JP2648835B2 - Bourdon tube vibration-proof measuring instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Bourdon tube type vibration-proof measuring instrument, and more particularly to a Bourdon tube type vibration meter such as a pressure gauge configured to convert a displacement of a Bourdon tube into a rotation of a pointer through a link mechanism. The present invention relates to the structure of a vibration-resistant measuring device.

[0002]

2. Description of the Related Art Conventionally, a Bourdon tube connected to a gas intake hole, a link mechanism connected to a tip of the Bourdon tube, a rack formed on an output side of the link mechanism, and meshing with the rack. 2. Description of the Related Art A pressure gauge having a rotary shaft provided with a pinion, a pointer attached to a tip of the rotary shaft, and a mainspring for urging the rotary shaft in a predetermined rotation direction is manufactured. This type of pressure gauge has an advantage that the mechanism is simple and can be manufactured at low cost because the pointer is directly moved by the displacement of the Bourdon tube.

However, when the measured pressure is constantly fluctuating finely, the Bourdon tube vibrates and the pointer also vibrates, so that it becomes difficult to read the indicated pressure. In addition, there is a problem that durability is inferior due to wear of the gear mechanism.

In order to cope with such a case, an oil-filled pressure gauge in which oil is filled in a case is commercially available. The viscosity of the oil sealed in the pressure gauge alleviates the vibration of the Bourdon tube and the link mechanism, thereby preventing the vibration of the pointer and the wear of the internal mechanism.

[0005]

However, in the above-mentioned conventional oil-filled pressure gauge, it is necessary to improve the sealing property of the case body in which the oil is sealed, so that the manufacturing cost is increased and the oil is increased as the oil is used. Leakage is likely to occur. In addition, vibration absorption by oil filling is usually not sufficient, and there is a problem in that if the viscosity of the oil is increased to sufficiently absorb vibration, the pressure indication of the pointer becomes inaccurate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce fluctuations in the pointer caused by pressure fluctuations, to suppress an increase in manufacturing cost, and to reduce the accuracy of pressure indication. An object of the present invention is to realize a new Bourdon tube vibration-proof measuring instrument which can prevent fluid leakage.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a Bourdon tube type vibration-resistant measuring instrument configured to convert displacement of a Bourdon tube into rotation of a pointer via a transmission mechanism. A rotation resistance portion formed to impart resistance to the rotation of the pointer, an impeller rotatably coupled to the pointer, and a case accommodating the impeller; Body, and a fluid housed inside the case body together with the impeller, wherein the amount of the fluid is less than half of the inner volume of the case body, and the measuring device is in any posture. A pressure reducing hole having an internal opening is formed in the case body at a position inside the case body which is not closed by the fluid.

Here, the fluid may be an oil or fat having a predetermined viscosity.

[0009] The fluid may be powder or granules.

[0010] Further, the transmission mechanism is connected with a margin to one of the displacement of the Bourdon tube, ie, a step-up displacement or a step-down displacement, and is connected to the displacement of the Bourdon tube with almost no margin. And a biasing element that constantly biases the connecting portion toward the side corresponding to the one displacement.

[0011]

[0012]

According to the first aspect of the present invention, by providing the rotation resistance portion connected to the pointer, it is possible to prevent the vibration of the pointer due to the pressure fluctuation and to reduce the pressure reduction hole formed in the case of the rotation resistance portion. Because the internal opening is configured so as not to be blocked by the fluid, only air is released through the decompression hole regardless of the installed position of the rotation resistance part, regardless of the installation position. And leakage of the fluid due to an increase in the internal pressure can be reliably prevented.

According to the fourth aspect, since the connecting portion is connected with a margin for one displacement of the Bourdon tube, the rotation of the pointer by the urging of the urging element causes the rotation resistance of the rotation resistance portion to be reduced. The instruction moves slowly because it hinders the movement, and the connecting part is connected with almost no margin for the other displacement of the Bourdon tube, but the urging force of the urging element and the rotational resistance by the rotation resistance part both hinder the rotation of the pointer. Therefore, since the pointer also moves slowly, vibration of the pointer can be suppressed in response to pressure fluctuation, and the durability of the internal transmission mechanism can be improved.

[0014]

[0015]

Next, an embodiment of a pressure gauge according to the present invention will be described with reference to the drawings. FIG. 1 shows the overall configuration of the present embodiment, in which a Bourdon tube 2 connected to a gas introduction hole 1a and extending in an arc shape is connected to an upper part of a mounting portion 1 having a gas introduction hole 1a therein. I have. A support plate 3 is mounted on the mounting portion 1, and three support shafts 4, 5, 6 are fixed between the support plate 3 and the support plate 7. A rotary shaft 8 is supported between the support plates 3 and 7, and a pointer 9 is attached to a tip end thereof. The pointer 9 rotates on a display plate 10 fixed to the front side of the support plate 3 and indicates a predetermined pressure value by a mechanism described later.

At the tip 2a of the Bourdon tube 2, a fixture 11 is provided.
Is fixed, and the distal end of the attachment 11 is movably engaged in a long hole 12 a formed at the distal end of the connecting member 12. The other end of the connecting member 12 is rotatably connected to a bent end 13 a of a turning member 13 rotatably supported on the support shaft 6. The other end of the rotating member 13 has a rack 1
3b is formed, and the rack 13b meshes with a pinion 14 formed on the rotating shaft 8. A mainspring 15 is wound around the rotating shaft 8, and the other end of the mainspring 15 is fixed to the support shaft 4. The rotation shaft 8 is introduced into a damper device 20 fixed to the back of the support plate 7. The projection 13c of the rotating member 13 stops rotation of the rotating member 13 by contacting the support shaft 5 so that the rack 13b does not come off the pinion 14.

FIG. 2 shows a mechanism portion of the above embodiment when the display plate 10 is removed and viewed from the side. The damper device 20 includes a fixed case 2 attached to the back of the support plate 7.
1 and a lid case 22 fitted into the fixed case 21
And Between the guide projections 23 formed on the outer peripheral surface of the fixed case body 21, a pair of left and right is formed,
The projections 25 formed on the left and right side surfaces of the fixed case body 2 are inserted, and the engagement projections 24 formed between the guide projections 23 on the outer peripheral surface of the fixed case body 21 are engaged with the engagement holes 25 of the projections 25.
The lid case body 22 is attached to the fixed case body 21 by being fitted to the fixed case body a.

FIG. 3 shows the internal structure of the damper device 20. The fixed case body 21 has a cylindrical shaft support 31 protruding from the center of the inside, and the rotary shaft 8 is sealed in the shaft support 31. For this purpose, seal rings 32 and 33 are accommodated. The shaft support 31 is provided with a shaft recess 34 of an impeller 34.
a and is rotatably supported by the impeller 34 press-fitted into the rotating shaft 8. The impeller 34 has a disk portion 35 extending therearound, and a large number of blade portions 36 are formed on the outer peripheral edge of the disk portion 35.

On the other hand, the lid case 22 is
The seal ring 38 is accommodated in the fixed case body 21 in a state where the seal ring 38 is accommodated in an annular concave portion 37 formed corresponding to the opening edge of the first case. An impeller 34 is provided at the center of the lid case body 22.
An annular frame portion 39 formed on the outer peripheral side of the shaft core portion is provided, and a part of the frame portion 39 is a thick portion, in which a decompression hole 40 is formed. This decompression hole 40 is
An inner opening 40 a is provided on the upper end surface of the frame portion 39, and has a small outer opening 40 b that becomes smaller in diameter as approaching the outer surface of the lid case body 22 and is invisible on the outer surface of the lid case body 22. Note that a cylindrical hole portion 41 formed deeper than the periphery is formed inside the frame portion 39.

An oil 42 such as silicon grease whose viscosity is adjusted or selected is accommodated in the damper device 20 which is sealed by the fixed case body 21 and the lid case body 22. The amount of the oil 42 is about one-third of the internal volume. With this amount, the internal opening 40a of the pressure reducing hole 40
2 prevents it from being blocked. For example, in the position shown in FIG. 3, the liquid level of the oil 42 is below the frame-shaped portion 39, and in the position where the lid case body 22 is turned down, the liquid level of the oil 42 is indicated by a two-dot chain line 42 '. Position, the internal opening 40a is not blocked by the oil 42 in either case.

According to this embodiment having the above-described structure, the mainspring 15 constantly urges the rotating shaft 8 and the pointer 9 to rotate in the pressure increasing direction. The connecting member 12 does not immediately rise even if the pressure rises and the fixture 11 attached to the bourdon tube 2 rises, so that the connecting member 12 does not immediately rise. It rises slowly due to the balance between the elastic force of the mainspring spring 15 and the rotational resistance of the damper device.

Further, the connecting member 12 immediately reacts to the displacement of the Bourdon tube 2 in the step-down direction, and rotates the rotating member 13. However, the rotational force of the rotating shaft 8 by the Bourdon tube 2, the connecting member 12 and the rotating member 13 is determined by the elastic force of the spring 15 attached to the rotating shaft 8 and the damper device 2.
Since the rotation is hindered by the rotation resistance of 0, the pointer slowly drops even at the time of step-down.

As described above, at the time of pressurization, the pointer slowly rises while the elastic force of the mainspring spring 15 is suppressed by the rotational resistance of the damper device 20. The pointer also slowly descends while being suppressed by the rotational resistance of the device 20. Therefore, in any case, since the function of holding the position of the pointer works, the vibration of the pointer caused by the pressure fluctuation is suppressed, a stable instruction is obtained, and the wear of the internal link mechanism, gear mechanism, etc. is suppressed. Thus, durability can be improved.

In the damper device 20, since the rotation of the impeller 34 connected to the rotary shaft 8 is suppressed by the movement resistance of the blade portion 36 in the oil 42, a predetermined rotation resistance can be given. Here, as shown in FIG. 3, the damper device 20 is sealed by the seal rings 32, 33, and 38, but there is a danger that oil leaks from the seal portion due to an increase in the pressure inside the case due to a rise in temperature or the like. is there. In this embodiment, by providing the pressure reducing hole 40, only the air inside was released, the pressure was reduced, and the cause of oil leakage from the seal portion was successfully removed. In this case, the pressure gauge may be mounted in various postures depending on the location. In this embodiment, the liquid level of the oil 42 is always lower than the internal opening 40a of the pressure reducing hole 40 regardless of the posture. With this configuration, there is no possibility that oil will flow out of the pressure reducing hole 40.

The fluid contained in the damper device 20 is not limited to a liquid such as the oil, but may be a powder or a granular material. Also in this case, the amount of the fluid accommodated inside is preferably about 1/3. Regardless of the posture of the case, the amount of the fluid is limited to the amount that the fluid does not block the internal opening 40a. The amount of the fluid can be reduced by forming the position of the internal opening substantially in the center of the case. It can be up to less than half the product.

The impeller 34 and the fixed case body 21 are both formed of a magnetic material, and the impeller 34 and the fixed case body 21 are formed of a magnetic material.
By rotating at least one of them so that different magnetic poles are arranged in the rotation direction, or by attaching a magnet that forms a similar magnetic field, rotation resistance due to magnetic force can be imparted.

In the present embodiment, the bourdon tube and the connecting member are connected with a margin in the pressure increasing direction and are connected without margin in the step-down direction. Conversely, the bourdon tube and the coupling member are marginally connected in the step-down direction. The same effect as described above can also be obtained by connecting with no margin in the pressure increasing direction and by urging the rotating shaft in the voltage decreasing direction with a mainspring spring. Note that the present embodiment and the above-described modified example can also be used as a vacuum gauge.

In this embodiment, the strength of the mainspring is
It is adjusted in consideration of the relationship with the rotational resistance of the damper device 20, and is determined based on a balance between the instruction speed at the time of increasing the pressure and the time constant of the pressure fluctuation to be absorbed. The rotational resistance of the damper device 20 can be adjusted within a range that does not exceed the return torque of the mainspring due to the viscosity, weight, and magnetic strength of the fluid. Although the embodiment described above is an example in which a pressure gauge or a vacuum gauge is configured, as a Bourdon tube vibration-proof measuring device of the present invention, in addition to these, for example, a liquid such as alcohol is introduced into a Bourdon tube. In addition, the present invention broadly includes a measuring instrument that performs measurement using displacement of a Bourdon tube, such as when used as a thermometer.

[0029]

As described above, according to the present invention, by providing the rotation resistance portion connected to the pointer, it is possible to prevent the vibration of the pointer due to the pressure fluctuation, and to provide the case of the rotation resistance portion with the rotation resistance portion. Since the internal opening of the formed decompression hole is configured so as not to be blocked by the fluid, no matter what position it is installed, even if the pressure inside the case of the rotation resistance part increases, only air will be The liquid can be discharged through the pressure reducing hole, so that leakage of the fluid due to an increase in the internal pressure can be reliably prevented, and an increase in manufacturing cost for improving the tightness of the case body can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a Bourdon tube vibration-proof measuring device according to the present invention.

FIG. 2 is a side view of the internal mechanism in the embodiment.

FIG. 3 is a sectional view of a damper device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Attachment part 2 Bourdon tube 3,7 Support plate 4,5,6 Support shaft 8 Rotating shaft 9 Pointer 10 Display plate 12 Connecting member 13 Rotating member 14 Pinion 15 Spring spring 20 Damper device 21 Fixed case body 22 Cover case body 34 Blade Car 40 Decompression hole 40a Internal opening 42 Oil

Claims (4)

(57) [Claims] 1. A Bourdon tube type vibration-proof device configured to convert displacement of a Bourdon tube into rotation of a pointer via a transmission mechanism.
The type measuring instrument is formed so as to provide resistance to the rotation of the pointer.
Provided with a rotating resistance part, and the rotation resistance part
And an impeller rotatably connected to the housing and a housing for accommodating the impeller.
And a case body and the impeller are housed inside the case body.
And the amount of the fluid is determined by the case body.
Less than half of the internal volume of the
Even the case is closed by the fluid inside the case body.
A decompression hole with an internal opening in the case
A Bourdon tube vibration-proof measuring instrument characterized by being installed . 2. The method according to claim 1, wherein the fluid is a predetermined fluid.
Bourdon tube type vibration-resistant measuring device characterized by viscous oil and fat . 3. The method according to claim 1, wherein the fluid is a powder.
Or a granular material . 4. The transmission mechanism according to claim 1, wherein:
One of pressure rise displacement and pressure drop displacement of the Bourdon tube
Is connected with a margin against the displacement of
Connection part with almost no margin for the other displacement of
And the connecting portion is always biased to the side corresponding to the one displacement.
A bourdon tube-type vibration-resistant measuring device, comprising: