JPS586112Y2 - pressure detection switch - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pressure detection switch that opens and closes electrical contacts based on changes in liquid pressure, and particularly relates to a pressure detection switch suitable as a pressure detection switch for detecting lubricant oil pressure in automobile engines. .

The engine lubrication system incorporates a pressure detection switch that operates in response to engine lubricant oil pressure within the lubrication system.

When the engine lubricating oil pressure is below a predetermined value, i.e. below the minimum value necessary for proper lubrication, this pressure detection switch closes the electrical contacts and lights up the oil pressure warning lamp to alert the driver. When the oil pressure is above a predetermined value, an electric contact is opened to extinguish the oil pressure warning lamp.

By the way, the viscosity of engine lubricating oil generally decreases as the oil temperature rises, so when the engine temperature is high, the pump blowing pressure decreases and the lubricating performance also decreases.

Therefore, the minimum lubricant oil pressure necessary for proper lubrication increases as the oil temperature rises.

However, in conventional pressure detection switches, the opening/closing set pressure is set to a fixed value by a spring, etc., and is not configured to automatically change in response to temperature etc., so the set pressure If it is set to the required minimum value at low temperatures, the warning lamp may not light up even though proper lubrication is not being performed at high temperatures, and operation may continue with insufficient lubrication. On the other hand, if the set pressure is adjusted to the required minimum value at high temperatures, there is a problem in which the warning lamp lights up even though sufficient lubricant oil pressure is obtained at low temperatures, and the warning lamp does not turn on. It is not possible to indicate whether or not the lubrication state is appropriate.

In view of the above-mentioned problems with conventional pressure detection switches, it is an object of the present invention to provide an improved pressure detection switch whose opening/closing set pressure automatically changes in response to temperature.

This object, according to the invention, comprises a casing, a diaphragm provided in the casing and cooperating with the casing to define a pressure fluid introduction chamber on one side, and a fixed contact carried by the casing; a movable contact supported by the diaphragm and facing the fixed contact; and a spring that flexibly drives the diaphragm in a direction in which the movable contact contacts the fixed contact, the spring acting on the diaphragm. When a fluid with a pressure that overcomes the spring force is introduced into the pressure fluid introduction chamber, the diaphragm biases the movable contact away from the fixed contact. At least one of the spring receiving seats is remotely connected by a pressure detection switch, such as a bimetal that deforms to the side that deflects the spring as the temperature of the bimetal increases.

According to this configuration, the preload of the spring is increased as the temperature of the bimetal rises, so the spring force of the spring acting on the diaphragm is increased, and the opening/closing set pressure of the switch is automatically adjusted as the temperature rises. It will be increased accordingly.

Preferably, the bimetal is placed at a position where it should be sensitive to the temperature of the pressure fluid introduced into the pressure fluid introduction chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of a pressure detection switch according to the present invention.

In the figure, 1 indicates a casing assembly, and this casing assembly 1 consists of a first cup-shaped element 1a made of an electrically insulating material such as plastic, and a second cup-shaped element 1b made of metal. It is composed of an assembly.

A diaphragm 2 is arranged in the second cup-shaped element 1b, which diaphragm 2 cooperates with the cup-shaped element 1b to define a pressure fluid introduction chamber 3 on its underside.

Pressure fluid, such as engine lubricating oil, is introduced into the pressure fluid introduction chamber 3 through a pressure fluid intake port 4 formed in the second cup-shaped element 1b.

Further, the second cup-shaped element 1b is connected to the diaphragm 2.
An annular fixed contact element 5 is supported substantially integrally with the first cup-shaped element 1a at the upper part thereof.

An actuator 7 whose outer periphery is surrounded by an insulating bushing 6 is fitted into a through hole formed in the center of the fixed contact element 5 in a vertically movable manner, and the actuator I has a lower end. A spring receiving seat 8 is provided at an upper end portion of the diaphragm 2 which is in contact with the upper surface of the diaphragm 2 at a portion thereof and which protrudes upwardly from the fixed contact element 5, and a movable contact element 9 is provided which faces the upper surface of the fixed contact element 5. It is held together.

A bimetal plate 10 is placed on the spring receiving seat 8, and a spring receiving plate 11 is placed on this bimetal plate 10, and the spring receiving plate 11 and the first Between the spring receiver and the seat 12 arranged in the cup-shaped element 1a, there is a predetermined normal contraction coil spring 13 that flexibly drives the movable contact element 9 together with the actuator 7 toward the upper surface of the fixed contact element 5. It is placed with a preload of .

The spring seat 12 has a fastener element 14 such as a rivet.
It is fixed to the first cup element 1a together with the connection terminal 15 provided on the outside of the second cup element 1a.

The mounting base of the connection terminal 15 is molded and covered with an electrically insulating material such as resin, and
the first cup-shaped element 1a and the second cup-shaped element 1b
An 01J ring 16 is interposed at the butt joint.

Until fluid with a pressure that overcomes the spring force of the compression coil spring 13 acting on the actuator 7 is introduced into the pressure fluid introduction chamber 3, the actuator 7 remains in the position shown in the figure. The movable contact element 9 is in contact with the upper surface of the fixed contact element 5.

Therefore, at this time, the current applied to the connection terminal 15 is applied to the fastener element 14, the spring seat 12, and the compression coil spring 1.
3, spring support plate 11, bimetal plate 10,
It flows through the spring receiving seat 8, the movable contact element 9, and the fixed contact element 5 to the second cup-shaped element 1b.

On the other hand, when fluid with a pressure that overcomes the spring force of the compression coil spring 13 acting on the actuator 7 is introduced into the pressure fluid introduction chamber 3, the diaphragm 2 The actuator 7 is biased upward in the figure against the spring force, and the movable contact element 9 is separated from the fixed contact element 5, and the flow of the current is interrupted.

As mentioned above, the minimum fluid pressure required to open the switch, that is, the switch opening/closing pressure, is uniformly determined by the preload of the compression coil spring 13, but according to the structure according to the present invention as described above, the preload is The plate 10 changes automatically in relation to the temperature.

That is, at low temperatures, the bimetal plate 8 is
The compression coil spring 13 has a flat plate shape as shown in FIG.
The compression coil spring 12 exerts a spring force corresponding to the preload at the time of assembly to move the movable contact element 9 together with the actuator 7 to the fixed contact element 5.
It is flexibly driven towards.

On the other hand, when the temperature of the bimetal 8 rises, the bimetal grate 10 is thermally deformed and warped as shown in FIG. This will compress the spring 13 and increase its preload.

Therefore, the preload of the compression coil spring 13, in other words, the switch opening/closing pressure increases as the temperature of the bimetal plate 10 rises, and at high temperatures a higher pressure fluid flows into the pressure fluid introduction chamber 3 than at low temperatures. If it is not introduced within the circuit, the switch will not open.

In this case, the bimetal 12 is configured so that the heat of the pressure fluid introduced into the pressure fluid introduction chamber 3 is transferred to the second cup-shaped element 1b, the fixed contact element 5, the movable contact element 9, the insulating bushing 6, and the spring receiving seat 8. It is conducted through the wire and thermally deforms in response to its temperature.

As described above (according to the pressure detection switch according to the present invention, the switch opening/closing pressure increases as the temperature rises,
It is suitable as a pressure detection switch in the lubrication system of an automobile engine.

Although the present invention has been described in detail with respect to specific embodiments above, it is clear to those skilled in the art that the present invention is not limited to this and that various embodiments are possible within the scope of the present invention. Will.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing one embodiment of the pressure detection switch according to the present invention, and Figs. 2 1 and 2 are views showing the main parts of the present invention, of which 1 is at low temperature and 2 is at low temperature. Shows the state at high temperatures. DESCRIPTION OF SYMBOLS 1...Casing assembly, 1a...First cup-shaped element, 1b...Second cup-shaped element, 2...Diaphragm, 3. ... Pressure fluid introduction chamber, 4 ... Pressure fluid intake port, 5
...Fixed contact element, 6 ... Insulation bushing, 7 ... Actuator, 8 ... Spring receiver, 9 ... Movable Contact element, 10...bimetal plate, 11...spring support plate,
12... Spring receiving seat, 13... Compression coil spring, 14... Fastener element, 15...
...Connection terminal, 16...O ring.

Claims (1)

[Scope of utility model registration request] a casing; a diaphragm disposed within the casing and cooperating with the casing to define a pressure fluid introduction chamber on one side; and a fixed contact carried by the diaphragm;
a movable contact supported by the diaphragm and facing the fixed contact; and a spring that flexibly drives the diaphragm in a direction in which the movable contact contacts the fixed contact, the spring acting on the diaphragm. In the pressure detection switch, the diaphragm biases the movable contact away from the fixed contact when fluid having a pressure that overcomes the spring force is introduced into the pressure fluid introduction chamber. A pressure detection switch characterized in that a bimetal is disposed on at least one side of the spring receiving seat portion, and the bimetal is biased toward a side that deflects the spring as the temperature of the switch increases.