JP2939148B2 - Seismic element and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, a signal processing device of an oil heater, a gas combustion device, or an electric device, and senses a vibration such as an earthquake to transmit a detection signal to the signal processing device. This is related to the seismic element.

[0002]

2. Description of the Related Art Several types of seismic devices have been proposed. For example, in Japanese Patent Application Laid-Open No. 57-76421, a movable contact piece is constantly pushed down by a steel ball, and when subjected to vibration or the like, the steel ball rolls along the mortar-shaped bottom and releases the pressing force on the movable contact piece. There is described a seismic device for moving a movable contact and a fixed contact disposed on the movable contact piece into and out of contact with each other. Japanese Patent Application Laid-Open No. Sho 59-228123 describes a seismic sensor in which mercury particles are sealed in a metal container.

[0003]

Recently, for example, a seismic sensor is attached to an oil heater or a gas-fired device, for example, and a vibration such as an earthquake is detected to be detected by the signal processing device of the oil heater or the gas-fired device. Appropriate security measures such as automatic fire extinguishing and the like are taken by a control device to send a signal, and these seismic sensors are required to be downsized. In the seismic device disclosed in JP-A-57-76421, it is necessary to increase the contact pressure to a certain degree or more so as not to increase the resistance between the contacts. This contact pressure depends on the weight of the steel ball that presses the movable contact piece in the case of the always-on type, and there is a limit to reducing the size of the steel ball in order to obtain sufficient inter-contact pressure. Therefore, it is difficult to reduce the size of the entire apparatus.

On the other hand, a normally-on type seismic sensor using mercury, such as the one described in Japanese Patent Application Laid-Open No. 59-228123, has no problem of contact resistance and is smaller than a steel ball type. Although it is a high-performance switch capable of obtaining stable performance over a long period of time, demand for a seismic sensor that does not use mercury has recently been increasing due to environmental problems and the like. Therefore, there is a need for a small, robust, mass-production-friendly, low-cost seismic sensor that has the same characteristics as conventional seismic sensors using mercury without using mercury. However, since the mercury particles are liquid, the structure of the switch cannot be directly applied to a device using solid conductive spheres. Therefore, there has been a demand for an always-on and small-sized seismic element and a seismic sensor using an inertial sphere.

The applicant has proposed a seismic element shown in FIG. 8 in Japanese Patent Application No. 6-208136. This example will be described with reference to the drawings.
1 is a bottomed cylindrical metal housing 102 and a disc 103
Are hermetically fixed to each other by ring projection welding or the like at the flanges of each other to form an airtight container. Disk 103
A conductive terminal pin 105 is hermetically sealed and fixed by an electrically insulating filler 104 such as glass at a substantially center of a through hole.

A lower insulator 106 made of an insulating material such as ceramic or synthetic resin is press-fitted and fixed inside the housing 102 inside the closed container. Lower insulator 106
Has a leg 106A, and a lower contact member 107 described later is disposed in a gap formed by the leg 106A. On the upper surface of the lower insulator 106, an inclined surface 1 gently rising concentrically outward from a substantially central portion of the lower insulator.
06B is formed. An insertion hole 106C is provided at the center of the inclined surface 106B, and a contact portion 107A at one end of the lower contact member 107 is inserted upward from below.

The lower contact member 107 has a thickness of, for example, 0.03.
It is a flexible spring made of phosphor bronze plate of about 0.2mm. The contact portion 107A described above is movably provided at one end of a lower contact member 107 located at the center of the housing 102, and the other end is fitted and fixed to one of fixed legs 106A also serving as a leg of the lower insulator 106. Connecting part 1 which is electrically connected to the inner wall of the housing 102
07B is provided.

On the inclined surface 106B of the lower insulator 106, an inertial sphere 108 made of a conductive metal such as iron or its alloy such as stainless steel is accommodated. The inertial sphere 108 has an inclined surface 10 when stationary in a normal normal posture.
It is located on the through hole 106C, which is the center of 6B, and is in contact with the contact portion 107A of the lower contact member 107, and does not roll until it receives vibration of a predetermined acceleration or more, and keeps the contact state. When the seismic element 101 receives a vibration equal to or more than a predetermined value due to an earthquake or the like, the inertial sphere 108 leaves the through hole 106C and rolls on the inclined surface 106B to cut off the contact with the contact portion 107A.

An upper contact member 109 is sandwiched between the conductive terminal pin 105 and the inner end of the sealed container so as to sandwich the protective plate 11.
0 is fixed by a method such as butt welding. The upper contact member 109 is provided with a plurality of flexible blade-like portions 109A. The vicinity of the tip of the wing-like portion 109A is always in contact with the inertial sphere. Further, the wing-like portion 109A has sufficient flexibility, so that even when the inertial ball 108 rolls, at least two follow the rolling of the inertial ball 108 and maintain contact.

Upper contact member 109 and conductive terminal pin 105
The lower surface of the fixed part with the upper contact member 10 of the inertial sphere 108
A protection plate 110 is fixed to prevent plastic deformation due to a collision near the fixing portion 9. Therefore, for example, even if the inertial sphere 108 jumps up due to vibration or the like during transportation when the inertial sphere 108 jumps, the inertial sphere 108 does not collide with the vicinity of the fixed portion between the upper contact member 109 and the conductive terminal pin 105 due to the protective plate 110. In addition, plastic deformation of the wing-like portion 109A can be prevented, and stable characteristics can be obtained for a long period of time.

A substantially cylindrical upper insulator 111 made of an insulator is provided so as to surround the periphery of the upper contact member 109. The upper insulator 111 cooperates with the lower insulator 106 to keep a small distance between the inertial sphere 108 and the inner wall of the housing 102 even at the maximum movement position of the inertial sphere 108 so that the two members do not come into contact with each other. To receive the inertial sphere. Therefore, the seismic element does not output an ON signal at the time of the maximum amplitude, and can be reliably turned OFF even when the control target device tilts or falls.

Although this seismic element 101 uses a solid inertial sphere, it realizes a small and always-on seismic element. Here, the wing-like portion 1 of the upper contact member 109
In order to have sufficient flexibility in 09A and follow the rolling of the inertial sphere 108 to maintain contact, for example, when a phosphor bronze plate is used, the thickness is reduced to about 0.01 to 0.02 mm. There is a need to. However, it is difficult to process a metal plate of such a thickness into a predetermined shape because of its flexibility, and high technology is required to align the shape of each product, and it is also possible to handle while maintaining the shape after processing. Further, it is necessary to prepare a special holder and a container, which is extremely difficult.

[0013]

The feature of the seismic element of the present invention is that a container is constituted by a conductive disk and a bottomed cylindrical conductive housing, and a conductive terminal pin is provided substantially at the center of the disk. A lower insulator that is penetrated and fixed by an electrically insulating filler material and that has a slope that gradually rises concentrically from the center to the outside is fixed to the bottom surface of the housing,
One end of a conductive lower contact member is provided at or near the bottom surface in the housing so as to be electrically connected to the housing, and a contact portion, which is the other end of the lower contact member, is inserted into the through hole of the lower insulator. When the conductive inertial sphere is rollable on the inclined surface of the lower insulator and the housing is stationary in a normal posture, the lower contact member is positioned on the through hole at the center of the inclined surface by gravity. A substantially cylindrical upper insulator having a through-hole through which the conductive terminal pin is inserted is provided on the inner side of the container of the disk so as to be in contact with and electrically connected to the contact portion of the disk. It is fixed so as to surround it, and a conductive material having a plurality of pliable elastic wings is provided at the inner end of the conductive terminal pin on the inner side of the container so that the contact portion is disposed substantially concentrically around the conductive terminal pin. Upper contact member is a blade Part always' preferred fixed and the upper contact member as the contacted electrically connected to the inertia ball a
Is fixed protective plate for preventing the free properly plastic deformation, the protection of the outer peripheral portion of the protective plate and upper insulator with the upper insulator and the upper contact member is fixed by fixing the protective plate to the conductive terminal pins By holding the vicinity of the root of the wing-shaped portion of the upper contact member between the inner peripheral portion of the plate mounting portion and the tip of the wing-shaped portion ,
The end direction is set to a predetermined angle .

Another feature is that the lower contact member has an elastic shape, and when the inertial sphere is positioned on the through hole of the insulator, the urging force for pressing the contact portion of the lower contact member against the inertial sphere is always provided. Is to give.

Another feature is that the upper insulator and the lower insulator cooperate so that the inertial sphere does not come into direct electrical contact with the inner surface of the housing even when moved to the maximum movement position. is there.

Still another feature is a method of manufacturing a seismic element, wherein an upper contact member is placed on an upper insulator or a protection plate so that its center axis is aligned, and then the upper insulator and the protection plate are separated. The outer periphery of the protection plate and the upper insulator
By holding the vicinity of the root of the wing-shaped portion of the upper contact member between the inner peripheral portion of the protection plate mounting portion and the tip of the wing-shaped portion,
The manufacturing method is such that the upper insulator and the upper contact member are fixed to the disk by deforming to a certain angle and further fixing the protective plate to the conductive terminal pins fixed to the disk.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. 1 has an airtight container in which a bottomed cylindrical metal housing 2 and a disk 3 are airtightly fixed by ring projection welding or the like. If the airtight container is sealed by replacing the air inside it with hydrogen, helium, argon, nitrogen or other pollution prevention gas,
It is preferable to protect the surfaces of the contact members and inertial spheres described below from corrosion and fouling to obtain stable characteristics for a long time.
A through-hole 3B is formed substantially at the center of the disk 3, and a conductive terminal pin 5 is hermetically sealed through an electrically insulating filler 4 such as glass.

A lower insulator 6 made of an insulating material such as ceramic or synthetic resin is press-fitted and fixed inside the housing 2 inside the closed container. The lower insulator 6 has a leg 6A, and a lower contact member 7 described later is disposed in a gap formed by the leg 6A. On the upper surface of the lower insulator 6, there is formed an inclined surface 6B which gradually rises concentrically from the center to the outside. In the present embodiment, the shape of the inclined surface is a conical surface obtained by rotating a straight line having a predetermined inclination angle, but the shape is not limited to this, and the inclination angle is It includes a changing conical surface and a concave or convex surface obtained by rotating a curve having a gentle curvature up and down. In addition, the curvature of the above-described curve may change midway or gradually as long as the inclination direction does not change. An insertion hole 6C is provided at the center of the inclined surface 6B, and the contact portion 7A of the lower contact member 7 is inserted upward from below. Symbol 6D is a rib for press-fitting.

The lower contact member 7 has a thickness of, for example, 0.03 to 0.03.
It is a flexible spring made of a phosphor bronze plate of about 0.2 mm and has a spiral shape as shown in FIG. 2, for example. The above-mentioned contact portion 7A is movably provided at one end located at the center of the housing 2, and the tip portion protrudes upward from the insertion hole 6C, and the contact portion moves upward in the vicinity of the contact portion 7A. The stopper 7B for regulating the amount is widened so as to reach the outside of the insertion hole 6C. At least the contact portion 7A of the lower contact member 7 is preferably subjected to a surface treatment such as a noble metal such as gold or silver, or a plating of nickel or solder so as not to impair conductivity by an oxide film or the like.

At the other end, there is provided a fixing portion 7C which is fitted and fixed to a fixing leg 6A1 also serving as a leg of the lower insulator 6,
A connecting portion 7D is provided near the fixing portion 7C and is in contact with the inner wall of the housing 2 and is electrically connected thereto. The fixing portion 7C has a plurality of cuts 7C1 provided in the embodiment around a hole slightly smaller than the outer diameter of the fixing leg 6A1, and is press-fitted into the fixing leg 6A1. Further, since the connecting portion 7D is sandwiched between the inner wall of the housing 2 and the outer wall of the lower insulator 6, the contact pressure is increased and the resistance value of the contact portion can be reduced, and the lower contact member 7 rotates about the fixed portion 7C. To prevent

On the inclined surface 6B of the lower insulator 6, an inertial sphere 8 made of a metal such as iron or its alloy such as stainless steel is accommodated. The inertial sphere 8 can be made of various metals other than iron, for example, copper or its alloy, or hard lead, and is easily oxidized in air such as iron or copper, and its oxide film may impair conductivity. Preferably, noble metals such as gold and silver, or those subjected to surface treatment such as nickel and solder plating made of lead and tin are selected according to the purpose, but the surface is made of a conductive material suitable for the intended use. The material and the surface treatment are not limited to these as long as they are solid spheres having

When the inertial sphere 8 is stationary in a normal normal posture, the inertial sphere 8 is located on the through hole 6C which is the center of the inclined surface 6B and comes into contact with the lower contact member 7 by pressing down the contact portion 7A. Until it receives a vibration equal to or higher than a predetermined acceleration, it does not roll and maintains a contact state. When the seismic element 1 receives a vibration equal to or more than a predetermined value due to an earthquake or the like, the inertial sphere 8 leaves the through hole 6C and rolls on the inclined surface 6B, thereby breaking the contact with the contact portion 7A. . In the case of the seismic element of FIG. 1, the rolling start acceleration α of the inertial sphere 8
And the radius of the insertion hole 6C is r.

[0023]

(Equation 1)

In practice, it is adjusted to a slightly higher value by being pressed by an upper contact member 9 described later.

A protective plate 10 is fixed to the inner end of the conductive terminal pin 5 inside the sealed container by a method such as butt welding. Here, the protective plate 10 is located between the conductive terminal pin 5 and the upper contact member 9.
And the upper insulator 11 is sandwiched between the disk 3 and the upper insulator 11. FIG. 3 is a plan view of the upper contact member 9, FIG. 4 is a bottom view of the state where the upper insulator 11 and the upper contact member 9 are fixed to the disk 3 by the protective plate 10, and FIG. FIG. At the center of the upper contact member 9 is provided a mounting hole 9B which is penetrated to avoid projection of a welding portion 10A between the conductive terminal pin 5 and the protective plate 10, and is generated when the conductive terminal pin and the protective plate are welded. In addition to reducing the influence of plastic deformation of the upper contact member due to heat, the periphery 9C of the mounting hole is connected to the conductive terminal pin 5
And the protection plate 10 to fix it.

The upper contact member 9 is provided with a plurality of flexible blade-like portions 9A as shown in FIG. In this embodiment, six blade-like portions 9A are provided at a uniform angle around the conductive terminal pin 5, that is, at every 60 °. When the mass of the inertial sphere is about 0.7 g, the upper contact member 9
Is preferably a phosphor bronze plate having a thickness of, for example, 0.01 to 0.02 mm. The vicinity of the tip of the wing-shaped portion 9A is set so as to be located slightly inside the surface position of the inertial sphere 8 in a free state in which the inertial sphere 8 does not exist, and is always in contact with the inertial sphere 8. The wing-shaped portion 9A has sufficient flexibility so that at least two of the wings 8 always follow the rolling of the inertial sphere 8 and keep contact with each other even when rolling, and preferably have a width of 0.3 mm. Degree. The number of the blades 9A and the repulsive force per one are determined in consideration of the influence on the rolling start acceleration of the inertial sphere 8 and the electrical contact resistance.

The protection plate 10 is fixed to the lower end of the conductive terminal pin 5 as described above, and prevents plastic deformation due to collision of the inertial sphere 8 near the fixed portion of the upper contact member 9. For example, the seismic element 1 may be subjected to vibration or the like during transportation, and the inertial sphere 8 may jump up to the position shown by the dotted line 8A in FIG. At this time, if the protective plate 10 is not provided, the inertial sphere 8 exceeds the position of the dotted line 8A and collides with the vicinity of the fixed portion between the upper contact member 9 and the conductive terminal pin 5 to cause undesirable deformation. As described above, when plastic deformation occurs on the base side of the wing-like portion 9A, the amount of deformation is enlarged at the tip of the wing-like portion 9A, and the position may be largely changed.
However, in this embodiment, by arranging the protection plate 10 so as not to be deformed in the vicinity of the fixed portion of the upper contact member 9, stable characteristics can be obtained for a long time.

The upper insulator 11 is made of an insulating material such as ceramic or synthetic resin similarly to the lower insulator 6, and has a substantially cylindrical shape having a through hole 11A at the center. 3 and the protection plate 10 and are fixed. Inside the upper insulator 11, a small-diameter portion 11B serving as a protection plate mounting portion having an inner diameter substantially the same as the outer diameter of the protection plate 10
And a large-diameter portion 11C having an inner diameter larger than this. A protection plate 10 is fitted into the small-diameter portion 11B, and the vicinity of the root of the wing-shaped portion 9A of the upper contact member 9 is clamped and fixed. At a position corresponding to the wing-shaped portion 9A of the upper insulator 11, a groove 11E wider than the width of the wing-shaped portion 9A is provided from the large diameter portion 11C to the opening end face 11D. The purpose of the groove 10E is to protect the upper contact member 9, for example, when the inertial sphere 8 abuts on the upper insulator 11 if the groove is not provided, the wing-like portion 9A is directly sandwiched between the two. When the impact is large or not large, repeated contact with the impact may cause plastic deformation of the wing-like portion 9A and change the characteristics as a seismic element. However, in the present embodiment, since the groove 11E is provided as described above, even when the inertial ball 8 abuts on the upper insulator 11, the wing-shaped portion 9A is located at the position of the groove 11E, so that the inertial ball 8 and the upper It is not directly sandwiched between the insulators 11 and does not plastically deform.

The upper insulator 11 cooperates with the lower insulator 6 to receive the inertial sphere 8 by the ends 11D and 6E even at the maximum lateral movement position of the inertial sphere 8 indicated by a dotted line 8B in FIG. In addition, even at the position 8B, the inertia ball 8 and the inner wall of the housing 2 are kept at a small distance, and the two members do not come into contact with each other. Therefore, the seismic element does not output an ON signal at the time of the maximum amplitude, and can be reliably turned OFF even when the control target device tilts or falls.

The operation of the seismic element 1 will be described. When the seismic element 1 is at rest in a normal posture, the inertial sphere 8 is located on the through hole 6C of the inclined surface 6B and is in contact with the lower contact member 7. 7A, and the pressing force is applied by the weight of the inertial sphere 8 itself and the upper contact member 9. Here, an electric path is formed by the route of the conductive terminal pin 5-the upper contact member 9-the wing-shaped portion 9A-the inertial ball 8-the contact portion 7A-the lower contact member 7-the housing 2-the disk 3.

When the seismic element 1 is subjected to a predetermined acceleration, for example, a horizontal vibration of 160 gal or more at a cycle of 0.2 to 1 second, the inertial sphere 8 leaves the through hole 6C and rolls on the inclined surface 6B. To cut off the contact with the contact portion 7A of the lower contact member 7,
The above-mentioned electric circuit is cut off for a predetermined time or more. Therefore, a detection signal is sent to a signal processing device connected to the seismic element 1, and for example, in the case of an oil heater or a gas combustion device, an appropriate security measure such as automatic fire extinguishing is performed by a control device. When the seismic element 1 returns to the rest state, the inertial sphere 8 returns to the center of the through hole 6C of the inclined surface 6B and contacts the contact portion 7A again to form an electric path. Here, since the wing-shaped portion 9A is always in sliding contact with the inertial ball 8, the electric path can be formed promptly by the inertial ball 8 coming into contact with the contact portion 7A when returning. Since the upper contact member 9 always brings the plurality of wing-shaped portions 9A into contact with the inertial ball 8 to give a pressing force, the contact resistance can be sufficiently reduced even when a smaller inertial ball is used as compared with the conventional one. it can.

Here, the attachment of parts such as the upper contact member in the portion shown in FIG. 5 of the seismic element 1 will be described. The upper contact member 9 is placed on an upper insulator 11 placed upside down from FIG. In this embodiment, the upper contact member 9 is used.
The mounting hole 9B provided at the center of the upper insulator 11 is aligned with the central axis of the upper insulator 11, and the wing-like portion 9A is aligned with the groove 11E of the upper insulator 11. At this time, the upper contact member 9
Has not been bent yet and has a flat shape as shown in FIG. 3, and is placed on the upper insulator 11 in a state shown by a dotted line 9D in FIG. 4, for example.

Next, the welded portion 10 passing through the central axis of the protection plate 10
In the state where the projection of A is aligned with the mounting hole 9B of the upper contact member 9, the protection plate 10 is fitted together with the upper contact member 9 into the small-diameter portion 11B which is the protection plate mounting portion of the upper insulator 11, and at the same time, the blade-like portion 9A Is deformed as shown in FIG. Here, the small diameter portion 11B of the upper insulator
Is substantially the same as the outer diameter of the protection plate 10, the upper insulator and the protection plate are temporarily fixed to each other. Further, since the upper contact member 9 is a thin plate, it is deformed and held between the two.

Next, the tip of the lead terminal pin 5 previously fixed to the disk 3 is inserted through the through hole 11A of the upper insulator 11, and the upper contact member 9 and the upper insulator 1 are disposed as described above.
The protective plate 10 is welded and fixed to the tip of the lead terminal pin 5 so that 1 is sandwiched between the lead terminal pin 5 and the disk 3.

Here, the opening-side end face 10B of the protection plate 10 is formed so as to open outward by a predetermined amount, and the intermediate portion of the blade-like portion 9A is supported here. It is automatically determined by the positional relationship between the side end face 10B and the terminal end 11B1 of the small diameter portion 11B of the upper insulator 11.

As described above, according to the manufacturing method of the present invention, the upper insulator 11, the upper contact member 9, and the protection plate 10
And the upper contact member 9 can be formed into a predetermined shape at the same time. Further, in this embodiment, the method has been described by way of example in which the protection plate is fitted and temporarily fixed after the upper contact member is placed on the upper insulator. For example, the protection plate 10 placed in the direction of FIG. The same applies to the method of mounting the upper insulator 11 from above and temporarily fixing the upper insulator 11 after placing the upper contact member 9 with the center axis aligned on the upper surface. Also, the lead terminal pins 5 fixed to the disk 3 are inserted through the through holes 11A of the upper insulator 11 in advance, and the protection plate 10 is fitted to the small-diameter portion 11B of the upper insulator, and at the same time, the protection plate 10 and the lead terminal pins are connected. 5 may be fixed by welding.

Since the mounting hole 9B is provided in the upper contact member 9 at the time of welding as described above, the welding current does not flow directly, so that the effect of plastic deformation of the upper contact member due to heat generated during welding is reduced. can do. Further, since the vicinity of the root of the wing-shaped portion 9A is clamped and fixed between the protection plate 10 and the small-diameter portion 11B before welding, even if the peripheral edge 9C of the mounting hole 9B is slightly deformed, the tip side of the wing-shaped portion 9A is hardly formed. It does not affect.

As described above, the wing-shaped portion 9A is automatically installed at the time of assembly.
Is determined, it is not necessary to deform the thin plate-shaped upper contact member 9 into a predetermined shape in advance, and it is possible to handle the flat contact member 9 in a flat shape, so that the handling becomes very easy. . Further, since the shape of the upper contact member 9 which has conventionally been difficult to be processed into a predetermined shape due to its flexibility can be determined by the shape and positional relationship of peripheral parts centering on the upper insulator and the protection plate, the Can be easily made uniform, and the performance variation as a seismic element can be eliminated. Further, since there is no need to process in advance, the number of steps in manufacturing is reduced. Further, the blade-shaped portion 9A can be regarded as a cantilever type leaf spring with the terminal end 11B1 of the small diameter portion as a fixed end, so that strength calculation at the time of design becomes easy.

In this embodiment, the lower contact member 7 is
Since A is constantly urged upward, a pressing force can be applied between the contact portion 7A and the inertial ball 8 at the time of contact with the inertial ball 8. For this reason, the contact pressure between the inertial ball 8 and the lower contact member 7 due to the rolling of the inertial ball 8 on the contact portion 7A due to the vibration less than a predetermined value which does not lead to the operation as the seismic sensor, or the fine vibration up and down. It is possible to prevent erroneous operation and erroneous determination of the signal processing device due to a change in resistance value caused by the change.

For example, when a very short-time temporary change in the contact resistance between the inertial sphere and the lower contact member does not cause a problem, or when a delay function or the like is added to the detection circuit side, for example, the seismic shock shown in FIG. The lower contact member 27 like the element 21
May be fixed contacts. In the case of this embodiment, the lower contact member 27 is a contact made of a silver alloy or the like, and the lower end in the figure is conductively fixed to the inner bottom surface 2A of the housing 2. The upper surface is provided with a concave portion 27A in which the inertial sphere 8 is located at rest in a normal posture, and a peripheral portion thereof serves as a contact portion 27B. Regarding other parts, the same parts as those in the above-described example are denoted by the same reference numerals, and description thereof is omitted. Also, the operation is the same as that of the above-described example except that the lower contact member 27 does not follow the movement of the inertial sphere 8, so that a change in the contact resistance or the like in a short time is likely to occur due to a small vibration or the like. .

Next, the seismic sensor 3 shown in FIGS.
FIG. 7A shows an embodiment 1 having a resin case 32 which is a member for holding the above-described seismic element 1 in a normal posture.
Is a longitudinal sectional view, and FIG. 7B is a transverse sectional view. Seismic sensor 1
A conductive welding pin 33 is fixed to the metal housing 2 or the disk 3 by welding. The seismic element 1 is inserted through the opening on the lower surface of the case, and the conductive terminal pins 5 and the welding pins 33 are inserted into the through holes 32A and 32B formed in the case.
The disc 3 is brought into contact with the position holding portions 32C of the protrusions to position the seismic element. In this state, the terminals 34 and 35 are respectively welded to the ends of the conductive terminal pins 5 and the welding pins 33 protruding above the case, so that the seismic element 1 is fixed to the case 32.

When attaching the seismic sensor 31 to, for example, an oil fan heater or the like, the case bottom surface 32D is brought into close contact with a horizontal surface such as a bottom plate of an oil fan heater (not shown), and a screw or the like is passed through a fixing hole 32E to fasten the seismic sensor 31. The seismic element 1 is positioned at a predetermined position between the case bottom surface 32D of the seismic device 31 and the seismic element 1 so that the seismic element 1 assumes a normal posture by being fixed. In this embodiment, the example in which the case is mounted on the horizontal surface has been described.
For example, the mounting surface can be easily formed as a vertical surface or an inclined surface having a predetermined angle by changing the design of the shape of the case. In addition to the above, various types of means for holding the seismic element in the normal posture can be considered. For example, a predetermined metal fitting such as a gate shape or an L-shape is welded to the conductive terminal pin 5, and this metal fitting is fixed to a predetermined mounting surface. To ensure that the seismic element is maintained in the correct position, or to suspend the seismic element in a case filled with silicone oil of appropriate viscosity and automatically correct the position of the seismic element itself. The one with the function is the actual opening 61-1
This is a well-known means from Japanese Patent No. 41551, Japanese Utility Model Application Laid-Open No. 62-204155, Japanese Patent Application Laid-Open No. 6-50804, and the like.

[0043]

According to the seismic element of the present invention, the shape of the wing-shaped portion provided on the outer periphery of the upper contact member is automatically determined when the upper contact member is assembled. It is not necessary to deform the contact member in a predetermined shape in advance, and the contact member can be handled in a flat state, so that the handling becomes very easy.

Further, since the shape of the upper contact member, which was conventionally difficult to be processed into a predetermined shape due to its flexibility, can be determined by the shape and positional relationship of peripheral parts centering on the upper insulator and the protection plate, It is easy to make the shape of each product uniform, and the performance as a seismic element can be eliminated.

Further, since there is no need to perform pre-processing, the number of steps in manufacturing is reduced. Further, the blade-like portion of the upper contact member can be regarded as a cantilever type leaf spring having a fixed end at the end of the small-diameter portion of the upper insulator, so that the strength calculation at the time of design becomes easy.

Further, by providing grooves at positions corresponding to the wings of the upper contact member of the upper insulator, the wings are sandwiched between the upper insulator and the inertia sphere even when the inertial sphere moves at the maximum. However, it is possible to prevent the plastic deformation of the wing-shaped portion and obtain a seismic element having stable performance over a long period of time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a seismic sensor according to the present invention.

2 is a sectional view of the seismic element shown in FIG.

FIG. 3 is a plan view before assembling an upper contact member used in the embodiment of FIG. 1;

FIG. 4 is a bottom view of the disk of the embodiment of FIG. 1 in which an upper insulator and an upper contact member are fixed by a protection plate;

FIG. 5 is an enlarged longitudinal sectional view of the component of FIG. 4;

FIG. 6 is a longitudinal sectional view of another embodiment of the seismic element of the present invention.

7A is a longitudinal sectional view of an embodiment of a seismic sensor using the seismic element of the present invention, and FIG.

FIG. 8 is a longitudinal sectional view of an example of a conventional seismic element.

[Explanation of symbols]

 1, 21: seismic element 2: housing 3: disk 5: conductive terminal pin 6: lower insulator 7, 27: lower contact member 8: inertial ball 9: upper contact member 9A: wing-shaped portion 10: protective plate 11 : Upper insulator 11B: Small diameter part (protection plate mounting part) 11E: Groove 31: Seismic sensor 32: Case 33: Welding pin 34, 35: Terminal

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01H 1/00 H01H 35/14

Claims (6)

(57) [Claims] A container is constituted by a conductive disk and a conductive housing having a cylindrical shape with a bottom, and a conductive terminal pin is penetrated and fixed to a hole formed substantially at the center of the disk by an electrically insulating filler. A lower insulator having a slope gradually rising concentrically from substantially the center toward the outside and having a through hole at the center is substantially fixed to the bottom surface of the housing. One end of a conductive lower contact member is provided on the bottom surface or near the bottom surface so as to be electrically connected to the housing, and a contact portion that is the other end of the lower contact member is inserted into a through hole of the lower insulator, When the conductive inertial sphere rolls on the inclined surface of the lower insulator and the housing is stationary in a normal posture, it is positioned above the through hole at the center of the inclined surface by gravity. Electrically contacts the contact part of the contact member A substantially cylindrical upper insulator having a through hole through which the conductive terminal pin is inserted is fixed so as to surround the conductive terminal pin on the inner side of the container of the disk. An upper contact member made of a conductive material having a plurality of pliable elastic wing-like portions in which a contact portion is disposed substantially concentrically with the conductive terminal pin as a center at the inner end of the container. preferably the fixed and the upper contact member so as to be electrically connected in contact with the inertia ball
A protection plate for preventing undesired plastic deformation is fixed, and the outer periphery of the protection plate and the inner periphery of the protection plate mounting portion of the upper insulator sandwich the vicinity of the root of the wing-like portion of the upper contact member. So that the tip direction of the wings is at a predetermined angle.
When the inertial sphere receives a vibration equal to or more than a predetermined value, the inertial sphere separates from the through hole and rolls on the inclined surface to break contact with the lower contact member. The seismic element is pressed against the contact portion of the lower contact member by the elasticity of the upper contact member. The lower contact member has an elastic shape, and its contact portion is provided with an urging force to be pressed against the inertial sphere whenever the inertial sphere is positioned on the through hole of the insulator. The seismic element according to claim 1, wherein: 3. An upper insulator and a lower insulator cooperate with each other to prevent direct contact with the inner surface of the housing even when the inertial sphere moves to a maximum movement position. The seismic element according to claim 1 or 2. 4. The upper insulator is provided with a groove at a position corresponding to the wing-like portion, so that the wing-like portion is not sandwiched between the inertial sphere and the upper insulator.
Or seismic device according to any one of claims 3. 5. A protective plate having a conductive disk in which conductive terminal pins are penetrated and fixed by an electrically insulative filler in a hole formed substantially in the center, and a through hole through which the conductive terminal pins are inserted. A substantially cylindrical upper insulator having a protection plate mounting portion having an inner diameter substantially the same as the outer diameter of the outer diameter, and a plurality of flexible elastic blades having a through hole at the center and arranged radially from the center. In a seismic sensor having a conductive thin plate upper contact member having a portion, and a protective plate for preventing deformation of the upper contact member, the planar upper contact member has a center located at an upper insulator or a protective plate, and After arranging them so that their central axes coincide with each other, the upper insulator and the protection plate are assembled so that the outer peripheral portion of the protection plate and the inner periphery of the protection plate mounting portion of the upper insulator have a blade shape of the upper contact member. By pinching near the base of the part
The tip of the wing is deformed so that the tip direction is at a predetermined angle, the middle part of the wing is supported by a protection plate, and the protection plate is fixed to the conductive terminal pins fixed to the disk, thereby insulating the upper part. A method for manufacturing a seismic element, wherein a body and an upper contact member are fixed to a disk. 6. A groove is provided at a position corresponding to the wing-shaped portion of the upper insulator, and the wing-shaped portion is mounted in accordance with the groove when the wing-shaped portion is mounted on the protection plate mounting portion of the upper insulator. The method for manufacturing a seismic element according to claim 5, wherein: