JPH0237637A - Pressure switch - Google Patents

Abstract

PURPOSE:To instantly perform the contact switching even for a slow type basic switch by providing hysteresis instantly performing the switching of contacts of the basic switch when the load pressure becomes the preset value or above. CONSTITUTION:A pressure switch 1 has a case 2 opened on the upper and lower faces, a basic switch 3, an exciting means 7, an operating member 4 and a rubber diaphragm 5. When the pressure is smaller than the force of the exciting means 7, the diaphragm 5 is in contact with a cover 6 to close a pressure guiding hole 14, the basic switch 3 is not operated. When the pressure becomes larger than the pressure of the exciting means 7, the pressure guiding hole 14 which has been closed by the diaphragm 5 is quickly opened, the area pressing the diaphragm 12 is increased, the basic switch 3 is instantly switched via the diaphragm 5, the operating member 4 and a switching operation section 12. The contact switching can be instantly performed even for the slow type basic switch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure switch that detects the pressure of liquid, gas, etc.

(Prior Art) A pressure switch is placed, for example, in the fuel supply system of an internal combustion engine, and is capable of detecting the pressure of fluid flowing in the fuel supply path and outputting a signal to control the fuel supply valve. .

FIG. 2 shows a conventional example of such a pressure switch.

In the figure, the pressure switch 31 includes a case 32 whose upper and lower surfaces are open, and a basic switch 33 that is attached to the case 32.
, a biasing means 41, an actuating member 34, a rubber diaphragm 35, a cover 36, and the like are sequentially assembled.

Furthermore, inside the case 32, 32
It is divided into an upper storage chamber 37 and a lower storage chamber 38 by a. Further, the partition wall 32a is integrally provided with a cylindrical portion 39 that protrudes toward the upper storage chamber 37, and through holes 40 formed in the three cylindrical portions are connected to the upper storage chamber 37 and the lower storage chamber 37. are in communication with each other. and,
The operating member 34 and the biasing means 41 are arranged in the upper storage chamber 37, and the basic switch 33 is arranged in the lower storage chamber 38.

The basic switch 33 disposed in the lower storage chamber 38 is a well-known low-load operation type microswitch. That is, this basic switch 33 has a flexible terminal 33b1, a fixed terminal 33c, and
33d, etc., and the movable terminal 33b is connected to the fixed terminal 33.
A switching operation part 42 is provided in a state protruding from the switch case 33a for externally switching the state from the state in which it contacts the fixed terminal 33d to the state in which it contacts the fixed terminal 33d. The basic switch 33 is fixed in the lower storage chamber 38 with the switching operation part 42 corresponding to the inside of the through hole 40.

On the other hand, the biasing means 41 arranged in the upper storage chamber 37 is
It is composed of a coil spring and is disposed around the outer periphery of the cylindrical portion 39. The actuating member 34, which is also arranged in the upper storage chamber 37, has a disk-shaped flange 34a, and a shaft 34b that is fixed at one end at the center of the flange 34a and extends downward at right angles. It is made up of. And the actuating member 3
4 is a through hole 40 after the biasing means 41 is attached.
It is attached by slidably inserting the shaft 34b therein.

Then, the collar portion 34a is placed on the upper end of the biasing means 41,
The shaft 34b is installed in the upper storage chamber 37 with the lower end of the shaft 34b lightly abutting the upper part of the switching operation section 42.

Next, after the biasing means 41 and the actuating member 34 are attached, the rubber diaphragm 35 is arranged to close the upper opening of the upper storage chamber 37 in a liquid-tight manner. The diaphragm 35 is provided with a circular flat part 35a at a portion corresponding to the flange part 34a, and this flat part 35a
A curved portion 35bff bent downward to the outside of
i is provided.

Next, the cover 36 attached to the top of the case 32 is
A locking portion 36 with a U-shaped cross section formed on its outer periphery.
At step a, the outer circumferential portion 35c of the diaphragm 35 is crimped and sealed to the case 32, and a pressure chamber 4 is formed in the upper part of the diaphragm 35.
It is installed in a state where 3 are defined. Further, a cylindrical portion 36c having a pressure introduction hole 44 is provided at the upper part of the cover 36.
is provided, and a branch vibe 45 on the side to be detected can be connected to this cylindrical portion 36c.

In the pressure switch 31 configured in this way, when the liquid pressure sent through the branch vibe 45 is applied from the pressure introduction hole 44, the pressure inside the pressure chamber 43 increases,
It acts as a force that pushes the diaphragm 35 downward. and,
When this force overcomes the force of the biasing means 41, the diaphragm 3
5 pushes down the actuating member 34. At the same time, the switching operation part 42 of the basic switch 33 is also pressed down, and the movable terminal 3
The contact of the terminal 3b is switched from the contact with the fixed terminal 33C to the contact with the fixed terminal 33d. Next, pressure chamber 4
When the pressure within 3 is reduced, the force of the biasing means 41 forces both the actuating member 34 and the diaphragm 35 upward again. As a result, the basic switch 33 also has the movable terminal 33b.
contacts the fixed terminal 33d, and is switched from the state to the state in which it contacts the fixed terminal 33C.

That is, in this pressure switch 31, when pressure is applied within the pressure chamber 43, the basic switch 33 is switched via the diaphragm 35 and the actuating member 34, and this is output as pressure information within the pressure chamber 43. In this structure, the pressure chamber 43 is always formed as a space having a volume above a certain level, and the pressure sent through the pressure introduction hole 44 is applied to the entire inside of the pressure chamber 43.

(Problems to be Solved by the Invention) As described above, in the conventional structure, when pressure is applied inside the pressure chamber 43, pressure is applied to the entire inside of the pressure chamber 43 from the beginning. Therefore, the pressure applied to the actuating member 34 via the diaphragm 35 is gradually applied in a gentle curve. For this reason,
The operating force to the basic switch 33 is also applied slowly. In this case, if the basic switch 33 has a built-in snap-action mechanism and the structure allows for instantaneous switching of contacts, this will not be much of a problem, but in the case of a slow type that does not have a built-in snap-action mechanism, the current may be interrupted more slowly. Therefore, there was a problem that instantaneous switching operation could not be obtained.

The present invention has been made in view of the above problems, and its purpose is to provide a switch having a structure that allows instantaneous switching of contacts even if it is a slow type basic switch. .

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a basic switch housed in a case, an actuation member for pressing down the OFF 8 operation part of the basic switch, and a biasing means for returning the pressed member to the pressing state; A pressure switch comprising the diaphragm and a cover defining a pressure chamber, wherein when no pressure is introduced into the pressure chamber, the diaphragm is brought into contact with the inner surface of the cover by the urging means and the The pressure introduction hole is opened at the diaphragm.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 shows a pressure switch according to an embodiment of the present invention.

In the figure, a pressure switch 1 includes a case 2 with open upper and lower surfaces, and this case 2 includes a basic switch 3, a biasing means 7, an actuating member 4, a rubber diaphragm 5, and a cover 6.
It has a structure that sequentially incorporates the following.

Further, the inside of the case 2 is divided into an upper storage chamber 8 and a lower storage chamber 9 by a partition wall 2a formed in the center. Further, the partition wall 2a is integrally provided with a cylindrical portion 10 that protrudes toward the upper storage chamber 8, and a through hole 11 formed in the cylindrical portion 10 connects the upper storage chamber 8 and the lower storage chamber 9. are in a connected state. The operating member 4 and the biasing means 7 are arranged in the upper storage chamber 8, and the basic switch 3 is arranged in the lower storage chamber 9.

The basic switch 3 arranged in the lower storage chamber 9 is a well-known low-load operation type microswitch, and has the same internal structure as the basic switch 33 shown in FIG. Then, the switching operation part 12 is connected to the through hole 1.
It is fixed in the lower storage chamber 9 in a state corresponding to the interior of the storage chamber 9.

On the other hand, the biasing means 7 disposed within the upper storage chamber 8 is composed of a coil spring, and is disposed around the outer periphery of the cylindrical portion 10. The actuating member 4, which is also arranged in the upper storage chamber 8, has a disk-shaped flange 4a, and a @4b whose one end is fixed at the center of the flange 4a and extends downward at right angles. It is made up of.

After the biasing means 7 is attached, the actuating member 4 is attached by slidably inserting the shaft 4b into the through hole 11. Then, the flange 4a is placed on the upper end of the biasing means 7, and the lower end of the shaft 4b is attached to the upper storage v8 with the lower end lightly abutting the upper part of the switching operation part 12.

Next, after the biasing means 7 and the actuating member 4 are attached, the rubber diaphragm 5 is arranged to close the upper opening of the upper storage chamber 8 in a fluid-tight manner. The diaphragm 5 is provided with a circular plane part 5a at a portion corresponding to the flange part 4a, and a curved part 5b bent downward into a new surface arch shape is provided on the outside of this plane part 5a. .

Next, the cover 6 attached to the upper part of the case 2 has a locking part 6 formed on its outer circumferential part, which has an opening-shaped cross section.
At a, the outer peripheral portion 5C of the diaphragm 5 is brought into close contact with the case 2 and sealed, and the diaphragm 5 is attached to the upper part of the diaphragm 5 in a state where a pressure v13 is defined. Normally, the flat portion 5a of the diaphragm 5 is brought into close contact with the inner surface of the cover 6 by means of force means 41. Further, a cylindrical portion 6C having a pressure introduction hole 14 is provided in the upper part of the cover 6, and a branch vibrator 15 on the side to be detected is attached to the cylindrical portion 6C.
can be connected.

In the pressure switch 1 configured in this manner, when fluid pressure is applied through the branch vibrator 15, this fluid pressure acts on the flat portion 5a of the diaphragm 5 within the pressure introduction hole 14. While this pressure is smaller than the force of the urging means 7, the pressure introduction hole 14 remains closed by the diaphragm 5, and no fluid enters the inside of the pressure chamber 13. On the other hand, when this pressure becomes greater than the pressure of the urging means 7, the diaphragm 5 is pushed down and the pressure introduction hole 14 is slightly audible. When the pressure introduction hole 14 is slightly opened in this manner, liquid flows into the pressure chamber through this opened gap. Then, the area where the liquid presses the diaphragm 5 becomes larger, so the force becomes stronger,
The diaphragm 5 and the actuating member 4 move rapidly to push down the switching operation part 12 of the basic switch 3, and the contacts in the basic switch 3 are switched instantly. Then, when the pressure within the pressure chamber 13 is weakened, the force of the urging means 7 pushes both the actuating member 4 and the diaphragm 5 upward again. As a result, the switching operation section 12 is also pushed upward,
The inside of the basic switch 3 is switched back to its initial state.

Therefore, in this pressure switch 1, when the pressure is below a predetermined pressure, the diaphragm 5 contacts the inner surface of the cover 6 to close the pressure introduction hole 14, thereby keeping the basic switch 3 in a non-operating state. be done. Conversely, when the pressure exceeds a predetermined value, the pressure introduction hole 14 that was closed by the diaphragm 5 suddenly opens, and the area that presses the diaphragm 5 increases, causing the diaphragm 5, the operating member 4, and the switching operation part 12 to The basic switch 3 can be instantaneously switched through the switch.

In the above embodiment, as long as the basic switch 3 is provided with the switching operation section 12 on the outside, the internal structure may be changed in various ways, and the basic switch 3 may be used exclusively for this pressure switch.

(Effects of the Invention) As explained above, the pressure switch according to the present invention has hysteresis that causes the contacts of the basic switch to be cut instantly when the load pressure exceeds a predetermined value, so that the basic switch slows down. type, the contacts can be switched instantaneously, and a small, inexpensive pressure switch with a clean intermittent current waveform can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional view of a pressure switch according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a conventional pressure switch. DESCRIPTION OF SYMBOLS 1... Pressure switch, 2... Case, 3... Basic switch, 4... Operating member, 5... Diaphragm,
6...Cover 7...Biasing means, 12...Switching operation section, 13...Pressure chamber, 14...Pressure introduction hole. Figure 1

Claims (1)

[Claims] A basic switch housed in a case, an actuating member for pressing down a switching operation part of the basic switch, a biasing means for restoring the pressing of the actuating member, and a device provided to cover the actuating member. A pressure switch comprising: a diaphragm having a pressure introduction hole; and a cover having a pressure introduction hole and disposed above the diaphragm and fixed to the case to define a pressure chamber with the diaphragm; 1. A pressure switch, wherein when no pressure is introduced into the pressure switch, the diaphragm is brought into contact with the inner surface of the cover by the urging means, and the pressure introduction hole is closed by the diaphragm.