JP2018036086A - Workpiece detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect whether or not a workpiece exists between a projector disposed for one of observation windows projecting outward from opposite wall surfaces of a treatment chamber and a light receiver disposed for the other of the observation windows by appropriately removing liquid deposits on the observation windows.SOLUTION: In a workpiece detector for detecting whether or not a workpiece w exists between a light projector 17a disposed for one of a pair of observation windows 11 projecting outward from opposite wall surfaces 20a and 20b of a treatment chamber 2 and a light receiver 17b disposed for the other, each of the observation windows includes an opening 11a formed on the wall surface, a cylinder 12 projecting outward from the opening, and a glass 13 closing an end of the cylinder and is provided with a groove 14 inclined from the glass toward the opening, in a lower part of the cylinder and is provided with a gas spray 19 for spraying a gas to the side of the glass in the cylinder, in an upper part of the cylinder 12.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a workpiece detection apparatus that detects the presence or absence of a workpiece in a processing chamber in a heat treatment furnace that quenches the workpiece. In particular, a pair of viewing windows provided in a protruding direction from the opposing wall surfaces of the processing chamber, a projector disposed close to one viewing window, and a light receiver disposed adjacent to the other viewing window And a workpiece detection device that detects the presence or absence of a workpiece between the projector and the light receiver, and is characterized in that the presence or absence of a workpiece can be accurately detected.

  Conventionally, a heat treatment apparatus as shown in Patent Document 1 is known as an apparatus for quenching a workpiece. And in this heat treatment apparatus, after the workpiece is heated in the heating furnace for a predetermined time, in the heat treatment furnace for quenching provided with an oil tank provided to be continuous with this heating furnace, as described above The heated workpiece is transferred, and the workpiece is immersed in an oil tank to cool the bath.

  Here, in such a heat treatment apparatus, the work was transferred to an elevator for raising and lowering provided in a heat treatment furnace for quenching, and the work was pulled up after being immersed in an oil tank by the elevator for raising and lowering. Need to be detected.

  As a device for detecting such a workpiece, a limit switch and a limit switch type detection device using an arm that presses the limit switch are known. However, in the case of the limit switch type detection device, there is a problem that the structure becomes complicated and the inside of the high-temperature heating furnace is thermally deformed to malfunction or break.

  By the way, as an open / close detection means for detecting the open / closed state of the partition door that opens and closes when a workpiece is loaded and unloaded, for example, FIG. 1 of Patent Document 2 shows a device using a photoelectric sensor. Here, in the case of the detection means using a photoelectric sensor, there is an advantage that the device structure becomes simpler than that of the limit switch type detection means, and it is not necessary to enter a high-temperature heating furnace.

  Therefore, it is conceivable to use a photoelectric sensor type detection device in order to detect the position of the workpiece in the heat treatment furnace for quenching as described above.

  Here, FIG. 11 shows a configuration of a heat treatment furnace using a photoelectric sensor type detection device. As shown in FIG. 11, observation windows 111 each having a cylindrical portion 112 closed with a transparent glass 113 are provided on opposing wall surfaces 120 a and 120 b of the housing 120 of the heat treatment furnace 100, and photoelectric sensors are provided outside the observation windows 111, respectively. The photoelectric sensor projector 117a is arranged in the vicinity of one of the observation windows 111, the photoelectric sensor 117b is arranged in the vicinity of the other observation window 111, and the work is passed through the observation window 111. w is detected. That is, the fact that the workpiece w has been transferred to the elevator 122 and that the workpiece w has been lifted from the oil tank 124 is detected by the output from the light receiver 117b by blocking the projection light emitted from the projector 117a. be able to.

  However, in the case of the heat treatment furnace for quenching as described above, since the heated workpiece w is immersed in the quenching oil 124a in the oil tank 124, a large amount of oil smoke and steam is generated, and as shown in FIG. The generated oil smoke and steam enter the cylindrical portion 112 forming the observation window 111, and even if the generation of oil smoke and steam is subsided, oil, water, etc. adhere to the corners of the glass 113 due to surface tension and accumulate. The glass 113 is clouded by the liquid deposits 200 such as oil and water accumulated on the glass 113 of the viewing window 111.

  Conventionally, in order to remove the liquid deposits 200 such as oil and water accumulated on the glass 113 of the viewing window 111 as described above, a gas is directed toward the glass 113 as shown in FIG. A method of spraying 201 is conceivable.

  However, since the inner diameter of the cylindrical portion 112 of the viewing window 111 is a small diameter of about 5 mm to 10 mm, even if the gas 201 is blown, the liquid deposit 200 such as oil or water is only scattered on the spot, and the surface tension is also reduced. The surface of the glass 113 cannot be sufficiently cleaned, the projector 117a provided in the vicinity of the one observation window 111, and the light receiver 117b provided in the vicinity of the other observation window 111. The problem that it becomes impossible to detect the presence / absence of the workpiece w properly between the two.

JP 2007-84863 A JP, 2006-33240, A

  The present invention is a pair of viewing windows provided in a projecting direction from the opposing wall surfaces of the processing chamber, a projector disposed in the vicinity of one viewing window, and disposed in the vicinity of the other viewing window. An object of the present invention is to solve the above-described problem in a workpiece detection apparatus that includes a light receiver and detects the presence or absence of a workpiece between the projector and the light receiver.

  In the workpiece detection apparatus as described above, even when liquid deposits such as oil or water adhere to the viewing window, the liquid deposits are appropriately removed to check whether or not there is a workpiece. It is an object to make it possible to accurately detect.

  In the workpiece detection apparatus according to the present invention, in order to solve the above-described problems, a pair of observation windows provided in a protruding direction outward from the opposing wall surfaces of the processing chamber, and the proximity of one observation window are arranged. A workpiece detector that detects the presence or absence of a workpiece between the projector and the light receiver. An opening formed in the wall surface of the tube, a cylindrical portion provided so as to protrude to the outside of the opening, and a transparent member that closes the end of the cylindrical portion facing the opening. A groove portion that is inclined from the transparent member toward the opening portion is provided in a lower portion of the cylindrical portion, and a gas injection portion that blows gas into the cylindrical portion side of the transparent member is provided in an upper portion of the cylindrical portion. The liquid deposit on the transparent member surface is gas. Blown, and returned to the processing chamber from the groove of the.

  According to such a structure, since the groove part inclined toward the opening part from the transparent member is provided in the lower part of the cylinder part, the liquid deposits blown off by the gas from the gas injection part are the groove part. , The surface of the transparent member is cleaned, and the projection light incident on the light receiver can be prevented from being reduced by liquid deposits.

  Here, the shape of the groove portion formed so as to be inclined from the transparent member toward the opening portion is not particularly limited in the lower portion of the cylindrical portion, but for example, a rectangular groove is formed as viewed from above the cylindrical portion. Or forming a groove having a tapered shape with a narrow transparent member side as viewed from above the cylindrical portion and a wide opening portion side, or forming a groove composed of a plurality of stripes when viewed from above the cylindrical portion. You may do it.

  In the workpiece detection apparatus according to the present invention, since the groove portion that is inclined from the transparent member toward the opening portion is provided in the lower portion of the cylindrical portion as described above, the liquid that has been blown off by the gas from the gas injection portion. The adhering material flows along the groove and returns to the processing chamber, the transparent member surface is cleaned, and the projection light incident on the light receiver can be prevented from being reduced by the liquid adhering material, thereby preventing erroneous detection of the workpiece. be able to.

It is a schematic diagram which shows the heat processing apparatus with which the workpiece | work detection apparatus which concerns on embodiment of this invention is used. It is the schematic diagram made into the cross section by the AA line of FIG. It is a schematic sectional drawing which shows the workpiece | work detection apparatus which concerns on embodiment of this invention. It is the schematic diagram seen from the BB line direction of FIG. It is the schematic diagram made into the cross section by the CC line of FIG. In the workpiece | work detection apparatus which concerns on the said embodiment, it is a schematic diagram which shows the 1st example of a change of the groove part provided in the cylinder part of a sight glass. In the workpiece | work detection apparatus which concerns on the said embodiment, it is a schematic diagram which shows the 2nd modification of the groove part provided in the cylinder part of a sight glass. In the heat processing apparatus with which the workpiece | work detection apparatus which concerns on embodiment of this invention is used, it is a schematic diagram which shows the state which immersed the workpiece | work in hardening oil. It is a schematic diagram which shows the principal part of the workpiece | work detection apparatus which concerns on embodiment of this invention, and shows the state which is spraying gas on the glass surface. It is a schematic diagram which shows the washing | cleaning apparatus with which the workpiece | work detection apparatus which concerns on embodiment of this invention is used. In a prior art example, it is a schematic diagram which shows the heat processing furnace using the workpiece | work detection apparatus. In a prior art example, it is a schematic diagram which shows the state in which oil adheres to the glass surface of the viewing window in which a photoelectric sensor is provided. In a prior art example, it is a schematic diagram which shows the state which sprays gas on liquid deposits, such as oil and water, which adhered to the glass surface of the viewing window in which a photoelectric sensor is provided.

  Hereinafter, a workpiece detection apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. In addition, the workpiece | work detection apparatus which concerns on this invention is not limited to what was shown to the following embodiment, In the range which does not change the summary of invention, it can change suitably and can implement.

  In the workpiece detection apparatus according to the embodiment of the present invention, as shown in FIGS. 1 and 2, a quenching heat treatment furnace 2 is used as a treatment chamber 2 to detect a workpiece w in the heat treatment furnace 2. It is.

  Here, in the heat treatment furnace 2 for quenching, the housing 20 is provided with an open / close door 21 for receiving the workpiece w from the heating furnace 3. Then, the open / close door 21 is opened to transfer the workpiece w heated in the heating furnace 3, and the workpiece w is transferred into the housing 20 of the heat treatment furnace 2.

  Here, the elevator 20 having a plurality of rollers 22 a is provided in the housing 20 into which the workpiece w is introduced, and the workpiece w is transferred to the elevator 22. And when the workpiece | work w is mounted in the raising / lowering elevator 22, the door 21 will be closed and the housing 20 will be sealed.

  An oil tank 24 in which quenching oil 24a is stored is provided at a lower portion of the housing 20 into which the workpiece w is introduced. And the workpiece | work w is immersed in the quenching oil 24a by dropping the said raising / lowering elevator 22 in which the workpiece | work w was mounted, and the workpiece | work w is cooled and quenched.

  Moreover, as shown in FIG.2 and FIG.3, the circular opening part 11a for comprising the observation window 11 is provided in the wall surface 20a, 20b which opposes the upper side of the housing 20 into which the workpiece | work w is introduce | transduced, The cylindrical portion 12 is provided so that the cylindrical portion 12 is fitted into the opening 11 a and protrudes to the outside of the housing 20. Generally, the inner diameter of the cylindrical portion 12 is about 5 mm to 10 mm, and the cylindrical portion 12 is configured by a small-diameter cylinder.

  Moreover, the outer side edge part on the opposite side to the opening part 11a of the cylinder part 12 is formed in the stepped shape, and the glass 13 which is a transparent member is inserted by this step part. Further, a male screw is provided on the outer periphery of the outer end portion, and a lid portion 16 provided with a female screw that meshes with the male screw is attached to the cylindrical portion 12. Then, the packing 15 is fitted between the lid portion 16 and the glass 13 and the lid portion 16 is screwed into the cylindrical portion 12 so that the inside of the viewing window 11 is shielded from the outside, so that each wall surface of the housing 20 is covered. A viewing window 11 projecting outward is provided on each of 20a and 20b. The transparent member is not limited to the glass 13 and may be a member made of a transparent material, and may be a transparent synthetic resin such as acrylic.

  Further, a projector 17a of a photoelectric sensor is attached by a holding bracket 18 in the vicinity of one viewing window 11, and a light receiver 17b of a photoelectric sensor is attached by a holding bracket 18 in the vicinity of the other viewing window 11. .

  Then, the projection light L emitted from the light projector 17a passes through the inside of the housing 20 from one observation window 11, passes through the other observation window 11, and is incident on the light receiver 17b. Whether or not the work w is at a predetermined position is detected by the output.

  Here, in the workpiece detection apparatus according to the present embodiment, an injection unit 19 for blowing gas to the glass 13 is provided at a position on the inner side of the housing 20 with respect to the glass 13 in the upper part of the cylindrical portion 12. The gas blown onto the surface of the glass 13 is controlled by controlling the opening and closing of the valve 19a of the injection unit 19. Here, as the gas, an inert gas such as nitrogen is used when the heat treatment furnace 2 for quenching is a vacuum furnace, and air is used when the furnace is an atmospheric furnace.

  Moreover, in the workpiece | work detection apparatus which concerns on this embodiment, as shown in FIGS. 3-5, the groove part 14 which inclines below toward the inner direction of the housing 20 from the glass 13 is provided in the lower part of the cylinder part 12. As shown in FIG. ing. As shown in FIG. 9, liquid deposits 30 such as oil and water blown off from the surface of the glass 13 by the gas blown toward the glass 13 flow through the groove 14 and return into the housing 20. It is configured. Further, accumulation of liquid deposits 30 such as oil and water at the corners of the glass 13 due to surface tension is reduced.

  Here, as shown in FIGS. 4 and 5, a plurality of the groove portions 14 are provided in the lower portion of the cylindrical portion 12 of the viewing window 11 from the housing 20 side. The shape of the groove portion 14 may be one groove as long as the liquid deposit 30 such as blown oil or water can easily flow, and the number of grooves is not limited.

  Further, as shown in FIG. 5, the shape of the groove portion 14 is a rectangular slit when viewed from above, or a taper that is narrower toward the housing 20 as viewed from above when the glass 13 side is narrow as shown in FIG. It may be of a shape or just having streaks as shown in FIG. Even if streaks are inserted, the surface tension is reduced, and liquid deposits 30 such as oil and water blown off from the glass 13 flow along the streaks and return into the housing 20 to clean the surface of the glass 13. it can.

  And in this workpiece | work detection apparatus, when the workpiece | work w is mounted on the raising / lowering elevator 22, the projection light L from the light projector 17a of a photoelectric sensor will be interrupted | blocked by the workpiece | work w, and it will not reach | attain the light receiver 17b. When it is detected that the projection light L is not detected by the light receiver 17b and the projection light L from the projector 17a is blocked, it is detected that the workpiece w is placed on the elevator 22.

  Next, when quenching, as shown in FIG. 8, the elevator 22 is lowered and the workpiece w is immersed in the quenching oil 24 a in the oil tank 24. At this time, when the workpiece w is immersed in the quenching oil 24a, the oil evaporates and oil smoke is generated. The adhering matter 30 may adhere, and the glass 13 may be clouded by the liquid adhering matter 30.

  Then, when the glass 13 is thus clouded by the liquid deposit 30 and the workpiece w is pulled up, the workpiece w is detected by the light projector 17a and the light receiver 17b of the photoelectric sensor, and the lift of the elevator 22 is stopped. Due to the fogging of the glass 13, the projection light L incident on the housing 20 from the light projector 17a of the photoelectric sensor decreases, and the light incident on the light receiver 17b after the projection light L passing through the housing 20 decreases. As a result, there is a possibility that erroneous detection may occur if the workpiece w is detected by the output of the light receiver 17b even though the projection light L is not blocked by the workpiece w.

  Therefore, in this embodiment, the valve 19a is controlled, and as shown in FIG. 9, the gas is injected from the injection unit 19 toward the surface of the glass 13, and the liquid deposit such as oil adhered to the glass 13. Blow away 30. And the liquid deposit 30 such as oil blown off is returned into the housing 20 through the groove portion 14 provided in the lower portion of the cylindrical portion 12, thereby removing the liquid deposit 30 such as oil, The glass 13 is cleaned.

  If it does in this way, the projection light L radiate | emitted from the light projector 17a of the photoelectric sensor through the cleaned glass 13 will be given to the light receiver 17b, and accurate detection by a photoelectric sensor can be performed. In this state, when the lift elevator 22 is raised and the projection light from the projector 17a is blocked by the workpiece w, the projection light L is not detected by the light receiver 17b, and the workpiece w is moved to a predetermined position by the lift elevator 22. Can be detected, and the lift of the elevator 22 can be stopped, and the workpiece w can be stopped at a predetermined position.

  The injection of the gas from the injection unit 19 is performed continuously or intermittently while the workpiece w is immersed in the quenching oil 24a, and the liquid deposit 30 such as oil adheres to the glass 13. It can be controlled to suppress.

  In addition, when performing a hot quench in which the quenching oil 24a in the oil tank 24 is heated, oil smoke is generated by this heating and a liquid deposit 30 such as oil adheres to the glass 13, and therefore the quenching oil 24a. It is possible to control so that the liquid 13 such as oil adheres to the glass 13 by continuously or intermittently injecting the gas from the injection unit 19 while the gas is heated.

  In the work detection apparatus according to the above-described embodiment, the case where the heat treatment furnace 2 for quenching is used as the processing chamber 2 has been described. In addition to the heat treatment furnace 2, the workpiece detection apparatus of the present invention can be applied.

  For example, as shown in FIG. 10, the processing chamber 2 can be used in a cleaning chamber 2 that cleans the workpiece w.

  In the cleaning chamber 2 shown in FIG. 10, the workpiece w is cleaned by ejecting the cleaning liquid 25 a from the shower nozzle 25 provided on the ceiling 20 c of the housing 20 for the workpiece w transferred into the housing 20.

  Here, the cleaning liquid 25 a is ejected while the workpiece w is placed on the carrier 26. The workpiece detection device detects whether or not the workpiece w is in the treatment position on the carrier 26. Water smoke or the like by the cleaning liquid 25a enters the viewing window 11, and an injection section 19 for blowing gas is provided in the viewing window 11 as shown in FIG. By controlling the opening and closing, gas is blown onto the surface of the glass 13.

  Further, a groove portion 14 that is inclined from the glass 13 toward the housing 20 is provided at a lower portion of the cylindrical portion 12. The cleaning liquid 25 a blown off by blowing gas onto the glass 13 flows through the groove 14 and returns into the housing 20. Then, by the gas injection from the injection part 19 and the groove part 14 provided in the cylinder part 12, the liquid deposit 30 such as the cleaning liquid 25a and water adhering to the glass 13 surface is blown off, and the housing together with the cleaning liquid 25a. Returning to 20, the glass 13 is cleaned, and erroneous detection of the workpiece w is prevented.

2: Processing chamber (heat treatment furnace, cleaning chamber)
3: Heating furnace 11: Viewing window 11a: Opening portion 12: Tube portion 13: Glass (transparent member)
14: Groove 15: Packing 16: Lid 17a: Projector 17b: Light receiver 18: Holding bracket 19: Injection unit 19a: Valve 20: Housing 20a: Wall 20b: Wall 20c: Ceiling 21: Opening / closing door 22: Lift elevator 22a: Roller 24: Oil tank 24a: Quenching oil 25: Shower nozzle 25a: Cleaning liquid 26: Carrier 30: Liquid deposit L: Projection light w: Workpiece

Claims (4)

A pair of sight windows provided in a protruding direction from the opposing wall surfaces of the processing chamber, a projector disposed near one of the sight windows, and a light receiver disposed near the other sight window In a workpiece detection device for detecting the presence or absence of a workpiece between the projector and the light receiver,
The viewing window includes an opening formed in the wall surface, a cylindrical portion provided so as to protrude to the outside of the opening, and a transparent member that closes an end of the cylindrical portion facing the opening. A groove portion that is inclined from the transparent member toward the opening is provided at a lower portion of the cylindrical portion, and a gas injection portion that blows gas into the cylindrical portion side of the transparent member A work detection apparatus provided at an upper portion of a cylindrical portion, wherein the liquid deposit on the surface of the transparent member is blown off with a gas and returned from the groove portion to the processing chamber.   The workpiece detection apparatus according to claim 1, wherein the groove portion is formed with a rectangular groove when viewed from above the cylinder portion.   2. The workpiece detection device according to claim 1, wherein the groove portion is formed with a tapered groove having a narrow transparent member side and a wide opening side when viewed from above the cylindrical portion. The workpiece detection apparatus according to claim 1, wherein the groove portion is formed of a plurality of stripes when viewed from above the cylinder portion.

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