JP2010069603A - Device for detecting seating of pallet of machine tool and method for detecting seating of pallet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cycle time by shortening time required to confirm the seating of a pallet on a table. <P>SOLUTION: This device 1 for detecting seating of the pallet includes a common air supplying route 10C on which a high pressure air supplying route 10A to supply high pressure air to clean the seating surface of the table 3 and a low pressure air supplying route 10B to supply low pressure air to confirm the close state of respective seating surfaces of the pallet 2 and the table 3 are arranged in parallel and the high pressure air supplying route 10A and the low pressure air supplying route 10B join on their respective downstream sides, and a pressure switch 18 is provided on the common air supplying route 10C. Each of the high pressure air supplying route 10A and the low pressure air supplying route 10B can be switched on and off with the pressure switch 18, and the high pressure air and the low pressure air are simultaneously supplied only for a set period of time in changing the high pressure air supplying route 10A over to the low pressure air supplying route 10B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pallet seating detection device and a pallet seating detection method for a machine tool for confirming the seating of a pallet in a machining center.

  Conventionally, in a machine tool such as a machining center, air is blown to the seating surface of the table to prevent poor seating due to foreign material such as chips adhering between the seating surface of the pallet and the seating surface of the table on which the pallet is placed. The thing provided with the air blow apparatus for removing is known. In this air blow device, for example, a large volume of air is ejected from an air ejection port provided on the table toward the seating surface, and the air flow velocity is increased by approaching when the pallet is seated on the table. Then, the seating surface of the table is cleaned. Furthermore, in addition to cleaning the seating surface of the table, techniques for confirming the closeness between the seating surface of the pallet and the seating surface of the table by air are disclosed in Patent Documents 1 and 2, for example.

Patent Documents 1 and 2 are composed of two systems, a path for supplying high-pressure air and a path for supplying low-pressure air. When the pallet is seated on the table, low-pressure (a small amount) air is supplied. When checking the closeness between the pallet and the table by detecting the pressure, if the air pressure has reached a preset value, there is no gap in the seating surface, so it is determined that the contact is in close contact However, there is described a confirmation device that determines that the closeness is low due to a gap in the seating surface when the air pressure does not reach the set value.
Japanese Unexamined Patent Publication No. 1-81254 JP 63-38950 A

However, the conventional machine tool pallet seating confirmation devices such as Patent Documents 1 and 2 have the following problems.
In other words, the low pressure air used to detect the closeness of the seating surfaces of the table and the pallet cannot be confirmed accurately unless the proper pressure and discharge amount are secured. There is. However, in Patent Documents 1 and 2, when the high pressure air is supplied, the pressure in the pipe on the low pressure air side is not maintained at a predetermined pressure. Therefore, when switching from high pressure to low pressure and checking the tightness on the seating surface at the low pressure, It takes time for the pressure in the air pipe to reach a predetermined pressure. Therefore, especially when the piping route is long, the time until the confirmation of the closeness due to the supply of low-pressure air is increased, which affects the start of operation of the next process, and as a result, the cycle time in the operation of the machine tool. Had the disadvantage of being delayed.

  The present invention has been made in view of the above-described problems. A machine tool pallet seating detection apparatus and a pallet seating detection method capable of improving cycle time by reducing the time required for checking the seating of a pallet on a table. The purpose is to provide.

  In order to achieve the above object, in the pallet seating detection device for a machine tool according to the present invention, air is supplied between the seating surface of the pallet and the seating surface of the table in the machine nig center to check the seating state. A machine tool pallet seating detection device for supplying high pressure air to clean a seating surface of a table and supplying a low pressure air to provide a close contact between the seating surfaces of the pallet and the table. The low-pressure air supply path for confirmation is arranged in parallel, and the high-pressure air supply path and the low-pressure air supply path have a common air supply path that joins on the downstream side. A switch is provided, and the high pressure air supply path and the low pressure air supply path can be turned on and off by the pressure switch, and the low pressure air supply from the high pressure air supply path It is characterized in that it has a structure having at the same time supplies the control means with the high-pressure air and the low pressure air only during set time when switching to the road.

  In the pallet seating detection method according to the present invention, air is supplied between the seating surface of the pallet and the seating surface of the table in the machine center, and the pallet using the pallet seating detection device for checking the seating state. A seating detection method for supplying high-pressure air to clean a seating surface of a table, and for supplying low-pressure air to check the closeness of the seating surfaces of a pallet and a table. The low-pressure air supply path is arranged in parallel, and the high-pressure air supply path and the low-pressure air supply path have a common air supply path that merges on the downstream side, and the shared air supply path includes a high-pressure air supply path and A pressure switch that can turn on / off each of the low-pressure air supply path is provided, and at the time of switching from the high-pressure air supply path to the low-pressure air supply path When the pressure switch is turned on, to supply only the high-pressure air and the low pressure air at the same time during the set time, it is characterized in that so as to stop the supply of high pressure air after a predetermined time has elapsed.

  In the present invention, when the pallet is lowered and placed on the seating surface of the table, high-pressure air is ejected through the high-pressure air supply path toward the seating portion between the pallet and the table, and the pallet descends and approaches the table. Accordingly, the high-pressure air ejected from the table bounces back to the pallet and the air scatters toward the seating surface of the table, so that foreign matters such as chips adhering to the seating surface of the table can be removed. Furthermore, as the pallet descends and approaches the table, the air discharge port is closed and the discharge pressure becomes high. When the set pressure is reached, the pressure switch is turned on and the low pressure air supply path is switched on. The air of the high-pressure air supply path and the low-pressure air supply path merges in the common air supply path and is supplied to the seating portion. Then, after the set time has elapsed, the high pressure air is stopped, only the low pressure air is supplied to the seating portion for a certain time, and it is detected that the discharge pressure does not decrease for a certain time, so that the pallet and the table You can confirm that you are seated closely.

  Then, when the pallet descends and the discharge pressure becomes a predetermined pressure and the pressure switch is turned on, air is supplied by two systems, a high pressure air supply system and a low pressure air supply system, for a certain period of time. Since air accumulates in the pipe of the path, the pressure in the pipe of the shared air supply path is maintained even immediately after switching to only the low-pressure air supply system, and a pressure drop can be prevented. Moreover, since the low-pressure air can be supplied to the seating section immediately after switching to the low-pressure air supply system only, when switching from the high-pressure air supply system to the low-pressure air supply system as in the past, the air in the piping of the low-pressure air supply system Therefore, it takes no time until the accumulator accumulates, and the detection time required for seating confirmation can be shortened.

  Further, in the pallet seating detection device for a machine tool according to the present invention, the table is provided with a lower end detection switch for detecting the lower end position of the pallet and an upper end detection switch for detecting the upper end position of the pallet, When the seating state between the pallet and the table is not detected at the pallet lowering position, the pallet is raised to an intermediate stop position below the pallet rising edge detection switch where the lowering edge detection switch is not detected. It is good also as a structure controlled so that the seating surface of a table may be cleaned by the high pressure air supplied from a high pressure air supply path | route sometimes.

  With such a configuration, when the seating confirmation between the pallet and the table due to the supply of low-pressure air is unconfirmed at the pallet descending end position, or when the descending end detection switch is undetected, the pallet is lifted. The solenoid valve of the drive unit that moves the pallet up and down at that position is slightly raised by raising it slightly to the intermediate stop position where the lower end detection switch is not detected below the end detection switch. While maintaining the neutral position for a certain period of time, the high-pressure air can be cleaned during that time. Further, since the upward movement amount of the pallet can be minimized, the time for the upward / downward movement operation can be shortened.

  According to the pallet seating detection apparatus and the pallet seating detection method of the present invention, when switching from the high-pressure air supply system to the low-pressure air supply system, the high-pressure air supply system and the low-pressure air supply system are used for two periods. By supplying air, the air can be accumulated in the pipe of the low-pressure air supply path in the meantime, and then the pressure in the pipe of the shared air supply path is maintained even immediately after switching to the low-pressure air supply system only. Since it becomes a state, the fall of discharge pressure can be prevented. Since the time until the air accumulates in the piping of the low-pressure air supply system can be omitted, the time required for checking the seating of the pallet on the table can be shortened, and the cycle time required for workpiece machining can be shortened. Can do.

Hereinafter, embodiments of a pallet seating detection device and a pallet seating detection method for a machine tool according to the present invention will be described with reference to FIGS. 1 to 11.
1 is a diagram showing a schematic configuration of a pallet seating detection apparatus according to an embodiment of the present invention, FIG. 2 is a partially broken side view showing a seating state of a table and a pallet, and FIG. 3 is an enlarged view of a seating block shown in FIG. 4 is a plan view of the table, FIG. 5 is a sectional view taken along line AA shown in FIG. 4, FIG. 6 is a cross-sectional view showing a schematic configuration of the pallet vertical position detecting mechanism, and FIG. FIG. 8 is a side view showing the configuration of the automatic pallet changer, FIG. 9 is a plan view of the automatic pallet changer shown in FIG. 8, and FIG. 10 is a time chart showing the pallet seating detection operation. FIG. 11 is an operation flowchart of the pallet seating detection method.

Reference numeral 1 shown in FIG. 1 indicates a pallet seating detection device for a machining center (machine tool) according to the present embodiment.
As shown in FIG. 1, the pallet seating detection apparatus 1 according to the present embodiment is configured so that the pallet 2 on which a work (not shown) is mounted is seated on the table 3 (the seating taper surface 33a described later). And is used for confirming both seating states (closeness).

Here, the configuration of the pallet 2 and the table 3 of the machine tool will be described with reference to FIGS.
As shown in FIG. 2, the pallet 2 is a table on which a work is placed, and can be moved with respect to the table 3 by telescopic arms 43A and 43B (see FIG. 9) described later. At a predetermined position on the lower surface of the pallet 2, a plurality of seating recesses 21 (sitting portions) that are slidably engaged with seating blocks 33 (sitting portions) of the table 3 described later are provided. As shown in FIG. 3, the seating recess 21 has seating locking surfaces 21 a and 21 a (seat surface of the pallet 2) corresponding to seating taper surfaces 33 a (described later) of the seating block 33 on the inner surface of the lower surface in a side sectional view. Is formed.

  As shown in FIGS. 2, 4, and 5, the table 3 includes a substantially disc-shaped table body 31, a support member 32 supported at the center of the table body 31, and a pallet 2 seated on the upper surface of the table body 31. .. (Sitting part), and the table main body 31, the support member 32, and the seating block 33 include an air supply system 10 (see FIG. 1) to be described later. ) Is connected to the air piping 34. Each seating block 33 is provided with a plurality (three in this case) of nozzles 35 (35A, 35B, 35C) that form a discharge portion of the air pipe 34, and one of them (reference numeral 35A) is the seating block 33. The other two (reference numerals 35B and 35C) are located on the side portion 33c of the seating block 33.

  In addition, a pallet placement unit 36 for placing the pallet 2 conveyed by the automatic pallet changer 4 described later is provided at the center position of the table main body 31. Further, the table main body 31 is provided with a pallet vertical position detection mechanism 5 that mechanically detects whether the pallet 2 is seated.

  As shown in FIG. 3, the seating block 33 is a convex body having a circular shape in plan view, and seating taper surfaces 33a and 33a (table 3) whose outer diameter gradually decreases from the lower portion toward the upper portion in the peripheral portion. In the state where the pallet 2 is lowered and seated on the table 3, the seating taper surface 33a and the seating locking surface 21a are in close contact with each other, and a gap is formed between the seating recess 21 and the seating block 33. P is in a formed state.

  Next, as shown in FIG. 6, when the pallet 2 and the table 3 are not seated in close contact with each other, the pallet vertical position detection mechanism 5 repeatedly raises and lowers the pallet 2 while the table 3 is seated. This is for cleaning the surface (the seating taper surface 33a). Specifically, the pallet vertical position detection mechanism 5 includes a first pin 51 that protrudes upward from the table body 31 and is supported so as to be movable up and down, a second pin 52 that is pressed downward by the first pin 51, From a moving plate 54 made of steel locked to the lower end of the second pin 52 via a spring member 53, and a pair of detection switches 55 and 56 (see FIG. 7) for detecting the upper and lower moving ends of the moving plate 54. It is roughly structured.

  The first pin 51 is inserted and supported so as to be movable in the vertical direction with respect to the table body 31 in a state where the upper end 51 a is locked to a locking recess 36 a formed on the lower surface of the table mounting portion 36. The lower part 51b of the first pin 51 is provided with a pressing part 52b that pushes the upper end part 52a of the second pin 52 downward.

  The second pin 52 has a central axis arranged in a direction parallel to the first pin 51, and projects a lower portion into the table recess 37 (see FIGS. 5 and 7), and a lower portion of the second pin 52 with the spring member 53 and the moving plate 54. And is fixed with a nut 57. As shown in FIG. 7, the spring member 53 inserted through the second pin 52 is disposed between the upper surface 37a of the table recess 37 and the moving plate 54, and when the pallet 2 is not seated on the table 3, that is, the table When the mounting portion 36 is in the raised position H1 (two-dot chain line in FIG. 6) and the first pin 51 and the second pin 52 are in the raised position, the moving plate 54 is lifted together with the nut 57 at the tip of the second pin 52 (see FIG. 7 is in a state where the spring member 53 is biased at the raised position H1. Conversely, when the pallet 2 is seated on the table 3, that is, when the table mounting portion 36 is in the lowered position H2 (solid line in FIG. 6) and the first pin 51 and the second pin 52 are in the lowered position, the second pin The moving plate 54 is lowered by the urging of the spring member 53 together with the bolt 57 at the tip of 52 (solid line shown in FIG. 7).

  As the pair of detection switches 55 and 56, known proximity switches are adopted, and a pallet lowering end detection switch 56 (hereinafter simply referred to as a lowering end detection switch 56) that detects the lowering end position of the pallet 2 (the lowering end position of the moving plate 54). ) And a pallet lift end detection switch 55 (hereinafter simply referred to as the lift end detection switch 55) for detecting the lift end position of the pallet 2 (the lift end position of the moving plate 54). That is, when the seating state between the pallet 2 and the table 3 is not detected at the pallet descending position, that is, when the seating confirmation between the pallet 2 and the table 3 by the supply of the low-pressure air E2 is unconfirmed, or the descending end When the detection switch 56 is not detected, the pallet 2 is raised to an intermediate stop position below the rising end detection switch 55 of the pallet 2 where the falling end detection switch 56 is not detected. The seating surface of the table 3 is controlled to be cleaned by the high-pressure air E1 supplied from above.

  The pallet up / down position detection mechanism 5 is controlled in conjunction with the pallet seating detection device 1 and detects that the rising edge detection switch 55 is ON and seating is not detected (the pressure switch 18 is OFF), high-pressure air is ejected from the nozzle 35 between the seating recess 21 of the pallet 2 and the seating block 33 of the table 3, and when the seating is detected (the pressure switch 18 is turned on), the pressure is increased. It is configured to be controlled to switch from air to low pressure air.

The configuration of the automatic pallet changer 4 that moves the pallet 2 in the machining center (machine tool) of the present embodiment will be described with reference to FIGS. 8 and 9.
The pallet 2 on which the workpiece is placed is automatically changed and placed on the table 3 by the automatic pallet changing device 4, and the workpiece is processed by a tool (not shown) in that state. The automatic pallet exchanging device 4 includes a support frame 41, a rotation base 42 that is rotatably supported by the support frame 41, and a pair of advancing and retreating in a horizontal direction along a guide rail 44 provided on the rotation base 42. A telescopic arm 43 (43A, 43B) is schematically provided.

  As shown in FIG. 9, each of the telescopic arms 43 </ b> A and 43 </ b> B includes a locking portion 43 a that can be attached to and detached from the pallet 2 at the tip of the advance side. That is, when the table 3 is moved to the replacement position of the processed pallet 2, one telescopic arm 43A is extended and received by the pallet 2 being latched by the latching portion 43a, and the other telescopic arm 43B is not shown. The conventional pallet 2 is exchanged by receiving the new pallet 2 on the table and turning the rotary base 42.

Next, the configuration of the pallet seating detection apparatus 1 will be specifically described.
As shown in FIG. 1, the pallet seating detection device 1 includes high-pressure air E1 for cleaning the seating taper surface 33a of the seating block 33, seating locking surfaces 21a and seating taper surfaces 33a of the seating recesses 21 in the pallet 2. The low-pressure air E2 for confirming the close state is supplied to the table 3 through the same pipe (corresponding to a shared air supply system 10C described later), and switching valves 13 and 15 for controlling the respective air supply are provided. It is comprised.

  That is, the air supply system 10 that constitutes the detection device 1 shown in FIG. 1 includes a high-pressure air supply system 10A that supplies a large amount of air (high-pressure air E1) through the pressure reducing valve 12 from the air source 11. , A low-pressure air supply system 10B that supplies a small flow rate air (low-pressure air E2) is arranged in parallel, and the high-pressure air supply system 10A and the low-pressure air supply system 10B join the supply air supply system 10C on the downstream side. The common air supply system 10C is connected to an air pipe 34 in the table 3, and when air is supplied to the table 3, air is ejected from the nozzles 35A to 35C (see FIG. 3) of each seating block 33. It has become.

  The high-pressure air supply system 10A is a path for supplying air that has been decompressed to a predetermined pressure by the pressure reducing valve 12 to the table 3, and the air at this time corresponds to the high-pressure air of the present invention. High pressure air E1 is jetted between the recess 21 and the peripheral surface of the seating block 33 (especially the seating taper surface 33a) is cleaned, and the first switching valve 13 and the first check valve 14 are upstream. They are arranged in series in that order from the side toward the downstream side.

  On the other hand, the low-pressure air supply system 10 </ b> B is a path that supplies the air adjusted to a predetermined pressure by the pressure reducing valve 12 to the table 3 by further reducing the flow rate by the throttle valve 16 to adjust the air to a predetermined pressure. The air at this time corresponds to the low-pressure air of the present invention, and is used to supply air in order to check the closeness of both of them while the pallet 2 is seated on the table 3, and the second switching valve 15 The throttle valve 16 and the second check valve 17 are arranged in series in that order from the upstream side to the downstream side.

  Further, the common air supply system 10C is provided with a pressure switch 18 that detects the pressure of the air supplied to the table 3 and turns on and off the first switching valve 13 and the second switching valve 15 based on the set predetermined pressure. It has been.

  The pallet seating detection device 1 can be turned on and off by the pressure switch 18 for the high pressure air supply path 10A and the low pressure air supply path 10B, and is set when switching from the high pressure air supply path 10A to the low pressure air supply path 10B. It has the structure which has the control means (illustration omitted) which supplies the high pressure air E1 and the low pressure air E2 simultaneously only for the time.

Next, the operation flow, action, and seating detection method of the above-described pallet seating detection apparatus 1 will be described with reference to drawings such as FIG. 1, FIG. 10, and FIG.
First, in step S1, before the operation of seating the pallet 2 on the table 3, the first switching valve 13 of the high-pressure air supply system 10A is turned on and the second switching valve 15 of the low-pressure air supply system 10B is turned off. High-pressure air E1 is ejected from the nozzles 35A, 35B, 35C (see FIG. 3) of the seating block 33 of the table 3 through the supply air supply system 10C. In this state, the pallet 2 in the raised position is lowered so that the seating recess 21 is engaged with the seating block 33 of the table 3 (step S2). That is, the seating locking surface 21 a of the seating recess 21 of the pallet 2 is locked and placed on the seating taper surface 33 a of the seating block 33.

  Further, as the pallet 2 descends and the seating recess 21 and the seating block 33 approach each other, the air ejected from the nozzles 35A to 35C (see FIG. 3) of each seating block 33 hits the inner surface of the seating recess 21 and rebounds. Since the bounced air is scattered toward the outer peripheral surface of the seating block 33, foreign matters such as chips on the seating taper surfaces 33a and 33a are removed and cleaned.

  In step S3, the on / off state of the pressure switch 18 is confirmed. In other words, as the pallet 2 descends and approaches the table 3, the air pressure (discharge pressure) in the seating recess 21 of the pallet 2 is closed, and the pressure switch 18 is turned on when the set pressure is reached. And go to step S4.

  Next, in the operation of step S4, in the pallet vertical position detection mechanism 5 shown in FIGS. 6 and 7, the moving plate 54 is lowered via the first pin 51 and the second pin 52 as the pallet 2 is lowered. When the lower end position of the moving plate 54 is detected by the pallet lower end detection switch 56 (step S4: Yes), it is confirmed that it is the lower end position, and the process proceeds to step S5.

  On the other hand, when the ON state of the pressure switch 18 cannot be detected (step S3: No), it is confirmed that the pressure switch 18 is not seated, and the pallet 2 is raised again (step S6). The seating block 33 is cleaned by the air, and the process proceeds to step S3. As described above, when ON of the pressure switch 18 cannot be detected at one time, that is, when foreign matter such as chips adhering to the seating surface of the seating block 33 cannot be removed, the ascending / descending operation of the pallet 2 is repeated a plurality of times. A retry will be performed.

  Next, in step S4, when it is not possible to detect ON of the descending end detection switch 56 (step S4: No), it is confirmed that it is in a non-sitting state, the pallet 2 is raised again (step S6), and the process returns to step S2. As the pallet 2 is lowered, the seating block 33 is cleaned by the high-pressure air, and the process proceeds to step S3.

  Specifically, the operation after the detection of the seating abnormality in step S3 and step S4 is as follows. As shown in FIGS. 6 and 7, the pallet vertical position detection mechanism 5 has a lower end lower than the upper end detection switch 55 of the pallet 2. A solenoid valve of a drive unit (not shown) that moves the pallet 2 (moving plate 54) up and down at a certain position by slightly raising the detection switch 56 to a non-detection intermediate stop position. By holding the neutral position for a certain period of time while switching to the neutral position, cleaning with the high-pressure air E1 can be performed during that time. Further, since the upward movement amount of the pallet 2 can be minimized, the time for the upward / downward movement operation can be shortened.

  Subsequently, the pressure switch 18 is turned on in step S3, and when the lower end position of the pallet 2 is detected in step S4, the second switching valve 15 is turned on (step S5), and the low pressure air supply system 10B is supplied with low pressure air. E2 flows, and the air of these two systems 10A and 10B joins the common air supply system 10C forming a common flow path and is supplied to the table 3 (between the seating recess 21 and the seating block 33).

Then, when a certain time (first time T1) elapses due to control by a timer (not shown), the first switching valve 13 is turned OFF, the supply of the high-pressure air E1 by the high-pressure air supply system 10A is stopped, and the low-pressure air supply system Only the low-pressure air E2 of 10B is supplied to the table 3 via the shared air supply system 10C (step S7).
In this embodiment, the timing of step S3 (specifically, when the pressure switch 18 is ON), the retracting operation of the telescopic arm 43 of the automatic pallet exchanging device 4 shown in FIGS. 8 and 9 is started.

  Next, in step S8, only the low-pressure air E2 is supplied to the seating portion, that is, the gap P (see FIG. 3) between the seating recess 21 of the pallet 2 and the seating block 33 of the table 3 for a certain time (second time T2). The discharge pressure is detected by the pressure switch 18 during this fixed time (second time T2). At this time, when it is detected that the discharge pressure does not decrease and is maintained at a constant pressure (step S8: No), the ON state of the pressure switch 18 is maintained, whereby the pallet 2 and the table 3 Is seated in close contact (step S9). In step S10, the second switching valve 15 is turned OFF, the supply of the low-pressure air E2 by the low-pressure air supply system 10B is stopped, and the seating confirmation operation ends. After the seating is confirmed, the work held on the pallet 2 is processed, and the pallet 2 is replaced by the automatic pallet exchanging device 4 (see FIGS. 8 and 9) after the processing.

  On the other hand, in step S8, when it is detected that the discharge pressure is reduced and is not maintained at a constant pressure, that is, when the pressure switch 18 is switched from ON to OFF (step S8: Yes), the seating recess 21 The seating surface 33 and the seating block 33 are not in close contact with each other (reference numerals 21a and 33a), but the low-pressure air E2 supplied with a gap is leaked, and chips or the like are provided between the seating surfaces. It is determined that the foreign object is present, and non-seating is confirmed (step S11).

  In this case, in the present embodiment, the pallet 2 is raised again (step S6) as in the case where the pressure switch 18 cannot detect in step S3 described above, and the process returns to step S2 and is seated by the high-pressure air as the pallet 2 is lowered. The block 33 is cleaned, the process proceeds to step S3, and the operation flow is sequentially repeated until the seating completion is confirmed. The number of repetitions is set as a fixed number (for example, 5 times, 10 times, etc.), and the device is stopped when foreign matter such as chips adhering to the seating surface cannot be removed by cleaning the number of times. It may be configured such that an abnormal signal is output.

In the pallet seating detection device 1, when the pallet 2 is lowered, the discharge pressure becomes a predetermined pressure and the pressure switch 18 is turned on, the high pressure air supply system 10A and the low pressure air supply system 10B are used for two periods. Since air is supplied and air accumulates in the pipe of the low-pressure air supply path 10B during that time, the pressure in the pipe of the common air supply path 10C is maintained even immediately after switching to the low-pressure air supply system 10B, and the pressure drops. Can be prevented. Moreover, since the low-pressure air E2 can be supplied to the seating portions of the pallet 2 and the table 3 immediately after switching to the low-pressure air supply system 10B only, when switching from the high-pressure air supply system to the low-pressure air supply system as in the past, For example, the time required for air to accumulate in the piping of the air supply system can be shortened by, for example, 3 to 5 seconds, thereby shortening the detection time required for seating confirmation. growing.
In addition, after the pallet 2 is seated in close contact with the table 3, the air supplied between the seating block 33 and the seating recess 21 is changed from the high pressure air E1 to the low pressure air E2. Lifting of the pallet 2 due to the supply of the high-pressure air E1 can be prevented.

As described above, in the pallet seating detection device and the pallet seating detection method of the machine tool according to the present embodiment, when switching from the high pressure air supply system 10A to the low pressure air supply system 10B, the high pressure air supply system 10A and the low pressure air are maintained for a certain period of time. By supplying air through the two systems of the supply system 10B, air can be stored in the pipe of the low-pressure air supply path 10B in the meantime, and then shared immediately after switching to only the low-pressure air supply system 10B. Since the pipe internal pressure of the air supply path 10C is maintained, it is possible to prevent the discharge pressure from being lowered.
Since the time until the air accumulates in the piping of the low-pressure air supply system 10B can be omitted, the time required for checking the seating of the pallet 2 with respect to the table 3 can be shortened, and the cycle time required for machining the workpiece can be shortened. Can be achieved.

The embodiments of the machine tool pallet seating detection device and the pallet seating detection method according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and may be appropriately selected within the scope of the invention. It can be changed.
For example, in this embodiment, the table 3 is provided with the pallet up / down position detection mechanism 5, and when the pallet 2 is lowered, the pallet 2 (moving) is detected by the pallet lowering end detection switch 56 in addition to the operation of turning on the pressure switch 18. When the lower end position of the plate 54) is detected, the second switching valve 15 of the low pressure air supply system 10B is turned ON and the low pressure air E2 is supplied, and in the case of non-detection, the lower end position is detected. The pallet 2 is repeatedly raised and lowered. However, the pallet 2 is not limited to such a configuration. For example, the pallet vertical position detection mechanism 5 may be omitted. In that case, for example, in the operation flow shown in FIG. 11, Step S4 and Step S6 are omitted, and when the pressure switch 18 is turned ON in Step S3, the second switching valve 15 of the low pressure air supply system 10B is turned on in Step S5. The low pressure air E2 is supplied by turning on. Further, when the discharge pressure is reduced and non-seating is confirmed in step S8 (step S11), for example, an abnormal signal can be output.

Moreover, the time during operation in the pallet seating detection apparatus 1 (the above-described first time T1 and second time T2) can be arbitrarily set.
Furthermore, the configuration of the pallet 2, the seating recess 21, the table 3, the seating block 33, the nozzle 35, the automatic pallet exchanging device 4, etc. is not limited to this embodiment. It can be set arbitrarily.

It is a figure which shows schematic structure of the pallet seating detection apparatus by embodiment of this invention. It is a partially broken side view which shows the seating state of a table and a pallet. It is an enlarged view of the seating block shown in FIG. It is a top view of a table. It is an AA arrow directional view shown in FIG. It is sectional drawing which shows schematic structure of a pallet vertical position detection mechanism. It is a principal part enlarged view of the pallet vertical position detection mechanism shown in FIG. It is a side view which shows the structure of an automatic pallet change apparatus. It is a top view of the automatic pallet change apparatus shown in FIG. It is a time chart which shows a pallet seating detection operation. It is an operation | movement flowchart of a pallet seating detection method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pallet seating detection apparatus 2 Pallet 3 Table 4 Automatic pallet exchange 5 Pallet vertical position detection mechanism 10 Air supply system 10A High pressure air supply system 10B Low pressure air supply system 10C Shared air supply system 13 First switching valve 15 Second switching valve 18 Pressure Switch 21 Seating recess (sitting part)
21a Seating locking surface (Pallet seating surface)
33 Seating block (sitting part)
33a Seating taper surface (table seating surface)
34 Air piping 35 Nozzle 43, 43A, 43B Telescopic arm 54 Moving plate 55 Pallet rising end detection switch 56 Pallet falling end detection switch E1 High pressure air E2 Low pressure air

Claims (3)

A machine tool pallet seating detection device for supplying air between a seating surface of a pallet and a seating surface of a table in a machine nig center to check a seating state,
A high-pressure air supply path for supplying high-pressure air to clean the seating surface of the table, and a low-pressure air supply path for supplying low-pressure air and confirming the close contact between the seating surfaces of the pallet and the table Are arranged in parallel, and has a shared air supply path where the high pressure air supply path and the low pressure air supply path merge on their downstream sides,
A pressure switch is provided in the shared air supply path,
Each of the high-pressure air supply path and the low-pressure air supply path can be turned on and off by the pressure switch, and the high-pressure air and the low-pressure air are set for a set time when switching from the high-pressure air supply path to the low-pressure air supply path. A pallet seating detection device for a machine tool, characterized by comprising control means for simultaneously supplying The table is provided with a lowering end detection switch for detecting the lowering end position of the pallet, and a rising end detection switch for detecting the rising end position of the pallet,
When the seating state of the pallet and the table is not detected at the pallet lowering end position, the pallet reaches the intermediate stop position below the pallet rising end detection switch and the lowering end detection switch is not detected. 2. The pallet seating of a machine tool according to claim 1, wherein the seating surface of the table is controlled to be cleaned by high-pressure air supplied from the high-pressure air supply path during the ascent. Detection device. A pallet seating detection method using a pallet seating detection device for supplying air between a seating surface of a pallet and a seating surface of a table in a machine nigg center,
The pallet seating detection device supplies high-pressure air to clean the seating surface of the table, and checks the contact state of the seating surfaces of the pallet and the table by supplying low-pressure air. A low-pressure air supply path to be arranged in parallel, and the high-pressure air supply path and the low-pressure air supply path have a shared air supply path that joins on the downstream side thereof,
The shared air supply path is provided with a pressure switch that can turn on and off each of the high-pressure air supply path and the low-pressure air supply path.
At the time of switching from the high pressure air supply path to the low pressure air supply path, when the pressure switch is turned on, the high pressure air and the low pressure air are simultaneously supplied for a set time, and after a predetermined time has passed, A pallet seating detection method characterized in that the supply of high-pressure air is stopped.

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