JPH02254332A - Pressure switch - Google Patents

Abstract

PURPOSE:To make it possible to take out an electric signal as a switch output at this time with an electronic circuit and the like by providing a constitution wherein light from a light emitting element is not transmitted to a photodetector element by screening of the light when a pointer is displaced so that it is located between the light emitting element and the photodetector element in correspondence with applied pressure. CONSTITUTION:A setting knob 2 is turned, and a setting pointer 1 can be arranged at any position of a cutout part 3 on a panel 7. A light emitting element always emits light, and the light is transmitted to a photodetector element 10. For example, when pressure is not applied on a Bourdon tube 9, a fan shaped pointer 4 is located at an optical axis between the element 11 and the element 10 so as to shield the light. Therefore, the element 10 does not receive the light. At this time, the output of an electronic circuit in a circuit board 16 becomes OFF. When the pressure is applied, the pointer 4 is turned together with a shaft 14, the light screening is removed and the light is received with the element 10; the output of the electronic circuit becomes ON. In this way, the electronic circuit is turned ON/OFF by the displacement of the pointer 4 caused by the pressure through the tube 9, and the device can be used as a pressure switch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure switch that utilizes the displacement of a Bourdon tube.

(Prior Art) Conventionally, as a pressure switch that utilizes the displacement of a Bourdon tube, one based on the principle shown in FIG. 4 has been used. This will be explained below with reference to the drawings.

In FIG. 4, when pressure is applied to the Bourdon tube 33 through the impulse tube 31, the Bourdon tube 33 swells so that its cross section approaches a circular shape, so the Bourdon tube deforms to make the circular shape approach a straight line. The tip of 33 is displaced in the direction of the arrow in the figure. At this time, the tip of the Bourdon tube 33 comes into contact with the plunger 34 and displaces it, so
The contacts inside the limit switch 32 are opened and closed, and an electric signal is transmitted to the outside through the lead wire 36. The switching pressure is set mainly by adjusting the contact between the tip of the Bourdon tube 33 and the plunger 34 using a screw. In this case, the pressure inside the impulse pipe can be measured by, for example, the pointer 41 of a pressure indicator M provided separately as shown in FIG.
The pressure can be set by checking the operating status of the equipment operated by air pressure by actually attaching a pressure gauge to the equipment and checking the operating status of the equipment.

(Problems to be Solved by the Invention) In the conventional pressure gauge described above, when setting the pressure value for switching, the pressure value is set while looking at the display on a separate pressure gauge, or the pressure value during switching operation is set. Confirming settings like this is troublesome,
After all, it is often necessary to install a pressure indicator, which increases costs and has the disadvantage that the installation requires a large amount of space.

Furthermore, there was also the problem that the pressure setting value easily fluctuated due to factors such as temperature, and the setting accuracy was poor.

The present invention aims to solve the above problems.

(Means for solving the problem) In order to achieve the above object, the following means are provided.

In order to detect the movement of the pointer of a Bourdon tube type pressure indicator using a photoelectric method, a light emitting element and a light receiving element are arranged at positions that sandwich the pointer. It is constructed so that it can be easily placed at any position.

In addition, by forming the pointer in a sector-like shape, the movement of the pointer is captured by a photoelectric system, so that it is possible to clearly detect whether the pressure is above or below a certain certain level.

Thus, the device is configured to receive and block light between the light emitting element and the light receiving element by displacement of the pointer due to a predetermined pressure.

(Function) According to the present invention, one light-emitting element and one light-receiving element are arranged at any position within the movable range of the pointer of the pressure indicator, and the pointer moves between the light-emitting element and the light-receiving element in response to a predetermined pressure. If the light emitting element is displaced so that it is interposed, the light from the light emitting element cannot be blocked and the light will not be transmitted to the light receiving element. Therefore, the electrical signal at this time can be extracted as a switch output using an electronic circuit or the like.

(Example) Examples according to the present invention will be described below with reference to the accompanying drawings.

1 is a plan view of a pressure switch according to an embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG. 3 is a plan view of FIG. 1.

In the figure, 1 is a setting needle, 2 is a setting knob, 3 is a notch,
4 is a fan-shaped pointer, 5 is an outer cover, 6 is a pilot lamp,
7 is a panel, 8 is an inner cover, 9 is a Bourdon tube, IO is a light receiving element, 11 is a light emitting element, 12 is a transparent panel, 14 is a panel and a shaft of the pointer, 15 is a flexible circuit board, 16
Reference numeral 17 indicates a circuit board, 17 indicates a wiring, and 18 indicates a voltage conducting portion.

When pressure is applied from the pressure guiding part 18, the pressure is transmitted to the Bourdon tube 9, and the Bourdon tube 9 is displaced according to the magnitude of the pressure.
This is also converted into a rotational movement of the pointer 4.

A light-receiving element 10 such as a photodiode and a light-emitting element 11 such as an LED are disposed inside the U-shaped cross-section of the setting needle 1 so that their optical axes are aligned with each other.

The U-shaped section of the setting needle 1 is formed so as to sandwich the panel 7 provided with the notch 3 and the fan-shaped pointer 4. A setting knob 2 is fixed to the end of the setting needle 1. Setting knob 2
By rotating the setting needle 1, the setting needle 1 can be placed at any position in the notch 3 on the panel 7. Light receiving element 10
and the terminals of the light emitting element 11 are wired inside the setting needle 1,
The flexible circuit board 15 is connected to one side by soldering or the like, and the other side of the flexible circuit board 15 is connected to the circuit board 16, so that even if the setting needle l is rotated, the Bourdon tube 9, etc. will not move. Electrical connection is made with the circuit board 16 without any support.

The light emitting element 11 always emits light and transmits light to the light receiving element 10. However, for example, when no pressure is applied to the Bourdon tube 9, the sector-shaped pointer 4 is connected to the light emitting element 1 and the light receiving element lO.
The light-receiving element 10 does not receive light because it is interposed between the optical axis of the circuit board 16 and blocks the light.
The electronic circuit inside is configured so that the output is turned off.
Next, when pressure is applied and the fan-shaped pointer 4 is rotated together with the shaft 14, the light shielding by the sector-shaped pointer 4 is removed and the light from the light emitting element 11 is received by the light receiving element 10, and conversely, the electronic circuit output is turned on. . In this manner, the electronic circuit of the circuit board 16 is turned on and off by the displacement of the sector pointer 4 due to pressure through the Bourdon tube 9, and can be used as a pressure switch. The pilot lamp 6 is provided so that the on/off operation of the electronic circuit can be confirmed from the outside, and is lit when the circuit is turned on, for example.

Naoki In the embodiment, a case has been described in which the electronic circuit is turned off when the fan-shaped pointer 4 is shielded from light, but it is of course possible to configure it so that it is turned on when the light is shielded and turned off when the light is opened. be.

Basically, the shape of the pointer 4 may be in the shape of a clock hand, such as the pointer 41 of the pressure indicator M in FIG. passes through, causing the output to change, and it is not possible to determine whether the needle is above the pressure setting position, has reached the pressure setting position, or has returned, so it is not suitable for pressure switches that are used continuously. Although unsuitable, it is suitable for limited applications where equipment is activated only when the pressure exceeds a predetermined value, and the pressure is returned to zero each time. However, by making the pointer fan-shaped, the above-mentioned defects in use can be solved. That is, even if the pressure exceeds the set value, since the pointer is fan-shaped, no light will pass through it and the switch will not change.

(Effects of the Invention) As described above, according to the present invention, the pressure can be easily set by turning the knob directly on the pressure display panel. Furthermore, since it has sufficient functions as a pressure indicator, there is no need to separately arrange a pressure indicator, which is advantageous in terms of cost and space. Furthermore, the pressure set value is less likely to fluctuate due to temperature factors, and has the advantage of having at least the same accuracy as that of a pressure indicator.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is a plan view of the pressure switch, FIG. 2 is a sectional view of FIG. 1,
FIG. 3 is a rear view of FIG. 1 with the inner cover removed. FIG. 4 is a principle diagram showing a conventional example, and FIG. 5 is a perspective view of a pressure indicator. l...Setting hand, 2...Setting knob, 4...Sector pointer, 7...Panel %9...Bourdon tube, 10...
・Light receiving element, 11... Light emitting element, 15... Flexible circuit board, 16... Circuit board, 18... Pressure conducting part, 20° 21... Crank. Applicant Copal Electronics Co., Ltd. Agent Patent Attorney Sakae Kobayashi 11/Light-emitting device 15: Flexible circuit board Figure Figure Figure

Claims (1)

[Claims] 1. In a pressure gauge that displays the pressure of gas applied to a Bourdon tube as the movement of a pointer, a light-emitting element and a light-receiving element whose optical axes are aligned can move the pointer at any position within the movable range of the pointer. 1. A pressure switch, which is arranged to sandwich a pointer, and generates an electric signal by receiving and blocking light between a light-emitting element and a light-receiving element by displacement of a pointer caused by a predetermined pressure. 2. The pressure switch according to claim 1, wherein the pointer comprises a single fan-shaped flat plate. 3. The pressure according to claim 1, characterized in that when no pressure is applied to the Bourdon tube, the pointer blocks light between the light emitting element and the light receiving element, and when pressure is applied, the pointer is displaced to release the light blocking. switch. 4. The pressure switch according to claim 1, wherein a light emitting element and a light receiving element are respectively provided so as to face each other in the U-shaped cross section of the setting needle. 5. The pressure switch according to claim 1, further comprising a panel having a sector-shaped pointer plate disposed below and a cutout through which light from a light emitting element can be transmitted and received by a light receiving element.