JPH04319220A - Adjustment of photoelectric switch - Google Patents

Abstract

PURPOSE:To make various detection distances comply with rotational angles of operation shafts for volume qadjustment by measuring detection distance for each switch after it is assebled, and by marking the volume operation shaft set at a fixed angle according to the detection distance. CONSTITUTION:An operation shaft 8 of a volume 5 of a photoelectric switch A for which a projection device 2, a light receiving device 3, and parts of various types are built in a main body case 1 is set at a fixed angle. The relationship between a rotationa angle theta and a detection distance L of the volume 5 is preliminarily determined. The assembled switch A is placed at a fixed point, and a detection distance L0 is actually measured by a distance measurement device 11 by moving a material to be detected 10, while a volume rotation angle theta0 corresponding to the distance L0 is calculated. The rotation of a security printing mechanism 12 is controlled by a motor 14 through a rotation angle controller 13, based on the angle theta0, and a mark M is printed on the terminal surface of the operation shaft 8.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a photoelectric switch.

0002

2. Description of the Related Art As shown in FIG.
and a circuit board 4 equipped with a distance detection circuit, a volume 5 for adjusting the detection distance, and an LED for display.
6 etc. are built into the main body case 1, and the cord 7 connected to the circuit board 4 is led out from the rear end of the case 1. Conventionally, the operating shaft 8 of the volume 5 can be rotated from outside the case. Adjustments were made to obtain a predetermined detection distance.

However, according to the detection distance adjusting means using the volume 5, even if the photoelectric switch has the same detection distance, if the adjustment amount of the volume 5 is different, the angle of the mark pre-marked on the outer surface of the operating shaft 8 will change depending on the switch. This was different for each user, and users often found it difficult to use.

[0004] As a means to eliminate such problems,
The rotation angle of the volume 5, that is, the rotation angle of the operating shaft 8, can be maintained at a predetermined level by laser trimming the resistor 9 for controlling the light emitting current mounted on the circuit board 4 or by replacing the resistor 9. A method is used to adjust the detection distance to a constant value.

That is, this improved adjustment method is as follows.

(1) Insert the interior parts into the main body case 1,
(2) Set the operating shaft 8 of the sensing distance adjustment volume 5 to a preset constant rotation angle, (3) Next, hold the sensing object at a certain distance from the switch until the switch output turns off using the resistor 9. Either perform laser trimming or replace the resistor 9 to adjust the resistance to an appropriate value.

According to this adjustment method, the rotation angle of the operating shaft 9 of each switch for a certain predetermined detection distance is constant, and the user can operate the switch without making mistakes.

[0008]

However, according to this adjustment method, since the adjustment process is inserted in the middle of the assembly process, there is a possibility that the detection distance may change depending on the subsequent process.

Further, the laser trimming process requires an expensive trimming device, and replacing the resistor requires time and effort, resulting in a decrease in productivity.

SUMMARY OF THE INVENTION An object of the present invention is to provide an adjustment method that allows the detection distance to correspond to the rotation angle of the volume adjustment operation shaft without the need for laser trimming or replacing the resistor.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the method for adjusting a photoelectric switch according to the present invention provides a method for adjusting a photoelectric switch according to the present invention, in which an operating shaft of a detection distance adjustment volume is exposed on the outer surface of a main body case. The adjustment method includes the step of actually measuring the detection distance with the operating shaft, which is not marked with a rotation angle display mark, set at a predetermined rotation angle, and the relationship between the volume rotation angle and the detection distance determined in advance. The configuration includes a step of determining a volume rotation angle with respect to an actually measured detection distance, and a step of attaching a mark to the operating shaft at a rotation angle phase corresponding to the determined volume rotation angle.

0012

[Operation] According to the method of the present invention, the detection distance is measured for each switch after the switch is assembled, and a mark is placed on the volume control shaft, which is set at a certain angle in advance, at an angle corresponding to the detection distance, so the detection distance is the same. The marks on the operating axes of the switches are at the same angle.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of the method of the present invention.

In the method of the present invention, the detection distance is adjusted on the assembled photoelectric switch as follows.

(1) The photoelectric switch A, in which various parts including the light emitting element 2 and the light receiving element 3 are assembled into the main body case 1, is configured so that the operating shaft 8 of the volume 5 is all at a fixed angle (for example, at the center of the adjustment angle range). , or maximum angle).

In this case, no mark has been placed on the end face of the operating shaft 8 yet.

Further, the relationship between the rotation angle θ of the volume 5 and the detection distance L is determined in advance as shown in FIG.

(2) Place the assembled photoelectric switch A at a fixed position, move the sensing object 10, and measure the distance measuring device 11.
In addition to actually measuring the detection distance L0, from the relational expression in FIG. 3, the volume rotation angle θ for this actual detection distance L0
Calculate 0.

(3) Based on the calculated rotation angle θ0, the rotation of the pad printing mechanism 12 is controlled by the motor 14 via the rotation angle control device 13.

(4) Print a mark M on the end face of the operating shaft 8.

FIG. 2 shows an example of a photoelectric switch adjusted by the method of the present invention.

For example, in a photoelectric switch with a standard detection distance of 50 cm, when the volume control shaft 8 is set at the center and the detection distance L0 is actually measured, for example, (a) 45 cm, (b) 50 cm.
There are variations such as cm, (c) 60 cm, etc.

Here, in the method of the present invention, the actual detection distance L0=5
The 0cm photoelectric switch has an operating shaft 8 as shown in (b).
A mark M is attached to the center of the photoelectric switch with an actual detection distance L0 = 45 cm, and a mark M is attached at an angle deviated by a predetermined angle toward the MIN side, as shown in (a), and the actual detection distance L0 is 45 cm.
For a switch with 0=60cm, a mark M is attached at an angle that is deviated by a predetermined angle toward the MAX side, and (a) (
For the switch c), the detection distance can be increased to 50 cm by adjusting the rotation so that the mark M on the operating shaft 8 is located in the center.
It will be adjusted to

In other words, all the switches located at the center of the mark M have a detection distance of 50 cm.

[0025]

[Effects of the Invention] As explained above, according to the method of the present invention, the following effects can be obtained.

(1) Since a means for adjusting the angle at which the mark is attached is used to adjust the detection distance to eliminate variations in the mark on the volume control axis, laser trimming is performed on the resistor for controlling the light emitting current. This eliminates the need for such expensive equipment or the troublesome replacement of resistors, resulting in reduced equipment costs and improved workability.

(2) Since mark attachment adjustment is performed after assembling the photoelectric switch, the detection distance does not change after the detection distance and volume are adjusted, which is advantageous for stabilizing quality.

(3) Marking on the operating axis is easy to automate and is effective in increasing production efficiency.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of the method of the present invention.

FIG. 2 is a plan view of a photoelectric switch with adjustable markings according to the invention;

FIG. 3 is a relationship diagram between volume rotation angle and detection distance.

FIG. 4 is a longitudinal side view showing the internal configuration of the photoelectric switch.

[Explanation of symbols]

1 Main body case 5 Detection distance adjustment volume 8
Operation axis θ, θ0 Volume rotation angle L, L0 Detection distance

Claims (1)

[Claims] Claim 1: In an adjustment method for a photoelectric switch in which an operating shaft (8) of a detection distance adjustment volume (5) is exposed on the outer surface of a main body case (1), a mark for indicating a rotation angle is attached. A step of actually measuring the detection distance with the operation shaft (8) not being rotated set at a predetermined rotation angle, and a step of measuring the volume rotation angle (θ) and detection distance (L) determined in advance.
The step of determining the volume rotation angle (θ0) with respect to the actually measured detection distance (L0) from the relationship between A method for adjusting a photoelectric switch, including an additional process.