, An object of the present invention is to provide a differential pressure sensor which is excellent in responsiveness, is inexpensive, and has a structure which does not overload the differential pressure detection portion of the diaphragm even if an abnormal differential pressure occurs.
【０００７】[0007]
本考案に係る差圧センサは、第１の圧力媒体が耐圧性の高い側の面に導入され かつ第２の圧力媒体が耐圧性の低い側の面に導入される両面受圧式のダイヤフラ ム部材を有し、ダイヤフラム部材の受圧部での差圧による歪み状態をダイヤフラ ム部材上に設けられた差圧検出部で検出して２つの圧力媒体の圧力差を測定する 差圧センサであり、第２の圧力媒体が導入される側の圧力が第１の圧力媒体が導 入される側の圧力を越えないように、第１の圧力媒体の通路と第２の圧力媒体の 通路との間に第２の圧力媒体を第１の圧力媒体側へバイパスさせるチェック弁を 設けるように構成される。 A differential pressure sensor according to the present invention is a double-sided pressure receiving type diaphragm member in which a first pressure medium is introduced into a surface having high pressure resistance and a second pressure medium is introduced into a surface having low pressure resistance. Is a differential pressure sensor for measuring a pressure difference between two pressure media by detecting a strained state due to a differential pressure at a pressure receiving portion of the diaphragm member by a differential pressure detecting portion provided on the diaphragm member. Between the passage of the first pressure medium and the passage of the second pressure medium so that the pressure on the side on which the second pressure medium is introduced does not exceed the pressure on the side on which the first pressure medium is introduced. A check valve for bypassing the second pressure medium to the first pressure medium side is provided.
【０００８】 前記の構成において、さらに、第２の圧力媒体の圧力よりも大きな圧力状態に 保持された第１の圧力媒体の圧力と、第２の圧力媒体の圧力との差が、所定値を 越えないように、第１の圧力媒体の通路と第２の圧力媒体の通路との間にリリー フ弁を設けるように構成される。In the above structure, the difference between the pressure of the first pressure medium and the pressure of the second pressure medium, which is maintained at a pressure state higher than the pressure of the second pressure medium, has a predetermined value. A relief valve is provided between the passage of the first pressure medium and the passage of the second pressure medium so as not to exceed.
【０００９】[0009]
本考案による差圧センサでは、測定しようとする差圧に関して、ダイヤフラム に逆圧状態が発生した場合には、保護用油圧回路によって逆圧をバイパスさせ、 ダイヤフラムに大きな逆圧をかけないようにする。さらに、ダイヤフラムの受圧 部両面に導入・印加される異なる圧力の作動油の差圧の大きさが、測定する必要 がないほど大きい場合には、保護用油圧回路によって、当該差圧を特定の一定値 に保持し、それ以上に大きな値にならないようにする。 With the differential pressure sensor according to the present invention, when a back pressure state occurs in the diaphragm with respect to the differential pressure to be measured, the back pressure is bypassed by the protective hydraulic circuit so that a large back pressure is not applied to the diaphragm. . Furthermore, if the differential pressure of the hydraulic oil of different pressures introduced / applied to both sides of the diaphragm pressure receiving part is so large that it is not necessary to measure it, the protective hydraulic circuit allows the differential pressure to be maintained at a specific level. Keep it at a value and make sure it doesn't get higher.
【００１０】[0010]
以下に、本考案の実施例を添付図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the accompanying drawings.
【００１１】 まず最初に、下記の実施例で説明する本考案による差圧センサが必要とされる 技術的前提について説明する。First, the technical premise that the differential pressure sensor according to the present invention described in the following embodiments is required will be described.
【００１２】 最近では、油圧機器を用いた建設機械などの油圧機械において、油圧回路中で 回路各部の差圧を測定し、差圧を一定にコントロールすることにより機械の操作 性を向上させたものが多くなってきた。このような装置では、回路各部の差圧を 測定することが必要であるが、回路各部の差圧の値を広範囲に測定する必要はな く、両者の差圧が一定値以下の定常状態で、差圧の測定が必要になる。本考案に よる差圧センサは、このような建設機械等に有用である。建設機械の駆動の具体 例を説明する。例えば、ポンプ圧力が、負荷を受けるアクチュエータの圧力より も、或る一定の圧力だけ高い値を保つように、メインポンプ吐出量を制御するこ とがある。このような場合には、コントロールバルブの前後の差圧を測定し、こ の差圧が一定になるようにメインポンプの吐出量を制御するのである。すなわち 、このようなロードセンシングポンプ制御システムを構築するためには、高圧力 （例えば３５０ｋｇｆ／ｃｍ2 ）のラインに使用でき、例えば、差圧３０ｋｇｆ ／ｃｍ2 を精度良く検出できる差圧センサが必要である。このような差圧センサ を実現するために、以下に説明する差圧センサが提案される。Recently, in a hydraulic machine such as a construction machine using a hydraulic device, the operability of the machine is improved by measuring the differential pressure of each part in the hydraulic circuit and controlling the differential pressure to be constant. Is increasing. With such a device, it is necessary to measure the differential pressure between each part of the circuit, but it is not necessary to measure the value of the differential pressure between each part of the circuit over a wide range. , It is necessary to measure the differential pressure. The differential pressure sensor according to the present invention is useful for such construction machines. A specific example of driving a construction machine will be described. For example, the main pump discharge amount may be controlled so that the pump pressure is maintained at a value higher than the pressure of the actuator that receives the load by a certain constant pressure. In such a case, the differential pressure before and after the control valve is measured, and the discharge amount of the main pump is controlled so that this differential pressure becomes constant. That is, in order to construct such a load sensing pump control system, a differential pressure sensor that can be used in a high pressure line (for example, 350 kgf / cm 2 ) and can accurately detect a differential pressure of 30 kgf / cm 2 is required. Is. In order to realize such a differential pressure sensor, the differential pressure sensor described below is proposed.
【００１３】 次に、差圧センサの構造を説明する。図１は本考案に係る差圧センサの縦断面 図、図２は要部の具体的な構造を示す拡大縦断面図である。この実施例では、油 圧機械における圧力作動油の例で説明するが、圧力作動油以外の他の圧力流体で あってもよい。図１において、１はダイヤフラム、２は差圧センサのセンサ本体 、３はセンサカバー、４はセンサ取付け部である。センサ取付け部４は、例えば 油圧機械の壁部であり、その内部に油圧回路が設けられる。センサ本体２は、セ ンサ取付け部４に形成された孔４ａに、３つのＯリング５ａ，５ｂ，５ｃを介し て螺着される。６は、孔４ａとセンサ本体２との間の螺着部である。センサ本体 ２は、内部に圧力を有した作動油（圧力媒体）を通すための２つの油路（作動油 用の通路）７，８と、ダイヤフラム１を配置するための凹部２ａ（図示例では、 後述の引出し部材１２で閉じられた空間に成っている）が形成されている。油路 ７には第１の作動油Ａが導入され、油路８には第２の作動油Ｂが導入される。油 路７，８のそれぞれの出口開口部は、凹部２ａに臨むように形成されている。ダ イヤフラム１は、両面で圧力を受けて歪みを発生する受圧部（または起歪部）１ ａを有し、かつセンサ本体２の凹部２ａにおいて油路７の出口開口部を塞ぐよう な状態で接着剤（または拡散接合または溶接）等によって取り付けられ、固定さ れる。図１に示されたダイヤフラム１の取付け状態において、作動油Ａによる圧 力はダイヤフラム１の受圧部１ａの下面（取付け側）に印加され、作動油Ｂによ る圧力はダイヤフラム１の受圧部１ａの上面（非取付け側）に印加される。ダイ ヤフラム１の上面には、例えば４つの歪みゲージが所定の配置状態で設けられ、 これによって差圧検出部が形成される。差圧検出部は、作動油Ａ，Ｂの圧力差を 検出する。差圧検出部は実際には保護膜で保護される。差圧検出部の出力信号は 、出力線９と引出し線１０を通して増幅器１１に送られる。引出し線１０は、引 出し部材１２に封止構造を介して固定される。Next, the structure of the differential pressure sensor will be described. FIG. 1 is a vertical cross-sectional view of a differential pressure sensor according to the present invention, and FIG. 2 is an enlarged vertical cross-sectional view showing a specific structure of a main part. In this embodiment, an example of the pressure hydraulic oil in the hydraulic machine will be described, but a pressure fluid other than the pressure hydraulic oil may be used. In FIG. 1, 1 is a diaphragm, 2 is a sensor body of a differential pressure sensor, 3 is a sensor cover, and 4 is a sensor mounting portion. The sensor mounting portion 4 is, for example, a wall portion of a hydraulic machine, and a hydraulic circuit is provided inside the wall portion. The sensor body 2 is screwed into a hole 4a formed in the sensor mounting portion 4 via three O-rings 5a, 5b, 5c. Reference numeral 6 denotes a screwed portion between the hole 4a and the sensor body 2. The sensor main body 2 includes two oil passages (passages for hydraulic oil) 7 and 8 for passing hydraulic oil (pressure medium) having pressure inside, and a recess 2a (in the illustrated example, for arranging the diaphragm 1). , Which constitutes a space closed by a drawer member 12 which will be described later). The first hydraulic oil A is introduced into the oil passage 7, and the second hydraulic oil B is introduced into the oil passage 8. The outlet openings of the oil passages 7 and 8 are formed to face the recess 2a. The diaphragm 1 has a pressure receiving portion (or strain generating portion) 1a that receives pressure on both sides to generate strain, and is configured to block the outlet opening of the oil passage 7 in the recess 2a of the sensor body 2. It is attached and fixed by glue (or diffusion bonding or welding). In the mounted state of the diaphragm 1 shown in FIG. 1, the pressure force of the hydraulic oil A is applied to the lower surface (mounting side) of the pressure receiving portion 1a of the diaphragm 1, and the pressure of the hydraulic oil B is applied to the pressure receiving portion 1a of the diaphragm 1. Applied to the upper surface (non-attached side) of. For example, four strain gauges are provided on the upper surface of the diaphragm 1 in a predetermined arrangement state, whereby a differential pressure detecting portion is formed. The differential pressure detector detects the pressure difference between the hydraulic oils A and B. The differential pressure detector is actually protected by a protective film. The output signal of the differential pressure detector is sent to the amplifier 11 through the output line 9 and the lead line 10. The lead wire 10 is fixed to the lead member 12 via a sealing structure.
【００１４】 センサカバー３は、センサ本体２の上部に嵌合状態で取り付けられる。センサ カバー３には、増幅器１１の出力端子１３を外部に取り出すための取出し部材１ ４が固定される。The sensor cover 3 is attached to the upper part of the sensor body 2 in a fitted state. An extraction member 14 for extracting the output terminal 13 of the amplifier 11 to the outside is fixed to the sensor cover 3.
【００１５】 前述のセンサ本体の油路７，８のそれぞれの内部には絞り部１５，１６が設け られ、さらに油路７と油路８の間にリリーフ弁１７およびチェック弁１８が設け られる。リリーフ弁１７は、油路７における絞り部１５の上流側と油路８におけ る絞り部１６の下流側とを接続し、チェック弁１８は、油路８における絞り部１ ６の上流側と油路７における絞り部１５の下流側とを接続する。Throttling portions 15 and 16 are provided inside the oil passages 7 and 8 of the sensor body, and a relief valve 17 and a check valve 18 are provided between the oil passages 7 and 8. The relief valve 17 connects the upstream side of the throttle portion 15 in the oil passage 7 and the downstream side of the throttle portion 16 in the oil passage 8, and the check valve 18 connects the upstream side of the throttle portion 16 in the oil passage 8. The downstream side of the throttle portion 15 in the oil passage 7 is connected.
【００１６】 図２は、センサ本体２における油路７，８、絞り弁１５，１６、リリーフ弁１ ７およびチェック弁１８の構造を具体的に示している。FIG. 2 specifically shows the structures of the oil passages 7 and 8, the throttle valves 15 and 16, the relief valve 17 and the check valve 18 in the sensor body 2.
【００１７】 上記構造を有する差圧センサの作用について説明する。The operation of the differential pressure sensor having the above structure will be described.
【００１８】 差圧を測定する対象である２つの作動油Ａ，Ｂにおいて、油路７で導入される 作動油Ａの圧力はダイヤフラム１における受圧部１ａの下面に印加され、油路８ で導入される作動油Ｂの圧力はダイヤフラム１における受圧部１ａの上面に印加 される。ここで、作動油Ａの圧力Ｐａ、作動油Ｂの圧力Ｐｂとする。本実施例の 差圧センサでは、その構造上、圧力Ｐａより圧力Ｐｂが高い場合にその差圧を測 定し、圧力Ｐｂよりも圧力Ｐａが高い場合にはその差圧を測定しないようにする 。油路７と油路８との間に設けた前述のチェック弁１８は、このような測定を行 うために設けられたものである。チェック弁１８を設けた構造によれば、油路７ に導入された作動油Ａの圧力Ｐａが作動油Ｂの圧力Ｐｂよりも大きい場合には、 作動油Ａが、チェック弁１８を介して油路８の絞り部１６の上流側に流れ込み、 その結果、油路７，８によって導入される圧力が実質的に同一の圧力になり、受 圧部１ａでは差圧が発生しない。また、作動油Ｂの圧力Ｐｂが作動油Ａの圧力Ｐ ａに比べて高くなった場合には、差圧測定が必要とされる範囲内でチェック弁１ ８は閉じられた状態に保持され、ダイヤフラム１の受圧部１ａの両面に各圧力が 印加され、受圧部１ａで差圧に対応する歪みが生じ、差圧検出部で差圧が検出さ れる。In the two hydraulic oils A and B whose differential pressures are to be measured, the pressure of the hydraulic oil A introduced in the oil passage 7 is applied to the lower surface of the pressure receiving portion 1a in the diaphragm 1 and introduced in the oil passage 8 The pressure of the hydraulic oil B to be applied is applied to the upper surface of the pressure receiving portion 1a of the diaphragm 1. Here, the pressure Pa of the hydraulic oil A and the pressure Pb of the hydraulic oil B are used. Due to its structure, the differential pressure sensor of the present embodiment measures the differential pressure when the pressure Pb is higher than the pressure Pa, and does not measure the differential pressure when the pressure Pa is higher than the pressure Pb. . The above-mentioned check valve 18 provided between the oil passage 7 and the oil passage 8 is provided for performing such measurement. According to the structure in which the check valve 18 is provided, when the pressure Pa of the hydraulic oil A introduced into the oil passage 7 is higher than the pressure Pb of the hydraulic oil B, the hydraulic oil A flows through the check valve 18 It flows into the passage 8 on the upstream side of the throttle portion 16, and as a result, the pressures introduced by the oil passages 7 and 8 become substantially the same pressure, and no differential pressure is generated in the pressure receiving portion 1a. Further, when the pressure Pb of the hydraulic oil B becomes higher than the pressure Pa of the hydraulic oil A, the check valve 18 is kept closed within the range in which the differential pressure measurement is required, Each pressure is applied to both surfaces of the pressure receiving portion 1a of the diaphragm 1, the strain corresponding to the differential pressure is generated in the pressure receiving portion 1a, and the differential pressure detecting portion detects the differential pressure.
【００１９】 またリリーフ弁１７の働きについて説明すると、リリーフ弁１７は、差圧測定 限度の値Ｐｒをセットするためのもので、油路７，８との間に設けられる。この ようなリリーフ弁１７を設けた構造によれば、作動油Ｂの圧力Ｐｂが、作動油Ａ の圧力Ｐａに比較してその差がＰｒ以上になった場合には、作動油Ｂが油路７の 絞り弁１５の上流側に流れ込み、両者の圧力差は一定値Ｐｒに保持され、Ｐｒ以 上になるのを回避することができるExplaining the function of the relief valve 17, the relief valve 17 is for setting the value Pr of the differential pressure measurement limit, and is provided between the oil passages 7 and 8. According to the structure provided with the relief valve 17 as described above, when the pressure Pb of the hydraulic oil B becomes larger than the pressure Pa of the hydraulic oil A by not less than Pr, the hydraulic oil B is supplied to the oil passage. No. 7 flows into the upstream side of the throttle valve 15, the pressure difference between the two is held at a constant value Pr, and it is possible to prevent the pressure from becoming higher than Pr.
【００２０】 上記のごとく、チェック弁１８を設けることによって、油路７を通る作動油Ａ の圧力Ｐａが油路８を通る作動油Ｂの圧力Ｐｂより高い場合は、ダイヤフラム１ の受圧部１ａにおいて差圧が生じないようにし、またリリーフ弁１７を設けるこ とによって、作動油Ｂの圧力Ｐｂが作動油Ａの圧力Ｐａよりも高い場合において は、差圧検出部によって、その差圧がＰｒ以下のときには当該差圧が測定され、 Ｐｒを越える差圧が発生したときには差圧Ｐｒが測定される。従って、ダイヤフ ラム１の受圧部１ａにはリリーフ弁１７の設定値Ｐｒ以上の圧力は印加されない ことになる。As described above, by providing the check valve 18, when the pressure Pa of the hydraulic oil A 1 passing through the oil passage 7 is higher than the pressure Pb of the hydraulic oil B passing through the oil passage 8, the pressure receiving portion 1 a of the diaphragm 1 is closed. When the pressure Pb of the hydraulic oil B is higher than the pressure Pa of the hydraulic oil A by preventing the differential pressure from being generated and by providing the relief valve 17, the differential pressure detector detects that the differential pressure is Pr or less. In the case of, the pressure difference is measured, and when the pressure difference exceeding Pr is generated, the pressure difference Pr is measured. Therefore, no pressure higher than the set value Pr of the relief valve 17 is applied to the pressure receiving portion 1a of the diaphragm 1.
【００２１】 以上で説明した２つの圧力Ｐａ，Ｐｂの大小関係と差圧センサの出力との各種 の関係を図３に示す。図３の（ａ）〜（ｄ）の各グラフにおいて、その横軸は作 動油Ｂの圧力Ｐｂと作動油Ａの圧力Ｐａの差であり、縦軸は差圧検出部の出力値 である。図３において、（ａ）は従来の差圧センサの出力図、（ｂ）は上記チェ ック弁１８のみを用いた差圧センサの出力図、（ｃ）は上記リリーフ弁１７のみ を用いた差圧センサの出力図、（ｄ）はチェック弁１８およびリリーフ弁１７を 併用した差圧センサの出力図である。FIG. 3 shows various relationships between the magnitude relationship between the two pressures Pa and Pb described above and the output of the differential pressure sensor. In each of graphs (a) to (d) of FIG. 3, the horizontal axis thereof is the difference between the pressure Pb of the hydraulic oil B and the pressure Pa of the hydraulic oil A, and the vertical axis is the output value of the differential pressure detection unit. . In FIG. 3, (a) is an output diagram of a conventional differential pressure sensor, (b) is an output diagram of a differential pressure sensor using only the check valve 18, and (c) is using only the relief valve 17 described above. The output diagram of the differential pressure sensor, (d) is the output diagram of the differential pressure sensor that also uses the check valve 18 and the relief valve 17.
【００２２】 図３のグラフ（ｄ）で明らかなように圧力Ｐａ，Ｐｂがいかに変化しようと、 ダイヤフラム１では、０〜Ｐｒの圧力範囲に含まれる圧力以外の圧力が負荷され ない構造となる。この０〜Ｐｒの圧力範囲は、必要に応じてまたユーザの要望に 応じてメーカサイドで任意に設定することができる。As is apparent from the graph (d) of FIG. 3, no matter how the pressures Pa and Pb change, the diaphragm 1 has a structure in which a pressure other than the pressure included in the pressure range of 0 to Pr is not applied. The pressure range of 0 to Pr can be arbitrarily set by the maker side as necessary and according to the user's request.
【００２３】 このために、ダイヤフラム１の設計強度は測定圧Ｐｒを基準にすればよい。つ まり、ライン圧力を基準にした設計を行わなくてもよい。具体的には、ダイヤフ ラム１の受圧部１ａ等の厚さを、測定圧に適した厚さにすることができる。この 結果、差圧センサの分解能が向上し、かつ温度特性も良好になる。このため仕様 を満足させるための組立て・調整がしやすくなり、製作工数を低減した差圧セン サを得ることができる。Therefore, the design strength of the diaphragm 1 may be based on the measurement pressure Pr. That is, it is not necessary to design based on the line pressure. Specifically, the thickness of the pressure receiving portion 1a of the diaphragm 1 and the like can be set to a thickness suitable for the measurement pressure. As a result, the resolution of the differential pressure sensor is improved and the temperature characteristics are improved. For this reason, it is easy to assemble and adjust to satisfy the specifications, and it is possible to obtain a differential pressure sensor with reduced manufacturing man-hours.
【００２４】[0024]
以上の説明で明らかなように、本考案によれば、分解能の優れた差圧センサを 作ることができ、差圧検出精度の優れた差圧センサを得ることができる。また工 数を低減でき、組立て・調整を行いやすい。さらに温度特性の良い差圧センサを 作ることができる。 As is clear from the above description, according to the present invention, a differential pressure sensor with excellent resolution can be manufactured, and a differential pressure sensor with excellent differential pressure detection accuracy can be obtained. Also, the number of steps can be reduced, and the assembly and adjustment are easy. Furthermore, a differential pressure sensor with good temperature characteristics can be created.
【図１】本考案に係る差圧センサの内部構造を示す縦断
面図である。FIG. 1 is a vertical sectional view showing an internal structure of a differential pressure sensor according to the present invention.
【図２】図１の要部を具体的に示した縦断面図である。FIG. 2 is a vertical sectional view specifically showing a main part of FIG.
【図３】差圧センサの各種の出力特性を示すグラフであ
る。FIG. 3 is a graph showing various output characteristics of the differential pressure sensor.
１ ダイヤフラム １ａ 受圧部 ２ センサ本体 ３ センサカバー ４ センサ取付け部 ７，８ 油路 １５，１６ 絞り部 １７ リリーフ弁 １８ チェック弁 1 Diaphragm 1a Pressure receiving part 2 Sensor body 3 Sensor cover 4 Sensor mounting part 7,8 Oil passage 15,16 Throttling part 17 Relief valve 18 Check valve
───────────────────────────────────────────────────── フロントページの続き (72)考案者 中村 重孝 茨城県土浦市神立町650番地 日立建機株 式会社土浦工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigetaka Nakamura Inventor Shigetaka Nakamura, Tsuchiura City, Ibaraki Prefecture 650 Kutatemachi, Hitachi Construction Machinery Co., Ltd. Tsuchiura Factory
Claims (2)
導入されかつ第２の圧力媒体が耐圧性の低い側の面に導
入される両面受圧式のダイヤフラム部材を有し、前記ダ
イヤフラム部材の受圧部での差圧による歪み状態を前記
ダイヤフラム部材上に設けられた差圧検出部で検出して
前記２つの圧力媒体の圧力差を測定する差圧センサにお
いて、 前記第２の圧力媒体が導入される側の圧力が前記第１の
圧力媒体が導入される側の圧力を越えないように、前記
第１の圧力媒体の通路と前記第２の圧力媒体の通路との
間に第２の圧力媒体を第１の圧力媒体側へバイパスさせ
るチェック弁を設けたことを特徴とする差圧センサ。1. A double-sided pressure-receiving diaphragm member, wherein a first pressure medium is introduced into a surface having a high pressure resistance and a second pressure medium is introduced into a surface having a low pressure resistance. A differential pressure sensor for measuring a pressure difference between the two pressure media by detecting a strained state due to a differential pressure at a pressure receiving portion of the diaphragm member by a differential pressure detecting portion provided on the diaphragm member, wherein the second pressure Between the passage of the first pressure medium and the passage of the second pressure medium, the pressure on the side on which the medium is introduced does not exceed the pressure on the side on which the first pressure medium is introduced. A differential pressure sensor comprising a check valve for bypassing the second pressure medium to the first pressure medium side.
記第２の圧力媒体の圧力よりも大きな圧力状態に保持さ
れた前記第１の圧力媒体の圧力と、前記第２の圧力媒体
の圧力との差が、所定値を越えないように、前記第１の
圧力媒体の通路と前記第２の圧力媒体の通路との間にリ
リーフ弁を設けたことを特徴とする差圧センサ。2. The differential pressure sensor according to claim 1, wherein the pressure of the first pressure medium and the pressure of the second pressure medium held at a pressure state higher than the pressure of the second pressure medium. A differential pressure sensor, wherein a relief valve is provided between the passage for the first pressure medium and the passage for the second pressure medium so that the difference between the passage and the passage does not exceed a predetermined value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5613893U JPH0720539U (en) | 1993-09-22 | 1993-09-22 | Differential pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5613893U JPH0720539U (en) | 1993-09-22 | 1993-09-22 | Differential pressure sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0720539U true JPH0720539U (en) | 1995-04-11 |
Family
ID=13018721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5613893U Pending JPH0720539U (en) | 1993-09-22 | 1993-09-22 | Differential pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0720539U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013181949A (en) * | 2012-03-05 | 2013-09-12 | Azbil Corp | Differential pressure transmitter |
| JP2017138113A (en) * | 2016-02-01 | 2017-08-10 | 日本電産トーソク株式会社 | Oil pressure sensor module |
| JP2022506199A (en) * | 2018-10-31 | 2022-01-17 | アシスト・メディカル・システムズ，インコーポレイテッド | Fluid pressure sensor protection |
-
1993
- 1993-09-22 JP JP5613893U patent/JPH0720539U/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013181949A (en) * | 2012-03-05 | 2013-09-12 | Azbil Corp | Differential pressure transmitter |
| JP2017138113A (en) * | 2016-02-01 | 2017-08-10 | 日本電産トーソク株式会社 | Oil pressure sensor module |
| JP2022506199A (en) * | 2018-10-31 | 2022-01-17 | アシスト・メディカル・システムズ，インコーポレイテッド | Fluid pressure sensor protection |
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