JPH0716049Y2 - Weak point pin breakage alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a weak pin breakage alarm device using a proximity switch.

(Prior Art) A weak point pin breakage alarm device using a conventional proximity switch is
As shown in FIG. 6, a long hole 3 of a weak point pin having a weak point portion 2
A core rod 8 is inserted therein so that an upward displacement force is always applied by a spring 11, a detection piece 10 at the tip of the core rod 8 is surrounded by a cover 4, and a proximity switch 12 is attached to the cover 4. The detection surface 13 is provided so as to face the detection piece 10 of the core rod 8 on the coaxial line, and this is applied for utility model registration in Japanese Utility Model Application No. Sho 63-35199 (Actual Kaihei No. 01-139087). Is going.

(Problems to be solved by the invention) However, such a conventional weak point pin breakage alarm device is
Since the detection piece 10 of the core rod 8 and the detection surface 13 of the proximity switch 12 are in a relationship of facing each other on the coaxial line, the distance L between the detection surface 13 of the proximity switch 12 and the lead wire 16 as shown in FIG. Is limited, and the dimension of the distance L cannot be shortened. Therefore, the use points of the weak point pin breakage alarm device were limited.

Further, in the conventional weakness-hin breakage alarm device, the weakness pin 1 is broken and the core rod 8 is cut at the same time, and the detection piece 10 side of the core rod 8 is pushed toward the detection surface 13 of the proximity switch 12 by the spring 11 so as to approach. Or it is a hit structure. Therefore, if the spring 11 is not properly adjusted and the spring force is strong,
The detection piece 10 of the core rod 8 pushed by the spring 11 is a proximity switch.
The detection piece 10 collides with the detection surface 13 of 12 and is destroyed,
It may not be possible to detect the approach.

An object of the present invention is to provide a weak point pin breakage alarm device which protects the detection surface of a proximity switch while reducing the overall size.

[Means for Solving the Problem] (Means for Solving the Problem) In the weak point pin breakage alarm device of the present invention, a core rod having a detection piece at its tip is always provided by a spring in a long hole provided in the central axial direction of the weak point pin. It is inserted so that a biasing force directed in the axial direction is applied, the head including the detection piece of the core rod of this weak point pin is surrounded by a cover, and a proximity switch is provided on the side of this cover with the detection surface of the core. It is characterized in that it is mounted so as to face the extension line of the detection piece of the rod at a right angle and at a right angle.

(Operation) In the present invention, since the proximity switch faces the extension line of the moving direction of the core rod at a right angle with a certain distance, the detection surface of the proximity switch is moved by the movement of the core rod when the weak point pin is broken. Will not be destroyed. Further, since the lead wire of the proximity switch is led out from the side surface of the cover, the lead-out dimension can be shortened.

(Embodiment) The present invention will be described below with reference to each embodiment shown in FIGS. 1 to 5. Referring to FIG. 1 showing the whole of a weakness pin breakage alarm device of the present invention, a weakness pin 1 is provided with a weakness portion 2 in the middle thereof.
For example, it is used for a guide vane opening / closing mechanism of a water turbine, and when foreign matter is caught in the guide vane during the opening / closing operation of the guide vane, the foreign matter is cut off from the weak point 2 and does not harm other healthy mechanisms. It is like this.

An axial long hole 3 is provided at the center of the weak point pin 1, and the long hole 3
The pedestal 5 of the cover 4 is screwed into the opening of the. An upper end of an acrylic tubular body 6 is fixed to a lower portion of the pedestal 5, and a cover receptacle 7 for attaching and detaching the cover 4 is provided on an upper portion thereof. Further, a plastic core rod 8 is provided so as to penetrate through an acrylic tubular body 6 inserted into a long hole 3 at the center of the weak point pin 1, and the lower end thereof is locked to the bottom of the acrylic tubular body 6 by a split pin 9. A detection piece 10 made of a material that hardly or does not rust is provided at the upper end thereof. Further, the core rod 8 is always provided with a displacement force that is directed upward in the drawing by a spring 11, so that the detection piece at the time of soundness
Ten positions are regulated.

Therefore, in the present invention, the proximity switch 12 for the detection piece 10 of the core rod 8 is fixed to the side surface of the cover 4 by the nut 14 so that the detection surface 13 is perpendicular to the axial direction of the core rod 8. It is characterized by. Then, the detection surface 13 of the proximity switch 12 faces the extension line of the detection piece 10 of the core rod 8 with a certain distance, and the lead wire 16 passing through the indicator light 15 is attached to the side portion of the cover 4 according to the mounting direction of the proximity switch 12. Will be derived from.

Further, the proximity switch 12 has a control power source P-, as shown in FIG.
It is connected between N, the indicator 15 of the light emitting diode is turned on by the operation of the proximity switch 12, and the buzzer 17
The circuit is configured to ring to issue an alarm.

Next, the operation of the weak point pin breakage alarm device of the present invention constructed as described above will be described. When the weak point pin 1 in the normal use state shown in FIG. 1 breaks under the weak point portion 2, the core rod 8 is also cut and the core rod on the side having the detection piece 10 is pushed upward by the spring 5. The state at the time of breakage is shown in FIG. 3, but the detection piece 10 at the tip approaches the detection surface 13 of the proximity switch 12 by the protrusion of the core rod 8, and the proximity switch 12 disconnects the core rod 8, that is, the weak pin To detect breakage. When the proximity switch 12 is detected, the indicator lamp 15 shown in FIG. 2 is turned on and the buzzer 17 is sounded to give an alarm.

In the present invention, however, the upward movement of the core rod 8 when the weak point pin 1 is broken is performed by the spring force of the spring 11, so if the spring force is adjusted too strongly, the core rod 8 There is also a possibility that the detection piece 10 of 8 may largely pop out.

However, in the present invention, since the detection surface 13 of the proximity switch 12 faces the moving direction of the core rod 8 at a constant distance, the detection surface 13 is destroyed by the collision of the core rod 8. It never goes undetected. Proximity switch 12
Since the lead wire 16 is also led out from the side portion of the cover 4, the dimension L in the conventional FIG. 6 can be shortened.

Next, referring to FIG. 4 showing another embodiment of the present invention, a groove 18 is provided on the outer peripheral surface of the cover receiver 7, and the cover 4 having the proximity switch 12 attached thereto is attached to the cover receiver 7 through a constant gap 19. , Attach the stopper 20 so that the tip of the stopper 20 fits into the groove 18 of the cover receiver 7.

Due to the relationship between the groove 18 of the cover receiver 7 and the fastener 20, the cover 4 is attached so that the cover 4 can be freely and lightly rotated. This rotation of the cover 4 allows the attachment position of the weak point pin breakage alarm device to be selected at an optimum position without interfering with the surroundings.

Also in the other embodiment shown in FIG. 5, the cover 4 is rotated in an arbitrary direction by interposing the bearing 21 with the stopper 20 between the cover 4 to which the proximity switch 12 is attached and the cover receiver 7. This is a configuration that makes it possible. Also in this embodiment, the mounting direction of the proximity switch 12 and the lead-out direction of the lead wire 16 can be arbitrarily selected by the rotation of the cover 4, and the cover 4 can be mounted at the optimum position where it is not interfered by the surrounding structures.

[Advantages of the Invention] As described above, according to the present invention, the proximity switch is mounted so as to face the moving direction of the detection piece of the core rod at a certain distance and at a right angle. Does not destroy the detection surface of the proximity switch. Further, since the proximity switch is attached to the side surface of the cover, the lead-out position of the lead wire can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a weak point pin breakage alarm device of the present invention, FIG. 2 is an electric circuit diagram of the weak point pin breakage alarm device, and FIG. 3 is a state when the weak point pin breakage device of the present invention is broken. FIGS. 4 and 5 are sectional views showing other different embodiments of the present invention, and FIG. 6 is a sectional view showing a conventional weak point pin breakage alarm device. 1 ...... weak point pin 2 ...... weak point 3 ...... long hole 4 ...... cover 5 ...... pedestal 6 ...... acrylic cylinder 7 ...... cover receiver 8 ...... core rod 9 ...... split pin 10 ...... detection Piece 11 …… Spring 12 …… Proximity switch 13 …… Detecting surface 14 …… Nut 15 …… Indicator 16 …… Lead wire 18 …… Groove 21 …… Bearing

Claims (1)

[Scope of utility model registration request] 1. A weakness pin is provided with a core rod having a detection piece at its tip inserted into an elongated hole provided in the axial direction of the weakness pin so as to always apply a biasing force in the axial direction by a spring. The head including the detection piece of the core rod is surrounded by a cover, and the proximity switch is provided on the side of the cover so that the detection surface faces the extension line of the detection piece of the core rod at a certain distance at a right angle. Weakness pin breakage alarm device characterized by being attached to.