JP2009060665A - Machine tool with photoelectric sensor, photoelectric sensor, and remote tuning method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machine tool including a photoelectric sensor remote tuning. <P>SOLUTION: A machine tool 11 is provided with: a moving means 14 for moving a position of an object to be worked or a tool; and a photoelectric sensor 15 for detecting the position of the object to be worked or the tool, wherein the photoelectric sensor 15 includes: a detection unit which outputs an electric signal corresponding to a physical quantity indicating a change of a detection target; an analog output circuit which has a gain adjustment function and/or an offset adjustment function, amplifies and externally outputs the electric signal outputted from the detection unit under the set gain and offset; and a remote adjustment means 15d for setting the gain and offset of the output circuit on the basis of an external input signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a machine tool including a photoelectric sensor for detecting a position of a workpiece or a tool, a photoelectric sensor thereof, and a remote tuning method.

In a machine tool, a photoelectric sensor is used to detect the position of a workpiece (workpiece) or a tool (tool). The analog output type photoelectric sensor is based on a change in the amount of light received by the light receiving unit due to light shielding by a detection target (work or tool) that has entered the optical path formed between the light projecting unit and the light receiving unit. The amount of detection object intrusion into the optical path (the position of the detection object) is detected, and a gain and an offset are set in advance for the electric signal from the light receiving unit that changes linearly according to the amount of light received. It is configured to amplify and output via an analog output circuit. The relationship between the amount of light received by the photoelectric sensor and the analog output is illustrated in FIG. The maximum value OPmax and the minimum value OPmin of the analog output of the photoelectric sensor are determined in advance according to the design specifications of the output circuit (the minimum value OPmin may be zero or a negative value). The slope of the straight line is gain, and the displacement is offset.

In such a photoelectric sensor, the gain and offset in the analog output circuit are usually set so that an appropriate analog output corresponding to the output specification can be obtained by operating a volume or a switch incorporated in the sensor body. [See, for example, Patent Document 1]. It has also been proposed to adjust the amount of light emitted from the light projecting unit so that an appropriate analog output can be obtained.
JP 2002-171162 A

By the way, in the above-described photoelectric sensor, when the amount of received light changes with time due to adhesion of dirt to the optical system, or when the detection condition changes due to frequent detection of the detection object itself, the gain described above is used. It is necessary to repeatedly adjust the offset and optimize the analog output, which is very troublesome. In addition, if the photoelectric sensor is installed in an explosion-proof environment or an extreme environment, or if a person (operator) entering the installation environment itself adversely affects the installation environment, it is built into the sensor body. It is extremely difficult to directly operate a volume or switch. In addition, it is necessary to perform the adjustment exclusively while monitoring the analog output. Therefore, there is a problem that the gain adjustment function and the offset adjustment function mounted on the photoelectric sensor cannot be effectively used.

The present invention has been made in view of such circumstances, and the object thereof is to easily match the analog output output according to the amount of received light indicating the change of the detection target to the required output specification. The object is to provide a machine tool including an optical sensor having a remote automatic adjustment function (remote tuning). That is, the present invention provides a gain and / or gain in an analog output circuit so that an analog output having a required output specification can be obtained by remotely controlling a photoelectric sensor having a gain adjustment function and / or an offset adjustment function. Another object of the present invention is to provide a machine tool and a photoelectric sensor including a photoelectric sensor having a function capable of automatically adjusting an offset.

In order to achieve the above-described object, a machine tool or the like provided with a photoelectric sensor according to the present invention includes a moving means for moving the position of a workpiece or tool and a photoelectric sensor for detecting the position of the workpiece or tool. In a machine tool, the photoelectric sensor has a detection unit that outputs an electrical signal corresponding to a physical quantity indicating a change in a detection target, and a gain adjustment function and / or an offset adjustment function. An analog output circuit that amplifies the electrical signal output from the unit and outputs it externally, and remote adjustment means that sets the gain and offset of the output circuit based on the external input signal, and that remote tuning is possible It is characterized by its characteristics.

According to the photoelectric sensor and the machine tool including the photoelectric sensor having the above-described configuration, the gain adjustment function and / or just by remotely inputting an external input signal that prompts adjustment of the analog output circuit when the detection target is in a predetermined state The gain and / or offset is automatically adjusted by the offset adjustment function.

Therefore, even if it is extremely difficult to directly operate the volume or switch incorporated in the photoelectric sensor body, the gain adjustment function and offset adjustment function can be enabled simply by instructing the remote adjustment of analog output. Leverage that and make adjustments automatically.

Hereinafter, a photoelectric sensor according to an embodiment of the present invention will be described with reference to the drawings. This photoelectric sensor basically has a detection unit 41 that outputs an electrical signal corresponding to a physical quantity indicating a change in a detection target, and an electrical signal output from the detection unit 41, as schematically shown in FIG. For example, an analog output circuit 42 that outputs the output as an analog output voltage to the outside. The detection unit 41 includes, for example, a light projecting unit and a light receiving unit that receives light projected from the light projecting unit, and part of the light is blocked by an object (target) that has entered the optical path. An electric signal (current) corresponding to the amount of light received by the light receiving unit that changes according to The analog output circuit 42 includes a gain adjustment function 43 and an offset adjustment function 44, and is configured to amplify an electrical signal output from the detection unit 41 under a set gain and offset and output the amplified signal. Is done.

In addition to the basic configuration described above, the photoelectric sensor according to the present invention operates in response to an instruction from the outside to control the gain adjustment function 43 and the offset adjustment function 44 in the analog output circuit 42, respectively. Remote adjustment means 45 for setting the gain and offset of 42 is provided. Specifically, the remote adjustment means 45 takes in a trigger signal given as a remote input from the outside via the input unit 46, and uses this as a start to detect the output of the detection unit 1 or the output of the analog output circuit 42. A function 47 and a signal given from the detection unit 41 in the analog output circuit 42 so that the analog output of the analog circuit 42 satisfies a predetermined output specification according to the output value detected by the monitor function 47 A gain and an offset for amplification and output are calculated, and a calculation function 48 for controlling the gain adjustment function 43 and the offset adjustment function 44 according to the calculated gain and offset is provided. The remote adjustment means 45 having the monitor function 7 and the calculation function 48 is realized by using, for example, a microprocessor (CPU) and a program executed thereby. (Hereinafter, the analog output circuit 42, the remote adjustment unit 45, and the input unit 46 may be collectively referred to as processing units 15d, 24d, and 34d.)

The trigger signal is manually input by an operator (monitor) when the detection target by the detector 41 is in a predetermined state, or automatically as a part of the initial setting operation when the photoelectric sensor is activated. Given. Further, when the photoelectric sensor is incorporated in an industrial production line or the like, it may be automatically given from a command device that controls the industrial production line.

Incidentally, when the above-described detection target is in a predetermined state, for example, there is no target (detection target) in the detection target region of the detector 41, or the target is at a predetermined position in the detection target region. This is a state in which (detection object) is positioned, and refers to a state set when manually adjusting the analog output in a conventional general sensor device. Such a state is set, for example, by manually operating the position of the target, or in a state where the target is not supplied to the detection target region in the industrial production line.

And the adjustment of the analog output in the above-described photoelectric sensor uses, for example, a photoelectric sensor including a light projecting unit and a light receiving unit as the detection unit 41, and changes depending on a target (detection target) that has entered the optical path (detection target region). In the case of a photoelectric sensor that detects the amount of target penetration (target position) into the optical path from the amount of light received by the light receiving unit (output of the detection unit 1), this is performed as follows.

That is, in the case of a photoelectric sensor using this type of photoelectric sensor, for example, from the state where the amount of light received by the light receiving unit is maximized in the state where no target is present in the optical path (all light incident state), the light projecting unit Until the light received from the light receiving unit is blocked by the target and the amount of light received by the light receiving unit is minimized (light shielding state), the amount of light received by the light receiving unit is It changes linearly according to the intrusion amount (position). In general, an analog output signal output from the detection output (electric signal corresponding to the amount of received light) of the detection unit 41 after being amplified through the analog output circuit 42 is, for example, a current output. [4 to 20 mA] is often set, and in the case of voltage output, [1 to 5 V] is often set.

For such an analog output signal specification, the analog output signal actually output from the analog output circuit 42 is applied from the total light shielding state to the total light incident state, for example, a minimum value OPmin as shown in FIG. When the maximum value OPmax is changed, the offset of the analog output circuit 42 is adjusted so that the analog output voltage becomes the minimum value OPmin only in the light shielding state, and then the analog output in the all light incident state is adjusted. Adjustment of the analog output signal is performed by adjusting the gain of the analog output circuit 42 so that the voltage becomes the maximum value OPmax. For example, when the output characteristic indicated by the alternate long and short dash line in FIG. 5 is set, a value larger than OPmin is output when all light is blocked, and OPmax is output when all light enters, and the output range is narrow. It cannot be said that the proper settings have been made. On the other hand, the solid line in FIG. 5 exemplifies output characteristics after appropriate adjustment. The minimum value OPmin is output for the amount of light received when light is blocked, and the maximum value OPmax is output for the amount of light received when light is totally incident, so that the output range is set to be sufficiently wide.

In the prior art, the adjustment of the offset and gain is performed by adjusting each of the adjustment components (variable resistors) of the gain adjustment function 43 and the offset adjustment function 44 provided in the apparatus body while monitoring the change of the analog output signal by the operator. ) Are directly operated. Further, depending on the configuration of the analog output circuit 42, offset adjustment and gain adjustment may affect each other. Therefore, in general, until the analog output signal conforms to the output characteristics defined as the output specifications, The gain adjustment is repeated alternately.

When the analog output signal is adjusted in this way, in this apparatus, when the detection target is in a predetermined state, the above-described remote adjustment means 45 is activated by giving a trigger signal. In the above state, the output of the detection unit 41 or the output of the analog output circuit 42 is detected by the monitor unit 47 described above, and then the calculation unit 48 responds to the detected value at 47 by the monitor unit. The gain and offset to be set in the analog output circuit 42 are calculated, and the gain adjustment function 43 and the offset adjustment function 44 of the analog output circuit 42 are controlled by remote input signals, respectively. Further, in order to enable such remote adjustment (setting) of the gain and offset of the analog output circuit 42, in the photoelectric sensor, each adjustment component of the gain adjustment function 43 and the offset adjustment function 44 described above is, for example, a digital signal value. It is realized as a so-called electronic volume whose resistance value changes according to the above, a control voltage generator for a programmable amplifier, or the like.

As described above, in this photoelectric sensor, the remote adjustment means 45 is activated by giving a trigger signal when the detection target is in a predetermined state, and the analog output circuit 42 when the light receiving condition at the light receiving unit is changed. The gain and offset set in the analog output circuit 42 are automatically adjusted according to the output. Therefore, even if the photoelectric sensor is installed in an explosion-proof environment, extreme environment, etc., or even if a human (operator) entering the installation environment itself adversely affects the installation environment, the photoelectric sensor By simply inputting a trigger signal remotely, gain and offset optimization adjustment is automatically executed, and a desired analog output signal can be obtained from the photoelectric sensor. Therefore, even if the characteristics of the detection unit 41 change with time, an analog output signal having stable output characteristics can be obtained at all times, and the industrial advantage is tremendous.

The present invention is not limited to the embodiment described above. For example, when the light projecting unit of the photoelectric sensor constituting the detection unit 41 has a function capable of variably adjusting the light emission amount, the analog output circuit 42 is adjusted to adjust the light emission amount itself so that the gain in the analog output circuit 42 is insufficient You may make it supplement. In other words, the gain of the photoelectric sensor may be adjusted by adjusting the light emission amount so that the change width of the analog output signal output from the analog output circuit 42 is optimized. However, even in this case, it is necessary to adjust the offset amount with respect to the analog output signal by using the offset adjustment function 44 of the analog output circuit 42.

When tuning an analog output signal, a completely light-shielded state may not always be obtained depending on the specification form of the photoelectric sensor. Therefore, in such a case, the analog output value in the state where the amount of received light is minimum (the state where the amount of received light is slightly larger than the total light shielding state) and the analog output value in the state where the amount of received light is maximum are shown respectively. The gain and offset in the analog output circuit 42 may be adjusted so that these analog output values become the minimum output value OPmin and the maximum output value OPmax of the analog output circuit 42. By performing such tuning, it is possible to perform sensing with high resolution by making maximum use of the dynamic range of the analog output circuit 42.

Further, the input unit 46 may be configured as a trigger switch pulled out from the apparatus main body via a cable and configured to be manually operated by an operator. In addition, a timer circuit may be incorporated in the input unit 46 so that a trigger signal for instructing tuning is automatically generated at a predetermined cycle according to the state of the detection target. In short, the photoelectric sensor according to the present invention remotely applies a trigger signal when the detection target is in a predetermined state, and monitors the output of the detection unit or the output of the analog output circuit at that time, thereby preventing the analog output. A feature of automatically adjusting the gain and offset is provided, and various modifications can be made without departing from the scope of the invention.

Next, a first embodiment of the machine tool of the present invention will be described with reference to FIG. The machine tool 11 according to the first embodiment is characterized in that a processing object is processed by adding another object to the processing object using a tool. Specifically, an electrical component (not shown) is mounted on the electrical circuit board 13 using the suction nozzle 12. The machine tool 11 includes a pair of rails for conveyance 14, a set of photoelectric sensors 15 (light projecting unit, light receiving unit, processing unit), and a suction nozzle 12, and the operation thereof is a controller 16 (for example, programmable logic). -It is controlled by the controller. In order to operate the above-described remote automatic adjustment function of the photoelectric sensor 15, the controller 16 or the push button switch 17 is connected to the processing unit of the photoelectric sensor 15 disposed remotely. The light projecting unit 15a and the light receiving unit 15b of the photoelectric sensor 15 are installed at predetermined positions, and an optical path 15c is formed from the light projecting unit 15a to the light receiving unit 15b. The electric circuit board 13 that is the object to be processed is conveyed by the rail 14 to a predetermined position. When the electric circuit board 13 arrives at a predetermined position, a part of the optical path 15c is blocked by the cross-sectional area of the board 13, and the amount of light received by the light receiving unit 15b decreases. The processing unit 15 d of the photoelectric sensor 15 detects a decrease in the amount of light received by the light receiving unit 15 b and transmits a signal to the controller 16. Upon receiving this signal, the controller 16 first causes the suction nozzle 12 to suck the electronic component, then moves the suction nozzle 12 to a predetermined position on the electric circuit board 13, and places the electronic component on the surface of the electric circuit board 13. Place. By the way, this machine tool 11 can change the space | interval of the rail 14 in order to respond | correspond to the electric circuit board 13 with various width. The light projecting unit 15a and the light receiving unit 15b of the photoelectric sensor 15 are fixed to the rail 14, and when the interval between the rails 14 is changed, the interval between the light projecting unit 15a and the light receiving unit 15b is changed accordingly. When the distance between the light projecting unit 15a and the light receiving unit 15b of the photoelectric sensor 15 is reduced, the amount of light received by the light receiving unit 15b is increased. When the interval is increased, the amount of received light by the light receiving unit 15b is decreased. Need to adjust. Therefore, the controller 16 transmits a trigger signal to the processing unit 15d of the photoelectric sensor 15 to activate the aforementioned automatic gain and offset adjustment function. Alternatively, a trigger signal may be transmitted to the processing unit 15d of the photoelectric sensor 15 when the operator of the machine tool 11 presses the push button switch 17. According to the first embodiment, the relationship between the amount of light received by the photoelectric sensor 15 and the analog output signal can be optimally maintained according to the width of the electric circuit board 13 that is the object to be processed.

Next, a second embodiment of the machine tool of the present invention will be described with reference to FIG. The machine tool 21 according to the second embodiment is characterized in that a processing object is processed by adding another object to the processing object using a tool. Specifically, a film is formed on the surface of the semiconductor substrate 22 using a film formation tank (not shown). The machine tool 21 includes a film formation tank (not shown), a pair of viewing windows 23 (viewports) provided in the film formation tank, and a moving table (a figure) for moving a silicon wafer 22 as a processing target in the film formation tank. Not shown), and a set of photoelectric sensors 24, the operations of which are controlled by a controller 25. In order to operate the above-described remote automatic adjustment function of the photoelectric sensor 24, the controller 25 or the push button type switch 26 is connected to the processing unit of the photoelectric sensor 24 disposed remotely. A light projecting unit 24a and a light receiving unit 24b of the photoelectric sensor 24 are installed at predetermined positions outside the pair of viewports 23, and an optical path 24c is formed from the light projecting unit 24a to the light receiving unit 24b. The wafer 22 that is the object to be processed is transported by the moving table to a predetermined position in the film formation tank. When the wafer 22 arrives at a predetermined position, a part of the optical path is blocked by the wafer 22, and the amount of light received by the light receiving portion is reduced. The processing unit 24 d of the photoelectric sensor 24 detects a decrease in the amount of received light 24 b of the light receiving unit 24 a and transmits a signal to the controller 25. Upon receiving this signal, the controller 25 activates incidental equipment (vacuum pump, heater, etc.) (not shown) to deposit a metal thin film on the surface of the wafer 22. By the way, a metal thin film is deposited on the viewport 23 of the machine tool 21, and the light transmittance gradually decreases with each use. As a result, the amount of light received by the light receiving unit 24a is reduced, so that the relationship between the amount of received light and the output needs to be adjusted. Therefore, the controller 25 transmits a trigger signal to the processing unit 24d of the photoelectric sensor 24 to activate the automatic gain and offset adjustment function. Alternatively, a trigger signal may be transmitted to the processing unit 24d of the photoelectric sensor 24 when the operator of the machine tool 21 presses the push button switch 26. According to the second embodiment, the relationship between the amount of light received by the photoelectric sensor 24 and the analog output signal can be optimally maintained in accordance with how dirty the viewport 23 is.

Next, a third embodiment of the machine tool of the present invention will be described with reference to FIG. The machine tool 31 according to the third embodiment is characterized in that a workpiece is machined by removing a part of the workpiece using a tool. Specifically, a cutting object 32 (not shown) is drilled and cut using a cutting tool 32 (metal, synthetic resin, glass, etc.). This machine tool includes a cutting tool 32 (drill, milling cutter, cutter, etc.), a motor (not shown) for rotating the cutting tool 32, a position adjusting mechanism 33 for moving the position of the cutting tool 32, and a set of photoelectric sensors. These operations are controlled by the controller 35. In order to operate the above-described remote automatic adjustment function of the photoelectric sensor 34, the controller 35 or the push button type switch 36 is connected to the processing unit 34d of the photoelectric sensor 34 disposed remotely. The automatic chuck 37 mounted on the rotating shaft of the motor can be replaced by selecting one necessary for machining from a plurality of cutting tools 32 according to an instruction from the controller 35. For example, when a workpiece is drilled with a cutter and then cut with a cutter, the size of the tool differs between the drill and the cutter. The controller 35 needs to recognize. In order to confirm the position of the tip of each cutting tool 32, a set of photoelectric sensors 34 in which an optical path 34c is formed between the light projector 34a and the light receiver 34b is used. Prior to drilling, the controller 35 moves the tip 32a of the drill into the optical path of the photoelectric sensor 34. At this time, a part of the optical path 35c is blocked by the tip 32a of the drill, and the amount of light received by the light receiving portion 34b is reduced. The processing unit 34 d of the photoelectric sensor 34 detects a decrease in the amount of light received by the light receiving unit 34 b and transmits a signal to the controller 35. The controller 35 calculates and stores the position of the drill tip 32a in the depth direction from the decrease in the amount of received light, and then moves the drill 32 to a workpiece (not shown) to execute a drilling operation with a predetermined depth. Let Thereafter, the controller 35 changes the cutting tool 32 attached to the motor rotation shaft from the drill to the cutter, moves the cutter tip 32a to the optical path 34c of the photoelectric sensor 34, and calculates and stores the position of the cutter tip 32a. Then, the cutting work of the workpiece is executed. By the way, the cutting powder generated by the cutting process adheres to the light projecting portion 34a and the light receiving portion 34b of the photoelectric sensor 34 of the machine tool 31, and the light projection amount 34a and the light reception amount gradually decrease with each use. There is a need to adjust the relationship between quantity and output. Therefore, the controller 35 transmits a trigger signal to the processing unit 34d of the photoelectric sensor 34 to activate the automatic gain and offset adjustment function. Alternatively, the trigger signal may be transmitted to the processing unit of the photoelectric sensor 34 when the operator of the machine tool 31 presses the push button switch 36. According to the third embodiment, the relationship between the received light amount of the photoelectric sensor 34 and the analog output signal can be optimally maintained according to the degree of contamination of the light projecting unit 34a and the light receiving unit 34b. In addition to the photoelectric sensor 34 described above, another set of photoelectric sensors (not shown) is used to constantly monitor the cutting tool 32 during drilling / cutting work, and breakage of the cutting tool 32 during the work. Can also be detected. A photoelectric sensor is installed in advance so that the cutting tool 32 blocks the optical path of the photoelectric sensor at the cutting work position. Specifically, the light projecting unit and the light receiving unit of the photoelectric sensor are installed at a position where the photoelectric sensor is moved by the position adjusting mechanism 33 together with the cutting tool 32. If the cutting tool 32 is broken during the cutting operation (for example, breakage of the drill), part or all of the blocked optical path is opened, and the amount of light received by the light receiving portion of the photoelectric sensor increases. Alternatively, when the damaged portion is irregular, the light shielding amount changes with the rotation of the cutting tool 32, and the light receiving amount of the photoelectric sensor increases or decreases with time. Thereby, the breakage and breakage state of the cutting tool 32 can be known.

The present invention is not limited to the above-described three embodiments, and any machine tool capable of starting the remote automatic adjustment function of the photoelectric sensor from a remote location belongs to the technical scope of the present invention.

The principal part schematic block diagram which concerns on 1st embodiment of the machine tool of this invention. The principal part schematic block diagram which concerns on 2nd embodiment of the machine tool of this invention. The principal part schematic block diagram which concerns on 3rd embodiment of the machine tool of this invention. The principal part schematic block diagram which concerns on embodiment of the photoelectric sensor of this invention. The figure for demonstrating the tuning method in the photoelectric sensor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Machine tool 12 Adsorption nozzle 13 Electric circuit board 14 Rail 15 Photoelectric sensor 15a Light projection part 15b Light reception part 15c Processing part 15d Processing part 16 Controller 17 Pushbutton switch 21 Machine tool 22 Semiconductor substrate (wafer)
23 Viewing Window 24 Photoelectric Sensor 24a Light Emitting Unit 24b Light Receiving Unit 24c Optical Path 24d Processing Unit 25 Controller 26 Push Button Switch 31 Machine Tool 32 Cutting Tool (Drill, Cutter)
32a tip 33 position adjustment mechanism 34 photoelectric sensor 34a light projecting unit 34b light receiving unit 34c optical path 34d processing unit 35 controller 36 push button switch 37 automatic chuck 41 detection unit 42 analog output circuit 43 gain adjustment function 44 offset adjustment function 45 adjustment means ( CPU)
46 Input unit 47 Monitor function 48 Calculation function

Claims (11)

In a machine tool including a moving means for moving the position of a workpiece or tool and a photoelectric sensor for detecting the position of the workpiece or tool, the photoelectric sensor is an electrical signal corresponding to a physical quantity indicating a change in the detection target. An analog output circuit that has a gain adjustment function and / or an offset adjustment function, amplifies an electrical signal output from the detection part under a set gain and offset, and outputs the external signal, and an external input A machine tool including a photoelectric sensor, comprising: a remote adjustment unit configured to set a gain and an offset of an output circuit based on a signal, and capable of remote tuning. 2. The machine tool having a photoelectric sensor according to claim 1, wherein the remote adjustment means automatically adjusts the gain and / or offset of the analog output circuit using an external input signal as a trigger. 2. The machine tool having a photoelectric sensor according to claim 1, wherein the remote adjustment means reads the gain and / or offset values included in the external input signal and sets them in an analog circuit. 3. The machine tool having a photoelectric sensor according to claim 1, wherein the external input signal is input from a switch operable by an operator. 3. The machine tool having a photoelectric sensor according to claim 1, wherein the external input signal is input from a programmable logic controller. The machine tool with a photoelectric sensor according to claim 1, wherein the processing object is processed by adding another object to the processing object using a tool. The machine tool provided with the photoelectric sensor according to claim 6, wherein an electric component is mounted on the electric circuit board using a suction nozzle. The machine tool provided with the photoelectric sensor according to claim 6, wherein the film is formed on the surface of the semiconductor substrate using a film formation tank. The machine tool provided with the photoelectric sensor according to claim 1, wherein the processing target object is processed by removing a part of the processing target object using a tool. A detection unit that outputs an electrical signal corresponding to a physical quantity indicating a change in a detection target, and a gain adjustment function and / or an offset adjustment function that amplifies the electrical signal output from the detection unit under a set gain and offset 10. The machine tool according to claim 1, further comprising: an analog output circuit that outputs externally and a remote adjustment unit that sets a gain and an offset of the output circuit based on an external input signal. A photoelectric sensor characterized by being used. In a machine tool comprising a moving means for moving the position of a workpiece or tool and a photoelectric sensor for detecting the position of the workpiece or tool, an electrical signal relating to reception of the photoelectric sensor by transmitting a signal from a remote location A remote tuning method for a machine tool, characterized by adjusting a gain and / or an offset value of the machine tool.