JP3378232B2 - Ultrasonic sensor probe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe of an ultrasonic sensor, and more particularly to a probe attached to the outside of the bottom of a container for detecting the liquid level in a liquid container. Is.

[0002]

2. Description of the Related Art Ultrasonic sensors are widely used as liquid level sensor devices because they are small and easy to handle, and their detection accuracy has been greatly improved with the recent development of digital processing technology. It is used. An ultrasonic liquid level detection device using such an ultrasonic sensor is intended to detect the liquid level position by emitting ultrasonic waves from a probe and receiving reflected waves from the liquid level. Originally, it is preferable that there is no obstacle between the probe and the liquid surface that obstructs the progress of ultrasonic waves. Therefore, when trying to detect the liquid surface in the container, It is preferable that the child is attached to the inside of the container.

However, for example, in the case of an airtight pressure vessel such as an LPG tank, it is difficult to mount the probe inside the vessel, so that the probe is mounted outside the vessel. The current situation. The probe is usually attached to the bottom surface of the container in this case. This is because if the side surface of the container is used, a plurality of probes must be arranged in the area where the height of the liquid changes, which is disadvantageous in terms of cost.

FIG. 12 is an explanatory diagram showing an example of the configuration of an ultrasonic liquid level detecting device in which the probe is attached to the outside of the bottom surface of the container as described above. In this figure, a container (LPG tank) 1 having a substantially cylindrical shape and curved surfaces formed on the top and bottom surfaces thereof 1
01 is installed in a predetermined place, and the liquid 102 (LP gas) is stored inside the container 101.

A probe 103 is attached to a central position outside the bottom surface of the container 101, and the ultrasonic wave oscillating operation and the receiving operation of the probe 103 are controlled by a controller 104. . The ultrasonic sensor is composed of the probe 103 and the controller 104.

Emission wave 105 emitted from the probe 103
Is reflected by the liquid surface 102a and becomes a reflected wave 106 and is received by the probe 103. The detection operation control circuit in the controller 104 A / D-converts the received ultrasonic signal to determine the liquid surface distance. Calculate Then, the controller 104 outputs a liquid surface distance detection signal to the tank control unit 107. The tank control unit 107 controls various devices such as valves associated with the container 101, and is connected to the management computer 108 via a telephone line. The liquid level detection signal is sent to the management computer 1 by the tank control unit 107.
08, the management computer 108 sends a control command signal to the tank controller 107 to refill the container 101 with the liquid 102 when the height of the liquid surface 102a drops below a certain level. There is.

FIG. 13 shows a conventional probe 1 shown in FIG.
It is sectional drawing which shows the structure of 03. In this figure, a head portion 110a having a diameter slightly smaller than that of the middle portion is formed at the end of the vibrator case 110 on the container 101 side.
A packing 111 made of a soft resin is attached around 10a. The vibrator 1 is placed inside the head 110a.
09 are provided. Container 101 and vibrator case 11
A grease-like transparent material 112 having an ultrasonic wave transmission characteristic substantially equal to that of the liquid 102 is interposed between 0 and 0, and a contact surface formed between the container 101 and the vibrator case 110 and the packing 111. In the interspace, the transparent material 112 is in a state of being uniformly distributed with no space.

A probe 103 having the structure shown in FIG.
Will be attached by being pressed to the container 101 side by an appropriate pressing means. FIG. 14 is an explanatory view showing an example of the pressing means (the detailed structure of the pressing means is
Japanese Patent Application No. 2000-15 already proposed by the present applicant
No. 8446. ). In this figure, a mounting member 113 is fixed to the outside of the bottom surface of the container 101, and a rotary lever 114 is rotatably mounted to the mounting member 113 via a shaft member 115. The operation knob 116 for attachment / detachment is attached to the base end 114a of the rotating lever 114.
Is attached, and the tip of the attachment / detachment operation knob 116 is in contact with the attachment member 113. Therefore, by rotating the attaching / detaching operation knob 116 clockwise or counterclockwise, the tip end portion 114b of the rotating lever 114 can be rotated counterclockwise or clockwise, and the container of the probe 103 can be rotated. It is possible to press or release the press on 101.

[0009]

Incidentally, the probe 10
In order to detect the height of the liquid surface 102a with high accuracy, the traveling directions of the emitted wave 105 and the reflected wave 106 are the liquid surface 1
It is required that the probe 103 be accurately attached to a position directly below the bottom surface portion in a vertical posture so as to be as perpendicular as possible to 02a. However, the installation method of the container 101 is as shown in FIG.
As shown in FIGS. 5 (a) and 5 (b), there are two types, a vertical type and a horizontal type. In both types, the probe 103 is attached to a portion where a curved surface is formed. Becomes It is not always easy to attach the probe 103 to such a curved surface forming portion in a state where the probe 103 is attached accurately.

Further, as described above, in the space between the contact surfaces formed between the container 101 and the vibrator case 110 and the packing 111, the grease-like permeating material 112 is evenly distributed without any gaps. The existence of an air layer that greatly affects the liquid level detection accuracy is eliminated.
However, it is not easy to evenly distribute the grease-like permeable material 112 in the curved surface forming portion without a gap.

Thus, the probe 103 is formed on the curved surface forming portion.
When mounting the
It was not easy to attach the device in a state of being perpendicular to a, and to attach the grease-like transmitting material 112 to the curved surface forming portion uniformly and without any gap. Here, in the case of the vertical placement method, since the radius of curvature of the attachment portion of the probe 103 is large, the degree of difficulty in attachment is reduced to some extent, but in the case of the horizontal placement method, Since the radius of curvature is the radius of the cylindrical portion of the container 101 and is small, the degree of difficulty is considerably large. In particular, when the container 101 is an existing one, the worker has to perform the mounting work in a narrow space, which makes it more difficult to perform the accurate mounting, and the worker has a heavy burden. The result was

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a probe of an ultrasonic sensor capable of easily and accurately performing the work of attaching it to the outside of the bottom surface of a container. .

[0013]

As a means for solving the above-mentioned problems, the invention according to claim 1 is attached to the outside of the bottom surface of a container for storing liquid, and ultrasonic waves are transmitted through the bottom surface to the liquid surface. In the probe of the ultrasonic sensor, which emits the ultrasonic wave reflected toward the liquid surface through the bottom surface of the probe, a soft resin protective case in which a cup housing is formed, and the soft resin protective case. A metal protective cup housed in the cup housing of the case, in which four claws that come into contact with the outside of the bottom surface are formed at equal intervals at the opening end, and a flat upper surface is formed from the claws. Arranged in the metal protection cup so as to be located slightly below,
A ring-shaped magnet member having a sufficient attraction force for attachment to the outside of the bottom surface portion, a minute displacement in the height direction of the hole, and a shaft of the hole in the hole of the ring-shaped magnet member. A vibrator which is mounted so that a minute rotation around the center is allowed and whose ultrasonic wave emitting / receiving surface is in contact with the outside of the bottom surface portion through a gel-like transparent sheet is arranged in the metal protective cup. A spring member that is provided to press and urge the vibrator toward the outside of the bottom surface portion.

According to a second aspect of the present invention, in the first aspect of the present invention, the soft resin protective case is formed integrally with the cup housing portion above the cup housing portion.
When the container is pressed against the outside of the bottom portion, the space formed between the outside of the bottom portion and the outside of the bottom portion has a negative pressure, and has a flange portion having an adsorption surface for adsorbing to the outside of the bottom portion. There is a feature.

According to a third aspect of the present invention, in the first or second aspect of the invention, the vibrator is a piezoelectric element that emits and receives ultrasonic waves, an element storage portion that stores the piezoelectric element, and the piezoelectric element. An element holder made of hard resin, in which a spring member mounting portion for mounting the pressing portion of the spring member is formed, and is configured.

According to a fourth aspect of the invention, in the third aspect of the invention, the element holder has a housing groove for housing a part of a lead wire connecting between the controller and the piezoelectric element, and A lead wire holding portion is formed so as to project to the side of the element housing portion, and the ring-shaped magnet member is provided on a fixing surface of a support metal fitting having a substantially same planar shape as the magnet member. Is fixed,
The support fitting has a plurality of mounting seats formed in a circumferential direction so as to project downward, and is attached to a bottom portion of the metal protective cup, and the lead wire holding portion includes the plurality of mounting seats. Of the individual mounting seats, the lead wire holding portion is rotatably disposed so as to be located between any one of a pair of mounting seats adjacent to each other, and the lead wire holding portion is disposed between one of the pair of mounting seats. By locking, the rotation of the element holder over a certain angle is restricted.

According to a fifth aspect of the present invention, in the second aspect of the invention, the collar portion has a handle portion for separating the suction surface from the outside of the bottom surface portion and releasing the negative pressure state of the space. It is characterized in that it is formed at a portion on the back side of this suction surface.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing an external configuration of a probe according to this embodiment. In this figure, the probe 1 is first provided with a soft resin protective case 2. The soft resin protective case 2 covers the outer side of the metal protective cup 3 and is formed by molding after mounting the metal protective cup 3 in the mold. The soft resin protective case 2 includes a cup housing 2a for housing the metal protective cup 3 and a dish-shaped brim 2b having a suction surface 2c that can be sucked on the outer bottom surface of the container 101. And have.

Four pawls 3a are formed at equal intervals on the open end of the metallic protection cup 3, and the pressing tongue 2d presses the open end between the pawls 3a. .
Therefore, the metal protective cup 3 is securely stored in the cup storage portion 2a without protruding from the cup storage portion 2a. Also, the suction surface 2c of the collar portion 2b
A grip portion 2e is provided on the surface opposite to the grip portion 2e. The grip portion 2e is used when pulling the grip portion 2e downward to separate the suction surface 2c that is in a suction state from the outer bottom surface portion of the container 101 from the outer bottom surface portion. Further, a cable pull-out portion 2f for pulling out the cable 4 is provided at the bottom of the cup storage portion 2a.

Inside the metal protective cup 3, a permanent magnet 5 which is a ring-shaped magnet member is arranged. The permanent magnet 5 has a flat upper surface and a lower surface, and the lower surface is firmly fixed to the fixing surface of the support fitting 6 with an adhesive material. A mounting seat 6a is formed in the lower portion of the support fitting 6, and the mounting seat 6a can be mounted on the bottom of the metal protection cup 3 by a screw member inserted from below the cup housing 2a. There is.

A vibrator 7 having an ultrasonic wave emitting / receiving surface 7a is mounted in the central hole of the permanent magnet 5. A coil spring 8 as a spring member is inserted between the vibrator 7 and the bottom of the metal protection cup 3, and the vibrator 7 is constantly urged upward, that is, toward the container 101 side. It is in a state. Then, the ultrasonic wave is emitted from the oscillator 7.
The receiving surface 7a is covered with a gel-like transparent sheet 9.
The gel-like transparent sheet 9 is formed by gel-forming the grease-like transparent material 112 described with reference to FIG. 13, and has become commercially available recently.

Next, the above-mentioned respective constituent members of FIG. 1 will be sequentially described in detail. 2A and 2B are explanatory views showing the shape of the soft resin protective case 2 in a state where the outer side of the metal protective cup 3 is covered, where FIG. 2A is a plan view, FIG. 2B is a side view, and FIG. It is a bottom view. As shown in FIG. 2 (a),
Four claw portions 3a are formed at equal intervals, that is, at intervals of 90 °, on the open end of the metal protection cup 3, and the pressing tongue piece 2d presses the open end between the claws 3a. ing. A hole 3b is formed in the bottom of the metal protection cup 3, and one end of the cable 4 inserted through the cable pull-out portion 2f projects slightly upward from the hole 3b. It should be noted that one end of the cable 4 is connected to a lead wire drawn from the vibrator 7 side, and the other end of the cable 4 (not shown) is connected to the controller (see FIG. 12) side. It is connected. Further, the screw portion of the mounting screw 13 is inserted through the bottom portions of the metal protective cup 3 and the cup housing portion 2a. The mounting screw 13 is for screwing a mounting seat 6a of the support fitting 6 to which a permanent magnet 5 described later is fixed.

The protective case 2 made of soft resin shown in FIG.
By covering the periphery of the metal protection cup 3 with the cup storage portion 2a, it is possible to achieve a rust preventive function for the metal protection cup 3, and by covering the vicinity of the opening of the metal protection cup 3 with the collar portion 2b. This is intended to exert a waterproof / dustproof function on the vibrator 7 disposed in the protective cup 3 made of plastic. Further, in this embodiment, since the suction surface 2c is formed on the collar portion 2b, the above-mentioned waterproof / dustproof function is more effectively exhibited. The suction function of the suction surface 2c is the same as when a rubber suction cup is sucked on the glass plate, and the space formed between the suction surface 2c and the outer bottom surface of the container 101 becomes a negative pressure, so that the atmospheric pressure causes This is an application of the principle that the suction surface 2c is pressed against the container 101 side. In the probe 1 configured as shown in FIG. 1, the fixing force to the outer bottom surface of the container 101 is secured mainly by the attraction force of the permanent magnet 5, but the attraction surface 2c.
This adsorption function of the is configured to provide an auxiliary fixing force.

FIG. 3 is a perspective view showing the external shape of the metal protective cup 3. As shown in this figure, the metal protection cup 3 has a substantially cup shape with an open top, and four claws 3a are formed at the open end. The width of this claw portion 3a becomes wider as it goes downward,
A gentle curve is formed between the claw portions 3a. Therefore, each claw portion 3a has sufficient strength so that it is not easily deformed or damaged even when it is pressed against the outer bottom surface portion of the container 101 with a certain strong pressing force. The metal protective cup 3 is preferably made of a magnetic material so that the magnetic path of the permanent magnet 5 can be easily formed.

FIG. 4 is a plan view of the metal protective cup 3 shown in FIG. As shown in this figure, the four claws 3a are formed at the opening ends at 90 ° intervals, that is, at equal intervals, with the center C as the center. The three mounting holes 3c formed at the bottom are holes through which a screw member for fixing the mounting seat 6a is inserted, and the hole 3b is used for pulling out one end of the cable 4 upward. It is a hole.

In the present invention, the number of the claw portions 3a is 4
Although the number is limited to a specific number, the reason for the limitation will be described. To summarize the reason why the number of the claw portions 3a is limited to four, even if the bottom surface portion of the container 101 is formed into a curved surface, the contact state of the four claw portions 3a with the outside of the bottom surface portion of the container 101 causes This is because the center position can be grasped to some extent.

For example, as shown in FIG. 15 (b), a container 101 is horizontally placed, and this horizontally placed container 10 is used.
Consider the case where a field worker attaches the probe 1 to the outer bottom surface of the probe 1. FIG. 5 shows this horizontally placed container 1.
FIG. 21 is a bottom view of 01, in which (a) shows a state where the probe 1 is properly attached, and (b) shows a state where the probe 1 is attached at an angle deviated from the regular state. . That is, in the state of FIG. 5A, the line CS1 of the probe 1 and the axis CT1 of the container 101 coincide with each other, and the four claw portions 3
Since all of a are in contact with the outside of the bottom surface of the container 101 at the same time, there is no wobbling. On the other hand, FIG.
In the state of (b), the line CS1 of the probe 1 is in the container 101.
Is deviated by an angle θ1 from the axis line CT1 and the one or two claw portions 3a are floated from the outside of the bottom surface portion of the container 101 and are in a wobbled state. The worker is shown in FIG.
Since it can be easily determined whether or not the wobbling state of (b) is present, if such wobbling state occurs, the probe 1 is turned by an appropriate angle, and the state shown in FIG. It can be in a state of not wobbling as in (a).

However, what has been described above is only the displacement of the probe 1 in the axial direction of the container 101, and there is a possibility that the probe 1 may be displaced in the circumferential direction of the container 101. That is, FIG. 6 is a side view of the container 101 placed horizontally, and FIG. 6A shows a state in which the probe 1 is properly attached (the axis CS2 of the probe 1 and the line CT2 of the container 101 coincide with each other). (B) shows a state in which the probe 1 is attached at an angle deviated from the normal state (the axis CS2 of the probe 1 deviates from the line CT2 of the container 101 by an angle θ2). ) Is shown. 6 (a) and 6 (b), the probe 1 may be in a wobbling state. Therefore, depending on the contact state of the claw portion 3a, the operator may not be able to perform the operation shown in FIG. 6 (b). It is not possible to determine that it is in a state. Therefore, the operator visually determines whether or not the state shown in FIG. 6B is reached. However, the probe 1 is placed outside the bottom of the container 101.
When fixing the probe, the most unavoidable situation is to fix the probe 1 in a wobbled state as shown in FIG. 5B, but with the four claws 3a, It is possible to reliably avoid such a situation. Therefore, although the state of FIG. 6B must be visually discriminated by the worker, the effect of the configuration in which the four claw portions 3a are provided can be said to be sufficiently large. In particular, when the probe 1 is attached to the existing container 101 or when performing maintenance, the worker is forced to work in a narrow space. Therefore, the contact state of the four claw portions 3a causes the container 101 to move. It can be said that it is a great advantage that the deviation with respect to the axial direction can be easily determined. For the above reason, in the present invention, the number of the claw portions 3a formed at equal intervals at the opening end portion of the metal protection cup 3 is limited to four. In the present embodiment, the case where the outside of the bottom surface of the container 101 to which the probe 1 is attached is formed to have a curved surface is described, but even if it is formed to have a planar shape, it is particularly inconvenient. Does not occur. Therefore, the outside of the bottom surface of the container 101, which is the attachment point of the probe 1, may be formed into a curved surface or a flat surface.

FIGS. 7A and 7B are perspective views showing the outer shapes of the permanent magnet 5 and the support fitting 6, where FIG. 7A shows a state in which the upper surface of the permanent magnet 5 is directed upward, and FIG. The state where the back surface is directed upward is shown. The permanent magnet 5 is the probe 1.
It has an adsorbing force sufficient to firmly fix the whole to the outside of the bottom surface of the container 101, and is formed of, for example, sintered ferrite. As described above, the lower surface of the permanent magnet 5 and the upper surface (that is, the fixing surface) of the support fitting 6 are firmly fixed by the adhesive material, and the both are integrated.

Holes 5a and 6c are formed in the permanent magnet 5 and the support fitting 6, respectively. The outer diameters of the permanent magnet 5 and the support fitting 6 are the same, but this hole 6c
Is slightly larger than the hole 5a. Further, three mounting seats 6a are formed on the support fitting 6 by cutting and raising from the inner circumference toward the outer circumference, and each mounting seat 6a is formed.
A screw hole 6b is formed in the. A tongue piece 6d is formed on the back surface of one of the three mounting seats 6a by cutting and raising from the outer peripheral side toward the inner peripheral side.

FIG. 8 is an explanatory view showing the structure and shape of the vibrator 7, where (a) is an external perspective view, (b) is a longitudinal sectional view, and FIG.
(C) is a side view about a part of (b). The vibrator 7 is roughly composed of a hard resin element holder 10 and
It is composed of a piezoelectric element 11 and a thermistor 14 housed in the element holder 10.

The element holder 10 has a substantially cylindrical body 1
0a and the collar portion 10 formed below the main body portion 10a.
b and a lead wire holding portion 10c formed so as to project laterally from the lower surface of the collar portion 10b. The outer diameter of the main body 10a is such that the main body 10a has a hole 5a in the permanent magnet 5.
The inner diameter of the hole 5a is slightly smaller than that of the hole 5a so that the outer diameter of the collar 10b is restricted so that the insertion of the collar 10b into the hole 5a is restricted. It is slightly larger than

A wall portion 10d is formed inside the lower portion of the main body portion 10a, and the coil spring 8 is provided inside the wall portion 10d.
The spring mounting portion 10e is formed so that one end of the spring mounting portion 10e is mounted. The piezoelectric element 11 is provided above the spring mounting portion 10e.
Is formed, and the piezoelectric element 11 is housed in the housing. A storage portion for storing the thermistor 14 is formed on the side of the piezoelectric element storage portion, and the thermistor 14 is stored in this storage portion. A resin layer 12 is laminated on the upper surface of the piezoelectric element 11 in order to improve ultrasonic emission characteristics and reception characteristics. The resin layer 12 is obtained by molding, for example, an epoxy resin together with the element holder 10 and then polishing the surface flat, whereby the ultrasonic wave emitting / receiving surface 7a is formed.

A lead wire 4a is connected to the piezoelectric element 11 and the thermistor 14. Then, the lead wire holding unit 1
0c has a plurality of storage grooves 10f formed therein, and the lead wires 4a are stored in the storage grooves 10f.
The connection state of the lead wire 4a and the shape of the storage groove 10f are not shown in detail because they are not important features of the present invention, but the lead wire 4a pulled out from the piezoelectric element 11 and the thermistor 14 side is not shown. The terminal and the lead wire 4 pulled out from the cable 4 side passing through the cable pulling portion 2f
The terminal a is connected to the end of the lead wire holding portion 10c by soldering or a crimping sleeve. Therefore, in order to accommodate the connecting portion between the terminals which is thicker than the normal lead wire 4a portion, in practice, the storage groove 1
A groove portion thicker than the other portions is formed in the middle portion of 0f. Then, the resin is injected and solidified into the storage groove 10f in a state where the lead wire 4a and the connecting portions of the terminals thereof are stored, so that the lead wire is reliably held and protected in the storage groove 10f. It has become.

FIG. 9 is a bottom view showing a state where the vibrator 7 is attached to the assembly of the permanent magnet 5 and the support fitting 6, and is a view taken along the line IX-IX in FIG. In this figure, the main body portion 10a of the element holder 10 is in a state of being inserted into the hole 5a of the permanent magnet 5, and the element holder 10 is small in the direction perpendicular to the paper surface (the height direction of the hole 5a). Displacement is possible. However, when the displacement from the front side to the other side of the paper surface exceeds a certain level, the collar portion 10b having a diameter larger than the hole 5a functions as a stopper and is restrained.

The element holder 10 is also rotatable on a plane parallel to the paper surface. Here, the lead wire holding portion 10c is located between the pair of adjacent mounting seats 6a, and the rotation of the element holder 10 beyond a certain angle is
Since the side surface of the lead wire holding portion 10c hits the left and right mounting seats 6a, it is restrained. Therefore, the vibrating range of the vibrator 7 is a range (about 85 degrees) until the side surface of the lead wire holding portion 10c hits the mounting seats 6a on both sides. When the probe 1 is attached, the range in which the vibrator 7 actually rotates is usually about 2 to 3 degrees, but by mechanically restraining the rotation of a certain angle or more in this way. It is possible to prevent the occurrence of an accident such as the lead wire 4a being broken due to the operator's carelessness causing the element holder 10 to pivot significantly. Moreover, the function of mechanically restraining the rotation of a predetermined angle or more is realized only by the members having the originally different functions, that is, the lead wire holding portion 10c and the mounting seat 6a, without using a dedicated member. ing. The lead wire 4a drawn out from the lead wire holding portion 10c passes between the tongue piece 6d and the mounting seat 6a, and the cable lead-out portion 2
It extends to the f side. That is, the plurality of lead wires 4a are provided in the narrow passage formed between the opposing surfaces of the tongue piece 6d and the mounting seat 6a.
Even if the lead wire holding portion 10c is rotated, it is possible to prevent the lead wires from being significantly disturbed by the passage.

The gel transparent sheet 9 is, as described above,
The grease-like transparent material 112 in FIG. 13 is formed into a gel. The original plate of the gel-like transparent sheet 9 is
It has a large area of a square or a rectangle, and by cutting this original plate, it is possible to obtain a square gel-like transparent sheet 9 as shown in FIG. Since the ultrasonic wave emitting / receiving surface 7a has a circular shape, at first glance, it seems preferable that the gel-like transparent sheet 9 also has a circular shape. Yield deteriorates. Further, in the case where it is necessary to peel off the gel-like transparent sheet 9 once placed on the ultrasonic wave emitting / receiving surface 7a during the mounting work, if the square shape makes it possible to easily pinch the corner portion. In the case of a circular shape, there is no easy place to pinch. For this reason, in the present embodiment, the gel transparent sheet 9 has a square shape.

In the past, the grease-like transparent material 11 was used.
2 was used, and it was difficult to uniformly distribute the transparent material 112 in the curved surface forming portion without a gap. Therefore, it is necessary for an operator who has some experience to perform the work of attaching the probe. There was a problem. However, in the present invention, since it is premised that the gel-like transparent sheet 9 is used, such a problem will be eliminated. Therefore, it is possible to always provide the probe 1 of constant quality regardless of the degree of skill of the worker.

Next, the operation of mounting the probe 1 of the present embodiment configured as described above on the outside of the bottom surface of the container 101 formed in the curved surface will be described with reference to FIGS. 10 and 11. . First, the worker, as shown in FIG.
The probe 1 is positioned directly below the center of the container 101 with the suction surface 2c facing upward. At this time, the worker puts the gel transmission sheet 9 prepared in advance on the ultrasonic wave emitting / receiving surface 7a as shown in the figure. In addition, the operator should have some idea of the attachment position of the probe 1, that is, the center position of the bottom surface of the container 101, by visual inspection or the like.

Incidentally, if a little explanation is added to the structure of the probe 1 shown in FIG. 10, the assembly of the permanent magnet 5 and the support metal 6 is attached to the bottom of the metal protective cup 3 by the mounting screw 13. The upper surface of the permanent magnet 5 is positioned below the top portion of the claw portion 3a by a minute distance h in the state of being fixed to. Therefore, 4 described above in FIG.
The permanent magnets 5 do not impede the function of the individual claw portions 3a. (If the upper surface of the permanent magnets 5 is located above the top of the claw portions 3a, it goes without saying that the claw portions 3a are located.
There is no meaning in forming. ). The vibrator 7 is constantly urged upward by the coil spring 8, that is, toward the container 101 side, and the ultrasonic wave emission / reception surface 7 a projects upward from the upper surface of the permanent magnet 5.

Now, after the operator has made a registration about the mounting position, the operator pushes the probe 1 at the registered position as shown in FIG. At this time, the suction surface 2c near the peripheral edge of the dish-shaped collar portion 2b first contacts the outside of the bottom surface portion of the container 101, but the worker still presses the probe 1 toward the container 101 side. Then,
In the space 15 formed between the outside of the bottom surface of the container 101 and the adsorption surface 2c, a part of the existing air is discharged to the outside, so that the pressure becomes lower than the atmospheric pressure, that is, a negative pressure. Therefore, the outer surface of the protective case 2 made of soft resin is not affected by the atmospheric pressure.
As a result, the suction surface 2c is sucked to the outside of the bottom surface of the container 101 by the suction function described above.

When the worker further brings the probe 1 closer to the container 101 side, the ultrasonic wave emitting / receiving surface 7a of the transducer 7 protruding from the upper surface of the permanent magnet 5 is gelled by the elastic repulsion from the coil spring 8. The outer bottom surface portion of the container 101 is contacted via the sheet-shaped transparent sheet 9, but the worker presses the probe 1 against the container 101 side against the biasing force of the coil spring 8. Then, the bottom of the metal protection cup 3 is coil spring 8
And the upper surface of the permanent magnet 5 approaches the outer bottom surface of the container 101, and the vicinity of the upper portion of the vibrator 7 which has been protruding from the upper surface of the permanent magnet 5 is sunk into the hole 5a of the permanent magnet 5. Becomes Then, finally, the claw portion 3a of the metal protective cup 3 comes into contact with the outer bottom surface portion of the container 101, and the approach of the probe 1 to the container 101 side is stopped.

In this state, the attraction force of the permanent magnet 5 to the container 101 acts, and the probe 1 is firmly fixed to the outer side of the bottom surface of the container 101 together with the attraction force of the attraction surface 2c. Becomes Then, the worker grasps the probe 1 by hand in this state and tries to move it. At this time, if the probe 1 rattles and wobbles, it means that the four claws 3a are not in contact with the outer bottom surface of the container 101 at the same time, that is, the probe. No. 1 is not attached to the center of the bottom of the container 101. In such a case, the worker manually rotates the probe 1 by a small angle as shown by the arrow (at this time, the probe 1 is moved because the suction force by the suction surface 2c is strong. If the handle portion 2e cannot be rotated in the direction of the arrow, the handle portion 2e is pinched with a finger and pulled down to release the negative pressure state in the space 15.) Then, search for an angle at which the probe 1 does not wobble without rattling,
When the hand is released at that position, the work of attaching the probe 1 to the container 101 is completed.

The above-mentioned mounting work is performed by the worker in the container 101.
The probe 1 is pressed against the outer side of the bottom surface of the to attract the probe 1, and then the probe 1 is rotated by a very small angle. Then, based on the contact state of the four claw portions 3a with the outside of the bottom surface portion of the container 101, the probe 1 can be accurately fixed to the position directly below the central portion. Further, since the gel-like permeable sheet 9 is used, there is concern about whether or not the permeable material is evenly distributed without gaps in the curved surface forming portion like the conventional probe using the grease-like permeable material. You don't even have to. Therefore, anyone can easily and accurately attach the probe 1 to the outside of the bottom surface of the container 101, regardless of the number of years of experience or skill of the worker.

In the above embodiment, the suction surface 2c is formed on the soft resin protective case 2. However, the suction surface 2c is omitted and a packing portion having no suction function is formed instead. It is also possible to do so.

[0046]

As described above, according to the present invention, four claw portions are formed at equal intervals on the open end of a metal protective cup covered with a soft resin protective case, and the metal protective cup is formed. A ring-shaped magnet member is fixed inside, and the vibrator is elastically urged inside the hole of this magnet member, and the ultrasonic wave emission / reception surface of the vibrator is placed on the container via a gel-like transparent sheet. Since the structure is brought into contact with the outside of the bottom surface portion, it is possible to realize a probe of an ultrasonic sensor that can be easily and accurately attached to the outside of the bottom surface portion of the container.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an external configuration of a probe according to an embodiment of the present invention.

2A and 2B are explanatory views showing the shape of a soft resin protective case 2 in a state of covering the outer side of the metal protective cup 3 in FIG. 1, in which FIG. 2A is a plan view, FIG. c)
Is the bottom view.

FIG. 3 is a perspective view showing an external shape of a metal protection cup 3 in FIG.

FIG. 4 is a plan view of the metal protective cup 3 shown in FIG.

5A and 5B are explanatory views of the action of the claw portion 3a of the metal protection cup 3, where FIG. 5A shows a state in which the probe 1 is properly attached to the container 101, and FIG. Is shown attached.

6A and 6B are explanatory views of the action of the claw portion 3a of the metal protection cup 3, where FIG. 6A shows a state in which the probe 1 is properly attached to the container 101, and FIG. Is shown attached.

FIG. 7 is a perspective view showing external shapes of the permanent magnet 5 and the support fitting 6 in FIG.

8A and 8B are explanatory views showing the configuration and shape of the vibrator 7 in FIG. 1, in which FIG. 8A is an external perspective view, FIG.
(C) is a side view of a part of (b).

9 is a view taken along the line IX-IX in FIG.

FIG. 10 is a vertical cross-sectional view for explaining an attachment operation of the probe 1 of FIG.

FIG. 11 is a vertical cross-sectional view for explaining an attaching operation of the probe 1 of FIG.

FIG. 12 is an explanatory diagram showing a configuration example of an ultrasonic liquid level detection device in which a conventional probe is attached to the outside of the bottom surface of a container.

13 is a cross-sectional view showing the structure of the conventional probe 103 in FIG.

14 is an explanatory diagram showing an example of a pressing unit that presses the probe 103 of FIG. 13 against the container 101. FIG.

15A and 15B are explanatory views showing an example of the installation method of the container 101, in which FIG. 15A is a vertical installation method, and FIG.

[Explanation of symbols]

1 probe 2 Protective case made of soft resin 2a cup storage 2b collar part 2c Adsorption surface 2d holding tongue 2e Handle part 2f cable extension 3 Metal protection cup 3a claw 3b hole 3c mounting hole 4 cables 4a lead wire 5 permanent magnets 6 Support bracket 6a Mounting seat 6b screw hole 6c hole 6d tongue 7 oscillators 7 Ultrasonic wave emission / reception surface 8 coil spring 9 Gel transparent sheet 10 element holder 10a main body 10b collar part 10c Lead wire holder 10d wall 10e Spring storage part 10f storage groove 11 Piezoelectric element 12 Resin layer 13 Mounting screw 14 Thermistor 101 container 102 liquid 102a liquid level 103 transducer 104 controller 105 launch wave 106 reflected wave 107 Tank control unit 108 management computer 109 oscillator 110 oscillator case 110a head 111 packing 112 transparent material 113 Mounting member 114 Rotating lever 114a base end 114b tip 115 Shaft member 116 Operation knob for attachment and detachment

Front page continuation (72) Inventor Hide Takashi Kizaki 8-3-11 Shimorenjaku, Mitaka-shi, Tokyo Kasuga Electric Co., Ltd. (72) Masao Iwamoto 8-3-11 Shimorenjaku, Mitaka-shi, Tokyo Kasuga Electric Co., Ltd. (72) Inventor Fumio Kaneko 8-3-11 Shimorenjaku, Mitaka-shi, Tokyo Kasuga Electric Co., Ltd. (72) Inventor Yukio Katagishi 8-chome Shimorenjaku, Mitaka-shi, Tokyo No. 11 within Kasuga Electric Co., Ltd. (56) Reference JP-A-8-166277 (JP, A) JP-A-49-25962 (JP, A) JP-A-1-313720 (JP, A) JP-A-8 -145764 (JP, A) JP 2000-314651 (JP, A) JP 9-126868 (JP, A) JP 9-126863 (JP, A) JP 10-234734 (JP, A) JP 2001-336967 (JP, A) Actual opening Sho 50-10287 (JP, U) Actual opening Sho 59-2310 (JP, U) Actual opening Sho 61-60600 (JP, U) Actual opening Sho 63-104468 ( JP, U) Actual public Sho 61-30175 (JP, Y ) (58) investigated the field (Int.Cl. ^7, DB name) G01F 23/296 H04R 1/02 330

Claims (5)

(57) [Claims] 1. A container attached to the outside of a bottom surface of a container for storing liquid, emitting ultrasonic waves toward the liquid surface through the bottom surface, and receiving ultrasonic waves reflected by the liquid surface through the bottom surface. In the probe of the ultrasonic sensor, a soft resin protective case in which a cup housing is formed, and a soft resin protective case are housed in the cup housing.
The metal protection cup has four claws that are in contact with the outside of the bottom surface and are formed at equal intervals at the opening end, and the flat upper surface is positioned slightly below the claws. A ring-shaped magnet member that is disposed in a metal protective cup and has a sufficient attraction force for attachment to the outside of the bottom surface, and a height direction of the hole in the hole of the ring-shaped magnet member. A vibrator which is mounted so as to allow a minute displacement in the hole and a minute rotation around the axis of the hole, and the ultrasonic wave emitting / receiving surface is in contact with the outside of the bottom surface portion via a gel-like transparent sheet. And a spring member that is disposed in the metal protection cup and presses and urges the vibrator toward the outside of the bottom surface portion. 2. The protective case made of soft resin is formed integrally with the cup housing portion on the upper side of the cup housing portion, and is formed on the outside of the bottom surface portion when pressed against the outside of the bottom surface portion of the container. The ultrasonic sensor probe according to claim 1, further comprising: a collar portion having a suction surface that is sucked to the outside of the bottom surface portion when the space formed between them has a negative pressure. . 3. The vibrator includes a piezoelectric element for emitting and receiving ultrasonic waves, an element housing portion for housing the piezoelectric element, and a spring member mounting portion for mounting a pressing portion of the spring member. An element holder made of a hard resin, and an element holder comprising: a probe for an ultrasonic sensor according to claim 1 or 2. 4. The element holder has an accommodating groove for accommodating a part of a lead wire connecting between the controller and the piezoelectric element, and is formed so as to protrude laterally of the element accommodating portion. The ring-shaped magnet member is fixed to a fixing surface of a supporting metal member having a substantially same planar shape as the magnet member, and the supporting metal member is located below the supporting metal member. A plurality of mounting seats formed in the circumferential direction so as to project to the side are mounted on the bottom portion of the metal protection cup, and the lead wire holding portion is one of the plurality of mounting seats. It is rotatably disposed so as to be located between any one of a pair of adjacent mounting seats, and the lead wire holding portion is locked with any one of the pair of mounting seats, Constant angle of element holder The probe of the ultrasonic sensor according to claim 3, wherein the rotation of the probe is constrained to be rotated more than a degree. 5. The collar portion has a grip portion for separating the suction surface from the outside of the bottom surface portion and for releasing a negative pressure state of the space, which is formed at a position on the back side of the suction surface. The probe of the ultrasonic sensor according to claim 2, wherein.