JP5833936B2 - Pressure sensor - Google Patents

Description

  The present invention relates to a pressure sensor, and more particularly to a liquid-filled pressure sensor in which a liquid is sealed in a pressure-receiving space that houses a pressure detection element.

  Conventionally, a liquid is enclosed in a pressure receiving space in which a pressure detection element is accommodated, and pressure applied from the outside to the pressure detection chamber is transmitted to the pressure detection element via the liquid, so that the pressure detection element responds to the external pressure. Various pressure sensors that output voltage signals have been proposed.

  As an example of the above-described liquid-sealed pressure sensor, Patent Document 1 discloses that one oil-sealed hole (hereinafter referred to as “enclosed hole”) that is sealed after injecting liquid into the pressure-receiving space is the same centered on the sensor chip. A base plate (hereinafter referred to as “base”) in which a plurality of hermetic holes (hereinafter referred to as “lead holes”) are arranged on the circumference is described.

  When manufacturing such a pressure sensor, an encapsulating hole and a plurality of lead holes are formed in the base, and each lead hole is fitted with a lead pin and a cylindrical glass for hermetic sealing that fills the gap. Each of the holes is fixed by, for example, and the holes are sealed, and after the oil is sealed, a sealing ball is attached to the sealing hole and sealed and fixed by welding or the like.

  Since the contents of the sealing operation of the sealing hole and the lead hole are somewhat different, as a preliminary step, the relative positional relationship between the sealing hole and the lead hole with respect to the base is grasped, and the base is set to a desired position with respect to the jig. It is necessary to mount so that it becomes a position. This is realized, for example, by forming a portion that fits with the sealing hole or the lead hole on the bottom surface of the jig and rotating them so as to fit them.

JP-A-10-122997

  However, in order to place the base in a desired position with respect to the jig, when a configuration is adopted in which a convex portion that engages the sealing hole is formed in the jig and these are fitted, The position is detected by an image, and according to the result, the base needs to be placed in a jig by rotating the base so that the sealing hole and the convex portion are fitted. Installation work is complicated and productivity is extremely low.

  On the other hand, even if a configuration is adopted in which protrusions that engage with the lead holes are formed on the jig and these are fitted, the cylindrical glass is inserted and mounted so that it has a uniform height relative to the lead holes. Therefore, it is necessary to form as many convex portions of the same shape as the number of the lead holes as engaging with all the lead holes.

  When the enclosing hole is formed on the circumference of the lead hole, the projecting portion formed in the jig is not fitted into the encapsulating hole, and the projecting portion formed in the jig is not fitted into the entire lead hole. Since it is necessary to be placed at the position where the part fits, the base placement work on the jig is complicated as in the case where the positioning is performed by forming one convex part that engages with the sealing hole. Become.

  Therefore, the present invention has been made to solve the above-described problems, and it is easy to place the base on the jig without requiring a complicated operation such as detecting the position of the lead hole with an image. An object of the present invention is to provide a pressure sensor that can improve productivity.

In order to achieve the above object, the present invention provides a pressure detection element, a base on which the pressure detection element is fixed to an inner surface , a receiving member disposed to face the inner surface of the base, the base and the receiving member. A diaphragm sandwiched between members, and a liquid sealed in a space between the base and the diaphragm, and the pressure in the space between the receiving member and the diaphragm causes the diaphragm and the liquid to flow. A pressure sensor that is transmitted to the pressure detection element via the sealing hole, and the base includes a sealing hole that is used when the liquid is sealed, and a lead member that is electrically connected to the pressure detection element. A plurality of lead holes to be mounted together are provided at equal intervals on the same circumference, and the inner diameter of the sealing hole is smaller than the outer diameter of the sealing member.

  In a preferred embodiment, the sealing member is a cylindrical glass for hermetic sealing.

  According to the present invention, the mounting operation of the base with respect to the jig can be performed without being aware of the positional relationship between the lead hole and the sealing hole. It is not necessary to rotate the workpiece for insertion into the jig, the manufacturing apparatus can be simplified, and the assembly / manufacturing efficiency of the pressure sensor can be improved.

  In addition, since the sealing hole and the lead hole are formed on the same circumference at equal intervals, the base strength and pressure resistance are uniform throughout, so the base is not easily damaged, and the pressure resistance of the pressure sensor , Airtightness can be improved.

  As described above, according to the present invention, since the base can be easily placed on the jig required for the sealing operation of the sealing hole and the lead hole, the assembly and manufacturing work of the pressure sensor is simplified. Productivity can be improved, and pressure resistance and airtightness of the pressure sensor can be improved.

It is a figure which shows one Embodiment of the pressure sensor which concerns on this invention, Comprising: (a) is a top view, (b) is the sectional view on the AA line of (a). The operation | work process which mounts a lead pin and the sealing member on the base of the pressure sensor which concerns on this invention is shown, the upper stage is a top view, and the lower stage is the BB sectional drawing of the upper stage. Further, (a) shows a state of only the jig, and (b) shows a state where all the holes of the base are fitted to the convex portions of the jig. FIGS. 3A and 3B are diagrams illustrating work steps performed subsequent to FIG. 2, in which FIG. 2C illustrates a state in which a lead pin is inserted into the base and the jig, and FIG. 3D illustrates a state in which a sealing member is mounted in the lead hole of the base. Show.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a pressure sensor according to the present invention. This pressure sensor 1 includes a pressure detection element 2, a base 4, and a receiving member 5 arranged to face the base 4. A diaphragm 6 or the like sandwiched between the base 4 and the receiving member 5 is provided. Liquid (oil) is sealed in the pressure receiving space 7 between the base 4 and the diaphragm 6.

  The pressure detection element 2 is fixed to the base 4 inside the pressure receiving space 7. A pressurizing space 8 as a pressure introducing space is formed between the receiving member 5 and the diaphragm 6, and the pressurizing space 8 communicates with the internal space of the inflow pipe 3 into which a fluid flows.

  The pressure detection element 2 is, for example, a piezo element. This piezo element is a kind of ferroelectric substance and is also called a piezoelectric element. When a force such as vibration or pressure is applied, a voltage is generated, and conversely, the voltage is When it is added, it expands and contracts.

  The base 4 is formed in a lid shape, and the pressure detection element 2 is fixed to the lower surface thereof. The base 4 is provided with one sealing hole 4a and eight lead holes 4b on the same circumference and at equal angles (equal intervals). That is, one sealing hole 4a and eight lead holes 4b are provided at an interval of 40 degrees.

  The eight lead holes 4b are all formed to have the same diameter, and the sealing hole 4a is formed to have a slightly smaller diameter than the lead hole 4b. The inner diameter of the lead hole 4b is set so that a sealing member 4e described later can be inserted. The inner diameter of the sealing hole 4a is set smaller than the outer diameter of the sealing member 4e.

  The sealing hole 4a of the base 4 is used when injecting liquid (oil) into the pressure receiving space 7, and after the liquid injection, the opening is sealed with a ball 9 by welding or the like. The lead hole 4b is inserted with a lead pin (lead member) 11 and then sealed with a hermetic seal 4c so as not to leak liquid (oil).

  The lead pins 11 (11A to 11H) are for adjusting lead pins 11A to 11E used for voltage correction at the time of manufacture and for outputting a voltage signal corresponding to the pressure detected by the pressure detection element 2 to the outside. It consists of output lead pins 11F to 11H.

  Each lead pin 11 </ b> A to 11 </ b> H is electrically connected to the pressure detection element 2 via the wire 10 at its lower end. Although not shown, the output lead pins 11F to 11H are connected to the substrate at their upper ends, and the substrate is further connected to a connector and an external output lead wire.

  The receiving member 5 is formed in a dish shape with an upper opening, and the inflow pipe 3 is brazed and fixed to the central opening.

  The outer peripheral edge of the diaphragm 6 is sandwiched between the flange of the base 4 and the flange of the receiving member 5, and these three members 4 to 6 are arranged at the outer peripheral edge where the outer periphery of the diaphragm 6 is exposed. They are simultaneously welded by laser welding or the like (welded portion 14) and integrated.

  The pressure sensor 1 having the above configuration changes the pressure of the pressurized space 8 due to the pressure change of the fluid flowing in from the inflow pipe 3 and deforms the diaphragm 6. Due to the deformation of the diaphragm 6, the pressure of the liquid (oil) sealed in the pressure receiving space 7 changes, and the pressure change propagates to the pressure detecting element 2. The pressure detected by the pressure detection element 2 is converted into a voltage, and at that time, a predetermined voltage correction according to the characteristics of the pressure sensor 1 is performed. The corrected voltage signal is transmitted to the external output lead wire via the output lead pins 11F to 11H, the substrate, and the connector.

  Next, a method of mounting the lead pin 11 on the base 4 of the pressure sensor 1 according to the present invention and sealing with the hermetic seal 4c will be described in detail with reference to FIGS. (A)-(d) of both figures are each after supplying the base 4 to the jig | tool 13 and performing rotation etc. until the lead pin 11 and the sealing member 4e for hermetic sealing are attached to the base 4. The process is shown.

  As shown in FIG. 2 (a), the jig 13 includes a plurality of recesses 13a having a columnar space in which the outer peripheral surface of the base 4 is accommodated without rattling (in the same figure, one recess 13a). Only). The bottom surface of the concave portion 13a has an outer diameter dimension that allows the sealing hole 4a to be fitted, and nine cylindrical convex portions 13b having the same height are arranged on the circumference where the sealing hole 4a and the lead hole 4b are arranged. Are formed at equal angles, that is, at intervals of 40 degrees. A pin hole 13c for inserting the lead pin 11 is recessed in the center of each convex portion 13b.

  Next, the base 4 is put into the concave portion 13a of the jig 13 with the upper surface 4d shown in FIG. At this stage, the sealing hole 4a and the lead hole 4b are not necessarily fitted into the convex portion 13b of the jig 13.

  Then, without considering the rotation direction, rotation angle, etc., the upper surface of the base 4 is pressed by a workpiece and rotated by the frictional force, or the jig 13 is rotated or vibrated in the horizontal direction. The base 4 is forcibly rotated within the 13 recesses 13a. By this rotation of the base 4, the sealing hole 4 a and the lead hole 4 b of the base 4 are fitted to all the convex portions 13 b of the jig 13 (FIG. 2B). In the example of FIG. 2B, the base 4 is positioned so that the sealing hole 4a is located on the left side.

  In this case, only the sealing hole 4a is precisely fitted to the convex portion 13b, and the lead hole 4b enters the convex portion 13b with a gap, but the concave portion 13a of the jig 13 has an outer peripheral surface of the base 4 Since it is formed in such a size that it does not rattle, the position of the entire base 4 is determined only by the fitting of the sealing hole 4a. Note that the position of the base 4 is only determined so as to be fitted to nine convex portions 13b formed at intervals of 40 degrees, and the sealing hole 4a is fitted to a specific convex portion 13b of the jig 13 (that is, The base 4 is always in a specific position with respect to the jig 13).

  Next, as shown in FIG. 3C, after the lead pins 11 are inserted into all the pin holes 13c, the hermetic glass (the holes for inserting the lead pins 11 are inserted into all the lead holes 4b and the sealing holes 4a. The formed cylindrical glass tablet, hereinafter referred to as “sealing member”) 4e (see FIG. 3D) is inserted. That is, the insertion operation of the sealing member 4e is performed regardless of whether the hole to be inserted is the lead hole 4b or the sealing hole 4a. This insertion is performed such that the lead pin 11 is inserted into the inner peripheral portion of the sealing member 4e.

  Here, since the inner diameter of the sealing hole 4a is smaller than the lead hole 4b and smaller than the outer diameter of the sealing member 4e, the sealing member 4e is inserted into the sealing hole 4a. If the sealing member 4e is forcibly inserted into the sealing hole 4a, for example, a predetermined load is applied to the insertion jig of the sealing member 4e. If the load at the time of insertion is detected by a sensor or the like, the position of the sealing hole 4a can be specified, and the insertion operation of the sealing member 4e into the sealing hole 4a can be stopped.

  As described above, the sealing member 4e can be attached only to the lead hole 4b regardless of whether or not it is the lead hole 4b (FIG. 3D). .

  After the sealing member 4e has been inserted into all the lead holes 4b in this way, the lead pin 11 is pulled out from the sealing hole 4a in which the sealing member 4e could not be inserted, and the sealing member 4e in the lead hole 4b is melted. Thus, the hermetic seal 4c (see FIG. 1) is formed. As a result, the gap between the lead hole 4b and the lead pin 11 is completely sealed, so that the liquid (oil) sealed in the pressure receiving space 7 oozes out from the gap, and the substrate, the external output lead wire, etc. It does not flow into the housing space (not shown).

  As described above, when the pressure sensor 1 is manufactured using the base 4 configured as described above, the base 4 is placed on the jig 13 when the lead pins 11 and the sealing member 4e are mounted on the base 4. Since the work can be performed without being aware of the rotation direction and its angle, the work process is simplified, and the assembly and manufacturing efficiency of the pressure sensor 1 is improved. In addition, since the sealing hole 4a and the lead hole 4b are formed at equal intervals on the same circumference, the base 4 is uniform in strength and pressure resistance as a whole, and the base is less likely to be damaged. The pressure resistance and airtightness of the sensor 1 are improved.

  In the present embodiment, the concave portion 13a formed in the jig 13 is described as a cylindrical space. However, the present invention is not limited to this, and the outer peripheral surface of the base 4 is not limited to this. As long as it is a space that can be accommodated without rattling, it can also be a rectangular shape when viewed from above.

DESCRIPTION OF SYMBOLS 1 Pressure sensor 2 Pressure detection element 3 Inflow pipe 4 Base 4a Enclosed hole 4b Lead hole 4c Hermetic seal 4d Upper surface 4e Sealing member (tablet)
5 Receiving member 6 Diaphragm 7 Pressure receiving space 8 Pressure space 9 Ball 10 Wire 11 Lead pin 11A to 11E Adjustment lead pin 11F to 11H Output lead pin
13 Jig 13a Concave part 13b Convex part 13c Pin hole 14 Welded part

Claims (2)

A pressure sensing element;
A base having the pressure detecting element fixed to the inner surface;
A receiving member disposed to face the inner surface of the base;
A diaphragm sandwiched between the base and the receiving member;
A liquid sealed in a space between the base and the diaphragm;
A pressure sensor in which a pressure in a space between the receiving member and the diaphragm is transmitted to the pressure detection element via the diaphragm and the liquid;
The base includes a sealing hole used when sealing the liquid, and a plurality of lead holes in which a lead member electrically connected to the pressure detection element is mounted together with a sealing member on the same circumference. A pressure sensor provided at an interval, wherein an inner diameter of the sealing hole is smaller than an outer diameter of the sealing member.   The pressure sensor according to claim 1, wherein the sealing member is a cylindrical glass for hermetic sealing.

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