JPH06188107A - Sensitivity adjuster of photoelectric sensor - Google Patents

Abstract

PURPOSE:To provide a sensitivity adjuster of a photoelectric sensor that does not damage a series of speed change gears even if a speed change gear connected to a rotary section of a single rotation-type variable resistor is rotated. CONSTITUTION:A speed change gear 14 which is rotated in linkage with a rotary section of a single rotation-type variable resistor 11 through an adjusting piece 21 can be separated from the other speed change gears including a speed change gear 13 by being moved up and down by means of a coil spring 22. When a rough adjustment is made, the speed change gear 14 which is rotated in linkage with the rotary section of the single rotation-type variable resistor 11 is rotated independently of the speed change gear 13. Therefore, even if the speed change gear 14 connected to the rotary section of the single rotation- type variable resistor 11 is rotated, a series of the speed change gears 13 and 14 are not damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensitivity adjusting device for a photoelectric sensor.

[0002]

2. Description of the Related Art The structure of a conventional photoelectric sensor sensitivity adjusting device will be described.

FIG. 4 is a sectional view of a conventional sensitivity adjusting device for a photoelectric sensor. In FIG. 4, reference numeral 1 is a single-rotation variable resistor, and reference numeral 2 is an adjusting knob for rotating a rotating portion (not shown) of the single-rotation variable resistor 1 to adjust the resistance value.
Reference numerals 3 and 4 denote speed change gears that reduce the amount of rotation of the adjusting knob 2 and transmit the reduced rotation amount to the rotating portion of the single-rotation variable resistor 1. Reference numeral 5 denotes a substrate to which the single-rotation variable resistor 1 is fixed. Reference numeral 6 denotes a cabinet that covers the single-rotation variable resistor 1, the adjustment knob 2, and the transmission gears 3 and 4, and is fixed to the substrate 5. Reference numeral 7 denotes a welding protrusion, and the cabinet 6 is fixed to the substrate 5 by ultrasonically welding the welding protrusion 7. Reference numeral 8 is a printable name plate for display. Reference numeral 9 is a retaining ring such as a C ring or an E ring for preventing the adjusting knob 2 from coming off when the adjusting knob 2 is attached to the cabinet 6, and 10 is a groove for inserting and rotating an adjusting tool when adjusting the adjusting knob 2. Is.

Generally, when the sensitivity of the photoelectric sensor is set, it is set at the midpoint between the OFF state of the incident light and the ON state of the light shielding, and when the adjusting knob 2 is rotated many times, the single rotation type variable resistor 1 The resistance value of 1 changes between Min and Max (the rotation amount of the rotating portion is less than one revolution), which enables sensitivity adjustment of the photoelectric sensor.

The operation of the conventional sensitivity adjusting device for a photoelectric sensor will be described below. In the description of the present invention, the midpoint is defined to mean the midpoint between the OFF state of the incident light and the ON state of the light shielding. .

First, when there is no significant change in the amount of light as a signal (in other words, the light-off state and the light-blocking O state).
Fine adjustment is sufficient for the sensitivity adjustment of the photoelectric sensor (when the difference in resistance value from the N state is small). In this case, turn the adjustment knob 2 for fine adjustment to adjust it.
The rotation amount of the single-rotation variable resistor 1 is significantly reduced by the transmission gears 3 and 4, and is transmitted to the rotating portion of the single-rotation variable resistor 1. By rotating the rotating portion of the single-rotation variable resistor 1 slightly, the single-rotation variable resistor is rotated. Fine adjustment is performed by changing the resistance value of 1 to the middle point.

Next, when there is a large variation in the amount of light as a signal, it is frustrating that the resistance value is changed by rotating the adjusting knob 2 for fine adjustment. In this case, in order to perform the rough adjustment, the speed change gear 4 connected to the rotating portion of the single-rotation variable resistor 1 is rotated by an adjusting tool to a resistance value of the single-rotation variable resistor 1 up to about an intermediate point. Is changed, and then the adjustment knob 2 is turned to make a fine adjustment.

[0008]

However, in the structure of the sensitivity adjusting device for the conventional photoelectric sensor as described above, the transmission gear 4 connected to the rotating portion of the single-rotation variable resistor 1 is used for adjustment. When turned, the amount of rotation on the adjusting knob 2 side increases, so the torque itself of the transmission gear 4 also increases. Therefore, there is a problem in that the gear teeth of the small transmission gears 3 and 4 that are interlocked are excessively loaded, and the transmission gears 3 and 4 are damaged.

The present invention solves the above problems and provides a sensitivity adjusting device for a photoelectric sensor which does not damage a series of transmission gears even when the transmission gear connected to the rotating portion of a single-rotation variable resistor is rotated. The purpose is to

[0010]

In order to achieve the above object, the present invention uses a coil spring to move up and down a transmission gear that rotates by being connected to a rotating portion of a single-rotation variable resistor through an adjusting piece. By doing so, it is possible to engage and disengage from the other transmission gear side.

[0011]

With this configuration, at the time of rough adjustment, the transmission gear that is connected to the rotating portion of the single-rotation variable resistor and rotates is separated from the other transmission gear side and rotates independently.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a photoelectric sensor sensitivity adjusting device of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a sensitivity adjusting device for a photoelectric sensor according to an embodiment of the present invention, FIG. 2 is a plan view of the sensitivity adjusting device for a photoelectric sensor according to an embodiment of the present invention, and FIG. FIG. 3 is a partially cutaway bottom view showing the transmission gear of the photoelectric sensor sensitivity adjusting device in the embodiment of the present invention.

In FIGS. 1 and 2, 11 is a single-rotation variable resistor, and 12 is an adjusting knob for rotating a rotating portion (not shown) of the single-rotation variable resistor 11 to adjust the resistance value. is there. Reference numerals 13 and 14 denote speed change gears that reduce the rotation amount of the adjusting knob 12 and transmit the rotation amount to the rotating portion of the single-rotation variable resistor 11. Reference numeral 15 denotes a substrate to which the single-rotation variable resistor 11 is fixed. Reference numeral 16 denotes a cabinet that covers the single-rotation variable resistor 11, the adjustment knob 12, and the transmission gears 13 and 14,
It is fixed to the substrate 15. Reference numeral 17 denotes a welding protrusion, and the cabinet 16 is fixed to the substrate 15 by ultrasonically welding the welding protrusion 17. Reference numeral 18 denotes a printable name plate for display. 19 is the adjusting knob 12 and the cabinet 16
A retaining ring such as a C-ring or an E-ring for preventing the retainer from being attached to the device 20 is a groove for inserting and rotating an adjusting tool when adjusting the adjusting knob 12. Reference numeral 21 is an adjusting piece that is combined with and connected to the speed change gear 14 to rotate. The speed change gear 14 is connected to the rotating portion of the single-rotation variable resistor 11 via the adjustment piece 21. 22 is a speed change gear 1
4 is a coil spring incorporated between the adjusting piece 21 and the adjusting piece 21 to repel the transmission gear 14 and the adjusting piece 21. 23,
Reference numeral 24 is a groove provided in the adjusting piece 21 and the transmission gear 14, respectively, for fixing the coil spring 22. Reference numeral 25 denotes a tenon provided on the transmission gear 14, and the tenon 25 is inserted into the tenon hole 26 of the adjustment piece 21 to connect the transmission gear 14 and the adjustment piece 21. Reference numeral 27 denotes a taper portion provided on the transmission gear 13. Reference numeral 28 denotes a groove provided on the head portion 29 of the transmission gear 14 for inserting and rotating an adjusting tool at the time of rough adjustment, and 30 denotes the number of rotations printed on the nameplate 18.

The operation of the sensitivity adjusting device for the photoelectric sensor in one embodiment of the present invention will be described below with reference to FIGS. 1 and 3.

First, when there is no large fluctuation in the light amount as a signal, the fine adjustment knob 12 is turned to greatly reduce the rotation amount of the fine knob 12 by the transmission gears 13 and 14, and the adjustment piece. It transmits to the rotating part of the single-rotation type variable resistor 11 connected with the transmission gear 14 via 21, and the rotating part of the single-rotation type variable resistor 11 is slightly rotated, so that the resistance value of the single-rotation type variable resistor 11 is increased. Fine adjustment is performed by changing to the middle point.

Next, when there is a large variation in the amount of light as a signal, rough adjustment must be performed. For this purpose, first, the adjusting piece 2 is attached to the rotating part of the single-turn variable resistor 11.
The head portion 29 of the transmission gear 14 connected via 1 is pushed down in the direction of arrow A to compress the coil spring 22, and the transmission gear 14 is separated from the other transmission gears including the transmission gear 13. Next, while the head 29 is being pushed down, an adjusting tool is inserted into the groove 28, and the transmission gear 14 separated from the other transmission gear side is rotated to change the resistance value of the single-rotation variable resistor 1 to approximately the midpoint. Let When the hand is released from the head 29, the compressed coil spring 22 repels to raise the transmission gear 14, and the transmission gear 14 and the transmission gear 13 side mesh again while sliding the taper portion 27 provided on the transmission gear 13. .
After that, the adjustment knob 12 is turned to perform fine adjustment.

[0018]

According to the sensitivity adjusting device of the photoelectric sensor of the present invention,
By using a coil spring to elevate and lower the speed change gear that rotates by being connected to the rotating part of the single-rotation variable resistor via the adjustment piece, it is possible to engage and disengage from the other speed change gear side.

With this configuration, at the time of rough adjustment, the transmission gear that is connected to the rotating portion of the single-rotation variable resistor and rotates is separated from the other transmission gear side and rotates independently. Even if the transmission gear connected to the rotating portion of the variable resistor is rotated, the series of transmission gears will not be damaged.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sensitivity adjusting device for a photoelectric sensor according to an embodiment of the present invention.

FIG. 2 is a plan view of a sensitivity adjusting device for a photoelectric sensor according to an embodiment of the present invention.

FIG. 3 is a partially cutaway bottom view showing a transmission gear of a photoelectric sensor sensitivity adjusting device according to an embodiment of the present invention.

FIG. 4 is a sectional view of a conventional sensitivity adjusting device for a photoelectric sensor.

[Explanation of symbols]

 11 Single-rotation Variable Resistor 12 Adjustment Knob 13 Speed Change Gear 14 Speed Change Gear 15 Board 16 Cabinet 21 Adjustment Piece 22 Coil Spring

Claims (1)

[Claims] 1. A rotation of a single-rotation variable resistor, comprising: an adjustment knob for adjusting a resistance value; and a plurality of speed change gears for reducing a rotation amount of the adjustment knob and transmitting the reduced rotation amount to a rotating portion of the single-rotation variable resistor. Is a sensitivity adjusting device for a photoelectric sensor capable of externally rotating a transmission gear that rotates by connecting to a rotating portion of a single-rotation variable resistor by rotating a transmission gear to raise or lower the other. A device for adjusting the sensitivity of a photoelectric sensor, wherein the device can be engaged with and disengaged from the transmission gear side.