JPH0119301Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention displaces one diaphragm in response to pressure changes in a pressure source, and sets two switches to different settings depending on the amount of displacement of this diaphragm. Concerning pressure switches operated by volume.

[Prior art]

Conventionally, in this type of pressure switch, one switch is built into each body, and therefore pressures that vary over a wide range from negative pressure to positive pressure, such as in the intake manifold of a turbocharged engine, can be used. If you want to detect two different set pressures for a source, such as a predetermined value of negative pressure and a predetermined value of positive pressure, you must connect two pressure switches with different set pressures to the pressure source. There is a problem that multiple pressure switches are required and the cost is high.

[Purpose of invention]

The present invention has been made in view of the above points, and its purpose is to provide a pressure switch that can detect two different set pressures without using two pressure switches.

[Summary of the idea]

The present invention provides a diaphragm on one side of the pressure chamber that displaces in one direction when the pressure in the pressure chamber increases and displaces in the other direction when the pressure decreases, and a first diaphragm that applies a pressing force to the surface of the diaphragm facing the pressure chamber. a push rod which is provided with a spring, a first threaded portion for adjusting the elastic force of the first spring, and which abuts against a surface opposite to the pressure chamber and is displaced in conjunction with the diaphragm; A second spring is provided which applies a pressing force to the surface of the diaphragm opposite to the pressure chamber through the spring, and has a first movable contact piece that is interlocked with movement of the push rod, and movement of the first movable contact piece. a first switch that is operated in accordance with the push rod; and a second movable contact that moves in conjunction with the push rod when the push rod is displaced in one direction by more than a predetermined amount; The second actuator is operated in response to the movement of the movable contact piece.
A switch is provided, and by applying a pressing force in the other direction to the second movable contact piece, when the push rod is displaced by more than a predetermined amount in one direction, the push rod is moved opposite the pressure chamber of the diaphragm through the push rod. The device is characterized in that a third spring is provided to apply a pressing force to the side surface, and a second screw portion is provided to adjust the elastic force of the third spring.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In Figures 1 and 2, 1 is a cylindrical body made of metal with a bottom, and 2 is a cylindrical part provided at the bottom of the body 1, which forms a pressure chamber 3 inside and has a screw threaded on the inner periphery of the tip. A hole 4 is formed. 5 is a diaphragm that closes one side of the pressure chamber 3; 6 is a disk-shaped fixed contact piece attached to the inner bottom of the body 1 so as to press the outer peripheral edge of the diaphragm 5; a guide hole 6a is provided in the center; The surface on the side opposite to the diaphragm 5 is plated with gold. Reference numeral 7 denotes a covered cylindrical insulator made of an insulating material that is integrated into the inner surface of a cylindrical metal earth body 8 by insert molding, and is pressed into contact with the outer peripheral edge of the fixed contact piece 6 via an O-ring 9. It is caulked to body 1. Reference numeral 10 denotes a receiving seat applied to the surface of the diaphragm 5 on the pressure chamber 3 side, and is integrated by caulking with a seat plate 11 placed on both sides of the diaphragm 5. Reference numeral 12 denotes a connection port body in which an adjustment screw 13 as a first screw formed at one end is screwed into a screw hole 4 of the cylindrical portion 2, and a connection pipe 14 connected to the other end of this connection port body connects the ventilation hole 15. The pressure chamber 3 is communicated with a pressure source (not shown) via the pressure chamber 3. A sealing O-ring 16 is fitted between the inner surface of the cylindrical portion 2 of the body 1 and the connection port body 12. Reference numeral 17 denotes a first spring mounted between a first spring receiver 18 supported on the end face of the adjusting screw portion 13 and the receiving seat 10, and this spring can be elasticized by screwing the adjusting screw portion 13 back and forth. The force is pre-adjusted and the cylindrical part 2
By caulking in the radial direction, the adjustment screw portion 13
is fixed. Reference numeral 19 denotes a push rod made of an insulating material, and a rod portion 19b protruding from one surface of a disc-shaped base 19a is inserted into the guide hole 6 of the fixed contact piece 6.
a and its tip is in contact with the seat plate 11, and a protrusion 19c is provided at the center of the other surface of the base 19a.
For example, three guide protrusions 19d are provided around the protrusion 19c. Reference numeral 20 designates a cup-shaped first movable contact piece, which includes a convex portion 19c formed on the push rod 19 and a guide protrusion 19.
d, and its inner surface is brought into contact with the other surface of the base 19a of the push rod 19, and a plurality of contact portions 21, for example, three contact portions 21 (only one is shown) are provided on the outer peripheral edge.
is formed. Reference numeral 22 denotes a disc-shaped second conductive spring receiver facing the first movable piece 20, which is caulked to two conductive rivets 23 inserted into the closed end 7a of the insulator 7, and is crimped to the insulator 7. It is fixed to 7. Reference numeral 24 denotes a second spring mounted between the first movable contact piece 20 and the second spring receiver 22 so as to be located on the outer peripheral surface of the convex portion 19c of the push rod 19. 1 movable contact piece 20
The contact portion 21 is pressed against the fixed contact piece 6. The first movable contact piece 20 and the fixed contact piece 6 constitute a first switch 25. 26 is a first soldered to the head 23a of the conductive rivet 23.
This is the lead wire. 27 is formed into a cup shape with a larger diameter than the first movable contact piece 20 and is connected to the guide protrusion 1.
The second movable contact piece is loosely fitted around the outer periphery of the narrow diameter portion 19e of the push rod 19, and its inner surface is spaced a predetermined distance A from the stepped receiving portion 28 integrally formed on the guide protrusion 19d of the push rod 19. A plurality of, for example, three, contact portions 29 (only one is shown) are formed on the outer peripheral edge. 30 is insulator 7
It is a conductive adjustment shaft rotatably provided in the center of the , and has an adjustment screw part 31 as a second screw at the tip.
is provided, and the collar portion 32 is in contact with the inner surface of the insulator 7. Reference numeral 33 designates a third electrically conductive disk-shaped spring receiver, and a screw hole 33a formed in the center is screwed into the adjustment screw portion 31. 34 is a third spring installed between the third spring receiver 33 and the second movable contact piece 27;
The elastic force of the third spring 34 can be adjusted by rotating the adjusting shaft 30 and screwing the adjusting screw portion 31 forward and backward. 2 movable contact piece 2
The contact portion 29 of 7 is pressed against the fixed contact piece 6.
Further, the second movable contact piece 27 and the fixed contact piece 6 constitute a second switch 35. 36 is a second lead wire soldered to the adjustment shaft 30.
In FIG. 3, 37 is a through hole formed in the closed end 7a of the insulator 7 and communicates between the inside and outside of the insulator 7, and 38 is a through hole formed in the closed end 7a concentrically with the through hole 37.
A circular recess is formed on the outer surface of the recess 38, and an annular groove 39 is formed on the outer periphery of the recess 38. 4
Reference numeral 0 denotes a breathable member inserted into the recess 38, which is made of, for example, Goretics film (trade name) and has breathability and water repellency. The breathable member 4 is caulked to the peripheral edge of the breathable member 4.
0 is held between the insulator 7 and the clamp 41. In this case, the sandwiched portion of the breathable member 40 is compressed and becomes thin, but the peripheral portion is formed by the annular groove 39.
The air permeable member 40 is fitted into the insulator 7 without being compressed and is surely prevented from slipping off between the insulator 7 and the clamp 41.
42 is a cover that covers the breathable member 40.

Incidentally, 43 and 44 are O for sealing watertightly between the insulator 7, the conductive rivet 23, and the adjustment shaft 30.
It's a ring.

Next, the operation of the above configuration will be explained. 1st
A case will be described in which the switch 25 and the second switch 35 operate under positive pressure (greater than atmospheric pressure) and negative pressure (lower than atmospheric pressure) from the pressure source, respectively.

(a) First, when the first switch 25 and the second switch 35 operate at pressures T ₁ and T ₂ (both are positive pressures).

In this case, as shown in FIG. 1, first, with the pressure chamber 3 open to the atmosphere, the adjusting screw part 13 of the connection port body 12 is screwed forward and backward, and the first spring 17
The elastic force Fp ₁ is the elastic force of the second spring 24
It is adjusted so that it is smaller than Fp ₂ , that is, (Fp ₁ <Fp ₂ ). As a result, the first and second switches 25 and 35 are closed, the first lead wire 26 is electrically connected to the body 1 via the first switch 25, and the second lead wire 36 is connected to the second switch 35. through body 1
It is placed in a conductive state. Therefore, the pressure source is communicated with the pressure chamber 3 via the connecting pipe 14 to increase the pressure of the pressure source 3, and when the pressure inside the pressure chamber 3 reaches _T1 , this pressure _T1 acts on the diaphragm 5. The sum of the pressure F ₁ and the elastic force Fp ₁ of the first spring 17 is larger than the elastic force Fp ₂ of the second spring 24, that is, (F ₁ +Fp ₁ >Fp ₂ ), and the diaphragm 5 is connected to the seat plate 11. , while compressing the second spring 24 via the rod portion 19b.
9 and the first movable contact piece 20 are displaced in the direction of arrow B. Then, the first movable contact piece 20 is displaced, the contact portion 21 is separated from the fixed contact piece 6, and the first switch 25 is opened. When the push rod 19 is further displaced by a dimension A in the direction B and the receiving portion 28 comes into contact with the second movable contact piece 27, the third spring 34 cooperates with the second spring 24 to push the diaphragm 5 through the push rod 19. Apply pressing force to. When the pressure in pressure chamber 3 further increases and reaches T ₂ , the pressure T ₂
The sum of the pressing force F2 acting on the diaphragm ₅ and the elastic force _Fp1 of the first spring 17 is the elastic force of the second and third springs 24 and 34, respectively.
Greater than the sum of Fp ₂ and Fp ₃ , that is, (F ₂ + Fp ₁ > Fp ₂ +
Fp ₃ ), and the diaphragm 5 is displaced while compressing the second and third springs 24 and 34 by a predetermined amount via the push rod 19, and the receiving portion 28
The contact portion 29 of the second movable contact piece 27 is separated from the fixed contact piece 6 by a predetermined distance, the second switch 35 is opened (see FIG. 4), and the body 1 and the first and second
The lead wires 26 and 36 are open. In this case, the elastic force Fp ₃ of the third spring 34 is adjusted by rotating the adjustment shaft 30 in advance and moving the third spring receiver 33.

(b) Second switch 35 and first switch 25
are pressures T ₃ and T ₄ (both are negative pressure and T ₃ > T ₄ )
If it operates in

In this case, with the pressure chamber 3 open to atmospheric pressure, as shown in _FIG . The elastic force Fp 3 of the third spring 34 is adjusted by screwing the adjusting screw portion 31 of the adjusting shaft 30 back and forth, so that the elastic force Fp ₁ of the first spring 17 becomes the same as that of the second and third springs _. springs 24 and 3
greater than the sum of the elastic forces Fp ₂ and Fp ₃ of 4, that is, (Fp ₁ >
Fp ₂ + Fp ₃ ). As a result, the first spring 17 resists the elastic forces Fp ₂ and Fp ₃ of the second and third springs 24 and 34 to move the push rod 19 and the first and second movable contact pieces 20.
and 27 in the direction of arrow B to open the first switch 25 and the second switch 35. When the pressure chamber 3 is connected to a pressure source and the pressure is reduced, the pressure inside the pressure chamber 3 becomes a negative pressure below atmospheric pressure, and the diaphragm 5 is urged in the opposite direction of arrow B. When the pressure inside the pressure chamber 3 is reduced to T ₃ , a biasing force F ₃ of the diaphragm 5 in the opposite direction of arrow B is applied.
The difference between the elastic forces Fp ₁ , Fp ₂ and Fp ₃ of the second and third springs 17, 24 and 34 is Fp ₂ +Fp ₃ +
The relationship F ₃ > Fp ₁ > Fp ₂ + F ₃ is established, and the diaphragm 5 is displaced in the opposite direction of arrow B, and the second movable contact piece 2
7 is also displaced in the opposite direction of arrow B together with the push rod 19, the contact portion 29 comes into contact with the fixed contact piece 6, the second switch 35 is closed, and the connection between the second lead wire 36 and the body 1 is closed. (See Figure 5). When the pressure inside the pressure chamber 3 is further reduced to T ₄ , the diaphragm 5
The sum of the biasing force F ₄ in the opposite direction of arrow B and the elastic force Fp ₂ of the second spring 24 is greater than the elastic force Fp ₁ of the first spring 17, that is, (Fp ₁ <Fp ₂ +F ₄ ) As a result, the push rod 19 and the first movable contact piece 20 are further displaced in the direction of arrow B, and the contact portion 21 contacts the fixed contact piece 6, closing the first switch 25 and connecting the body 1 and the first lead. The line 26 is closed (see FIG. 1).

(c) When the first switch 25 operates at T ₅ (negative pressure) and the second switch 35 operates at T ₆ (positive pressure).

In this case, with the pressure chamber 3 open to atmospheric pressure, as shown in _FIG . The elastic force Fp ₃ of the third spring 34 is adjusted by screwing the adjusting screw portion 31 of the adjusting shaft 30 back and forth, so that the elastic force of the first spring 17 becomes equal to the elastic force of the second spring 24. is larger than the force Fp ₂ and the second and third springs 24 and 3
Adjust the elastic force so that it is smaller than the sum of the elastic forces Fp ₂ and Fp ₃ of No. 4 (Fp ₂ +Fp ₃ >Fp ₁ >Fp ₂ ). As a result, the diaphragm 5 and the push rod 19 are displaced in the direction of arrow B by the elastic force Fp ₁ of the first spring 17, and the receiving seat 28 of the push rod 19 is moved to the second position.
It stops when it comes into contact with the movable contact piece 27 of the first
The switch 25 is opened and the second switch 35 is closed, so that the connection between the body 1 and the first lead wire 26 is in the open state, and the connection between the body 1 and the second lead wire 36 is in the closed state. Become. Therefore, the inside of the pressure chamber 3 is communicated with a pressure source, the pressure inside the pressure chamber 3 is increased, and when the pressure reaches _T6 , the diaphragm 5 is connected to the second and third springs 24 and 34 as in the case (a) above.
The pushing body 19 resists the elastic forces Fp ₂ and Fp ₃ of
Then, the second contact piece 27 is displaced in the direction of arrow B to open the second switch 35. On the other hand, if the pressure inside the pressure chamber 3 is reduced to _T5 from the above state,
As in the case of (b) above, the diaphragm 5 is pressed by the second spring 24 via the push body 19 and is displaced in the opposite direction of arrow B, so that the first switch 2
Close 5.

According to the above embodiment, the first switch 25 and the second switch 35 are provided in the body 1, and the diaphragm 5
The first switch 25 and the second switch 35 can be operated in accordance with the amount of displacement, and therefore two different set pressures can be detected independently.

[Effect of idea]

As is clear from the above description, the present invention is capable of operating two switches at different set values and detecting two different set pressures, compared to the conventional one using two pressure switches. This has the practical effect that it can be manufactured at a correspondingly lower cost.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal sectional view, FIG. 2 is a plan view, FIG. 3 is a sectional view taken along the line - in FIG. 2, and FIGS. 4 and 5. 1 and 2 are views corresponding to FIG. 1 showing different states of the diaphragm, respectively. In the drawing, 3 is a pressure chamber, 5 is a diaphragm, 13
17 is a first spring, 24 is a second spring, 25 is a first switch, 31 is an adjustment screw portion (second screw), 3
4 represents a third spring, and 35 represents a second switch.

Claims (1)

[Scope of utility model registration request] A diaphragm provided on one side of the pressure chamber and displaced in one direction when the pressure in the pressure chamber increases and displaced in the other direction when the pressure decreases; and a first spring that applies a pressing force to the surface of the diaphragm facing the pressure chamber. , a first threaded portion for adjusting the elastic force of the first spring; a push rod that comes into contact with the surface opposite to the pressure chamber and is displaced in conjunction with the diaphragm; a second spring that applies a pressing force to a surface opposite to the pressure chamber; and a first movable contact piece that moves in conjunction with the movement of the push rod, and is actuated in accordance with the movement of the first movable contact piece. a first switch;
The push rod has a second movable contact piece that moves in conjunction with the push rod when the push rod is displaced beyond a predetermined amount in one direction, and a second movable contact piece that is operated in response to the movement of the second movable contact piece. and the second switch.
By applying a pressing force in the other direction to the movable contact piece, when the push rod is displaced in one direction by more than a predetermined amount, a pressing force is applied to the surface of the diaphragm opposite to the pressure chamber through the push rod. A pressure switch comprising a third spring and a second threaded portion for adjusting the elastic force of the third spring.