JP7384606B2 - Lighting equipment for machine tools - Google Patents

Description

The present invention relates to a machine tool lighting device used in a machine tool.

Patent Document 1 discloses a configuration that changes the illuminance of a light emitting diode according to opening and closing of a refrigerator door.

Further, Patent Document 2 describes an interior lighting device for a vehicle interior that detects the opening and closing of a door and controls turning on and off of a light emitting body.

Japanese Patent Application Publication No. 2009-115371 Utility Model Publication No. 05-072577

Both of the configurations of Patent Documents 1 and 2 are such that the illuminance is increased when the door is opened, and the illuminance is decreased when the door is closed.

On the other hand, in a machine tool, an operator may perform work within the machine tool for maintenance or the like. When working inside a machine tool, the distance from the illumination becomes close, causing the operator to experience unpleasant glare and reduced visibility.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lighting device for a machine tool that prevents unpleasant glare and reduced visibility when performing maintenance work inside the machine tool.

A lighting device for a machine tool according to the present invention includes a lighting installed inside the machine tool, an opening/closing door detection means for detecting the opening/closing of the opening/closing door of the machine tool, and an opening/closing door detecting means for detecting the open state of the opening/closing door. and a dimming mechanism that lowers the illuminance of the illumination when detected.

In this way, in the machine tool lighting device of the present invention, the illuminance decreases when the door is opened. Therefore, when the operator opens the door and works inside the machine tool, the illuminance is automatically lowered and there is no unpleasant glare or reduction in visibility.

Note that the opening/closing door detection means may be an interlock switch. Machine tools are equipped with interlock switches for safety reasons. In this example, by using an interlock switch as the opening/closing door detection means, there is no need to newly provide a configuration for detecting opening/closing of the door.

Further, it is preferable that the light control mechanism is directly connected to the opening/closing door detection means and is not newly attached externally.

Further, the lighting device for a machine tool includes a power source for the lighting, and wiring that connects the lighting and the power source, and the dimming mechanism is connected to the wiring via the opening/closing door detection means. You can.

In this way, the machine tool lighting device achieves wiring savings by using the lighting power supply wiring. Additionally, power supplies generally have a configuration that absorbs high voltage noise. Therefore, by connecting the dimming mechanism to the wiring of the power source, a structure for absorbing high voltage noise can be shared, and there is no need to take new noise countermeasures.

Further, the light control mechanism may include a control IC for the lighting, and a power line of the wiring may be connected to the control IC via the opening/closing door detection means. By using the dimming function of the control IC, there is no need to add a new external dimming mechanism. In addition, by configuring the lighting wiring (power line) and control IC to be connected when the door is opened, wiring can be saved.

According to the present invention, it is possible to prevent unpleasant glare and deterioration of visibility when performing work in a machine tool for maintenance or the like.

FIG. 2 is a schematic diagram showing the appearance of a machine tool. FIG. 2 is a block diagram showing the main configuration of a lighting device for a machine tool. FIG. 2 is a circuit diagram showing a connection configuration of a lighting device for a machine tool. FIG. 4(A) is a diagram showing the relationship between the resistance value of the resistor 131 and the voltage at the input terminal P1, and FIG. 4(B) is a diagram showing the relationship between the voltage at the input terminal P1 and the amount of current supplied to the LED. It is. 7 is a circuit diagram showing a connection configuration of a lighting device for a machine tool according to Modification 1. FIG. FIG. 3 is a circuit diagram showing a connection configuration of a machine tool illumination device 5A according to a second modification. 13 is a circuit diagram showing a connection configuration from a PLC 51 to a control IC 134 according to modification 3. FIG.

FIG. 1 is a schematic diagram showing the appearance of a machine tool. The machine tool 1 includes a housing 70, a lighting device 10, a device main body 20, an opening/closing door 30, a stage 25, a workpiece 40, an interlock switch 12, and a front panel 50.

The housing 70 has a hollow rectangular parallelepiped shape. The housing 70 houses the lighting equipment 10, the apparatus main body 20, the stage 25, and the workpiece 40 therein. The center of the front surface of the housing 70 is open. The opening is closed by an opening/closing door 30. However, in the present invention, the shape of the casing is not limited to a rectangular parallelepiped shape.

The front panel 50 includes a display section, an operator, etc. (not shown). The front panel 50 displays the status of the machine tool and receives operations from the operator.

The apparatus main body 20 is a machine for performing processing such as drilling, grinding, or bending on the work 40 on the stage 25. The workpiece 40 is made of metal, wood, stone, resin, or the like, and is a member to be processed.

The lighting device 10 uses, for example, an LED as a light source. The lighting device 10 illuminates the inside of the casing 70, including the stage 25 and the work 40.

The interlock switch 12 is installed near the opening of the housing 70. The interlock switch 12 is an example of an opening/closing door detection means that detects opening/closing of the opening/closing door 30 of a machine tool. An actuator (not shown) is attached to the opening/closing door 30. When the door 30 is closed, the actuator is inserted into the interlock switch 12. Interlock switch 12 has a plurality of a contacts and b contacts. When the actuator is inserted into the interlock switch 12, these contacts toggle. As a result, the interlock switch 12 permits operation of the device main body 20 only when the opening/closing door 30 is closed.

FIG. 2 is a block diagram showing the main configuration of a lighting device for a machine tool. The machine tool lighting device 5 includes a power source 11, an interlock switch (opening/closing door detection means) 12, and lighting equipment 10.

The lighting device 10 includes a light source 15 and a dimming mechanism 13, and is connected to a power source 11 via an interlock switch (opening/closing door detection means) 12. The light control mechanism 13 is capable of controlling on/off of the light source 15 and changing the illumination intensity when the light source 15 is turned on (light control).

FIG. 3 is a circuit diagram showing a connection configuration of a lighting device for a machine tool. The light control mechanism 13 includes a control IC 134. The light source 15 includes a plurality of LED elements. The control IC 134 is a power IC for controlling the light source 15 and is connected to the light source 15. The control IC 134 supplies constant current to the plurality of LED elements. The wiring connecting the power supply 11 and the dimming mechanism 13 includes a signal line 102 in addition to the power supply line 101 and the ground line (GND).

The control IC 134 lowers the illuminance of the light source 15 when the signal line 102 and the power line 101 are short-circuited and the DC voltage of the power line 101 is applied to the connection terminal of the signal line 102. The dimming method may be any method such as PWM (Pulse Width Modulation) dimming, phase control dimming, or digital control dimming, but for example, the following analog dimming (voltage dimming) ) is used.

The control IC 134 includes an input terminal P1 for dimming. A pull-down resistor 131 is connected to the dimming input terminal P1. Resistor 131 is connected to a ground line (GND) via transistor 132. The interlock switch 12 is connected to the base of the transistor 132 via the signal line 102 , and the signal line 102 is short-circuited to the power supply line 101 via the interlock switch 12 . The interlock switch 12 has a b contact, which closes when the door 30 is opened and opens when the door 30 closes.

Therefore, when the door 30 is open, the b contact of the interlock switch 12 is closed, and the signal line 102 and the power line 101 are short-circuited. When the opening/closing door 30 is closed, the b contact of the interlock switch 12 is opened, and the connection between the signal line 102 and the power supply line 101 is released.

When the opening/closing door 30 opens, the b contact of the interlock switch 12 closes, and the signal line 102 is short-circuited to the power supply line 101, the DC voltage of the power supply line 101 is applied to the base of the transistor 132. Therefore, the dimming input terminal P1 is connected to the ground line (GND) via the pull-down resistor 131. As a result, the voltage at the input terminal P1 drops according to the resistance value of the resistor 131.

FIG. 4A is a diagram showing the relationship between the resistance value of the resistor 131 and the voltage at the input terminal P1. The horizontal axis of the graph is the resistance value (kΩ) of the resistor 131, and the vertical axis is the voltage (V) of the input terminal P1. As shown in FIG. 4A, when a pull-down resistor 131 is connected to the dimming input terminal P1, the voltage at the input terminal P1 drops according to the resistance value of the resistor 131.

FIG. 4(B) is a diagram showing the relationship between the voltage of the input terminal P1 and the dimming ratio. The horizontal axis of the graph is the voltage (V) of the input terminal P1, and the vertical axis is the dimming ratio (%). As shown in FIG. 4(B), the dimming ratio (%), that is, the illumination intensity, decreases in accordance with the voltage drop at the input terminal P1. In this example, the control IC 134 has the maximum illuminance (the maximum amount of supplied current) when the voltage at the input terminal P1 is 2V, and the illuminance of the light source 15 decreases as the voltage at the input terminal P1 decreases. Moreover, when the voltage of the input terminal P1 becomes less than a predetermined value, the light source 15 is turned off.

Therefore, when the door 30 is opened, the illuminance of the light source 15 decreases. When the operator opens the door 30 and performs maintenance work inside the machine tool, the illuminance is automatically lowered, so there is no unpleasant glare or reduced visibility.

Note that if lighting is not required during maintenance, the light source 15 can be turned off when the door 30 is opened by reducing the resistance value of the resistor 131 or by eliminating the resistor and grounding it. In addition, when the control IC 134 has an enable terminal, the door 30 can be opened by applying a DC voltage to the enable terminal or by grounding it to stop the function of the control IC 134 when the door 30 is opened. In such a case, the light source 15 can also be turned off.

The machine tool lighting device 5 of this embodiment uses the dimming function of the control IC 134, so there is no need to provide a new dimming mechanism. Further, when the opening/closing door 30 is opened, the wiring originally provided for power supply is connected to the dimming input terminal of the control IC 134, thereby realizing wiring saving. Further, the power supply line is generally provided with a structure that absorbs high voltage noise. Therefore, in the machine tool illumination device 5 of this embodiment, by connecting the control IC 134 to the power supply wiring, there is no need to newly take noise countermeasures for the dimming mechanism.

Note that the opening/closing door detection means may also be a sensor that detects opening/closing, a door switch, a light curtain, or the like. However, a switch such as the interlock switch 12 has a structure in which a contact is switched (an a contact or a b contact) depending on whether the door is opened or closed. The machine tool lighting device 5 of this embodiment utilizes the redundant contacts of the switch as a means for detecting opening/closing of the door, or can be configured to newly detect the opening/closing of the door by simply adding contacts to the switch. There is no need to provide one.

For industrial machines such as machine tools, it is preferable not to change the original design by adding new configurations such as sensors. The machine tool lighting device 5 of this embodiment uses an interlock switch originally provided in the machine tool, and dims light in conjunction with the opening and closing of the door without adding any new sensor or other configuration. can be done.

(Modification 1)
FIG. 5 is a diagram showing a connection configuration from the interlock switch 12 to the control IC 134 according to the first modification. Components common to those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In the first modification, a diode 135 is connected to the dimming input terminal P1 instead of the resistor 131. Diode 135 is connected to the ground line (GND) via transistor 132. Interlock switch 12 is connected to the base of transistor 132 via signal line 102 .

When the contact of the interlock switch 12 is closed and the signal line 102 is short-circuited to the power supply line 101, the dimming input terminal P1 is connected to the ground line (GND) via the diode 135. As a result, the voltage at the input terminal P1 decreases in accordance with the forward voltage drop of the diode 135.

Accordingly, in the first modification as well, when the door 30 is opened, the illuminance of the light source 15 is reduced. Therefore, when the operator opens the door 30 and performs maintenance work inside the machine tool, the illuminance is automatically lowered and no unpleasant glare or reduction in visibility occurs.

In the first modification, the forward voltage drop of the diode 135 realizes the dimming function. There is some variation in the constant current output from the control IC 134. In the first modification, a diode is used instead of a resistor to suppress variations in the degree of dimming due to variations in constant current. Diodes also have lower temperature dependence than resistors. In Modification 1, a diode is used instead of a resistor to suppress variations in the degree of dimming due to temperature dependence. In this way, in Modification 1, even if there are variations in the current of the control IC or variations in the temperature characteristics of the elements, variations in the degree of dimming can be suppressed more than when using a resistor.

Note that although two diodes 135 are connected in series in FIG. 5, the number of diodes is not limited to this example. The number of diodes may be appropriately selected depending on the forward voltage drop and the required amount of voltage drop (required degree of dimming).

Note that the resistor 131 and the diode 135 may be connected in parallel. In this case, the voltage at the input terminal P1 can be lowered using either the resistor 131 or the diode 135 as necessary.

(Modification 2)
FIG. 6 is a block diagram showing the main configuration of a machine tool lighting device 5A according to a second modification. Components common to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The machine tool lighting device 5A further includes a PLC (Programmable Logic Controller) 51. An input terminal of the PLC 51 is connected to the interlock switch 12. An output terminal of the PLC 51 is connected to the dimming mechanism 13. The connection configuration from the PLC 51 to the light control mechanism 13 is the same as the example shown in FIG. 3 or FIG. 5.

When the PLC 51 detects that the contact of the interlock switch 12 is closed, it transmits a control signal to the dimming mechanism 13. Thereby, the PLC 51 enables the light control function of the light control mechanism 13 when the door 30 is opened.

Industrial machines such as machine tools are often originally equipped with a PLC. Therefore, in the second modification as well, there is no need to newly provide a configuration for detecting opening/closing of the door.

As described above, the lighting device for a machine tool of the present invention includes at least a lighting installed inside the machine tool, an opening/closing door detection means for detecting the opening/closing of the opening/closing door of the machine tool, and an opening/closing door detecting means for detecting the opening/closing door of the machine tool. It is only necessary to include a dimming mechanism that lowers the illuminance of the illumination when an open state is detected. Therefore, as in the second modification, the illuminance may be lowered in conjunction with the open state of the door 30 by using the PLC function.

(Modification 3)
FIG. 7 is a diagram showing a connection configuration from the PLC 51 to the control IC 134 according to Modification 3. Components common to those in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted.

In modification 3, diodes 135A, 135B, and 135C are connected in series to the input terminal P1 for dimming, and connected to a ground line (GND) via a transistor 132C. A transistor 132A is connected between diode 135A and diode 135B. Further, a transistor 132B is connected between the diode 135B and the diode 135C. Transistor 132A and transistor 132B are connected to the ground line. The bases of a transistor 132A, a transistor 132B, and a transistor 132C are connected to the output terminal of the PLC 51.

The PLC 51 turns on the transistor 132A when the door 30 opens, the contacts of the interlock switch 12 close, and the signal line 102 is connected to the power supply line 101. When the transistor 132A is turned on, the voltage at the input terminal P1 decreases in accordance with the forward voltage drop of the diode 135A (dimming state 1).

On the other hand, when the PLC 51 turns off the transistor 132A and turns on the transistor 132B when the door 30 is opened, the voltage at the input terminal P1 decreases according to the forward voltage drop of both the diode 135A and the diode 135B. Therefore, the voltage at the input terminal P1 is lower than in the dimming state 1 described above. Therefore, when the transistor 132A is turned off and the transistor 132B is turned on, the illuminance is lower than in the dimming state 1 (dimming state 2).

Furthermore, when the door 30 is opened, the PLC 51 turns off the transistors 132A and 132B, and turns on the transistor 132C. It decreases depending on the voltage. Therefore, the voltage at input terminal P1 is further lower than in dimming state 2. Therefore, when the transistor 132A and the transistor 132B are turned off and the transistor 132C is turned on, the illuminance is lower than in the dimming state 2 (dimming state 3).

The operator can change the program of the PLC 51 to select whether to turn on or turn off the transistors 132A, 132B, and 132C when the door 30 is opened. Thereby, the operator can select the degree of dimming when the opening/closing door 30 is opened according to his/her preference.

The example in FIG. 7 shows an example using three stages of transistors and diodes, but it may be two stages, or by using multiple stages of transistors and diodes, the degree of dimming can be changed in more stages. You can also.

Further, if the machine tool has a vacant switch (switch that is not used), the switch may be connected to the transistor 132A, the transistor 132B, or the transistor 132C. For example, connect an empty switch to transistor 132C. If the user turns off the switch connected to the transistor 132C to keep the transistor 132C off at all times, the diode 135C will not be connected to the ground line. Can only be enabled. If the user turns on the switch and keeps the transistor 132C always on, it is possible to use any of dimming state 1, dimming state 2, and dimming state 3 by adjusting the PLC program. can.

Note that the description of this embodiment is merely an example in all respects, and does not limit the technical scope of the present invention. The technical scope of the present invention is indicated by the claims rather than the above-described embodiments. Furthermore, the technical scope of the present invention is intended to include all changes within the meaning and technical scope equivalent to the claims.

1... Machine tool 5, 5A... Machine tool lighting device 10... Lighting equipment 15... Light source 11... Power supply 12... Interlock switch (opening/closing door detection means)
13...Dimmer mechanism 134...Control IC
20...Device body 25...Stage 40...Workpiece 30...Opening/closing door 50...Front panel 51...PLC
70...Casing 101...Power line 102...Signal line 131...Resistor 132, 132A, 132B, 132C...Transistor 135, 135A, 135B, 135C...Diode

Claims (3)

A light source installed inside the machine tool,
an opening/closing door detection means for detecting opening/closing of the opening/closing door of the machine tool;
a dimming mechanism that lowers the illuminance of the light source when the open/close door detection means detects an open state of the open/close door;
a power source connected to the light control mechanism via a power line and driving the light control mechanism;
Equipped with
The opening/closing door detection means is connected between a signal line for controlling the light control mechanism and the power line, and when detecting an open state of the opening/closing door, the opening/closing door detection means detects the power line and the signal line. connect the
Lighting equipment for machine tools. The opening/closing door detection means is an interlock switch.
The lighting device for a machine tool according to claim 1. The light control mechanism includes a control IC for the light source ,
When an open state of the opening/closing door is detected, the power line is connected to the control IC via the opening/closing door detection means.
A lighting device for a machine tool according to claim 1 or 2 .

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