JPH03292404A - Diaphragm type driving device - Google Patents

Abstract

PURPOSE:To facilitate the assembling work of a driving device by making it smaller and lighter to improve its economical efficiency by fitting a fastening member which is formed in its section into a tapered U-shape narrowing in its inside toward a peripheral edge and along the peripheral edge of a jaw part in the jaw part for fastening them. CONSTITUTION:A peripheral edge of a diaphragm 2 is sandwichedly held by fastening members 3 between cases 1 having a jaw part 1a formed on the periph eral edge, respectively to form a diaphragm driving device. The fastening mem ber 3 is formed in its section into a tapered U-shape narrowing in its inside toward the peripheral edge and along the peripheral edge of the jaw part 1a, and fitted on the outer peripheries of the jaw parts 3a to sandwichedly hold the diaphragm 2, and the ends of the fastening member 3 are mutually fastened with a bolt and a nut 3a. Thus, the width of the jaw part 1a can be reduced to make a case smaller and lighter, and a production process can be decreased to improve assembling efficiency.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can easily and reliably form a pressure-tight chamber that is airtightly held on one side with a diaphragm in between, and a spring-pressure chamber on the other side. This invention relates to a diaphragm drive device.

[Conventional technology]

For example, in order to remotely control a controlled object such as a globe valve, cage valve, Sanders valve, etc. by moving the control shaft of the controlled object in the direction of its axis, - compressed air generally supplied. A diaphragm type drive device is used that controls a controlled object by transmitting the displacement of a diaphragm caused by this to a control shaft.

To briefly explain the structure of this diaphragm type drive device, as shown in Fig. 6, the case is divided into two halves, each with a flange formed on the peripheral edge, and the periphery is held between the flange of these cases. A spring press chamber in which a compression coil spring is installed on one side with the diaphragm in between, and a pressure airtight chamber in which a compression coil spring is installed on the other side are formed by the diaphragm, and the former spring press chamber has a case. The diaphragm is pressed toward the pressure-tight chamber by a compression coil spring disposed between the inner surface of the diaphragm and the diaphragm holding plate, and the latter pressure-tight chamber is provided with a stopper that regulates the maximum displacement of the diaphragm. A through hole is formed in the center of the diaphragm holding plate and the stopper, into which a diaphragm rod connected to the control shaft of the controlled object is inserted. When the nut is tightened, the diaphragm is configured to move up and down integrally with the diaphragm rod while being held between the diaphragm holding plate and the stopper. The latter pressure-tight chamber is formed by a diaphragm and a case, and is configured such that compressed air is supplied and discharged from a compressed air supply hole bored in the case.

Diaphragm type drive devices configured in this way are of the reverse-acting type, in which the diaphragm rod descends when the pressure in the pressure-tight chamber to which compressed air is supplied from the compressed air supply hole decreases, and the diaphragm rod moves down when the pressure in the pressure-tight chamber decreases. There is a direct-acting type in which the rod rises, but the structure of the reverse-acting type and the direct-acting type is essentially the same except that the arrangement of the pressure airtight chamber and the spring pressurized chamber is upside down. The case of an actuated diaphragm drive device will be explained as an example.

In the conventional diaphragm drive device configured as described above, the diaphragm and the lower case for forming the pressure-tight chamber and the upper case for forming the spring pressurized chamber are fastened together at the circumferences of the upper and lower cases, respectively. A comparatively wide flange is formed at the end edge, the periphery of the diaphragm is held between the flange, and the bolt is passed through the through hole drilled in the flange of the case and the periphery of the diaphragm, respectively, in this sandwiched state. It was concluded by Natsuto.

However, in such conventional diaphragm drive devices, the periphery of the diaphragm is evenly held between the flange of the case and the pressure-tight chamber is kept airtight. Since the bolt must be fastened, the formed flange must be at least wider than the maximum external dimension of the bolt head to be fastened, which may increase the size of the diaphragm drive device or increase the pressure in the pressure-tight chamber. If the circumference of the case is long, the number of bolts and nuts must be increased and the distance between adjacent bolts and nuts must be narrowed to prevent the compressed air inside the pressure-tight chamber from leaking. The diaphragm, whose periphery is held between the flange of the case, and the process of drilling and assembling the flange of the case require a great deal of effort and time, resulting in a reduction in work efficiency.

[Problem to be solved by the invention]

The present invention eliminates the drawbacks of the prior art as described above, allows easy assembly even for large diaphragm drive devices, and eliminates the step of drilling bolt holes to connect the case and diaphragm. It is an object of the present invention to provide a diaphragm drive device that uses a small number of bolts and nuts and is highly economical.

[Means to solve the problem]

As a result of various studies in order to solve the above-mentioned drawbacks of the prior art, the inventor of the present invention found that in the conventional diaphragm type drive device, a case is required to fasten the two halves of the case that sandwich the periphery of the diaphragm. Since the structure is fastened with a bolt and nut that pass through a through hole drilled in the case flange and diaphragm, it acts on the contact surface between the case flange and the diaphragm between adjacent bolts and nuts. Due to the fact that the load is not uniform and the distance between adjacent bolts and nuts must be narrowed, there are a large number of bolts and nuts.
Focusing on the need for a nut, we created an airtight seal on one side by sandwiching the diaphragm between two cases, each with a flange formed on the peripheral edge, and a diaphragm whose periphery is held between the flange of these cases. In a diaphragm type drive device, a pressure airtight chamber is formed in which the pressure is held, and a spring pressing chamber is formed in which a compression coil spring is installed on the other side, and a diaphragm rod that is connected to the control shaft of the controlled object is fixed to the diaphragm. , a fastening member having a tapered cross-section that narrows toward the periphery of the case and having a shape that follows the periphery of the flange of the case is attached to the 2-part case that holds the periphery of the diaphragm. The present invention was completed by discovering that it is sufficient to fasten it while being fitted into the flange.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A diaphragm drive device according to the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a sectional view of essential parts showing one embodiment of the diaphragm type drive device according to the present invention, FIG. 2 is a plan view of the diaphragm type drive device shown in FIG. 1, and FIG. 3 is the same as shown in FIG. FIG. 4 is an enlarged side view corresponding to FIG. 3 of another embodiment of the diaphragm drive device according to the present invention, and FIG. 4
FIG. 8 is an enlarged sectional view taken along line 8-A in the figure.

In the drawing, 1 is a case divided into upper and lower halves, each having a flange 1a formed on its peripheral edge, and 2 is a diaphragm made of a flexible material such as rubber. The periphery of the case 1 is sandwiched by the flange 1a of the case 1, and the inside of the case 1 is divided into a pressure-tight chamber 4 and a spring-pressing chamber 5, which will be described later, with a diaphragm 2 in between. In addition, a through hole is bored approximately in the center of the diaphragm 2 and one case 1 (the lower case 1 in FIG. 1), through which a diaphragm rod 6 (to be described later) is connected to the control shaft of the controlled object. ing. Reference numeral 3 designates a fastening member having a substantially U-shaped cross section with a tapered inner surface that becomes narrower toward the periphery, and having a shape along the periphery of the flange portion 1a of the case 1 to be fastened. is fitted into the flange 1a of the case 1 and fastened. It is preferable that the fastening member 3 is formed into a shape that is divided into approximately two equal parts with respect to the entire circumference of the flange portion 1a of the case 1.

If the length of the flange 1a of the case 1 is long, it may be formed into a shape divided into 3 or 4 equal parts, and the ends may be connected with bolts or
It is fastened with a nut 3a. Reference numeral 4 denotes a pressure-tight chamber formed on one side with the diaphragm 2 in between, and this pressure-tight chamber 4 is compressed into the case 1 (the lower case 1 in the embodiment shown in FIG. 1). A compressed air supply hole 4a for supplying and exhausting air is provided, and the diaphragm 2
A stopper 4 that regulates the maximum displacement amount toward the pressure-tight chamber 4 side.
b is provided. As shown in FIG. 1, this stopper 4b has a through hole similar to the through hole formed in the diaphragm 2 at approximately the center of the lid-shaped ceiling surface, and this through hole and the through hole of the diaphragm 2 The ceiling surface is brought into contact with the diaphragm 2 with the diaphragm 2 aligned. 5 is formed on the opposite side of the pressure-tight chamber 4 with the diaphragm 2 in between, and is placed at a predetermined position between the inner surface of the case 1 (the upper case 1 in the embodiment shown in FIG. 1) and the diaphragm holding plate. The compression coil shown in FIG. In the embodiment, the upper case 1) is provided with an atmosphere opening hole 5a for communicating the inside with the atmosphere, and a stopper 5c is provided for regulating the maximum displacement of the diaphragm 2 toward the spring pressing chamber 5 side. There is. A through hole similar to the through hole formed in the diaphragm 2 is bored approximately in the center of the presser plate 5b and the stopper 5c. One end of 6 is inserted through through holes formed in the stopper 4b, the diaphragm 2.degree. presser plate 5b, and the stopper 5c, respectively, so that the stopper 4b, the diaphragm 2.
A diaphragm rod 6 is fixed to the diaphragm 2 with the presser plate 5b and stopper 5c stacked on top of each other, and is fixed to a through hole bored in the center of the case 1 forming the pressure-tight chamber 4. A bearing metal 9 is provided in a through hole 8a formed in a partition wall 8, and a diaphragm rod 6 is slidably passed through the bearing metal 9 in the axial direction while being held by the bearing metal 9. A ring 10 is attached to the partition wall 8 on which the rod 6 slides in order to keep the inside of the pressure-tight chamber 4 airtight. Reference numeral 7 denotes a hanging metal fitting through which a bolt 3a for fastening the ends of the fastening member 3 is inserted between the ends of the fastening member 3 to hang the case l and install it at a predetermined position.

[For production]

In order to assemble the diaphragm type drive device according to the present invention having such a configuration, a hole is drilled in the partition wall 8 fixed to the through hole drilled in the center of the case 1 forming the pressure-tight chamber 4. The flange of the case 1, which is divided into upper and lower halves, clamps the periphery of the diaphragm 2 to which the diaphragm rod 6, which is axially slidably held through the bearing metal 9 provided in the through hole 8a, is fixed. The fastening member 3 that fastens the portion 1a has a tapered cross section whose inner surface becomes narrower toward the periphery, and is formed in a substantially U-shape and in a shape that follows the periphery of the flange portion 1a of the case 1. ,
This fastening member 3 is fitted over almost the entire circumference of the flanges 1a of the upper and lower cases 1 that sandwich the periphery of the diaphragm 2, and the edges of the fastening member 3 are fastened together with bolts and nuts 3a. That is, since the fastening member 3 has a tapered cross-section where the inner surface becomes narrower toward the periphery, the cross section is approximately U-shaped. Since the space between the inner surfaces is wide, the flange 1a of the case 1 can be easily inserted into it, and the bolt/nut 3
When fastened at point a, the flanges of the upper and lower case 1 are fitted over almost the entire periphery of the flange 1a of the case 1, and when inserted, the flange of the upper and lower case 1 sandwiches the periphery of the diaphragm 2 with a taper whose inner surface becomes narrower toward the periphery. The portions 1a are pressed in the direction toward each other, and the periphery of the diaphragm 2 is held in close contact with the flange portions 1a of the upper and lower cases 1 with a -like surface pressure. At this time, if the surface of the flange 1a of the case 1 that comes into contact with the inner surface of the fastening member 3 is provided with a taper that is approximately the same as the taper of the inner surface of the fastening member 3 whose cross section is approximately U-shaped, the flange of the case 1 Since the portion 1a and the inner surface of the fastening member 3 abut over a wide area, the peripheral edge of the diaphragm 2 can be securely held between the collar portions 1a of the upper and lower cases 1, which is preferable. At this time, if the fastening member 3 is divided into two equal parts as shown in FIG. 2, it is possible to fasten the two halves of the case 1 just by using two or four sets of bolts and nuts 3a. . That is, if the fastening member 3 is divided into equal parts, the case 1 divided into two parts can be fastened together simply by using one or twice as many bolts and nuts 3a as the number of parts.

Also, a bolt for fastening the case 1, that is, a fastening member 3
Since the bolt 3a for fastening the ends of the fastening member 3 is used to fit the peripheral edge of the fastening member 3 into the flange 1a of the case 1, a bolt with a relatively small outer diameter can be used.

〔Effect of the invention〕

As detailed above, in the diaphragm drive device according to the present invention, the bolts and nuts used to fasten the two halves of the case that sandwich the periphery of the diaphragm are small, and the outer diameter of the threads of these bolts is small. Since it is sufficient that the width of the flange of the case is /h, the case is relatively small and lightweight, and the tapered cross section where the inner surface narrows toward the periphery is approximately Since the U-shaped fastening member is inserted into the flange and the two halves of the case are fastened together, the flange of the case can be easily inserted into the approximately U-shaped cross section of the fastening member. Since there is no need to drill bolt holes in the periphery of the diaphragm and the flange of the case, the manufacturing process for the diaphragm and the case is reduced, and assembly can be done easily and in a short time, resulting in good assembly efficiency.

Furthermore, since the fastening member has a tapered cross section in which the inner surface becomes narrower as it goes toward the periphery, it has a substantially U-shape, so that the relationship between the periphery of the diaphragm and the flange of the case is reduced in the direction of the periphery of the flange of the case. Even if the diaphragm type drive device is large, it is possible to generate various surface pressures on the contact surfaces, and the pressure-tight chamber can be reliably kept airtight with a small number of bolts and nuts, making it highly economical. -ing

The diaphragm type drive device according to the present invention, which has various advantages as described above, has great industrial value.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing one embodiment of the diaphragm type drive device according to the present invention, FIG. 2 is a plan view of the diaphragm type drive device shown in FIG. 1, and FIG. 3 is the same as shown in FIG. FIG. 4 is an enlarged side view corresponding to FIG. 3 of another embodiment of the diaphragm drive device according to the present invention, and FIG. 4
FIG. 6 is an enlarged cross-sectional view taken along the line 8-A in the figure, and FIG. 6 is a cross-sectional view of essential parts showing a conventional diaphragm type drive device. In the drawings 1... Case 1a... Flange 2... Diaphragm 3... Fastening member 3a... Bolt/nut 4... Pressure airtight chamber 4a... Compression Air supply hole 4b...Stopper 5-...Spring pressure chamber 5a...Atmospheric release hole 5b...Press plate 5c...Stopper 5d...Compression coil spring 6...・Diaphragm rod 7... Hanging fittings 8... Bulkhead 8a... Through hole 9... Bearing metal 10... O-ring 13a 14 Figure 211

Claims (1)

[Claims] 1. A flange (1a) is formed on each peripheral edge. 2.
Split case (1) and flange (1a) of the case (1)
A diaphragm (2
), a pressure airtight chamber (4) held airtightly on one side with the diaphragm (2) in between, and a spring pressing chamber (5) in which a compression coil spring (5d) is installed on the other side are formed. In a diaphragm type drive device in which a diaphragm rod (6) connected to a control shaft of a controlled object is fixed to the diaphragm (2), the inner surface becomes narrower toward the periphery. A case (1) divided into two parts, in which a fastening member (3) having a substantially U-shaped cross section and a shape along the circumference of the flange (1a) of the case (1) clamps the circumference of the diaphragm (2). A diaphragm type drive device characterized in that the diaphragm drive device is fastened while being fitted into a flange (1a). 2. The diaphragm drive device according to claim 1, wherein the fastening member (3) is equally divided in the circumferential direction of the flange (1a) of the case (1). 3. The diaphragm drive device according to claim 1 or 2, wherein the hanging member (7) is installed between adjacent fastening members (3). 4. The surface of the flange (1a) of the case (1) that comes into contact with the inner surface of the fastening member (3) is provided with a taper that is approximately the same as the taper on the inner surface of the fastening member (3), which has a substantially U-shaped cross section. A diaphragm drive device according to any one of claims 1 to 3.