JP5274497B2 - Manufacturing method of sensor cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a sensor cap, capable of increasing the flatness of a contact surface of a flange coming into contact with a diaphragm, when a sensor cap is formed by press working. <P>SOLUTION: The sensor cap 10 of a diaphragm type pressure sensor includes a closed-end cylindrical cap part 11, the flange 12 projecting from an opening end of the cap part 11, the contact surface 13 of the diaphragm formed of the surface on the outer peripheral side of the surface of the flange 12, and an escape part 14 of the diaphragm disposed inside the contact surface 13. In the method of manufacturing the sensor cap 10, an intermediate molding 2 having the cap part 11 and flange 12 is formed from a flat metal plate 1 by press working, then the escape part 14 is formed by single press working, and simultaneously many regularly arranged dimples 15 are formed on the backside of the contact surface 13 of the flange 12. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a sensor cap, and more particularly, to a method for manufacturing a sensor cap used in a diaphragm type pressure sensor that detects a change in fluid pressure by deformation of the diaphragm.

  There are various types of pressure sensors for detecting a change in fluid pressure in the fluid path. Among them, for example, as shown in FIG. 3, a diaphragm 130 made of a thin metal plate is used. There is a diaphragm type pressure sensor 100 that detects that the pressure is higher than a predetermined value or lower than a predetermined value.

  The diaphragm type pressure sensor 100 includes a cylindrical sensor body 110 that is attached to a fluid path by screwing, welding, or the like, and in which fluid pressure is applied to the inner surface, and a diaphragm 130 that is stretched at an end of the sensor body. The deformation of the diaphragm 130 caused by the change in fluid pressure is sensed by the strain sensor 140.

  3 illustrates a diaphragm type pressure sensor 100 of a type in which the deformation of the diaphragm 130 is sensed by the strain sensor 140 mounted on the diaphragm 130. However, the diaphragm type pressure sensor 100 is not limited to this. There are various types such as those using the diaphragm 130 with the built-in strain sensor 140 and those in which the strain sensor 140 itself has a sheet shape and the diaphragm 130 is configured by the strain sensor 140.

  By the way, in this type of diaphragm type pressure sensor 100, a sensor cap 120 is attached to protect the diaphragm 130 and the strain sensor 140. The sensor cap 120 includes a bottomed cylindrical cap portion 121 and a flange portion 122 that protrudes in the radial direction from the opening end of the cap portion 121, and the flange portion 122 is an outer peripheral edge portion of the diaphragm 130. It abuts against.

  In addition, on the surface of the flange portion 122 of the sensor cap 120, an inner peripheral side around the opening of the cap portion 121 in order to ensure a sufficient effective area of the diaphragm 130 so that the diaphragm 130 is accurately deformed by a change in fluid pressure. An escape portion 124 that is not in contact with the diaphragm 130 is provided, and the surface of the flange portion 122 around the escape portion 124, that is, the outer peripheral surface of the flange portion 122 becomes a contact surface 123 that contacts the diaphragm 130. Yes.

  In the diaphragm type pressure sensor 100 shown in FIG. 3, the diaphragm 130 is disposed between the end surface of the sensor body 10 and the flange portion 122 of the sensor cap 120, and the outer peripheral edges of the sensor body 110, the diaphragm 130, and the sensor cap 120. Is welded by laser processing or the like (light ink portion A in FIG. 3), the sensor body 110, the diaphragm 130, and the sensor cap 120 are arranged so that the diaphragm 130 is sandwiched between the sensor body 110 and the sensor cap 120. It is integrated.

  Similarly to the sensor cap 120, the sensor main body 110 has a flange portion 112 at the end of the cylindrical main body portion 111, and the surface of the flange portion 112 of the sensor main body 110 escapes to the inner peripheral side. A portion 114 is provided, and a surface around the relief portion 114 is a contact surface 113 of the diaphragm 130.

  The sensor body of a diaphragm type pressure sensor is usually formed by cutting, and the sensor cap is also generally formed by cutting. In recent years, sensor caps formed by pressing are also is there.

  However, when the sensor cap is formed of a press-processed product, the following problem occurs.

  A high degree of flatness can be ensured by cutting on the contact surface of the flange portion that contacts the diaphragm and clamps the diaphragm with the sensor body. It is difficult to secure. The reason for this is that in order to form a flat metal plate into a cylindrical shape having a flange portion at the end by pressing, drawing processing through multiple stages of pressing is performed. This is because a shock line is generated on the surface of the flange portion according to the drawing process through the press process.

  In particular, as shown in FIGS. 3 and 4, in the sensor cap 120 having the relief portion 124 of the diaphragm 130 on the inner peripheral side of the surface of the flange portion 122, the flange portion is formed when the relief portion 124 is formed by press working. 122, the material of the contact surface 123, which is the outer peripheral surface of the surface, so-called “meat” is pulled to the escape portion 124 side. Therefore, it is very difficult to obtain the required flatness at the contact surface 123 of the flange portion 122 that requires high flatness.

  Therefore, as shown in FIG. 5, in the conventional sensor cap 120 that is simply formed by pressing, the entire contact surface 123 of the flange portion 122 that comes into contact with the diaphragm is not a highly flat surface. The outermost and innermost surfaces (cross-hatched portion B) are slightly receding surfaces, and the substantial effective width of the contact surface 123 that contacts the diaphragm and sandwiches the diaphragm is reduced. . Further, the shape of the contact surface 123 that actually contacts the diaphragm was not an advanced circular shape.

  In this way, the effective width of the contact surface of the flange portion is narrow and the shape of the contact surface that is actually in contact with the diaphragm is not a highly circular sensor cap, so that the diaphragm that deforms according to changes in fluid pressure is as set. There arises a problem that the material is not deformed, and that the material is easily damaged without being applied with a uniform stress in the circumferential direction during the deformation. Therefore, in the sensor cap, a high degree of flatness is required on the contact surface of the flange portion. However, simply forming the sensor cap by press working cannot sufficiently satisfy this requirement.

  The present invention has been made in view of the above-described situation, and in forming a sensor cap by press working, a sensor cap that can increase the flatness of a contact surface of a flange portion that comes into contact with the diaphragm and sandwiches the diaphragm. It is an object to provide a manufacturing method.

The main means taken by the present invention to solve the above problems are as follows:
“It is a sensor cap for a diaphragm type pressure sensor, and is composed of a bottomed cylindrical cap portion, a flange portion projecting radially from the opening end of the cap portion, and a surface on the outer peripheral side of the surface of the flange portion. A sensor cap having a contact surface of a diaphragm and a relief portion of the diaphragm provided inside the contact surface,
After forming an intermediate molded product having the cap part and the flange part from a flat metal plate by pressing, the relief part forming process for forming the relief part is performed at the same time by a single pressing process. A dimple forming process for forming a large number of dimples regularly arranged on the back side of the contact surface of the flange portion is performed. "
It is.

  Here, the specific shape of the dimple can be exemplified by a circular shape, more specifically, a cylindrical shape, a conical shape, a hemispherical shape, etc., but is not limited to this, and a corner such as a triangle or a quadrangle. It may be a shape, an elliptical shape, an oval shape, or the like.

  In addition, as an arrangement pattern in which a large number of dimples are regularly arranged, a circumferential arrangement pattern in which a large number of dimples are arranged at a predetermined pitch angle on the same circumference, and this circumferential arrangement pattern is concentric. A plurality of rows, arranged concentric circumferential arrangement patterns, lattice patterns, staggered patterns, and the like can be exemplified.

  In the manufacturing method of the sensor cap having the above configuration, a large number of dimples regularly arranged on the back surface of the flange portion are formed, so that the material on the back surface side of the flange portion flows to the front surface side of the flange portion by the amount of the dimple. And the shock line on the surface side of the flange portion can be eliminated. Therefore, the flatness of the surface of the flange portion can be improved.

  In addition, since the relief portion is formed on the front surface side of the flange portion and the dimple is formed on the rear surface side of the flange portion by a single press process, the material on the contact surface side that is reduced by being pulled to the relief portion side is reduced to the flange portion. It can be compensated by forming dimples on the back surface. Therefore, also from this point, even if the relief portion is formed on the inner peripheral side of the flange portion, the flatness can be improved on the contact surface on the outer peripheral side of the flange portion.

  By the way, it can be assumed that the surface of the flange portion is flattened by forming an annular groove on the back surface of the flange portion instead of the dimple, but in the annular groove, the shape of the annular groove is the flange portion. There is a possibility that the unevenness of the shock line is promoted by overlapping with the shock line, and conversely, the flatness of the surface of the flange portion may be lowered.

  On the other hand, in the present invention, since the surface of the flange portion is flattened with a large number of dimples instead of an annular groove, the unevenness of the shock line is not promoted in conformity with the shock line. Therefore, the surface of the flange portion can be accurately flattened.

  In addition, since a large number of dimples are regularly arranged, the material can flow uniformly between the dimples. Therefore, also from this point, the surface of the flange portion can be accurately flattened.

In the means described above,
“In the dimple forming process, the dimple is also formed on the back side of the relief portion in the flange portion”.
Is preferable.

  In the sensor cap manufacturing method configured as described above, since dimples are formed also on the back surface of the escape portion, the material on the back surface side of the escape portion can also flow to the contact surface side. Therefore, the flatness of the contact surface of the flange portion can be improved more accurately.

  Further, since the material on the back surface side of the relief portion flows toward the contact surface side, a highly accurate dimensional shape can be realized as the dimensional shape of the boundary portion between the contact surface and the relief portion.

  As described above, according to the method for manufacturing a sensor cap according to the present invention, when the sensor cap is formed by press working, the flatness of the contact surface of the flange portion that comes into contact with the diaphragm and sandwiches the diaphragm can be increased.

It is explanatory drawing which shows an example of the manufacturing method of the sensor cap which concerns on this invention. It is a figure which shows an example of the sensor cap manufactured with the manufacturing method of the sensor cap which concerns on this invention, (a) is a top view, (b) is a bottom view. It is a sectional front view showing an example of a diaphragm type pressure sensor. It is a perspective view which shows an example of a sensor cap. It is a bottom view of the conventional sensor cap manufactured by press work.

  Hereinafter, an example as an embodiment of a manufacturing method of a sensor cap concerning the present invention is explained in detail according to a drawing.

  The sensor cap described in this example is used for the diaphragm type pressure sensor 100 shown in FIG. 3, and the overall shape of the sensor cap is the same as that of the sensor cap 120 shown in FIG.

  As shown in FIG. 1, first, an appropriate metal material such as a rolled steel plate is punched to form a flat metal plate 1 having a desired shape (a). Next, by pressing the flat metal plate 1, more specifically, by drawing through a plurality of stages of pressing, the bottomed cylindrical cap portion 11 and the cap portion 11 are processed. An intermediate molded product 2 having a desired shape as the sensor cap 10 is formed.

  After forming the intermediate molded product 2 having the shape as the sensor cap 10 in this manner, as a final step, the diaphragm relief portion 14 is formed on the inner peripheral side of the surface of the flange portion 12 which is the surface on the diaphragm side by pressing. The outer surface of the escape portion 14 is formed as a contact surface 13 that comes into contact with the diaphragm and clamps the diaphragm (c).

  Here, as shown in FIG. 2A, a large number of dimples 15 are formed on the back surface of the flange portion 12 at the same time as the relief portion 14 is formed by a single press forming the relief portion 14. Then, the shock line generated on the surface of the flange portion 12 is erased, and a high degree of flatness can be obtained as the flatness of the contact surface 13 that comes into contact with the diaphragm and sandwiches the diaphragm.

  Further, as shown in FIG. 2B, the contact surface 13 that is a highly flat surface becomes a surface that comes into close contact with the diaphragm with high accuracy, and has a sufficient effective width for contacting the diaphragm (cross-hatching). Part C) can be formed.

  In this example, in forming the relief portion 14 having an outer diameter of 21 mm and a depth of about 0.01 to 0.1 mm in the flange portion 12 having an outer diameter of 25 mm, an inner diameter of 17 mm, and a thickness of 1 mm, the back surface of the flange portion 12 is formed. In addition, a large number of minute hemispherical dimples 15 having a diameter of about 0.05 to 0.3 mm are provided.

  A large number of dimples 15 are regularly arranged. In this example, a large number of dimples 15 are arranged around the axis of the sensor cap 10 at a predetermined pitch angle on the same circumference. Further, as a circumferential pattern row of a large number of dimples 15 arranged at a predetermined pitch angle on the same circumference, a plurality of the circumferential pattern rows are arranged concentrically.

  Here, the shape of the dimple 15 is not limited to the hemisphere as described above, and other shapes such as a quadrangle and a triangle can be adopted. However, when the circular dimple 15 is used, the shape of the dimple 15 is uniform around the dimple 15. It is preferable because the material can flow.

  Further, the pattern in which the dimples 15 are regularly arranged is not limited to the above-mentioned pattern, but may be another arrangement pattern such as a lattice shape or a staggered shape. However, the contact surface 13 of the flange portion 12 has an annular shape. Therefore, a pattern in which a large number of dimples 15 are arranged on the circumference at equal intervals is preferable. This is because the flow of the material can be made uniform in the circumferential direction of the annular contact surface 13 by arranging a large number of dimples 15 on the circumference at equal intervals.

  By the way, in this example, as shown in FIG. 2A, the dimples 15 are formed not only on the back surface of the contact surface 13 but also on the back surface of the escape portion 14. Thereby, the material on the back surface side of the relief portion 14 can be flowed to the contact surface 13 side, and higher flatness can be obtained on the contact surface 13 of the flange portion 12. In addition, since the material on the back surface side of the relief portion 14 flows toward the contact surface 13, a highly accurate dimensional shape can be realized as the dimensional shape of the boundary portion between the contact surface 13 and the relief portion 14.

  As mentioned above, although an example of the manufacturing method of the sensor cap which concerns on this invention was shown, this invention is not limited to this example, You may change suitably in the range which does not deviate from the summary of this invention.

  For example, in this example, a large number of dimples have the same shape and the same dimensions, but the inner dimple and the outer dimple of the flange portion, for example, the inner dimple is smaller and the outer dimple is larger, or Conversely, the shape and dimensions may be different, such that the inner dimple is larger and the outer dimple is smaller.

DESCRIPTION OF SYMBOLS 1 Metal plate 2 Intermediate molded product 10 Sensor cap 11 Cap part 12 Flange part 13 Contact surface 14 Relief part 15 Dimple

Claims (2)

Diaphragm type pressure sensor sensor cap, comprising a bottomed cylindrical cap portion, a flange portion projecting radially from the opening end of the cap portion, and a surface on the outer peripheral side of the surface of the flange portion And a sensor cap having a diaphragm relief provided inside the contact surface, comprising:
After forming an intermediate molded product having the cap part and the flange part from a flat metal plate by pressing, the relief part forming process for forming the relief part is performed at the same time by a single pressing process. A method of manufacturing a sensor cap, comprising performing dimple formation processing for forming a large number of dimples regularly arranged on the back side of the contact surface of the flange portion.   The method for manufacturing a sensor cap according to claim 1, wherein, in the dimple formation process, the dimple is also formed on the back side of the relief portion in the flange portion.

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