JP6144432B2 - Non-contact pressure switch - Google Patents

Description

  The present invention relates to a contactless pressure switch.

  In an air conditioner or the like, generally, a pipe is provided with a contact-type pressure switch for detecting the pressure of refrigerant, carbon dioxide gas, etc. in the pipe and sending a detection output. In automobiles and the like, pressure switches are used to detect pressure changes in detected parts such as engine intake pressure, exhaust pressure, crank chamber pressure, various control actuator operating pressures, and lubricating oil pressure. ing. For example, as disclosed in Patent Document 1, the contact-type pressure switch includes a main body case connected to a refrigerant passage through one end of a joint pipe, a diaphragm group that partitions a pressure receiving chamber in the main body case, and a displacement of the diaphragm group Accordingly, the movable contact and the fixed contact disposed in the main body case are configured to include an operation pin that can approach or separate. In such a contact-type pressure switch, a foreign matter that has entered from the outside or a foreign matter that has adhered to an internal component may be caught between the movable contact and the fixed contact, resulting in poor conduction.

  As a countermeasure for such a case, for example, a contactless pressure switch as shown in Patent Document 2 has been proposed. The contactless pressure switch is a diaphragm that partitions the pressure chamber communicating with the fluid passage, a reaction pin that is fixed at one end to the diaphragm, and a signal that is sent to the contactless detection means according to the movement of the diaphragm and the reaction pin according to the pressure fluctuation in the pressure chamber. And a movable transmission member that generates The holding posture of the movable transmission member is finely adjusted by an adjusting screw so that the shadow part of the movable piece generates a signal to the contactless detection means.

  Further, for example, as shown in Patent Documents 3 to 5, as a contactless detection switch, a switch including a magnet and a Hall element, or a light projecting element and a light receiving element, and a light projecting element and a light receiving element are mutually connected. There has also been proposed an optical fiber switch mechanism including a shielding plate for selectively blocking an optical path therebetween.

JP 2004-12140 A JP 2004-95253 A JP 2000-173424 A JP 2004-14451 A Japanese Patent Laid-Open No. 5-36334

  The contactless pressure switch as shown in the above-mentioned Patent Document 2 requires many parts including an adjusting mechanism such as an adjusting screw for adjusting the holding posture of the movable transmission member. As the switch becomes larger, the manufacturing cost may increase.

  In view of the above problems, the present invention is a contactless pressure switch, which can reduce the size of the contactless pressure switch and can reduce the manufacturing cost. The purpose is to provide.

In order to achieve the above object, a contactless pressure switch according to the present invention houses a light emitter that emits a detection light beam and a light receiver that receives the detection light beam from the light emitter. A diaphragm comprising: a housing; at least one diaphragm coupled to the housing and connected to a pipe line to which an operating pressure is supplied and displaced according to the operating pressure; and a support member that supports a peripheral edge of the diaphragm An assembly, and a signal processing unit for transmitting a detection output signal representing an operating pressure based on the detection light beam received by the light receiver, the light receiver from the light emitter through the first hole of the support member. A detection light beam incident on the surface, reflected by the surface of the diaphragm, and between the surface of the diaphragm and the opposite surface of the support member It passes through the light guide path formed, characterized in that for receiving the first detection light beam passing through the second hole spaced relative to the hole in the support member.

Further, a slope having a gradient corresponding to the curvature of the inverted diaphragm may be formed between the first hole of the support member and the second hole between the first hole and the surface of the support member facing each other. . Further, the light emitter may be a light emitting diode, and the light receiver may be a phototransistor. The diaphragm may be formed of a stainless steel plate and may be composed of a plurality of diaphragms.

  According to the contactless pressure switch according to the present invention, the light emitter that emits the detection light beam, the light receiver that receives the detection light beam from the light emitter, and the detection light beam received by the light receiver. A signal processing unit for transmitting a detection output signal representing the working pressure, and the light receiver receives the detection light beam incident on the surface of the diaphragm from the light emitter and reflected by the surface of the diaphragm This eliminates the need for movable pieces, adjustment screws, etc., used in conventional devices in the housing, so that the contactless pressure switch can be reduced in size and the manufacturing cost can be reduced. it can.

FIG. 1A is a plan view showing a configuration of a first embodiment of a contactless pressure switch according to the present invention. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A. 1C is a cross-sectional view taken along line IB-IB in FIG. 1A. FIG. 2 is a cross-sectional view showing the configuration of the first embodiment of the contactless pressure switch according to the present invention. FIG. 3A is a circuit diagram showing an example of a signal demodulation circuit section provided in the first to fourth embodiments of the contactless pressure switch according to the present invention. FIG. 3B is a circuit diagram showing an example of a signal demodulation circuit unit provided in the first to fourth embodiments of the contactless pressure switch according to the present invention. FIG. 4 is a circuit diagram showing another example of the signal demodulation circuit section provided in the first to fourth embodiments of the contactless pressure switch according to the present invention. FIG. 5 is a circuit diagram showing still another example of the signal demodulation circuit section provided in the first to fourth embodiments of the contactless pressure switch according to the present invention. FIG. 6A is a plan view showing a configuration of a second embodiment of the contactless pressure switch according to the present invention. 6B is a cross-sectional view taken along line VIB-VIB in FIG. 6A. 6C is a partially enlarged view showing a part of the example shown in FIG. 6B in an enlarged manner. FIG. 7A is a block diagram for explaining the operation of the second embodiment of the contactless pressure switch according to the present invention. FIG. 7B is a partially enlarged view showing a part of the example shown in FIG. 7A in an enlarged manner. FIG. 8A is a plan view showing a configuration of a third embodiment of the contactless pressure switch according to the present invention. 8B is a cross-sectional view taken along line VIIIB-VIIIB in FIG. 8A. FIG. 8C is a partially enlarged view showing a part of the example shown in FIG. 8B in an enlarged manner. FIG. 9A is a block diagram for explaining the operation of the third embodiment of the contactless pressure switch according to the present invention. FIG. 9B is a partially enlarged view showing a part of the example shown in FIG. 9A in an enlarged manner. FIG. 10A is a plan view showing a configuration of a fourth embodiment of the contactless pressure switch according to the present invention. 10B is a cross-sectional view taken along line XB-XB in FIG. 10A. 10C is a cross-sectional view taken along line XB-XB in FIG. 10A. FIG. 11A is a cross-sectional view showing a configuration of a fifth embodiment of the contactless pressure switch according to the present invention. FIG. 11B is a cross-sectional view for explaining the operation in the example shown in FIG. 11A.

  FIG. 2 shows the configuration of a first embodiment of the contactless pressure switch according to the present invention.

  The contactless pressure switch is attached to, for example, a hydraulic device (not shown) or a pipe for supplying a fluid such as air, refrigerant, water or the like via a connection joint 28 described later.

  As shown in FIG. 2, the contactless pressure switch is connected to a diaphragm assembly 20 coupled to one inner side of the connection joint 28, and the diaphragm assembly 20, and includes a light emitter 16 and a light receiver 22 described later. The cover 10 and a signal demodulating circuit section which is arranged inside one end of the connection joint 28 and sends out a detection output representing a predetermined pressure of a fluid according to the displacement of a diaphragm 20B described later are configured as main elements. ing.

  The cover 10 as a housing is formed of, for example, a resin material, and has a concave portion 10A in which the light emitter 16 and the light receiver 22 are accommodated. As shown in FIGS. 1A and 1B, the light emitter 16 and the light receiver 22 face the center of the cover 10 on one surface of the upper plate 20A of the diaphragm assembly 20 with a predetermined distance from each other. It is fixed on a common straight line.

  The light emitter 16 is a light emitting element, for example, a light emitting diode (LED) that emits a light beam LB such as visible light, infrared light, or ultraviolet light. Further, the light emitter 16 is not limited to such an example, and may be, for example, a semiconductor laser element. The light receiver 22 is a phototransistor that receives the light beam LB reflected by the surface of the light receiving element, for example, the diaphragm 20B. A current from the emitter of the phototransistor is supplied to a signal demodulation circuit section described later based on the received light beam LB. As shown in FIG. 3B, the signal demodulation circuit section includes a transistor TR1 and a resistor R3. The base of the transistor TR 1 is connected to the emitter of a phototransistor that is the light receiver 22. The collector of the transistor TR1 is connected to the power supply line of the power supply E1 through the resistor R3. The light emitter 16 is connected in series to the power line of the common power supply E1 via the resistor R1. The collector of the phototransistor that is the light receiver 22 is also connected to the line of the power source E1 through the resistor R2. When the phototransistor receives the light beam LB, when the transistor TR1 supplies the collector current based on the base current from the emitter of the phototransistor, the low level detection pulse signal So is applied to the collector and resistor of the transistor TR1. It is sent from the output terminal through the connection end with R3.

  The signal demodulating circuit unit is not limited to such an example. For example, as shown in FIG. 3A, the detection pulse signal So is not a phototransistor without including the transistor TR1 and the resistor R3 as described above. The configuration may be such that the output is sent from the output terminal through the connection end between the collector and the resistor R2.

  Furthermore, the signal demodulation circuit unit may be configured such that the light emitter 16 and the light receiver 22 are individually connected to predetermined potentials Vcc1 and Vcc2, respectively, as shown in FIG. In FIG. 4, the light emitter 16 is connected to a predetermined potential Vcc1 via a resistor R4. The collector of the phototransistor 22 that is the light receiver 22 is connected to a predetermined potential Vcc2 via the resistor R5, and the emitter of the phototransistor is grounded. Thereby, when the phototransistor receives the light beam LB, an output voltage is sent from the output terminal Vout connected to the collector of the phototransistor.

  Further, in the signal demodulating circuit unit, for example, as shown in FIG. 5, the light emitter 16 is connected in series to the power supply line of the power source E2 via the resistor R7, and the phototransistor as the light receiver 22 is connected to the other. It may be configured to be connected to the potential Vcc. In FIG. 5, the collector of the phototransistor 22 that is the light receiver 22 is connected to a predetermined potential Vcc via a resistor R8, and the emitter of the phototransistor is grounded. Thereby, when the phototransistor receives the light beam LB, an output voltage is sent from the output terminal Vout connected to the collector of the phototransistor.

  As shown in FIGS. 4 and 5, when the light emitter 16 and the light receiver 22 are individually connected to a predetermined potential, it is advantageous in terms of noise resistance.

  The output terminal of the signal demodulation circuit unit described above is connected to the lead wire 12 through the slit of the cover 10. In addition, the light emitter 16, the light receiver 22, and the signal demodulation circuit unit are connected to a predetermined power source (potential) via the lead wire 14. For example, the signal demodulation circuit unit is connected to a control circuit (not shown).

  As shown in FIG. 2, an O-ring 18 is disposed in the groove formed at the opening end of the cover 10. The O-ring 18 is in contact with one surface of the upper plate 20 </ b> A of the diaphragm assembly 20. Thereby, the O-ring 18 seals between the surface of the upper plate 20A and the end surface of the opening end of the cover 10, so that the inside of the recess 10A becomes a sealed space, so that light leakage can be prevented, Intrusion of moisture and foreign matter from the outside can be prevented.

  The diaphragm assembly 20 includes an upper plate 20 </ b> A that contacts the peripheral edge of the opening end of the cover 10 and the O-ring 18, and a lower plate that is disposed on the peripheral edge of the pressure receiving chamber 28 </ b> A formed inside the connection joint 28 via the O-ring 24. 20C and a diaphragm 20B sandwiched between the upper plate 20A and the lower plate 20C facing each other are the main elements.

  The upper plate 20A as the support member is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The upper plate 20A has a through hole 20a as an opening at the center. The light beam LB from the light emitter 16 and the reflected light from the diaphragm 20B pass through the through hole 20a. Note that the shape of the through hole 20a may be, for example, a circle or a rectangle.

  The lower plate 20C is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The lower plate 20 </ b> C has an opening 20 </ b> Cf that opens toward a funnel-shaped pressure receiving chamber 28 </ b> A formed inside the connection joint 28 at the center. An O-ring 24 is in contact with the peripheral edge of the opening 20Cf of the lower plate 20C that is in contact with the inner peripheral surface of the connection joint 28. The O-ring 24 is inserted into an annular groove formed on the inner peripheral surface of the connection joint 28 adjacent to the pressure receiving chamber 28A.

  The outer peripheral edge of the diaphragm 20B is sandwiched between the upper plate 20A and the lower plate 20C.

  The diaphragm 20B is formed of, for example, a material having corrosion resistance to the fluid supplied through the flow path 28a in the connection joint 28, for example, a stainless steel thin plate. The surface 20bs facing the upper plate 20A of the flexible diaphragm 20B may be subjected to nickel plating, gold or silver plating after quenching in order to increase the light reflection efficiency. Alternatively, the surface 20bs may be mirror-finished.

  Diaphragm 20B may be composed of one diaphragm or a plurality of diaphragms. The number of the plurality of diaphragms is appropriately selected according to the specifications of the contactless pressure switch.

  The upper plate 20 </ b> A and the lower plate 20 </ b> C are joined together by welding the outer peripheral edges with the diaphragm 20 </ b> B sandwiched therebetween, whereby the diaphragm assembly 20 is obtained. Thereby, a fusion | melting part is formed in the outer peripheral part of 20 A of upper plates, and the lower plate 20C. Then, the connecting joint 28 into which the obtained diaphragm assembly 20 is inserted and the above-described cover 10 are joined by caulking the upper end portion of the connecting joint 28 to the outer peripheral surface of the cover 10.

  The diaphragm assembly is not limited to such an example. For example, the diaphragm assembly may be configured such that the outer peripheral edge of the diaphragm 20B is supported by one support member in which the upper plate 20A and the lower plate 20C are integrated. Further, in the diaphragm assembly, for example, the upper plate 20A and the lower plate 20C as support members for supporting the outer peripheral edge of the diaphragm 20B are used as a part of a connection joint or a part of another device (for example, a base). It may be configured. Further, the lower plate and the diaphragm or only the upper plate and the diaphragm may be used.

  In such a configuration, when the fluid enters or leaves the pressure receiving chamber 28A through the flow path 28a in the connection joint 28 along the direction indicated by the arrow P shown in FIG. 2, the pressure of the fluid in the pressure receiving chamber 28A is a predetermined value. If it is less than that, as shown in FIG. 1B, the central portion of the diaphragm 20B bends in a convex shape toward the pressure receiving chamber 28A with a predetermined deflection angle. At that time, a predetermined gap is formed between the surface 20bs facing the upper plate 20A at the center of the diaphragm 20B and the lower surface of the upper plate 20A. Thus, after the light beam LB from the light emitter 16 is incident on the surface 20bs via the through hole 20a, it collides with the inner peripheral surface forming the through hole 20a, so the light receiver 22 does not receive the light beam LB. It will be. Therefore, a high level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value is transmitted.

  On the other hand, when the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value, as shown in FIG. 1C, when the central portion of the diaphragm 20B is gradually displaced by the pressure of the fluid, the pressure reaches a predetermined value. The surface 20bs that is inverted and faces the upper plate 20A and the lower surface of the upper plate 20A come into contact with each other, so the above-described gap becomes substantially zero. Thereby, after the light beam LB from the light emitter 16 is incident on the surface 20bs via the through hole 20a, the reflected light beam LB is emitted toward the light receiver 22 via the through hole 20a. The photoreceptor 22 receives the light beam LB. Accordingly, a low-level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value is transmitted. By utilizing the snap action operation that inverts the diaphragm 20B in this way, chattering of ON / OFF signals based on chattering of the introduced pressure can be performed without performing special processing such as a timer on the hysteresis of the photoreceptor or a signal processing circuit. There is an effect that the occurrence can be prevented.

  In such a configuration, as shown in FIG. 2, the height H from the periphery of the opening 20Cf of the lower plate 20C contacting the inner peripheral surface of the connection joint 28 to the upper surface of the cover 10 is shown in Patent Document 1. Therefore, the contactless pressure switch can be miniaturized because it is lower than the corresponding height in the pressure detector. Further, after the light beam LB from the light emitter 16 is directly incident on the center surface 20bs of the diaphragm 20B through the through hole 20a, the reflected light beam LB is received through the through hole 20a. By emitting toward 22, the displacement of the central portion of the diaphragm 20 </ b> B is detected, so that the number of parts constituting the contactless pressure switch is reduced.

  In the above example, when the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value, as shown in FIG. 1B, the photoreceptor 22 does not receive the light beam LB, so the pressure of the fluid in the pressure receiving chamber 28A is a predetermined value. However, the present invention is not limited to such an example. For example, when the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value, the light receiving body 22 By changing the incident angle and reflection angle of the light beam LB with respect to the central surface 20bs of the diaphragm 20B and the diameter of the through hole 20a so as to receive the beam LB, the low-level detection pulse signal So is transmitted. May be configured.

  6A, 6B, and 6C each show the configuration of a second embodiment of the contactless pressure switch according to the present invention.

  In the example shown in FIGS. 1A to 1C, the light beam LB is directly incident on the surface 20bs of the diaphragm 20B through the through hole 20a, and then the reflected light beam LB is transmitted through the through hole 20a. 6A to 6C, instead, the light beam LB is transmitted through the through hole 40a and the center surface 40bs of the diaphragm 40B. And the lower surface of the upper plate 40A (light guide path), and the light is emitted toward the photoreceptor 22 through the through hole 40b.

  6A to 6C, the same components as those in the example illustrated in FIGS. 1A to 1C are denoted by the same reference numerals, and redundant description thereof is omitted. In the example shown in FIGS. 6A to 6C, although not shown, a signal demodulation circuit unit similar to the signal demodulation circuit unit described above is provided.

  The contactless pressure switch includes a diaphragm assembly 40 coupled to one inner side of the connection joint 28, a cover 30 that is connected to the diaphragm assembly 40 and incorporates the light emitter 16 and the light receiver 22 described later, and a connection joint 28. A signal demodulating circuit section that is arranged inside one end and sends out a detection output representing a predetermined pressure of a fluid according to the displacement of a diaphragm 40B described later is configured as a main element.

  The cover 30 as a housing is formed of, for example, a resin material and has a concave portion 30A in which the light emitter 16 and the light receiver 22 are accommodated. The light emitter 16 and the light receiver 22 are fixed to one surface of the upper plate 40A of the diaphragm assembly 40 so as to face each other on a common straight line with a predetermined interval. The photoreceptor 22 is disposed at a substantially central portion of the cover 30. On the other hand, the light emitter 16 is set at a position separated from the position of the substantially central portion of the cover 30 by a predetermined distance in the radial direction.

  The diaphragm assembly 40 includes an upper plate 40 </ b> A that contacts the peripheral edge of the opening end of the cover 30 and the O-ring 18, and a lower plate disposed via the O-ring 24 at the peripheral edge of the pressure receiving chamber 28 </ b> A formed inside the connection joint 28. 40C and a diaphragm 40B sandwiched between an upper plate 40A and a lower plate 40C facing each other are configured as main elements.

  The upper plate 40A is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The upper plate 40A has through-holes 40a and 40b as openings at positions directly below the light emitter 16 and the light receiver 22, respectively. The shape of the through holes 40a and 40b may be, for example, a circle or a rectangle.

  The light beam LB emitted from the light emitter 16 enters the through hole 40a toward the diaphragm 40B. Further, when a gap (light guide path) is formed between the lower surface of the portion 40c between the through holes 40a and 40b of the upper plate 40A and the surface 40bs of the diaphragm 40B, the through hole 40b is connected to the light guide path from the light guide path. The reflected light passes through to the outside. A slope 40CS having a predetermined slope corresponding to the curvature of the inverted diaphragm 40B is formed on the lower surface of the portion 40c, as shown in a partially enlarged view in FIG. 6C. As a result, both ends of the inclined surface 40CS come into contact with the surface 40bs of the inverted diaphragm 40B, so that the diaphragm 40B is reliably inverted.

  The lower plate 40C is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The lower plate 40 </ b> C has an opening 40 </ b> Cf that opens toward a funnel-shaped pressure receiving chamber 28 </ b> A formed inside the connection joint 28 at the center. The O-ring 24 is in contact with the periphery of the opening 40Cf of the lower plate 40C that is in contact with the inner peripheral surface of the connection joint 28.

  The outer peripheral edge of the diaphragm 40B is sandwiched between the upper plate 40A and the lower plate 40C.

  The diaphragm 40B is formed of, for example, a material having corrosion resistance to the fluid supplied through the flow path 28a in the connection joint 28, for example, a stainless steel thin plate. The surface 40bs facing the upper plate 40A of the diaphragm 40B may be subjected to surface treatment such as nickel plating, gold or silver plating after quenching in order to increase the light reflection efficiency. Alternatively, the surface 40bs may be mirror-finished.

  Diaphragm 40B may be composed of one diaphragm or a plurality of diaphragms. The number of the plurality of diaphragms is appropriately selected according to the specifications of the contactless pressure switch.

  The upper plate 40 </ b> A and the lower plate 40 </ b> C are integrated by welding the outer peripheral edges with the diaphragm 40 </ b> B sandwiched therebetween, whereby the diaphragm assembly 40 is obtained. Thereby, a fusion | melting part is formed in the outer peripheral part of 40 A of upper plates, and the lower plate 40C. Then, the connection joint 28 into which the obtained diaphragm assembly 40 is inserted and the above-described cover 30 are joined by caulking the upper end portion of the connection joint 28 to the outer peripheral surface of the cover 30.

  In such a configuration, when the fluid enters or leaves the pressure receiving chamber 28A through the flow path 28a in the connection joint 28 along the direction indicated by the arrow P shown in FIG. 2, the pressure of the fluid in the pressure receiving chamber 28A is a predetermined value. 6B and 6C, the center portion of the diaphragm 40B bends in a convex shape toward the pressure receiving chamber 28A with a predetermined deflection angle. At that time, a predetermined gap (light guide path) is formed between the surface 40bs facing the portion 40c of the upper plate 40A in the center portion of the diaphragm 40B and the lower surface of the portion 40c. Thus, after the light beam LB from the light emitter 16 is incident on the surface 40bs via the through hole 40a, the light receiver 22 receives the light beam LB that has passed through the light guide path and the through hole 40b. Accordingly, a low-level detection pulse signal So indicating that the fluid pressure in the pressure receiving chamber 28A is less than a predetermined value is transmitted.

  On the other hand, when the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value, as shown in FIGS. 7A and 7B, the central portion of the diaphragm 40B is reversed by the pressure of the fluid and faces the portion 40c of the upper plate 40A. Since 40bs contacts the lower surface of the portion 40c, the above-described gap (light guide path) becomes substantially zero. Thereby, after the light beam LB from the light emitter 16 is incident on the surface 40bs via the through hole 40a, the light beam LB is blocked. That is, the photoreceptor 22 does not receive the light beam LB. Accordingly, a high level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value is transmitted. 7A and 7B show the same components as those in the example shown in FIGS. 1A to 1C with the same reference numerals, and a duplicate description thereof is omitted.

  Also in such an embodiment, the contactless pressure switch can be miniaturized. Further, after the light beam LB from the light emitter 16 is directly incident on the central surface 40bs of the diaphragm 40B through the through hole 40a, the reflected light beam LB is transmitted through the above-described light guide path and the through-hole. By emitting toward the photoreceptor 22 through the hole 40b, the displacement of the central portion of the diaphragm 40B is detected, so that the number of parts constituting the contactless pressure switch is reduced.

  8A, 8B, and 8C each show the configuration of a third embodiment of the contactless pressure switch according to the present invention.

  In the example shown in FIGS. 1A to 1C, the light beam LB is directly incident on the surface 20bs of the diaphragm 20B through the through hole 20a, and then the reflected light beam LB is transmitted through the through hole 20a. However, instead, in the example shown in FIGS. 8A to 8C, the light beam LB is transmitted through the through hole 40′a and the central portion of the diaphragm 40′B. It is comprised so that it may radiate | emit toward the photoreceptor 22 through the clearance gap (light guide path) between the surface 40'bs of this, and the lower surface of upper plate 40'A, and through-hole 40'b.

  8A to 8C and FIGS. 9A and 9B to be described later, the same components as those in the example shown in FIGS. 1A to 1C are denoted by the same reference numerals, and redundant description thereof is omitted. 8A to 8C also include a signal demodulation circuit unit similar to the signal demodulation circuit unit described above, although not shown.

  The contactless pressure switch is connected to a diaphragm assembly 40 ′ coupled to one inner side of the connection joint 28, a diaphragm assembly 40 ′, and a cover 30 ′ including a light emitter 16 and a light receiver 22 described later. A signal demodulating circuit section that is arranged inside one end of the joint 28 and sends out a detection output that represents a predetermined pressure of the fluid according to the displacement of a diaphragm 40'B, which will be described later, is configured as a main element.

  The cover 30 ′ as a housing is formed of, for example, a resin material, and has a recess 30 ′ A in which the light emitter 16 and the light receiver 22 are accommodated. The light emitter 16 and the light receiver 22 are respectively fixed to one surface of the upper plate 40′A of the diaphragm assembly 40 ′ so as to face each other on a common straight line with a predetermined interval. The light emitter 16 and the light receiver 22 are set at positions that are separated from each other in the radial direction by the same distance from the approximate center position of the cover 30.

  The diaphragm assembly 40 ′ includes an O plate as an annular elastic member on the periphery of the opening end portion of the cover 30 ′ and the upper plate 40 ′ A contacting the O-ring 18 and the periphery of the pressure receiving chamber 28 A formed inside the connection joint 28. The lower plate 40′C disposed via the ring 24 and the diaphragm 40′B sandwiched between the upper plate 40′A and the lower plate 40′C facing each other are mainly configured. .

  The upper plate 40′A is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The upper plate 40 ′ A has through holes 40 ′ a and 40 ′ b as openings at positions directly below the light emitter 16 and the light receiver 22. The shapes of the through holes 40′a and 40′b may be, for example, circular or rectangular.

  The light beam LB emitted from the light emitter 16 is incident on the through-hole 40'a toward the diaphragm 40'B. Further, a gap (light guide path) is formed between the lower surface of the portion 40'c between the through holes 40'a and 40'b in the upper plate 40'A and the surface 40'bs of the diaphragm 40'B. In this case, the reflected light from the light guide path passes through the through hole 40'b. A concave surface 40'CS having a predetermined radius of curvature corresponding to the curvature of the inverted diaphragm 40'B is formed on the lower surface of the portion 40'c, as shown in a partially enlarged view in FIG. 8C. As a result, both ends of the concave surface 40′CS and the surface 40′bs of the diaphragm 40′B whose center portion is reversed come into contact with the diaphragm 40′B, so that the diaphragm 40′B is reliably reversed.

  The lower plate 40′C is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The lower plate 40 ′ C has an opening 40 ′ Cf at the center that opens toward a funnel-shaped pressure receiving chamber 28 A formed inside the connection joint 28. An O-ring 24 is in contact with the periphery of the opening 40′Cf of the lower plate 40′C that is in contact with the inner peripheral surface of the connection joint 28.

  The outer peripheral edge of the diaphragm 40'B is sandwiched between the upper plate 40'A and the lower plate 40'C.

  The diaphragm 40'B is formed of, for example, a material having corrosion resistance against the fluid supplied through the flow path 28a in the connection joint 28, for example, a stainless steel thin plate. The surface 40'bs facing the upper plate 40'A of the diaphragm 40'B may be subjected to surface treatment such as nickel plating, gold or silver plating after quenching in order to increase the light reflection efficiency. Alternatively, the surface 40'bs may be mirror-finished.

  The diaphragm 40′B may be composed of one diaphragm or a plurality of diaphragms. The number of the plurality of diaphragms is appropriately selected according to the specifications of the contactless pressure switch.

  The upper plate 40 ′ A and the lower plate 40 ′ C are joined together by welding the outer peripheral edges with the diaphragm 40 ′ B sandwiched therebetween, thereby obtaining a diaphragm assembly 40 ′. Thereby, a fusion | melting part is formed in the outer peripheral part of upper plate 40'A and lower plate 40'C. The connecting joint 28 into which the obtained diaphragm assembly 40 ′ is inserted and the above-described cover 30 ′ are joined by caulking the upper end portion of the connecting joint 28 to the outer peripheral surface of the cover 30 ′.

  In such a configuration, when the fluid enters or leaves the pressure receiving chamber 28A through the flow path 28a in the connection joint 28 along the direction indicated by the arrow P shown in FIG. 2, the pressure of the fluid in the pressure receiving chamber 28A is a predetermined value. If it is less than that, as shown in FIGS. 8B and 8C, the central portion of the diaphragm 40 ′ B bends in a convex shape toward the pressure receiving chamber 28 </ b> A with a predetermined deflection angle. At that time, a predetermined gap (light guide path) is formed between the surface 40'bs facing the portion 40'c of the upper plate 40'A in the central portion of the diaphragm 40'B and the lower surface of the portion 40'c. Is done. Thus, after the light beam LB from the light emitter 16 is incident on the surface 40'bs via the through hole 40'a, the light receiver 22 receives the light beam LB that has passed through the light guide path and the through hole 40'b. Receive light. Accordingly, a low-level detection pulse signal So indicating that the fluid pressure in the pressure receiving chamber 28A is less than a predetermined value is transmitted.

  On the other hand, when the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value, as shown in FIGS. 9A and 9B, the central portion of the diaphragm 40'B is reversed by the pressure of the fluid, and the upper plate 40'A portion Since the surface 40'bs facing 40'c comes into contact with the lower surface of the portion 40'c, the above-described gap (light guide path) becomes substantially zero. Thereby, after the light beam LB from the light emitter 16 is incident on the surface 40'bs via the through hole 40'a, the light beam LB is blocked. The photoreceptor 22 does not receive the light beam LB. Accordingly, a high level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value is transmitted.

  Also in such an embodiment, the contactless pressure switch can be miniaturized. Further, after the light beam LB from the light emitter 16 is directly incident on the surface 40bs of the central portion of the diaphragm 40B through the through hole 40'a, the reflected light beam LB is reflected by the above-described light guide path, and Since the displacement of the central portion of the diaphragm 40'B is detected by being emitted toward the photoreceptor 22 through the through hole 40'b, the number of components constituting the contactless pressure switch is reduced. It becomes.

  10A to 10C each show the configuration of a fourth embodiment of the contactless pressure switch according to the present invention.

  In the example shown in FIGS. 1A to 1C, the light beam LB from the light emitter 16 is directly incident on the surface 20bs of the diaphragm 20B through the through hole 20a, and then the reflected light beam LB is By being configured to be emitted toward the photoreceptor 22 through the through hole 20a, the presence or absence of inversion of the diaphragm 20B is detected. Instead, in the example shown in FIGS. 10A to 10C, The detection of the presence or absence of inversion of the diaphragm 60B, which will be described later, is configured such that the light beam LB from the light emitter 16 is emitted toward the light receiver 22 through the light guide path 52r of the slider 52 that abuts the central portion of the diaphragm 60B. It is supposed to be done.

  10A to 10C, the same components as those in the example illustrated in FIGS. 1A to 1C are denoted by the same reference numerals, and redundant description thereof is omitted.

  The contactless pressure switch includes a diaphragm assembly 60 coupled to one inner side of one end of the connection joint 28, a cover 50 that is connected to the diaphragm assembly 60 and contains the light emitter 16 and the light receiver 22, and one end of the connection joint 28. A signal demodulating circuit unit that sends a detection output representing a predetermined pressure of the fluid according to the displacement of a diaphragm 60B, which will be described later, is provided as a main element. Although not shown in the examples shown in FIGS. 10A to 10C, the signal demodulation circuit unit similar to the signal demodulation circuit unit described above is provided.

  The cover 50 as a housing is formed of a resin material, for example, and has a concave portion 50A in which the light emitter 16 and the light receiver 22 are accommodated. The light emitter 16 and the light receiver 22 are fixed to one surface of the upper plate 60A of the diaphragm assembly 60 so as to face each other on a common straight line with a predetermined interval. The light emitter 16 and the light receiver 22 are set at positions that are separated from each other in the radial direction by the same distance from the approximate center position of the cover 50. A slider 52 is disposed between the light emitter 16 and the light receiver 22 so as to be movable up and down.

  The slider 52 is composed of a large diameter part and a small diameter part connected to the large diameter part. Between the inner peripheral portion of the concave portion 52a at the upper end of the large diameter portion of the slider 52 and the bottom portion of the concave portion 50a formed in the inner peripheral portion of the center portion of the cover 50, the slider 52 is attached toward the surface of the diaphragm 60B. An energizing coil spring 54 is disposed. Thereby, the lower end surface of the small diameter portion of the slider 52 described later is always in contact with the surface of the diaphragm 60B.

  On the outer peripheral portion of the large diameter portion of the slider 52, flat surfaces facing each other in parallel are formed. Each flat surface is formed to face the light emitter 16 and the light receiver 22. Thereby, since each flat surface interferes with the light emitter 16 and the light receiver 22, the rotation of the slider 52 is avoided.

  Inside the large-diameter portion of the slider 52, a light guide path 52r through which the light beam LB from the light emitter 16 passes is formed at a predetermined position. The light guide path 52r having a predetermined inner diameter is formed so as to be substantially orthogonal to the central axis of the large diameter portion and extend in the radial direction. As shown in FIG. 10B, the position of the light guide path 52r does not coincide with the optical path of the light beam LB from the light emitter 16 when the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value. When the pressure of the fluid is equal to or higher than a predetermined value, the position of the light guide path 52r is a position that matches the optical path of the light beam LB from the light emitter 16, as shown in FIG. 10C. Thereby, when the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value, the light beam LB from the light emitter 16 is received by the light receiver 22 through the light guide path 52r.

  The lower end of the small diameter portion of the slider 52 protrudes toward the surface of the diaphragm 60B through the hole 60a of the upper plate 60A.

  The diaphragm assembly 60 includes an upper plate 60 </ b> A that contacts the peripheral edge of the opening end of the cover 50 and the O-ring 18, and a lower plate that is disposed on the peripheral edge of the pressure receiving chamber 28 </ b> A formed inside the connection joint 28 via the O-ring 24. The main elements are 60C and a diaphragm 60B sandwiched between the upper plate 60A and the lower plate 60C facing each other.

  The upper plate 60A is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The upper plate 60A has a hole 60a into which the small diameter portion of the slider 52 is inserted.

  The lower plate 60C is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The lower plate 60 </ b> C has an opening 60 </ b> Cf that opens toward a funnel-shaped pressure receiving chamber 28 </ b> A formed inside the connection joint 28 at the center. An O-ring 24 is in contact with the periphery of the opening 60Cf of the lower plate 60C that is in contact with the inner peripheral surface of the connection joint 28.

  The outer peripheral edge of the diaphragm 60B is sandwiched between the upper plate 60A and the lower plate 60C.

  The diaphragm 60B is formed of, for example, a material having corrosion resistance against the fluid supplied through the flow path 28a in the connection joint 28, for example, a stainless steel thin plate. Diaphragm 60B may be composed of one diaphragm or a plurality of diaphragms. The number of the plurality of diaphragms is appropriately selected according to the specifications of the contactless pressure switch.

  The upper plate 60 </ b> A and the lower plate 60 </ b> C are joined together by welding the outer peripheral edges with the diaphragm 60 </ b> B sandwiched therebetween, whereby the diaphragm assembly 60 is obtained. Thereby, a fusion | melting part is formed in the outer peripheral part of 60 A of upper plates, and the lower plate 60C. Then, the connecting joint 28 into which the obtained diaphragm assembly 60 is inserted and the above-described cover 50 are joined by caulking the upper end portion of the connecting joint 28 to the outer peripheral surface of the cover 50. For example, when the connection joint 28 is disposed in the pipe Bo, the above-described light emitter 16 and the light receiver 22 are grounded via the connection joint 28 and the pipe Bo.

  In such a configuration, when the fluid enters or leaves the pressure receiving chamber 28A through the flow path 28a in the connection joint 28 along the direction indicated by the arrow P shown in FIG. 2, the pressure of the fluid in the pressure receiving chamber 28A is a predetermined value. If it is less than that, as shown in FIG. 10B, the central portion of the diaphragm 40B bends in a convex shape toward the pressure receiving chamber 28A with a predetermined deflection angle. At this time, the position of the optical path of the light beam LB from the light emitter 16 and the position of the light guide path 52r of the slider 52 do not match. Thereby, the light receiver 22 does not receive the light beam LB from the light emitter 16. Therefore, a high level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value is transmitted.

  On the other hand, when the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value, as shown in FIG. 10C, the central portion of the diaphragm 60B is reversed by the pressure of the fluid, and the small diameter of the slider 52 contacting the surface of the upper plate 60A. The portion is raised to a predetermined position against the urging force of the coil spring 54. Accordingly, the position of the optical path of the light beam LB from the light emitter 16 and the position of the light guide path 52r of the slider 52 coincide with each other, so that the light receiver 22 receives the light beam LB from the light emitter 16. Accordingly, a low-level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber 28A is equal to or higher than a predetermined value is transmitted.

  Also in such an embodiment, the contactless pressure switch can be miniaturized. Further, the light beam LB from the light emitter 16 is emitted toward the light receiver 22 through the light guide path 52r of the slider 52 that is moved in accordance with the inversion of the diaphragm 60B, so that the displacement of the central portion of the diaphragm 60B is achieved. Since (reversal) is detected, the number of parts constituting the contactless pressure switch is reduced.

  In the above-described example, when the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value, the light receiving body 22 does not receive the light beam LB from the light emitting body 16 as shown in FIG. For example, when the pressure of the fluid in the pressure receiving chamber 28 </ b> A is less than a predetermined value, the light receiving body 22 receives the light beam LB from the light emitting body 16. By changing the position of the light guide path 52r of the slider 52 so as to receive light, the low-level detection pulse signal So is sent out when the pressure of the fluid in the pressure receiving chamber 28A is less than a predetermined value. Also good.

  11A and 11B are partial cross-sectional views showing the configuration of a fifth embodiment of the contactless pressure switch according to the present invention. 11A and 11B, the same components as those in the example shown in FIG. 2 are denoted by the same reference numerals, and redundant description thereof is omitted.

  As shown in FIG. 11A, the contactless pressure switch includes a diaphragm assembly 70 coupled to the inside of one end of the connection joint 28, and a cover (not shown) coupled to the diaphragm assembly 70 and incorporating the diaphragm assembly 70. And a signal demodulating circuit section which is arranged inside one end of the connection joint 28 and sends out a detection output representing a predetermined pressure of the fluid in accordance with the displacement of a diaphragm 70B which will be described later.

  The sealed light-emitting body 16 and light-receiving body 22 pass through the center of the cover 10 facing each other at a predetermined interval in a recess formed in a lower plate 70C constituting a part of a diaphragm assembly 70 described later. It is fixed on a common straight line. The concave portion is formed by a pair of inclined surface portions of the lower plate 70C that form a part of the pressure receiving chamber PR. In FIG. 11B, the light emitter 16 and the light receiver 22 are respectively disposed on the slope portion inclined downward to the left and the slope portion inclined obliquely to the right. The upper end of the slope part inclined downward to the left and the upper end of the slope part inclined downward to the right are connected by a flat surface forming the top. One end of a flow path 70 </ b> R communicating with the flow path 28 a in the connection joint 28 is opened on the flat surface.

  It should be noted that the sealed light emitter 16 and light receiver 22 are necessarily fixed on a common straight line that passes through the center of the cover 10 so as to face each other with a predetermined interval between the recesses formed in the lower plate 70C. For example, after the light beam LB from the light emitter 16 is incident on the surface via the fluid LIQ and the gap, the reflected light beam LB is applied to the photoreceptor 22 via the fluid LIQ and the gap. In order to receive light, the light emitter 16 and the light receiver 22 may be arranged at any predetermined position in the pressure receiving chamber PR, and preferably, a region inside a common circle or a common circumference You may arrange | position so that a predetermined | prescribed circumference angle may be made | formed above.

  Furthermore, the arrangement of the sealed light-emitting body 16 and light-receiving body 22 is not limited to such an example, and may be arranged on a common plane in the lower plate 70 </ b> C, for example, instead of the slope portion.

  The diaphragm assembly 70 is sandwiched between the upper plate 70A disposed in the cover, the lower plate 70C disposed inside the connection joint 28, and the upper plate 70A and the lower plate 70C facing each other via the O-ring 24. The main element is the diaphragm 70B.

  The upper plate 70A as the support member is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. The upper plate 70A has a through hole 70a as an opening at the center. The through hole 70a communicates with the internal space of the cover. One open end of the through hole 70a is connected to the funnel-shaped inner surface of the upper plate 70A. In addition, the one opening end of the through-hole 70a is not restricted to such an example, For example, you may form in concave shape or substantially planar shape.

  The lower plate 70C is formed into a thin plate shape with a metal material, for example, by press molding, cutting, die casting, forging, or the like. An annular groove into which the O-ring 24 is inserted is formed at the periphery of the lower plate 70C that contacts the periphery of the diaphragm 70B.

  The outer peripheral edge of the diaphragm 70B is sandwiched between the upper plate 70A and the lower plate 70C. The diaphragm 70B is formed of, for example, a material having corrosion resistance to the fluid supplied through the flow path 28a in the connection joint 28, for example, a stainless steel thin plate. The surface facing the lower plate 70C of the flexible diaphragm 70B may be subjected to nickel plating, gold or silver plating after quenching in order to increase the light reflection efficiency. Alternatively, the surface may be mirror-finished. Further, the surface of the diaphragm 70B facing the lower plate 70C may be subjected to a coating process using, for example, a white pigment or dye instead of the plating process in order to increase the light reflection efficiency. Further, the above quenching process may be omitted.

  Diaphragm 70B may be composed of one diaphragm or a plurality of diaphragms. The number of the plurality of diaphragms is appropriately selected according to the specifications of the contactless pressure switch.

  The upper plate 70A and the lower plate 70C are joined together by, for example, welding, with the diaphragm 70B sandwiched therebetween, whereby the diaphragm assembly 70 is obtained. Thereby, a fusion | melting part is formed in the outer peripheral part of 70 A of upper plates, and the lower plate 70C. Then, the connecting joint 28 into which the obtained diaphragm assembly 70 is inserted and the above-described cover are joined by caulking the upper end portion of the connecting joint 28 to the outer peripheral surface of the cover. The diaphragm assembly 70 is not limited to such an example. For example, instead of welding, the upper plate 70A and the diaphragm 70B are sealed and joined by a sealing material such as an O-ring. May be.

  In such a configuration, when the fluid LIQ enters or exits the pressure receiving chamber PR through the flow path 28a in the connection joint 28, when the pressure of the fluid LIQ in the pressure receiving chamber PR is less than a predetermined value, as shown in FIG. 11A. In the central portion of the diaphragm 70B, the surface facing the lower plate 70C and the flat surface of the lower plate 70C come into contact with each other, so that the gap between the diaphragm 70B and the flat surface of the lower plate 70C becomes substantially zero. As a result, the light beam LB from the light emitter 16 collides with the surface of the diaphragm 70B in contact with the flat surface of the lower plate 70C, so that the light receiver 22 does not receive the light beam LB. Therefore, a high level detection pulse signal So representing that the pressure of the fluid LIQ in the pressure receiving chamber PR is less than a predetermined value is transmitted.

  On the other hand, when the pressure of the fluid in the pressure receiving chamber PR is equal to or higher than a predetermined value, the center portion of the diaphragm 70B is inverted toward the funnel-shaped inner surface of the upper plate 70A with a predetermined deflection angle, and is bent in a convex shape. . At this time, a predetermined gap is formed between the surface facing the lower plate 70C at the center of the diaphragm 70B and the flat surface of the lower plate 70C. Thus, after the light beam LB from the light emitter 16 is incident on the surface via the fluid LIQ and the gap, the reflected light beam LB is directed toward the photoreceptor 22 via the fluid LIQ and the gap. Since it is emitted, the light receiver 22 receives the light beam LB. Accordingly, a low-level detection pulse signal So representing that the pressure of the fluid in the pressure receiving chamber PR is equal to or higher than a predetermined value is transmitted.

10, 30, 30 ', 50 Cover 16 Light emitter 20, 40, 40', 60 Diaphragm assembly 20a Through hole 20B, 40B, 40'B, 60B Diaphragm 22 Light receiver 52 Slider LB Light beam

Claims (4)

A housing that houses a light emitter that emits a light beam for detection and a light receiver that receives the light beam for detection from the light emitter;
A diaphragm comprising: at least one diaphragm coupled to the housing and connected to a pipe line to which an operating pressure is supplied and displaced in accordance with the operating pressure; and a support member supporting a peripheral edge of the diaphragm Assembly,
A signal processing unit that sends out a detection output signal representing an operating pressure based on the light beam for detection received by the photoreceptor; and
The light receiver is the detection light beam incident on the surface of the diaphragm from the light emitter through the first hole of the support member, and is reflected by the surface of the diaphragm. The surface of the diaphragm and the support member The contactless light beam that receives the detection light beam that has passed through a second hole spaced apart from the first hole in the support member and that has passed through a light guide formed between the opposing surfaces. Pressure switch. A slope having a slope corresponding to the curvature of the inverted diaphragm is formed between the first hole of the support member and the surface of the diaphragm facing the surface of the support member between the second holes. The contactless pressure switch according to claim 1. The contactless pressure switch according to claim 1 , wherein the light emitter is a light emitting diode, and the light receiver is a phototransistor . 2. The contactless pressure switch according to claim 1 , wherein the diaphragm is formed of a stainless steel plate and includes a plurality of diaphragms .

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