JPH089624Y2 - Pressure detector - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a pressure detector for detecting fluid pressure, and can be used for controlling equipment and devices utilizing hydraulic pressure, pneumatic pressure, or the like.

[Background technology]

Conventionally, as a pressure detector for detecting fluid pressure,
It is often used to convert the pressure of the fluid introduced into the inside into a mechanical displacement by using a Bourdon tube or a diaphragm housed in a prescribed casing. Pressure fluctuations with respect to the set value are detected with a switch.

When using such a pressure detector, it is necessary to fix the casing and to connect a predetermined detection fluid pipe or the like to the pressure introducing portion communicated with the casing surface from the internal Bourdon tube or the like. Also, when applied to a hydraulic system of an automobile, etc., if there are many vibrations in the environment of use, it is necessary to take measures such as preventing looseness of mounting and rotation.
Various structures are used for mounting.

For example, in the pressure detector 40 shown in FIG. 4, in order to fix the casing 41 to the base 42, an elongated mounting portion 43 is provided at the bottom and is fastened with two bolts 44. Further, in order to introduce the detection fluid, the pressure introducing portion 45 on the bottom surface of the casing 41 and the base
The fluid outlet 46 on the surface 42 is disposed so as to face each other, and the casing 41 is fixed to the base 42 so that the casing 41 is automatically and closely connected via the O-ring 47.

On the other hand, in the pressure detector 50 of FIG. 5, the pipe joint 53 for the detection fluid is screwed to the pressure introducing portion 52 on the bottom surface of the casing 51, and the joint 53 holds the base 54 to sandwich the casing 51.
Is fixed. At this time, since the casing 51 and the base 54 are connected at only one point, the casing 51 is fastened to the base 54 with bolts 56 from the side of the protrusion 55 on the bottom surface of the casing 51 to prevent the casing 51 from rotating around the pressure introducing portion 52. It is carried out.

Further, in the pressure detector 60 of FIG. 6, a pipe joint for the detection fluid, which is screwed and connected to the pressure introducing portion 62 on the bottom surface of the casing 61.
The base 61 is sandwiched by 63 to fix the casing 61, and the projections 65 on the bottom surface of the casing 61 are engaged with the holes 66 of the base 64 to prevent the casing 61 from rotating.

Further, in the pressure detector 70 of FIG. 7, a substantially rectangular parallelepiped protrusion 72 is provided on the bottom surface of the casing 71, and the protrusion 72 is clamped and fixed between the protrusion 72 and the base 73 by a bolt 74 and a pressing piece 75. A pipe joint 77 for the detection fluid is connected to the pressure introducing portion 76 on the bottom surface of the protrusion 72.

[Problems to be solved by the device]

By the way, in the structure shown in FIG. 4 among the mounting structures as described above, the pressure introducing portion 45 and the fluid outlet 46 can be simultaneously connected by fixing the casing 41 to the base 42. However, in this structure, the mounting part is
43 overhangs to increase the installation space and the mounting area
If the accuracy of the contact surface between 43 and the base 42 is low, there is a problem that the connection of the pressure introducing portion 45 may be leaked or damaged.

On the other hand, according to the structure of FIGS. 5 to 7, since the fixing and connection are performed on the bottom side of the casing, respectively, the degree of freedom in installation can be increased, and the connection by the screw joints is basically performed. There is no fear of leaks.

However, in the structure shown in FIG. 7, in order to stabilize the posture of the contact surface between the protrusion 72 and the base 73, it is required to improve the processing accuracy of each, and the number of parts of the bolt 74 and the pressing piece 75 is large. There is a cost problem.

Further, in the structure shown in FIG. 5, the protrusion 55 is tightened and fixed to the base 54 with the bolt 56 as a detent, so that the protrusion 55 and the base 54
If the accuracy of the contact surface with is low, the casing 51 will be distorted,
Alternatively, an unreasonable force is applied to the connection between the pressure introducing portion 52 and the joint 53, which may cause leakage or damage.

On the other hand, according to the structure of FIG. 6, the pressure introducing portion 62 and the joint 63
By connecting and, the casing 61 can be fixed to the base 64,
The work is simple, the structure is simple, and the cost can be reduced. However, due to the engagement between the protrusion 65 and the hole 66, the casing 61
Therefore, if the precision is low, sufficient rotation cannot be prevented, and there is a risk that the pressure introducing portion 62 and the joint 63 will be loosely screwed together.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure detector which has a simple structure and can be easily mounted and fixed and fluid connection.

[Means for solving the problem]

In the present invention, most of the problems of the mounting structure in the conventional pressure sensor are caused by the rotation stop, and the rotation of the casing that requires the rotation stop is caused mainly by the inertial force based on the vibration in the usage environment. It was made based on the knowledge that

That is, according to the present invention, a switching operation having a pressure introducing portion at a position away from the geometric center of the entire pressure detector is fixedly supported by the pressure introducing portion, and the position of the pressure introducing portion is fixed to the pressure detector. The position of the center of gravity of the whole is approximately matched.

At this time, as the position of the center of gravity, it is preferable to determine the position in the actual usage state of the pressure detector by actually measuring or estimating the portion of the pressure detector before the pressure introducing portion. Further, as the pressure introducing portion, a fixing structure by screwing or the like may be appropriately adopted, and it may be set so that its axis line substantially coincides with the position of the center of gravity.

[Action]

In the present invention, the pressure detector is mounted by fixing the pressure introducing portion. At this time, the inertial force caused by the vibration of the operating environment acts on the position of the center of gravity as the point of action, but it acts on the position of the center of gravity by making the position of the center of gravity of the entire pressure detector approximately coincide with the position of the pressure introducing portion. The force is prevented from acting as a moment around the fixed position, and the occurrence around the pressure sensor itself is avoided. Therefore, it is not necessary to separately install a detent, and even if the pressure introducing portion is fixed at only one point, sufficient attachment can be achieved, thereby achieving the above object.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the pressure detector 1 according to the present embodiment has a detection mechanism inside a flat cylindrical casing 10.
The detection mechanism 20 includes a bourdon tube 21, a microswitch 22 and the like, and performs a switching operation according to the pressure of the fluid to be detected introduced from the outside.

The casing 10 includes a disk-shaped base 11 and a cup-shaped cover 12 that covers the upper surface of the base 11, and the detection mechanism 20 is attached to a portion of the upper surface of the base 11 that is covered with the cover 12.

The Bourdon tube 21 has a base end portion into which a detection fluid is introduced and is fixed to a raised portion 14 on the upper surface of the base 11 via a hollow box-shaped connection portion 23, and an operation protrusion is provided at a tip end portion for detecting displacement.
24 is fixed. Inside the arcuate shape of the Bourdon tube 21, the lever 25 and the micro switch 22 described above are provided as support plates.
It is supported on the upper surface of the base 11 via 26. Lever 25
Is rotatably supported, one end and the other end thereof are arranged to face the actuating projection 24 and the micro switch 22, and one end is constantly urged by the unillustrated coil spring or the like so as to be in constant contact with the actuating projection 24. .

The microswitch 22 is switched when the displacement of the tip of the Bourdon tube 21 is transmitted via the lever 25 and the displacement, that is, the fluid pressure changes with respect to a predetermined value. The lead wire 27 connected to each terminal of the microswitch 22 is a base
11 It is pulled out through the packing 13 on the lower surface.

On the other hand, the pressure introducing portion 16 is formed on the lower surface of the base 11,
The pressure introducing portion 16 is communicated with the connecting portion 23 through the introducing passage 15 formed by perforation inside the raised portion 14 on the upper surface side, and is also communicated with the inside of the Bourdon tube 21. Further, the pressure introducing portion 16 is projected from the lower surface of the base 11, is formed with an internal thread inside, and the joint 17 of the pipe for supplying the detection fluid is screwed and connected via a seal washer or the like. At this time, a base 18 is sandwiched between the pressure introducing portion 16 and the joint 17, and the pressure detector 1 is fixedly supported by the base 18 at one point of the pressure introducing portion 16.

The central axis C of the pressure introducing portion 16 is set so as to pass through the center of gravity G of the pressure detector 1. This position setting determines the position of the pressure introducing portion 16 in accordance with the position of the center of gravity (including the pressure detector 1 itself and the fluid to be introduced) that is estimated in advance at the design stage, and also determines the actual position of the center of gravity. Is measured and the balance weight is appropriately added so as to fit the pressure introducing portion 16, and the like.

In the present embodiment configured as described above, the micro switch 22 is operated according to the pressure of the fluid introduced from the joint 17 through the pressure introducing portion 16 into the Bourdon tube 21, and the micro switch 22 is output from the lead wire 27.

Here, the pressure detector 1 is fixedly supported on the base 18 only by the screwing connection portion between the pressure introducing portion 16 and the joint 17. For this reason,
The center of gravity of the pressure detector 1 is at a position G ′ at a distance R from the central axis C.
In case (see FIG. 3), when the inertial force F is generated due to the vibration of the usage environment, the central axis C has a moment M = F ×
R may occur and the casing 10 may rotate.
However, in this embodiment, since the center of gravity G of the pressure detector 1 and the center axis C of the pressure introducing portion 16 are aligned with each other, even if the inertial force due to the vibration of the operating environment acts on the center of gravity G, It does not act as a rotational force around the axis C, and it is not necessary to separately provide a rotation stopper or the like.

According to this embodiment, there are the following effects.

That is, since the pressure detector 1 is fixedly supported by sandwiching the base 18 when the pressure introducing portion 16 and the joint 17 are screwed and connected, they are simultaneously attached by the connection for fluid introduction, and are installed. Work is extremely easy. Further, the structure for mounting can be simplified, the installation space can be reduced, and the manufacturing cost can be reduced.

In particular, by matching the center of gravity G of the pressure detector 1 with the central axis C of the pressure introducing portion 16, it is possible to fundamentally eliminate the occurrence of rotation of the pressure detector 1 due to vibration of the operating environment, etc. Occurrence of accompanying failures can be prevented, and since it is not necessary to separately provide a rotation stopper or the like, the mounting structure is not complicated, and the mounting structure and the workability are not impaired.

On the other hand, when the center of gravity position G and the central axis C are made to coincide with each other, since the introduction passage 15 that passes through the raised portion 14 that fixes the Bourdon tube 21 is used, the pressure introduction portion 16 can be arranged at an arbitrary position along the base 11.

Further, even after the position of the pressure introducing portion 16 is preset, the center of gravity position G and the central axis C can be surely matched with each other by adjusting the balance weight in actual use, and the adjustment can be easily performed. .

Further, each of the above-mentioned effects is basically realized by making the center of gravity G and the center axis C coincide with each other. Specifically, the position of the pressure introducing portion 16 may be adjusted, and the existing pressure It can be implemented very easily by partially changing the design of the detector 1.

It should be noted that the present invention is not limited to the above-described embodiment, but may include the following modifications.

That is, the shape, structure, etc. of the casing 10 and the like in the pressure detector 1 may be appropriately selected for implementation.

Further, the pressure detector 1 is not limited to the one for detecting the height with respect to a predetermined value by the Bourdon tube 21 and the micro switch 22, and other mechanism such as a diaphragm may be used for converting the pressure into a mechanical displacement, The detection may be performed by converting the displacement amount into an electric signal and outputting the electric signal, and the present invention can be applied to various types of pressure detectors to obtain excellent effects.

Further, in the above embodiment, the casing 10 is fixed by sandwiching the base 18 when the pressure introducing portion 16 and the joint 17 are screw-connected, but the casing 10 is fixed by using one ordinary bolt.
It may be applied to the type in which the base is attached to the base 18 and the piping is connected separately.In such a case, the rotation around the bolt can be prevented by matching the center axis of the bolt and the center of gravity of the mounting part. It is possible to prevent it, and it is effective in ensuring and simplifying the mounting structure.

[Effect of device]

As described above, according to the pressure detector of the present invention,
By using the pressure introduction part, it is possible to connect the fluid and fix the whole body at the same time, and by making the position of the pressure introduction part almost coincide with the position of the center of gravity of the whole, there is no need for a whirl stop, etc. It is possible to prevent complication.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing the same embodiment, and FIG. 3 is a bottom view showing the same embodiment.
4 (A) and (B) to FIGS. 7 (A) and (B) are a side view and a bottom view showing another conventional example. 1 ... Pressure detector, 10 ... Casing, 16 ... Pressure inlet, 21 ... Bourdon tube, C ... Central axis of pressure inlet,
G: Center of gravity position.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-81174 (JP, A) Actually opened 62-146940 (JP, U) Actually opened 63-135245 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A switch element which has a pressure introducing portion arranged toward the outside at a position away from the geometric center of the whole and which switches in accordance with the pressure of a fluid introduced from the pressure introducing portion to the inside. A pressure detector having the pressure introducing unit fixedly supported, and the position of the pressure introducing unit and the position of the center of gravity of the entire pressure detecting unit are substantially coincident with each other.