JP5105245B2 - Detection switch - Google Patents

Description

  The present invention relates to a detection switch that detects the pressure and flow rate of a fluid such as air.

  As a conventional detection switch, Patent Document 1 describes a pressure detection switch. This pressure detection switch detects nozzle back pressure by blowing air onto the workpiece in order to detect the position, for example, whether or not the workpiece is correctly seated on the seating surface.

  In such a pressure detection switch, as shown in FIG. 6, as a conventional mounting structure of an O-ring 52 that seals between a pressure sensor 50 and a detection port 51 connected to external piping, an O-ring 52 is a flat washer. There is a structure in which the O-ring 52 is pressed by pressing the peripheral portion 55 of the flat washer 53 of the component 54 constituting the detection port 51. As another conventional O-ring mounting structure, as shown in FIG. 7, there is a structure in which a pressure sensor 50 is applied to an O-ring 52 and the pressure sensor 50 is pressed by a cover 56 and sealed.

Japanese Utility Model Publication No. 5-40852

  As shown in FIG. 6, in the conventional structure in which the O-ring 52 is pressed by the flat washer 53, the O-ring 52 may be damaged when the flat washer 53 is attached, and fluid may leak from the damaged portion, and caulking work is required. Therefore, there is a problem that the assembly process increases. Further, as shown in FIG. 7, in the conventional structure in which the O-ring 52 is pressed by the pressure sensor 50, the O-ring 52 is not sufficiently fixed, there is a risk of fluid leakage, and the sealing performance is not good. There is.

  In view of the above problems, the present invention is to provide a detection switch in which sealing performance by an O-ring between a detection port and a sensor is improved and an assembling operation is facilitated.

The detection switch of the present invention includes a casing containing the sensor,
A block provided in the casing and having a detection port;
A stepped circular recess provided in a passage between the detection port and the sensor in the block;
An O-ring for sealing made of a stretchable material housed in the circular recess,
A lateral groove provided in a direction crossing the passage on the sensor side of the circular recess;
An O-ring stopper that has a shape that matches the lateral groove, is slidably fitted into the lateral groove, has a through-hole, and one surface abuts on the sensor-side surface of the O-ring;
The sensor is provided with a through-hole of the O-ring stopper and a detection convex portion that fits into the O-ring.

  In the detection switch of the present invention, the lateral groove has a taper shape with a narrow width on the sensor side, and the O-ring stopper has a trapezoidal shape that matches the lateral groove.

  In the detection switch according to the present invention, the O-ring stopper is made of a synthetic resin.

  The detection switch of the present invention has a structure in which the O-ring for sealing is pressed by an O-ring stopper that is slidably fitted in the lateral groove, so that the O-ring can be attached without being damaged. Further, since the O-ring can be pressed by inserting the O-ring stopper into the lateral groove from the side, assembly is easy. Further, since the O-ring stopper is fitted in the lateral groove, there is no possibility that the O-ring stopper is displaced in the axial direction of the O-ring, and a detection switch with improved fluid sealing performance can be provided.

  In the detection switch of the present invention, the lateral groove has a tapered shape with a narrow width on the sensor side, and the O-ring stopper has a trapezoidal shape that matches the lateral groove. Deviation in the direction perpendicular to the axial direction of the ring is also prevented, and the O-ring stopper can be fixed in the lateral groove without rattling.

  In the detection switch of the present invention, by using a synthetic resin for the O-ring stopper, it is possible to more reliably prevent the O-ring from being damaged by the O-ring stopper.

  1 to 5 show an embodiment of the detection switch of the present invention. In this embodiment, the detection switch is a pressure detection switch. Reference numeral 1 denotes a synthetic resin casing. Reference numeral 1a denotes a synthetic resin block constituting a part of the casing 1. This block 1a includes a detection port 2 for connecting an external pressure detection pipe (not shown), a mounting portion 3 for the pressure sensor 4 shown in FIGS. 4 and 5, and a mounting hole for other equipment by a fixing tool (not shown). And 5. The casing 1 contains a calculation board 6. The arithmetic substrate 6 converts an analog signal that is an output signal of the pressure sensor 4 into a digital signal, and performs arithmetic processing such as pressure level evaluation. The casing 1 and the block 1a are configured to be thin in order to reduce the installation space, and are preferably configured to have a thickness of 15 mm or less, more preferably 12 mm or less.

  Reference numeral 7 denotes a display frame provided on the upper surface of the casing 1, and reference numeral 8 denotes a display substrate to be combined with the lower surface of the display frame 7. The display frame 7 is provided with a pressure value display surface 9. The display substrate 8 has a switch 10 for selecting whether to set a reference value or display a detection value, a switch 11 operated to increase the reference value, and a switch 12 operated to lower the reference value. Is provided. Each of these switches 10 to 12 is provided with its upper portion protruding from the display frame 7. Reference numeral 13 denotes a connector including an output terminal of a detection signal obtained from the arithmetic substrate 6 and a power supply terminal. This connector 13 is connected to an external controller via another connector and a cable (not shown).

  Reference numerals 14 and 15 denote indicator lamps provided at the corners of the display surface 9 constituted by the display frame 7. These indicator lamps 14 and 15 indicate in steps which level the pressure detected by the pressure sensor 4 is at. These indicator lamps 14 and 15 incorporate light emitting elements (not shown), and are provided to face three surfaces at corner portions adjacent to each other in the thickness direction of the display surface 9. That is, the light emitting surface of one indicator lamp 14 is exposed on the front surface, side surface, and top surface of the casing 1. The other indicator lamp 15 has a light emitting surface exposed on the back surface, side surface, and top surface of the casing. The indicator lamps 14 and 15 are transparent or semi-transparent materials constituting the surface, and a partition 17 made of an opaque material is provided between the indicator lamps 14 and 15. Thus, the visibility of the indicator lamps 14 and 15 is improved by adopting a configuration in which the indicator lamps 14 and 15 are visible from three directions.

  As shown in FIGS. 4 and 5, the block 1 a has a passage 20 for communicating between the detection port 2 and the sensor mounting portion 3. 21 is an O-ring made of a stretchable material such as rubber. The O-ring 21 is fitted and attached to a stepped circular recess 22 provided in the passage 20.

  Reference numeral 23 denotes a tapered lateral groove provided in a direction crossing the passage 20 between the pressure sensor 4 and the O-ring 21 provided in the block 1a. The lateral groove 23 has a shape in which the O-ring 21 side is wider than the diameter of the circular recess 22 and the pressure sensor 4 side is narrowed.

  Reference numeral 24 denotes an O-ring stopper made of a synthetic resin. The O-ring stopper 24 has a trapezoidal shape that matches the tapered lateral groove 23. The O-ring stopper 24 has a through hole 24a at the center. The O-ring stopper 24 is attached to the tapered lateral groove 23 by sliding fitting. In a state where the O-ring stopper 24 is attached to the lateral groove 23, the O-ring 21 comes into contact with the O-ring stopper 24 and is sealed between the two. The pressure sensor 4 integrally has a detection convex portion 4 a communicating with the detection port 2. This detection convex portion 4 a constitutes a conduit that guides the fluid whose pressure is to be detected to the pressure detection portion of the pressure sensor 4. The detection convex portion 4 a is fitted into the through-hole 24 a and the O-ring 21 of the O-ring stopper 24 and fixed to the casing 1 and attached. Reference numeral 25 denotes a substrate to which the terminal 4b of the pressure sensor 4 is soldered. The substrate 25 is electrically connected to the arithmetic substrate 6.

  Reference numeral 30 denotes an adapter for attaching this detection switch to a DIN rail (not shown). The adapter 30 has a hook receiving portion 1c in which one end of the pivot locking portion 30a is hung on a pivot receiving portion 1b (see FIG. 1) provided in the casing 1, and the other hook portion 30b is provided in the block 1a. (Refer to FIG. 2) to be detachable.

  As described above, the O-ring 21 can be attached without being damaged by adopting a structure in which the O-ring 21 is pressed by the O-ring stopper 24 fitted in the lateral groove 23. Further, since the O-ring is pressed by inserting the O-ring stopper 24 into the lateral groove 23 from the side, the assembly is easy. Further, since the O-ring stopper 24 is fitted in the lateral groove 23, there is no possibility that the O-ring stopper 24 is displaced in the axial direction of the O-ring 21, and a detection switch with improved fluid sealing performance can be provided. .

  Further, in the present embodiment, the lateral groove 23 has a tapered shape with a narrow width on the sensor 4 side, and the O-ring stopper 24 has a trapezoidal shape that matches the lateral groove 23. The vertical deviation in the axial direction of the O-ring is also prevented, and the O-ring stopper 24 can be fixed in the lateral groove 23 without rattling. In addition, if a synthetic resin is used for the O-ring stopper 24 as in the present embodiment, damage to the O-ring 21 due to the O-ring stopper 24 can be prevented more reliably.

  Although the case where the sensor 4 is a pressure sensor has been described in the above embodiment, the present invention can also be applied to the case where the sensor 4 is a flow sensor. In the case of the flow rate sensor, a flow path for flowing fluid to the passage 20 is provided in the vertical direction, and the tip of the detection convex portion 4a is projected into the flow path for flowing fluid. Two thermistors are provided at the tip of the detection convex portion. A constant current is passed through the two thermistors via cables passing through the detection convex portions 4a. One thermistor is supplied with a large current to raise the temperature so that the electric resistance is increased, and the change in the resistance value due to the flow rate is increased. The current flowing through the other thermistor is set to be small, and the change in resistance value due to the flow rate is reduced. The difference between the resistance values of the two thermistors is detected as a voltage difference. Since the flow rate sensor is configured in this way, in the case of a flow rate detection switch having a flow rate sensor, the detection convex portion 4a is configured as a convex portion containing a cable.

It is the perspective view which looked at the detection switch of one embodiment of this invention from diagonally upward from the connector side. It is the perspective view which looked at the detection switch of this Embodiment from diagonally upward from the non-connector side. It is a longitudinal cross-sectional view of the detection switch of this Embodiment. It is a disassembled perspective view which shows the attachment structure of the O-ring of this Embodiment. It is a longitudinal cross-sectional view which shows the attachment structure of the O-ring of this Embodiment. It is sectional drawing which shows an example of the attachment structure of the conventional O-ring. It is sectional drawing which shows the other example of the attachment structure of the conventional O-ring.

Explanation of symbols

1: casing, 1a: block, 1b: pivot receiving portion, 1c: hook receiving portion, 2: detection port, 3: pressure sensor mounting portion, 4: pressure sensor, 4a: conduit, 4b: terminal, 5: Mounting holes, 6: calculation board, 7: display frame, 8: display board, 9: digital display, 10-12: switch, 13: connector, 14, 15: indicator lamp, 17: partition, 20: passage , 21: O-ring, 22: circular recess, 23: transverse groove, 24: O-ring stopper, 24a: through-hole, 30: adapter, 30a: pivot locking portion, 30b: hook portion

Claims (3)

A casing containing the sensor;
A block provided in the casing and having a detection port;
A stepped circular recess provided in a passage between the detection port and the sensor in the block;
An O-ring for sealing made of a stretchable material housed in the circular recess,
A lateral groove provided in a direction crossing the passage on the sensor side of the circular recess;
An O-ring stopper that has a shape that matches the lateral groove, is slidably fitted into the lateral groove, has a through-hole, and one surface abuts on the sensor-side surface of the O-ring;
A detection switch provided in the sensor, comprising a through hole of the O-ring stopper and a detection convex portion fitted into the O-ring. The detection switch according to claim 1,
The detection switch according to claim 1, wherein the lateral groove has a tapered shape with a narrow width on the sensor side, and the O-ring stopper has a trapezoidal shape that matches the lateral groove. The detection switch according to claim 1 or 2,
The detection switch, wherein the O-ring stopper is made of a synthetic resin.

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