JPS59676Y2 - pressure switch - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a pressure switch.

In internal combustion engines for automobiles, a pressure switch is used that detects the pressure and activates an alarm device when its suction negative pressure becomes abnormally large.

In a pressure switch, the contacts do not close under normal pressure, but when abnormally large pressure is applied, the contacts close and activate an alarm device such as a lamp.
There is a strong desire to check whether the pressure switch is functioning properly before starting the engine.

Japanese Utility Model Publication No. 52-18972 discloses a configuration in which the contacts of a reed switch can be inspected, but this configuration has the disadvantage that abnormal pressure cannot be detected.

In consideration of the above, this device has a function that can detect three states of pressure: close the contact when there is no pressure, open the contact in the normal pressure range, and close the contact when there is abnormally large pressure. This paper proposes a new pressure switch.

That is, a single reed switch is placed on the outside of the device, a permanent magnet is fixed on the inside of the reed switch, and two L-shaped magnetic bodies are placed on both ends of the permanent magnet so that the new curved portions face each other. , a magnetic piece that moves vertically between the opposing bends of both magnetic bodies in conjunction with the diaphragm that moves under pressure; and a magnetic piece that moves when no pressure is applied to the diaphragm. The present invention is characterized in that a spring is provided that biases the diaphragm so that the diaphragm is located at a position away from between the opposing bent portions of both the magnetic bodies.

Next, embodiments of the drawings will be described.

1 is a vessel body, 2 is a cover fixed to vessel body 1, 3 is a diaphragm whose periphery is airtightly sandwiched between vessel body 1 and cover 2, and its central part is sandwiched between shell 4 and rod 5. has been done.

A magnetic piece 6 made of iron or the like is fixed to the upper end of the rod 5.

On the inner surface of the upper part of the vessel body 1, there is a permanent magnet 7 magnetized in the left and right direction.
is fixed, and L-shaped (iron) magnetic bodies 8, 8' are embedded and fixed in the vessel body 1 at their upper ends in contact with the left and right end surfaces thereof.

The lower ends of both magnetic bodies 8, 8' are bent inward to form an L-shape as shown.

On the upper outer surface (upper surface) of the vessel body 1, the above-mentioned C-shaped magnetic bodies 8, 8 are provided.
A reed switch 9 is arranged and fixed in the left-right direction adjacent to the upper end of the reed switch 9.

Reference numeral 10 designates an air hole that communicates the inside and outside of the container body 1, 11 a spring that always urges the diaphragm 3 upward, and 12 a negative pressure inlet provided in the cover 2.

When negative pressure is not applied to diaphragm 3, spring 1
1, the diaphragm 3 is in the position shown, the magnetic piece 6 is also in the position shown, and the two L-shaped magnetic bodies 8, 8'
Since the distance between the permanent magnet 7 and the reed switch 9 is large, the lines of magnetic force of the permanent magnet 7 pass through the upper part of the container body 1 and act on the reed switch 9 to close its contact.

Since the reed switch 9 is connected to alarm means such as a lamp, by closing a power switch of an electric circuit (not shown), the lamp lights up and it can be known that the contact function of the pressure switch is normal.

Next, a negative pressure is generated in the diaphragm 3, and when the value is within the normal range, the diaphragm 3 moves slightly downward, and the magnetic piece 6 is placed between the bent portions of the lower ends of the L-shaped magnetic bodies 8 and 8'. In order to reduce the magnetic resistance between both magnetic bodies, the lines of magnetic force of the permanent magnet 7 flow through a closed magnetic path formed by the two L-shaped magnetic bodies 8 and 8' and the magnetic piece 6, and the reed switch 9 becomes inoperable and opens its contacts, thus extinguishing the connected alarm lamp.

When the negative pressure further increases and becomes abnormally large, the magnetic piece 6 passes through the bent portions of the lower ends of the L-shaped magnetic bodies 8 and 8' and separates further downward, so that the lines of magnetic force of the permanent magnet act on the reed switch 9 again. Close the contacts and turn on the alarm lamp.

As is clear from the above explanation, according to this invention, the reed switch closes when negative pressure is not present or becomes abnormally high, and remains open within the normal pressure range. Since the three states can be detected, it is easy to check the contact function, and it is possible to realize a pressure switch suitable for use as a monitor.

In addition, since it is possible to check abnormal pressure increases and contact function without contact, it is highly practical as a low pressure switch for suction negative pressure, etc.

In addition, when the variation range of the applied pressure is large, two springs with different spring constants and initial loads are provided to bias the diaphragm, so that the relationship between the pressure and the amount of diaphragm movement is non-linear. By doing so, there is no need to increase the amount of movement so much even when the pressure is large, and the overall shape can be kept small.

[Brief explanation of the drawing]

The drawing is a sectional view of an embodiment of this invention. 1... vessel body, 3... diaphragm, 6
...Magnetic material piece, 7...Permanent magnet, 8,
8'... L-shaped magnetic body, 9... Reed switch, 11... Spring.

Claims (1)

[Scope of utility model registration request] A single reed switch disposed on the outside of the container, a permanent magnet fixed on the inside thereof, and two L-shaped magnetic bodies disposed at both ends of the permanent magnet so that the bent portions face each other, A magnetic piece moves vertically between the opposing bent portions of the two magnetic bodies in conjunction with the diaphragm moving under pressure, and a magnetic piece moves when no pressure is applied to the diaphragm. A pressure switch characterized in that a spring is provided that biases the diaphragm to a position away from between the opposing bent portions of both the magnetic bodies.