JP3107480U - Dry type diaphragm pressure gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry diaphragm type pressure gauge capable of mechanically measuring the pressure of gas or liquid.
SOLUTION: A dry diaphragm type pressure gauge G includes a casing 8 having an opening 7, a diaphragm 3 closing the opening 7 of the casing 8, an advance / retreat rod 6 housed inside the casing 8, and an advance / retreat rod 6 A linear motion bearing 9 that guides the shaft forward and backward in the axial direction, positioning means 11 for positioning the spring seat 10 in the axial direction of the forward and backward rod 6, and a base material fixed near the opening 7 inside the housing 8 12 and a coil spring 13 having one end fixed to the substrate 12 and the other end fixed to the spring seat 10.
[Selection] Figure 2

Description

  The present invention relates to a dry diaphragm type pressure gauge attached to a tank or pipe for storing gas or liquid and measuring the pressure of the gas or liquid.

FIG. 5 shows a pressure gauge g that causes the pointer n to follow the elastic deformation of the bourdon tube b via a sector gear s and a pinion p connected to the bag end of the bourdon tube b. When measuring the pressure of food or medical chemicals stored in a tank or pipe, bourdon tube b is filled with medium m such as silicon or glycerin, and the pressure of food or chemical is applied to medium m with diaphragm d such as diaphragm. The Bourdon tube b is elastically deformed by being transmitted through. Such a technique is disclosed in the following patent documents.
JP 09-138171 A

  The reason why the medium m is applied as described above is to avoid introducing food or medicine directly into the Bourdon tube b and to prevent the food or medicine from deteriorating due to staying in the Bourdon tube b. . However, the diaphragm d vibrates violently when the pressure of the food or medicine fluctuates due to cavitation accompanying the flow of the food or medicine. As a result, the diaphragm d is fatigued and the medium m leaks into the food or medicine.

  In addition, a technique for measuring pressure by detecting the deformation amount of the diaphragm d with a strain gauge so as not to use the medium m is well known, but since a strain gauge power supply and its wiring are required, the tank Or electrical work around pipes etc. must be done. Furthermore, in order to install such an electrical facility in a place where flammable chemicals are stored, an explosion-proof measure must be taken in addition to the electrical work described above.

  Then, this invention is made | formed in view of said situation, and it aims at providing the dry type diaphragm-type pressure gauge which can measure the pressure of gas or a liquid mechanically.

  The dry diaphragm type pressure gauge according to the present invention includes a diaphragm in which the back surface of the pressure receiving surface protrudes in proportion to the pressure received by the pressure receiving surface, and an axial tip that engages the back surface of the diaphragm to follow the pointer. An advancing / retreating rod, and the advancing / retreating rod is displaced in accordance with a protruding amount of the back surface of the diaphragm.

  Furthermore, the dry diaphragm type pressure gauge according to the present invention is characterized in that the back surface of the diaphragm and the tip of the advance / retreat rod are in contact with each other.

  The dry diaphragm type pressure gauge according to the present invention includes a diaphragm in which the back surface of the pressure receiving surface protrudes in proportion to the pressure received by the pressure receiving surface, and an axial tip that contacts the back surface of the diaphragm. An advancing / retreating rod to be driven; and an elastic body for holding the advancing / retreating rod at a position where a tip of the advancing / retreating rod comes into contact with the back surface of the diaphragm. It is characterized by being displaced while elastically deforming.

  Further, the dry diaphragm type pressure gauge according to the present invention includes a housing having an opening and a back surface of the pressure receiving surface of the housing in proportion to the pressure received by the pressure receiving surface that closes the opening of the housing. A diaphragm projecting inward, an advancing / retracting rod housed inside the housing, contacting a back end of the diaphragm in the axial direction and driving a pointer at the rear end, and a spring in the middle of the advancing / retreating rod in the axial direction A positioning means for positioning a seat; and a coil spring having one end joined in the vicinity of the opening inside the housing and the other end joined to the spring seat; However, the coil spring is displaced while being extended.

  Further, in the dry diaphragm type pressure gauge according to the present invention, the positioning means includes a male screw portion formed on the advance / retreat rod, a female screw portion formed through the spring seat and screwed into the male screw portion, A lock nut is provided that is screwed into a male thread portion and fastens the spring seat to the advance / retreat rod.

  Furthermore, in the dry diaphragm type pressure gauge according to the present invention, the spring seat is a position where the coil spring has a natural length with respect to the advancing / retracting rod in a state where the tip of the advancing / retreating rod is in contact with the back surface of the diaphragm. It is characterized by being screwed together.

  Furthermore, the dry diaphragm type pressure gauge according to the present invention includes a linear motion bearing for guiding the advance / retreat rod so as to advance and retreat in its axial direction.

  According to the dry diaphragm type pressure gauge according to the present invention, the diaphragm projects the back surface in proportion to the pressure received by the pressure receiving surface. Since the advance / retreat rod is displaced in the axial direction in accordance with the protrusion amount, the pointer driven by the advance / retreat rod can indicate a pressure value corresponding to the magnitude of the pressure received by the pressure receiving surface.

  Moreover, since the pressure gauge measures pressure only by a mechanical structure and does not measure pressure via a medium such as glycerin, the medium may leak even if the diaphragm is damaged due to fatigue or the like. Absent. Therefore, when measuring the pressure of food or medicine using the pressure gauge, there is no concern that the medium is mixed into the food or medicine. Further, since the pressure gauge does not require a power source, electrical work such as installation of a power supply device or wiring for the power device is unnecessary. In addition, even if the pressure gauge that does not use electricity is installed at a storage location for flammable chemicals, for example, it is not necessary to take explosion-proof measures, so the work related to installation or maintenance of the pressure gauge is easy. Can be done.

  Further, according to the dry diaphragm type pressure gauge according to the present invention, the following advantages can be obtained by bringing the tip of the advance / retreat rod into contact with the back surface of the diaphragm. That is, the direction in which the back surface of the diaphragm projects in the process of increasing the pressure received by the pressure receiving surface of the diaphragm, or the direction in which the back surface of the diaphragm is restored in the process of decreasing the pressure is completely coincident with the axial direction of the advancing and retracting rod. Not exclusively. In other words, the diaphragm may protrude or restore in a posture slightly inclined with respect to the axial direction of the advance / retreat rod. In this case, if the back surface of the diaphragm and the tip of the advance / retreat rod are inseparably connected to each other, the diaphragm is pushed by the advance / retreat rod and is tensioned. Smooth advance / retreat operation is hindered. Therefore, by allowing the slip between the rear surface of the diaphragm and the tip of the advance / retreat rod, it is possible to avoid the mechanical interference between the diaphragm and the advance / retreat rod as described above, and to improve the measurement accuracy of the pressure gauge.

  Further, according to the dry type diaphragm type pressure gauge according to the present invention, when the pressure receiving surface of the diaphragm receives pressure, or when the back surface of the diaphragm protrudes in the process of increasing the pressure, the advancing / retreating rod elastically deforms the elastic body. fall back. On the contrary, when the back surface of the diaphragm is restored in the process in which the pressure received by the pressure receiving surface of the diaphragm decreases, the advance / retreat rod is advanced by the elastic force of the elastic body.

  Then, when the pressure received by the pressure receiving surface of the diaphragm drops to, for example, atmospheric pressure or a pressure at which the pointer indicates zero, the advance / retreat rod advances to a position where the tip contacts the back surface of the diaphragm and is held by the elastic body as it is. Is done. As a result, even if the advance / retreat rod tries to retreat from the position where the tip contacts the back surface of the diaphragm, the advance / retreat rod is biased by the elastic force of the elastic body to the opposite side (advancing direction). As long as the surface is not under pressure, it will not retract. Therefore, even if the external pressure is applied to the advance / retreat rod, the pressure gauge does not malfunction such that the pointer moves carelessly.

  Furthermore, the dry diaphragm type pressure gauge according to the present invention is a form of elastic body in which the diaphragm is closed in the opening of the casing, and the spring seat is positioned in the middle of the advancing / retracting rod housed inside the casing. When one end of the coil spring is joined to the inside opening of the housing and the other end of the coil spring is joined to the spring seat, when the pressure receiving surface of the diaphragm receives pressure and the back surface protrudes, the advance / retreat rod However, it retracts while extending the coil spring. On the contrary, when the back surface of the diaphragm is restored in the process of decreasing the pressure received by the pressure receiving surface of the diaphragm, the advancing / retreating rod is advanced by the elastic force that the coil spring attempts to shorten.

  When the pressure received by the pressure receiving surface of the diaphragm drops to, for example, atmospheric pressure or a pressure at which the pointer indicates zero, the advance / retreat rod advances to a position where the tip contacts the back surface of the diaphragm, and at this position the coil spring Held by. Here, “held” means that unless the coil spring is compressed, the advancing / retreating rod is restricted from advancing further toward the diaphragm than the position where the tip of the rod is in contact with the back surface of the diaphragm. Such a force for compressing the coil spring is not possible in normal use of the pressure gauge. Therefore, the pressure gauge does not cause a malfunction such that the pointer moves carelessly even when external vibration is applied to the forward / backward rod while the pointer is pointing to zero.

  Further, in order to position the spring seat on the forward / backward rod as described above, the male thread portion formed on the forward / backward rod, the female thread portion formed through the spring seat and screwed to the male screw portion, and the male thread portion are screwed. When the positioning means including the lock nut is applied, the following adjustment can be performed according to the natural length of the coil spring.

  That is, in order to hold the forward / backward rod by the coil spring at a position where the tip contacts the back surface of the diaphragm, one end of the coil spring is joined to the inside of the housing so that the natural length of the coil spring can be maintained in this state. It is desirable to set the distance from the position to the spring seat equal to the natural length of the coil spring. However, the plurality of coil springs prepared for manufacturing a plurality of pressure gauges have slightly different natural lengths. Therefore, if the spring seat screwed to the advance / retreat rod is rotated and the spring seat is displaced relative to the advance / retreat rod, the above distance can be matched with the natural length of the coil spring. Thereby, it is possible to prevent the advance / retreat rod from receiving an extra elastic force from the coil spring in a state where the pointer points to zero. The lock nut can be fixed by tightening the spring seat positioned as described above to the advance / retreat rod.

  Furthermore, when the dry diaphragm type pressure gauge according to the present invention includes a linear motion bearing that guides the advance / retreat rod so that it can advance and retreat in its axial direction, the advance / retreat rod is compared with a case where the advance / retreat rod is slid and guided by a guide sleeve or the like. It is possible to reduce the frictional force generated when the motor moves forward and backward. Further, even if the pressure gauge is used for many years, there is almost no wear as compared to a guide sleeve or the like, and there is almost no runout of the advancing / retreating rod due to wear. Moreover, if the maintenance of the pressure gauge is taken into account, there is an advantage that the labor of frequently replacing the linear motion bearing can be saved.

  Hereinafter, a dry diaphragm type pressure gauge according to an embodiment of the present invention will be described with reference to the drawings. Also, as means for attaching the pressure gauge to a food or chemical storage tank, etc., an in-instrument mechanism that moves the pointer according to the pressure converted into the change (displacement) of the position of the advance / retreat rod, or a linear motion bearing Detailed illustration and description of the obvious elements are omitted.

  FIG. 1 schematically shows a dry diaphragm type pressure gauge G according to an embodiment of the present invention. The dry diaphragm type pressure gauge G includes a diaphragm 3 whose back surface 2 protrudes upward in the drawing when the pressure receiving surface 1 receives pressure, an axial front end 4 engaged with the rear surface 2 of the diaphragm 3, and a pointer at the rear end 5. and an advancing / retreating rod 6 for driving n, and the advancing / retreating rod 6 is displaced according to the protruding amount of the back surface 2 of the diaphragm 3. Details are as follows.

  As shown in FIGS. 2 and 3, the dry-type diaphragm pressure gauge G includes a casing 8 having an opening 7, a diaphragm 3 that closes the opening 7 of the casing 8, and an advancing / retracting rod housed inside the casing 8. 6, a linear motion bearing 9 that guides the advance / retreat rod 6 so as to advance and retreat in the axial direction, positioning means 11 for positioning the spring seat 10 in the middle of the advance / retreat rod 6 in the axial direction, and the vicinity of the opening 7 inside the housing 8 And a coil spring 13 having one end fixed to the base 12 and the other end fixed to the spring seat 10.

  The casing 8 includes a cylindrical column portion 81 formed with the opening 7 at one end, and a display portion 84 that is connected to the other end of the column portion 81 and has a well-known instrument mechanism 82 built inside the scale plate 83. Is provided. The in-instrument mechanism 82 only needs to be able to convert the displacement of the advance / retreat rod 6 into a rotational motion for turning the pointer n using, for example, a crank or a rack and a pinion. The diaphragm 3 is bonded to a lip of the opening 7 with a diaphragm in which the back surface 2 of the pressure receiving surface 1 protrudes upward in the figure toward the inside of the housing 8 in proportion to the pressure received by the pressure receiving surface 1. It is a thing. What is necessary is just to apply the thing which can move the advance / retreat rod 6 smoothly along an axial direction as a linear motion bearing 9 using a ball or a roller as a rolling element.

  The spring seat 10 may be fixed by welding or the like to the advance / retreat rod 6. However, the positioning means 11 applied in this embodiment is provided with a male screw portion 14 formed on the peripheral surface of the advance / retreat rod 6 and a male screw portion 14. A female screw portion 15 formed through the spring seat 10 so as to be screwed and a lock nut 16 screwed into the male screw portion 14 are provided. The coil spring 13 only needs to be an elastic body interposed between the base material 12 and the spring seat 10. For example, a bamboo pup spring, an air spring, rubber, silicon, or a foamed resin lump may be used instead.

  Next, the operation of the dry diaphragm type pressure gauge G will be described. The following arrows UP and DW coincide with the axial direction of the advance / retreat rod 6. Further, the arrows UP and DW point up and down in the figure, but do not mean that the dry diaphragm type pressure gauge G is used in a standing posture.

  First, the dry diaphragm type pressure gauge G is attached to a tank or a pipe or the like, and the pressure receiving surface 1 of the diaphragm 3 is brought into contact with the liquid or gas stored therein. In this state, since the pressure receiving surface 1 receives pressure from the liquid or gas, the diaphragm 3 projects the back surface 2 to the inside of the housing 8 in proportion to the pressure of the liquid or gas. According to this protrusion amount, the advance / retreat rod 6 moves backward in the direction indicated by the arrow UP from the position where the tip 4 contacts the back surface 2 of the diaphragm 3 (hereinafter referred to as “zero position”). The pointer n follows the end 5 via the in-instrument mechanism 82. The pointer n pivots from the zero (0) of the scale plate 83 as an origin by an angle corresponding to the magnitude of the pressure received by the pressure receiving surface 1 from the liquid or gas.

  Thus, the dry diaphragm type pressure gauge G measures the pressure only by the mechanical structure, and does not measure the pressure through a medium such as glycerin as in the prior art. For example, even if the diaphragm 3 is damaged by metal fatigue, There is no risk of the medium leaking into the liquid or gas. In particular, when measuring the pressure of food or medicine, there is no concern that the medium will be mixed into these food or medicine. Moreover, the dry diaphragm type pressure gauge G does not require a power source.

  Furthermore, since the back surface 2 of the diaphragm 3 and the tip 4 of the advance / retreat rod 6 are only in contact with each other, the dry diaphragm pressure gauge G has the following advantages. That is, the direction in which the pressure received by the pressure receiving surface 1 of the diaphragm 3 increases and the rear surface 2 of the diaphragm 3 protrudes, or the direction in which the pressure decreases and the rear surface 2 of the diaphragm 3 recovers is completely in the axial direction of the advance / retreat rod 6. Does not necessarily match. It is conceivable that the diaphragm 3 repeats protruding and restoring in a posture slightly inclined with respect to the axial direction of the advance / retreat rod 6. In this case, when the back surface 2 of the diaphragm 3 and the tip 4 of the advance / retreat rod 6 are inseparably connected to each other, the diaphragm 3 is slightly pushed and tensioned by the advance / retreat rod 6, while the advance / retreat rod 6 is twisted or bent. In addition, the smooth advance / retreat operation of the advance / retreat rod 6 is hindered by these stresses. Therefore, by allowing the slip between the back surface 2 of the diaphragm 3 and the tip 4 of the advance / retreat rod 6, the above-described mechanical interference between the diaphragm 3 and the advance / retreat rod 6 is avoided.

  Further, when the back surface 2 of the diaphragm 3 protrudes, the vicinity of the center of the back surface 2 swells, so that a conical recess as shown in FIG. good. However, even if the diaphragm 3 and the forward / backward rod 6 are joined by welding or the like, the function of the dry diaphragm pressure gauge G is not impaired. In this case, since the advance / retreat rod 6 is displaced integrally with the diaphragm 3, the coil spring 13 may be omitted.

  Further, in the process in which the back surface 2 of the diaphragm 3 protrudes to the inside of the housing 8 as described above, the advance / retreat rod 6 moves backward while extending the coil spring 13. On the contrary, when the pressure received by the pressure receiving surface 1 of the diaphragm 3 drops and the back surface 2 of the diaphragm 3 is restored, the advance / retreat rod 6 is pointed by the arrow DW due to the elastic force that the coil spring 13 tries to shorten (restore). It is advanced in the direction. Then, when the pressure received by the pressure receiving surface 1 of the diaphragm 3 drops to, for example, atmospheric pressure or the pressure at which the pointer n indicates the zero of the scale plate 83, the advance / retreat rod 6 moves forward to the zero point position, and the coil is moved at this zero point position. It is held by a spring 13.

  That is, unless the coil spring 13 is compressed, the advance / retreat rod 6 is restricted from moving forward from the zero point position toward the diaphragm 3. Such a force for compressing the coil spring 13 is not possible in normal use of the dry diaphragm type pressure gauge G. Further, even if the advance / retreat rod 6 at the zero point position tries to retreat, it is biased by the elastic force of the coil spring 13 to the opposite side (forward direction). Accordingly, the dry diaphragm type pressure gauge G does not malfunction such that the pointer n moves carelessly even if external vibration is applied to the advance / retreat rod 6.

  Furthermore, when the positioning means 11 as described above is configured, the following adjustment can be performed in accordance with the natural length of the coil spring 13. That is, in order to hold the advance / retreat rod 6 at the zero point position by the coil spring 13, the spring seat 10 and one end of the coil spring 13 are joined to the inside of the housing 8 so that the natural length of the coil spring 13 can be maintained in this state. It is desirable to set the distance between the coil 12 and the base material 12 to be the same as the natural length of the coil spring 13. However, when several coil springs 13 are manufactured, their natural lengths are slightly different. Therefore, by rotating the spring seat 10 screwed to the advance / retreat rod 6 and displacing the spring seat 10 with respect to the advance / retreat rod 6, the above distance can be matched with the natural length of the coil spring 13. Thereby, it is possible to prevent the advance / retreat rod 6 from receiving an extra elastic force from the coil spring 13 in a state where the pointer n points to zero of the scale plate 83, in other words, in a state where the advance / retreat rod 6 is at the zero point position. Further, the lock nut 16 can fix the position of the spring seat 10 by tightening the spring seat 10 positioned as described above to the advance / retreat rod 6.

  In addition, a guide sleeve or the like through which the advance / retreat rod 6 is inserted may be used instead of the linear motion bearing 9 described above. However, the linear motion bearing 9 has an advance / retreat rod 6 that is different from the sliding guide by the guide sleeve or the like. The frictional force generated when moving forward and backward can be reduced. Further, even if the dry diaphragm pressure gauge G has been used for many years, the linear motion bearing 9 is less likely to wear than the guide sleeve or the like even if the advance / retreat rod 6 repeatedly advances and retracts in the axial direction. The rod 6 hardly shakes.

  It should be noted that the present invention can be implemented in a mode in which various improvements, modifications, or variations are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention. For example, the dry diaphragm type pressure gauge G1 shown in FIG. 4 includes a diaphragm 3, an advancing / retracting rod 6, and a coil spring 13 that holds the advancing / retreating rod 6 at the zero point position, and the back surface 2 of the diaphragm 3 is a liquid or gas pressure. Then, the forward / backward rod 6 retracts in the direction indicated by the arrow UP while shortening (elastically deforming) the coil spring 13.

  The dry-type diaphragm pressure gauge according to the present invention is not limited to being applicable to a plant or the like used for the production of food or medicine, but measures the pressure of any chemical substance in which purity is important, in addition to cosmetics or fuel. It is beneficial to.

Schematic which shows the structure of the dry type diaphragm-type pressure gauge which concerns on embodiment of this invention. Sectional drawing which shows the principal part of the dry type diaphragm-type pressure gauge which concerns on embodiment of this invention. (A) is the front view which fractured | ruptured partially the dry type diaphragm-type pressure gauge which concerns on embodiment of this invention, (b) is the side view which abbreviate | omitted the part. Sectional drawing which shows the principal part of the modification of the dry type diaphragm-type pressure gauge which concerns on embodiment of this invention. Schematic which shows the structure of the diaphragm type pressure gauge of a prior art example.

Explanation of symbols

1: pressure receiving surface 2: back surface 3: diaphragm 4: front end 5: rear end 6: forward / backward rod 7: opening 8: housing 9: linear motion bearing 10: spring seat 11: positioning means 13: coil spring 14: male screw portion 15 : Female thread 16: Lock nut

Claims (7)

  A diaphragm in which the back surface of the pressure receiving surface protrudes in proportion to the pressure received by the pressure receiving surface, and an advancing / retracting rod that engages the tip of the axial direction on the back surface of the diaphragm and drives the pointer. The dry-type diaphragm pressure gauge is characterized in that the advance / retreat rod is displaced according to the amount of protrusion of.   The dry diaphragm type pressure gauge according to claim 1, wherein a back surface of the diaphragm and a tip of the advance / retreat rod are in contact with each other. A diaphragm in which the back surface of the pressure receiving surface protrudes in proportion to the pressure received by the pressure receiving surface;
An advancing / retracting rod that contacts the tip of the axial direction on the back surface of the diaphragm and follows the pointer;
An elastic body for holding the advance / retreat rod at a position where the tip of the advance / retreat rod contacts the back surface of the diaphragm;
The dry diaphragm type pressure gauge is characterized in that the advancing / retreating rod is displaced while elastically deforming the elastic body by projecting the back surface of the diaphragm. A housing having an opening;
In proportion to the pressure received by the pressure receiving surface that closes the opening of the housing, a diaphragm in which the back surface of the pressure receiving surface protrudes to the inside of the housing;
An advancing / retreating rod that is housed inside the housing, contacts the tip in the axial direction to the back surface of the diaphragm, and follows the pointer at the rear end;
Positioning means for positioning a spring seat in the axial direction of the advance / retreat rod;
A coil spring having one end joined near the opening inside the housing and the other end joined to the spring seat;
A dry diaphragm type pressure gauge characterized in that the back and forth rod of the diaphragm projects and the advance / retreat rod is displaced while extending the coil spring.   The positioning means includes a male screw portion formed in the advance / retreat rod, a female screw portion formed through the spring seat and screwed into the male screw portion, and screwed into the male screw portion, thereby moving the spring seat into the advance / retract rod. The dry-type diaphragm type pressure gauge according to claim 4, further comprising: a lock nut that is tightened on the pressure gauge.   The said spring seat is screwed in the position where the said coil spring becomes natural length with respect to the said advance / retreat rod in the state which the front-end | tip of the said advance / retreat rod contacts the back surface of the said diaphragm. 2. A dry diaphragm type pressure gauge according to 1.   The dry diaphragm type pressure gauge according to any one of claims 1 to 6, further comprising a linear motion bearing that guides the advance / retreat rod in an axial direction.

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