JP2935490B2 - 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 that can provide stable performance for a long period of time, there is an increasing demand for a mercury-free seismic sensor in recent years due to concerns about environmental pollution at the time of disposal. 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. In the seismic element 101, an airtight container is formed by tightly fixing a bottomed cylindrical metal housing 102 and a circular plate 103 by ring projection welding or the like with each other's flanges. . A through hole is formed substantially at the center of the disk 103, and a conductive terminal pin 105 is hermetically sealed through an electrically insulating filler 104 such as glass.

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.

When the protective plate 110 is made of metal, collision of the inertial sphere 108 near the fixed portion between the upper contact member 109 and the conductive terminal pin 105 is prevented. There was a possibility that the surface was damaged or surface treatment such as plating applied to the surface of the inertial sphere was peeled off.

Further, in the structure of the seismic element 101, the wing-like portion 109A of the upper contact member 109 is sandwiched between the inertial sphere 108 and the upper insulator 111 with an impact every time vibration is received. There is a problem that the repetition of this causes deformation of the wing-like portion of the contact member, which lowers the durability performance. Therefore, the tip of the wing-like portion 109A is
It is conceivable to provide a groove at a position corresponding to the upper insulator so as not to directly contact the upper insulator 1. However, since the upper insulator 111 is only fixed and fixed between the protective plate 110 and the disc 103, If the condition is weak, the upper insulator rotates with respect to the conductive terminal pins, and the groove provided in the upper insulator and the wing-shaped part of the upper contact member may come into contact after assembly or the wing-shaped part may be twisted. There was sex. For this reason, there has been a demand for a method capable of easily and reliably positioning and fixing the upper insulator and preventing the mounting posture from being changed due to rotation or the like.

[0015]

The seismic element according to the present invention is characterized in that a container is constituted by a conductive disk and a conductive housing having a cylindrical shape with a bottom, and a hole formed substantially in the center of the disk. conductive terminal pins are passed through and fixed by an electrically insulating filler, the vessel conductive inertia ball is rollably accommodated in the container interior side of the disc is inserted through the conductive terminal pin at one end through An upper insulator having a hole and the other end having a portion in contact with the inertial sphere is fixed so as to surround the conductive terminal pin, and an end of the conductive terminal pin on the inner side of the container is substantially concentric with the conductive terminal pin as a center. An upper contact member made of a conductive material having a plurality of wing-like portions having flexible elasticity in which the contact portions are arranged radially, which is fixed together with a metal backing plate,
Corresponding to the outer peripheral part of the plate and the fitting part provided in the upper insulator .
By pinching the vicinity of the root of the wing-shaped portion of the upper contact member with the peripheral portion , the vicinity of the tip of the wing-shaped portion is always brought into contact with the inertial sphere and molded into a predetermined shape so as to be electrically connected thereto. The portion where the inertial ball of the body abuts is provided with a movement restricting portion for preventing the inertial ball from contacting the metal backing plate, so that the shape of the upper contact member can be easily and accurately molded. In addition, the inertial sphere is prevented from being injured by contacting the caul plate or the like.

Another feature is that, by attaching the shape of the backing plate to the upper insulator, the two can be prevented from rotating with each other. By preventing rotation with respect to the pin, even when the upper insulator has a structure to prevent deformation of the upper contact member, the positional relationship between the two does not change and the upper contact member is surely prevented from being deformed. It is that the endurance performance can be improved.

[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 electric insulator such as ceramic or synthetic resin is press-fitted and fixed inside the housing 2 inside the closed container. The lower insulator 6 is a leg 6
A lower contact member 7, which will be described later, is disposed in the gap formed by the leg 6A. On the upper surface of the lower insulator 6, an inclined surface 6B gradually rising concentrically from the center to the outside is formed, and the peripheral portion thereof regulates the maximum rolling position of the inertial ball 8 described later. Is provided. 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 or the like, and its planar shape is, for example, a ring type having a substantially spiral elastic portion 7B inside as shown in FIG. One end located at the center of the housing 2 has the contact portion 7A described above.
Is provided movably, and its tip protrudes upward from the insertion hole 6C, and a stopper 7C for restricting the upward movement of the contact portion is provided near the contact portion 7A.
It is widened so as to reach outside of C. 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.

The lower contact member 7 is provided with a plurality of through-holes 7D. In this embodiment, as shown in FIG. At the same time as one of the fixing portions 6A is inserted, two fixing portions 6F provided on the lower insulator 6 are inserted into the other through hole 7D. Then, the lower contact member 7 is fixed to the lower insulator 6 by widening the tip of the fixing portion 6F using an electric iron or an ultrasonic welder. A connecting portion 7E extends from an edge of the lower contact member 7. When the lower contact member 7 together with the lower insulator 6 is press-fitted into the housing 2, the connection portion 7 </ b> E is sandwiched between the inner wall of the housing 2 and the outer wall of the lower insulator 6, so that the contact pressure increases and the lower contact member 7 contacts the housing. Secure electrical connection with the member.

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. It is preferable to select a metal that has been subjected to a surface treatment such as plating with a noble metal such as gold or silver or nickel, or a solder plating made of lead and tin according to the purpose. The material and surface treatment are not limited to solid spheres having suitable conductivity.

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, which is determined by the following equation.

[0023]

(Equation 1)

In practice, the inertial sphere 8 is pressed by the upper contact member 9 described later and pushed up by the lower contact member 7, so that the inertia ball 8 is adjusted to a slightly different value.

A metal backing plate 10 is fixed to the inside end of the conductive terminal pin 5 inside the sealed container by a method such as butt welding. Here, the contact plate 10 conductively sandwiches the upper contact member 9 between the conductive plate and the conductive terminal pin 5 and sandwiches the upper insulator 11 between the contact plate 10 and the disk 3. FIG. 4 is a plan view of the upper contact member 9, FIG. 5 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 backing plate 10, and FIG. FIG. At the center of the upper contact member 9 is provided a mounting hole 9B which is penetrated in order to avoid projection of a welding portion 10A between the conductive terminal pin 5 and the backing plate 10, and is generated when the conductive terminal pin and the backing plate are welded. The effect of heat such as plastic deformation of the upper contact member is reduced, and the peripheral edge 9C of the mounting hole is sandwiched and fixed between the end face of the conductive terminal pin 5 and the backing plate 10.

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 upper insulator 11 has a shape as shown in the perspective view of FIG. 7 and is made of an electric insulator such as a synthetic resin.
It has a substantially cylindrical shape, one end of which is substantially closed, and a through-hole 11A through which the tip of the conductive terminal pin 5 is inserted is provided at the center thereof. A fitting portion 11B serving as a patch plate attaching portion having substantially the same shape is provided. By inserting the contact plate 10 into the fitting portion 11B and fixing it to the tip of the conductive terminal pin 5, as described above, the upper insulator 1 is
The bottom surface of the fitting portion 11B around the one through hole 11A is clamped, and the upper insulator is fixed. In this fitting portion 11B,
The contact plate 10 is fitted, and the vicinity of the root of the wing-like portion 9A of the upper contact member 9 is clamped and fixed at the outer peripheral portion of the contact plate 10. The wing-shaped portion 9A is pinched and fixed and simultaneously molded into a predetermined shape by defining the shape of the portion sandwiched by the fitting portion 11B and the backing plate 10 in advance.

Around the fitting portion 11B, a movement restricting portion for preventing collision of the inertial sphere 8 near the fixed portion of the upper contact member 9 and the contact plate 10 to prevent plastic deformation of the upper contact member.
Stepped portion 11C is provided at. This step 11C
Is provided with a notch at a position corresponding to the wing-shaped portion so that the wing-shaped portion 9A of the upper contact member 9 is not sandwiched between the step portion 11C and the inertial sphere 8, and in this embodiment, the notch is provided. The part 11C is divided into six parts in order to avoid a blade-like part.

The effect of the step 11C will be described. For example, the inertial sphere 8 may jump up to the position shown by the dotted line 8A in FIG. At this time, if there is no step 11C, the inertial sphere 8 exceeds the position of the dotted line 8A, collides with the vicinity of the fixed portion between the upper contact member 9 and the conductive terminal pin 5, and causes undesired deformation. As described above, when plastic deformation occurs at the base side of the wing-like portion 9A, the wing-like portion 9A
At the tip, the amount of deformation is enlarged, and the position may be largely changed. However, in this embodiment, the upper insulator 11
A step portion 11C is provided as a portion for restricting the movement of the inertial sphere so as to prevent a collision between the upper contact member 9 of the inertial sphere 8 and the vicinity of the fixed portion between the conductive terminal pin 5 and the vicinity of the fixed portion of the upper contact member 9. By arranging them so as not to cause deformation, stable characteristics can be obtained over a long period of time. Step 1
By providing 1C, the inertial sphere 8 does not come into contact with the metal backing plate 10, and the surface of the inertial sphere 8 is prevented from being damaged and surface treatment such as plating is removed.

In this embodiment, two portions 11D of the step portion 11C are projected from the fitting portion 11B. By providing the protruding portion 11D and making the fitting portion 11B non-circular, the upper insulator 11 does not rotate with respect to the backing plate 10, and is fixed to the conductive terminal pins 5 after the backing plate is fitted. The upper insulator can be prevented from rotating with respect to the conductive terminal pins.

The upper contact member 9 is located at a position corresponding to the wing-like portion 9A on the opening end face 11E of the peripheral wall of the upper insulator 11.
A groove 11F wider than the width of the wing-shaped portion 9A is provided. The purpose of this groove 11F is to protect the upper contact member 9 in the same manner as the above-described notch between the stepped portions 11C. For example, if the groove is not provided, when the inertial ball 8 comes into contact with the opening end face 11E, the blade 11F When the impact is large or the impact is not large, the wings 9A may be plastically deformed and the characteristics as the seismic element may be changed. . However, in this embodiment, by providing the groove 11F as described above,
Even when the inertial ball 8 comes into contact with the upper insulator 11, the wing-like portion 9A is located at the position of the groove 11F, so that the wing-shaped portion 9A is not directly sandwiched between the inertial ball 8 and the upper insulator 11, and is not plastically deformed. In this embodiment, each groove 11F is further provided with a positioning groove 11G for positioning at the time of assembling the upper contact member 9, which will be described later, and the blade-like portion 9A of the upper contact member is mounted on this positioning groove. By arranging, the mounting position of the upper contact member is easily and reliably determined.

The upper insulator 11 cooperates with the lower insulator 6 to regulate the maximum lateral movement position of the inertial sphere 8 at a position indicated by a dotted line 8B in FIG. Since the inertial sphere 8 is received at the position 8B by the contact portion 11E and the contact portion 6E, the inertial sphere 8 and the inner wall of the housing 2 are kept at a small distance, and there is no contact between the two members. Of course, the tip 9D of the wing-like portion 9A is also prevented from contacting the inner surface of the housing. Therefore, the seismic element 1 does not output an ON signal at the maximum amplitude, and can be reliably turned OFF even when the control target device is inclined or falls.

The provision of the groove 11F on the opening end face 11E of the upper insulator 11 allows the inertial sphere 8 to move to the maximum lateral movement position 8
Even in the position B, the wing-like portion 9A of the upper contact member does not get caught between the inertial sphere 8 and the upper insulator 11. Further, by providing a step 11C inside the upper insulator 11, the inertial sphere 8 jumps during transportation of the seismic element 1 and the inertial sphere moves even when the seismic element falls down, especially when the element is in an inverted state. The position is stopped at the position indicated by 8A in FIG. 1, and the inertial ball 8 does not hit the vicinity of the root of the blade-like portion 9A. Further, since a notch is provided at a position corresponding to the wing-shaped portion of the step portion 11C, the wing-shaped portion 9A is not sandwiched between the inertial ball 8 and the upper insulator 11 even at this position, and Deformation can be prevented. Also , a step 11 as a movement restricting portion
By providing C, the inertial sphere 8 does not come into contact with the metal backing plate 10, and the surface of the inertial sphere 8 is prevented from being damaged and surface treatment such as plating is removed.

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 of the lower insulator 6 and is in contact with the lower contact. The contact portion 7 </ b> A of the member 7 contacts the weight of the inertial sphere 8 itself and the pressing force is applied by the upper contact member 9. Here, the conductive terminal pin 5-upper contact member 9-wing-like portion 9A-
Inertia ball 8-contact portion 7A-lower contact member 7-connection portion 7E-
An electric path is formed by the path between the housing 2 and the disk 3.

When the seismic element 1 receives a horizontal acceleration of 160 gal or more at a predetermined acceleration, for example, 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 contact the lower part. The contact of the member 7 with the contact portion 7A is cut off, and the above-described 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 resting state, the inertial sphere 8 moves to the through hole 6 at the center of the inclined surface 6B.
Returning to C, the electrical path is formed by contacting the contact portion 7A again. Here, since the wing-like portion 9A always follows the movement of the inertial ball 8 and maintains the sliding contact state, the electric path can be formed quickly by the inertial ball 8 coming into contact with the contact portion 7A when returning.

Here, the attachment of parts such as the upper contact member in the portion shown in FIG. 6 of the seismic element 1 will be described. In this mounting, the upper contact member 9 is placed on the upper insulator 11 placed with the opening end face 11E side up as shown in the perspective view of FIG. At this time, the upper contact member 9 has not yet been bent and has a flat shape as shown in FIG. 4, and its tip 9D is placed on the upper insulator 11 at a position shown by a dotted line in FIG. Is placed. In this embodiment, the wing-shaped portion 9A of the upper contact member 9 is placed in alignment with the positioning groove 11G of the upper insulator 11, so that the mounting hole 9B provided at the center of the upper contact member is moved to the upper insulator. 11 on the central axis.

Next, the projection of the welding portion 10A provided at the center of the backing plate 10 is inserted into the mounting hole 9 of the upper contact member 9.
In the state adjusted to B, the backing plate 10 is fitted into the fitting portion 11B, which is a mounting plate attachment portion of the upper insulator 11, and at the same time, the vicinity of the root of the wing-like portion 9A of the upper contact member is in contact with the fitting plate 10 and the fitting portion 11B. As a result, the wing-like portion is deformed, and its cross-sectional shape is deformed to a substantially predetermined shape. Here, since the inner peripheral shape of the fitting portion 11B of the upper insulator is substantially the same as the outer shape of the backing plate 10, the upper insulator and the backing 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 backing plate 10 is welded and fixed to the leading end of the lead terminal pin 5 so as to hold the lead 1 together with the lead terminal pin 5 and the disk 3. Here, the blade-like portion 9 sandwiched between the peripheral portions of the backing plate 10
The shape of A is determined to a predetermined shape. For example, in the embodiment, the shape is set substantially perpendicular to the disk 3 as shown in FIG.

As described above, according to the manufacturing method of the present invention, the upper insulator 11, the upper contact member 9, and the contact plate 10
And the upper contact member 9 can be formed into a predetermined shape at the same time. In the present embodiment, the method has been described by way of example in which the upper contact member is placed on the upper insulator, and then the backing plate is fitted and temporarily fixed, but, for example, the backing 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. 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 contact plate 10 is fitted to the fitting portion 11B of the upper insulator, and at the same time, the contact plate 10 and the lead terminal pins are inserted. 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 base of the wing-shaped portion 9A is clamped and fixed by the backing plate 10 and the fitting portion 11B before welding, even if the peripheral portion 9C of the mounting hole 9B is slightly deformed, the tip 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 caul 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. In addition, the wing-like portion 9A has a backing plate 10 and a fitting portion 11 of the upper insulator.
B can be regarded as a cantilever type leaf spring with the portion sandwiched by B as a fixed end, so that the calculation of the spring constant 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, the lower contact member is omitted from the drawing. The member may be a normal fixed contact. For example, the lower contact member can be a contact made of a silver alloy or the like conductively fixed to the inner bottom surface of the housing.
The operation is the same as that of the above-described example except that the lower contact member does not follow the movement of the inertial sphere, 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.

In this embodiment, as a structure for preventing the backing plate and the upper insulator from rotating with respect to each other, an example in which the plane shape of the backing plate and the fitting portion of the upper insulator are made non-circular will be described. However, the anti-rotation structure is not limited to this. For example, one or a plurality of protrusions are provided on a contact surface of the backing plate with the upper insulator, and a concave portion or a convex portion is provided on a fitting portion of the upper insulator. Thus, they may not rotate with each other.

The attachment of the seismic element 1 of the present invention to a device to be controlled, such as an oil fan heater, will be described. For example, by providing predetermined mounting terminals on each of the disk and conductive terminal pins of the seismic element, direct printing is performed. The seismic element 1 can be attached to a board or the like in a normal posture, or the seismic element is put in a case or the like, and the bottom of the case is closely attached to a horizontal surface such as the bottom plate of an oil fan heater to fix the seismic element 1 You can also keep your posture. In addition to mounting the case on a horizontal surface, it is easy to change the mounting surface to, for example, 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 or an L-shape is welded to the conductive terminal pin, and this metal fitting is attached to a predetermined mounting surface. By attaching it, the seismic element can be maintained in the normal posture, or the seismic element can be suspended in a case filled with silicone oil of appropriate viscosity to automatically correct the seismic element itself. Are known means from Japanese Utility Model Application Laid-Open No. 61-141551, Japanese Utility Model Application Laid-Open No. 62-204155, Japanese Patent Application Laid-Open No. 6-50804, and the like.

[0046]

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 the peripheral parts centering on the upper insulator and the backing 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 during manufacturing is reduced. Further, the wing-like portion of the upper contact member can be regarded as a cantilever type leaf spring having a fixed end at a portion sandwiched between the backing plate and the fitting portion of the upper insulator, so that strength calculation at the time of design becomes easy. .

In addition, since the step is provided on the upper insulator so that the inertial sphere does not abut against the metal backing plate, the surface of the inertial sphere is prevented from being damaged and the surface treatment such as plating is prevented from coming off. .

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 during the maximum movement of the inertial sphere. 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.

In addition, by employing a structure that prevents the backing plate and the upper insulator from rotating with each other, the positional relationship between the groove provided in the upper insulator and the wing-like portion of the upper contact member does not change. In addition, there is no possibility that the wing-like portion of the upper contact member comes into contact after being assembled into the groove or the wing-like portion is twisted. Therefore, deformation of the upper contact member can be reliably prevented, and long-term durability is improved.

[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 of a lower contact member used in the embodiment of FIG. 1;

FIG. 4 is a plan view before assembling an upper contact member used in the embodiment of FIG. 1;

FIG. 5 is a bottom view of the disk of the embodiment of FIG. 1 in which the upper insulator and the upper contact member are fixed by a contact plate;

FIG. 6 is an enlarged longitudinal sectional view of a main part of the part shown in FIG. 5;

FIG. 7 is a perspective view of an embodiment of an upper insulator used in the seismic element of the present invention.

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

[Explanation of symbols]

 1: Seismic element 2: Housing 3: Disk 5: Conductive terminal pin 6: Lower insulator 7: Lower contact member 8: Inertial ball 9: Upper contact member 9A: Blade-like portion 9B: Mounting hole 10: Patch plate 11 : Upper insulator 11B: Fitting part (backing plate mounting part) 11C: Step part 11D: Projection part (rotation prevention structure) 11F: Groove 11G: Positioning groove

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-137928 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01H 1/00-1/16

Claims (7)

(57) [Claims] 1. A container is constituted by a conductive disk and a bottomed cylindrical conductive housing, and a conductive terminal pin is penetrated and fixed by an electrically insulating filler into a hole formed substantially in the center of the disk. A lower insulator having a slope gradually rising concentrically from the center to the outside and having a through-hole formed in the center is substantially fixed to the bottom surface of the housing; Alternatively, in the vicinity of the bottom surface, one end of a conductive lower contact member is provided so as to be electrically connected to the housing, and a contact portion as 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 insulator and the housing is stationary in the normal posture, it is positioned on the through hole at the center of the inclined surface by gravity and the lower contact Contact and electrical contact with the contact part of the member An upper insulator having a through hole through which the conductive terminal pin is inserted at one end and a portion with which the inertial ball comes into contact with the other end is provided at one end on the inner side of the container of the disk. A conductive material having a plurality of pliable elastic wing-like portions which are fixed so as to surround the pins, and in which the contact portions are disposed at the inner side end of the conductive terminal pins in a substantially concentric radial manner with the conductive terminal pins as the center. made in the upper contact member is fixed with a metal caul plate, the corresponding Te of the fitting portion provided on the outer peripheral portion and the upper insulator plate
By pinching the vicinity of the root of the wing-shaped part of the upper contact member with the peripheral part , the vicinity of the tip of the wing-shaped part is always brought into contact with the inertial sphere and molded into a predetermined shape so as to be electrically connected. In the part where the inertial sphere of the body abuts, a movement restricting part for preventing the inertial sphere from contacting the metal backing plate is provided, and the inertial sphere passes over the through hole by receiving a vibration of a predetermined value or more. It is configured to roll away on the inclined surface to break contact with the lower contact member, and the inertial sphere is pressed from the wing-like portion of the upper contact member to the contact portion of the lower contact member when stationary on the through hole. And a contact state with the wing-shaped portion is maintained even in the rolling state. 2. The caul plate is shaped so that it can not rotate with respect to each other by being attached to the upper insulator.
The seismic element according to claim 1, wherein the upper insulator is prevented from rotating with respect to the conductive terminal pin by fixing the contact plate to the conductive terminal pin. 3. The lower contact member has an elastic shape, and the contact portion is provided with an urging force to be pressed against the inertial sphere whenever the inertial sphere is located on the through hole of the insulator. The seismic element according to claim 1 or 2, wherein 4. 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 the maximum movement position. Any one of claims 1 to 3
Seismic element according to the paragraph . 5. The upper insulator is provided with a groove at a position corresponding to the wing portion, so that the inertial sphere and the upper insulator do not sandwich the wing portion.
Or seismic device according to any one of claims 4. 6. A conductive terminal pin is inserted into a substantially central hole.
Conductive disc fixed through with electrically insulating filler
And a through hole for inserting the conductive terminal pin and
An upper insulator having a structure for preventing rotation of a backing plate in a mounting portion;
Made of conductive material with a number of flexible elastic wings
A thin upper contact member and a metal contact for securing the upper contact member to the conductive terminal pin.
In a seismic element having a backing plate, the center of the planar upper contact member is
After arranging the plate and its central axis so that they coincide, the upper insulator and the caul plate are assembled to
BoardOuter circumferenceAnd upper insulatorInner circumference of the fitting part provided inWhen
The area near the root of the wing of the upper contact memberTo pinch
The wings are always in contact with and electrically connected to the inertial sphere.
Predetermined Molded into a shape,  Furthermore, fix the contact plate to the conductive terminal pin fixed to the disk.
The upper insulator and upper contact member
A method for manufacturing a seismic element, wherein the element is fixed. 7. A groove is provided at a position corresponding to the wing-like portion of the upper insulator, and the groove is provided when the wing-like portion is mounted on the backing plate mounting portion of the upper insulator. The method for manufacturing a seismic element according to claim 6, wherein the seismic element is mounted according to the following.