JP2019098473A - Air pressure confirming master and work seating detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air pressure confirmation master and a work seating detection device having an adjusting groove capable of dimension control even on a tapered surface. SOLUTION: This is an air pressure confirmation master 20 having a truncated cone-shaped adjusting surface corresponding to a work seating surface and an adjusting groove formed in a circumferential direction with respect to the adjusting surface, and for example, a work seating detection. When adjusting the back pressure of the device, a plurality of air pressure confirmation masters 20 having adjustment grooves having different depths are used, or the first adjustment surface 211 has both front and back surfaces as the first adjustment surface 211 and the second adjustment surface. Is formed with a first adjusting groove 25 having a predetermined depth, and an air pressure confirmation master 20 having a second adjusting groove having a depth different from that of the first adjusting groove is used on the second adjusting surface. [Selection diagram] Fig. 3

Description

  The present invention relates to a master for checking air pressure, which is used for an adjustment operation for performing accurate seating detection of a work, with respect to a chuck in which a seating surface of a winning metal is a tapered surface.

  In a lathe or the like, a work is fixed to a chuck of a main spindle, and cutting is performed by applying a cutting tool to a rotating work. At this time, if the workpiece is not in precise contact with the seating surface of the chuck, the quality of the finished product may be degraded, for example, the workpiece may be extra scraped off. Therefore, a determination is made using the work seating detection device as to whether or not the work is properly seated against the chuck's counter metal. Specifically, compressed air is supplied from the air supply source to the detection hole opened in the seating surface of the counter metal, and the seating determination is performed based on the back pressure according to the gap between the seating surface and the work. In order for accurate seating determination to be performed, it is necessary that back pressure adjustment be performed according to the amount of air leaked from the gap when a gap is generated between the work and the seating surface of the counter metal. It is.

  In order to adjust the back pressure, an air pressure confirmation master is used as a member that generates a predetermined gap on the seating surface of the work. And although the adjustment groove which produces a fixed air leak is formed in the air pressure confirmation master, the groove depth is formed with the dimensional accuracy of 1/100 mm unit. Then, in the following patent document 1, the master for air pressure confirmation which paid attention to the point which the amount of leaks of air from a crevice changes by the coarseness of the work surface is proposed. The air pressure confirmation master is provided with a screw so as to protrude from the groove bottom with respect to the adjustment groove causing air leakage, and the size of the gap can be adjusted according to the amount of projection of the screw. .

Unexamined-Japanese-Patent No. 2017-024090

  As described above, the adjustment groove of the air pressure confirmation master is extremely minute, and different adjustment grooves for determining the appropriate state and the improper state of the seating are, for example, groove depths of 0.03 mm and 0.05 mm, for example. It is formed of And since accuracy is calculated | required by the adjustment groove | channel processed into the master for air pressure confirmation, the dimension management using a dial gauge etc. is performed about the groove depth after a process. However, in the case where the contact surface of the work against the seating surface is a tapered surface having an inverted truncated cone shape, the air pressure confirmation master has a truncated cone shape, and the surface is a tapered surface. And an adjustment groove will be formed in the taper surface. However, the tapered surface is a curved surface when viewed in the circumferential direction, and it is difficult to accurately control the dimension of the groove depth if the adjusting groove is formed linearly as in the conventional case. .

  Then, this invention aims at providing the air pressure confirmation master and workpiece | work seating detection apparatus which have an adjustment groove which can be dimension-controlled even if it is a taper surface in order to solve this subject.

  The air pressure confirmation master according to one aspect of the present invention has a frusto-conical adjustment surface corresponding to the work seating surface, and an adjustment groove formed circumferentially with respect to the adjustment surface.

  According to another aspect of the present invention, there is provided a work seating detection apparatus including a work metal having a work seating surface in the shape of an inverted truncated cone formed on a chuck for gripping a work, and a plurality of ones formed on the seating surface. A detection hole for air discharge formed at a position deviated from the same circumference, a detection flow path connecting an air supply source for supplying air at a predetermined pressure and the detection hole, and the detection flow path A pressure switch for detecting the secondary pressure of the throttling portion formed in the pressure regulator, a pressure regulator for adjusting the secondary pressure, a frusto-conical adjustment surface corresponding to the work seating surface, and the adjustment surface A workpiece seating detection device comprising: an air pressure confirmation master including an adjustment groove formed in a circumferential direction.

  According to the above configuration, the first adjustment groove and the second adjustment groove are formed in the circumferential direction even if the first adjustment surface and the second adjustment surface of the master for checking air pressure are frusto-conical tapered surfaces. This enables dimensional control of the groove depth.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic block diagram which showed one Embodiment of the workpiece | work seating detection apparatus. It is sectional drawing which showed the chuck of a machine tool. It is a perspective view showing one embodiment of a master for air pressure check. It is the figure which showed the state which made the master of air pressure confirmation sit on the contact metal of a chuck. It is the figure which showed a part of air pressure confirmation master and the cross section of a winning metal.

  Next, one embodiment of the air pressure confirmation master and the work seating detection device according to the present invention will be described below with reference to the drawings. The workpiece seating detection apparatus of the present embodiment is configured as a chuck of a spindle in a machine tool. FIG. 1 is a schematic configuration view showing the work seating detection device. In a machine tool such as a lathe, for example, a workpiece is fixed to a chuck of a main shaft, and cutting is performed with a cutting tool placed on a rotating workpiece, so that the workpiece must be properly positioned. Therefore, the work seating detection device 1 for detecting the correct seating of the work is incorporated in the machine tool.

  A detection hole 11 is formed in the work clamp of the chuck in the work seating detection device 1 and the opening of the detection hole 11 is closed by the work W when the work W is correctly gripped by the chuck. . The detection hole 11 is a through hole having a diameter of about 1 mm, and is open to the seating surface of the counter metal. For example, three detection holes are formed at an interval of 120 ° in the annular winch, and seating confirmation of the work W is performed at three places. One of the detection holes 11 is represented in the drawing. Then, compressed air is supplied from the air supply source 3 through the detection flow path 2, and the pressure in the flow path due to the seating of the work W is detected.

  Compressed air is fed into the workpiece seating detection device 1 from an air supply source 3 such as a compressor in a factory, for example. The machine tool is provided with a connection port for taking in compressed air, and a detection flow path 2 extending from the connection port to the detection hole 11 is provided. A metering orifice 4 is provided in the detection flow channel 2 at a predetermined distance before the detection hole 11. The metering orifice 4 is for adjusting the pressure and flow rate of the compressed air supplied to the secondary side, and the flow rate adjusting valve 5 is integrally formed so that the throttling amount of the air flow path can be adjusted. There is. Therefore, the back pressure adjustment of the detection hole 11 is performed by the flow rate adjustment valve 5.

  In the detection flow channel 2, the supply side pressure gauge 6 is provided in the primary flow channel 201, and the back pressure gauge 7 and the pressure switch 8 are provided in the secondary flow channel 202, with the metering orifice 4 interposed therebetween. There is. In the pressure switch 8 of the present embodiment, the inside of the body 82 is divided up and down by the flexible diaphragm 81, and the lower chamber of the diaphragm 81 is connected to the detection flow path 2 (secondary side flow A rod 84 is fixed to the diaphragm 81 at the upper chamber side, connected to the passage 202). The rod 84 is connected to the switch lever 86 of the switch section 85, and the diaphragm 81 is bent to switch ON / OFF the first contact point 87 and the second contact point 88.

  The ON signal of the first contact point 87 indicates that the back pressure in the secondary flow passage 202 is low. That is, it can be seen that a large amount of compressed air is ejected from the detection hole 11 and the seating condition of the work W having a large gap G with respect to the seating surface 151 is improper. On the other hand, the ON signal of the second contact point 88 indicates that the back pressure in the secondary side flow passage 202 is high. That is, since the work W is properly seated on the seating surface 151, it is understood that the compressed air is not discharged from the closed detection hole 11 and the back pressure is increased. The pressure switch 8 is an example shown in this embodiment, and there is no problem in using different pressure switches.

  The workpiece seating detection device 1 of the present embodiment is set such that a state where the workpiece W floats 0.05 mm or more from the seating surface 151 (a state where a gap G of 0.05 mm or more is generated) is inappropriate. That is, if the gap G is less than 0.05 mm, it is acceptable for proper seating, and the second contact point 88 needs to be in the ON state within a predetermined time due to the back pressure in the rising secondary side flow passage 202. Therefore, in the work seating detection device 1, the back pressure adjustment for appropriately operating the pressure switch 8 is performed according to the size of the gap G between the work W and the seating surface 151. And the air pressure confirmation master according to the structure of a chuck | zipper is used for the back pressure adjustment.

  Here, FIG. 2 is a cross-sectional view showing a chuck that constitutes a main shaft of a machine tool. The chuck 10 is configured such that a workpiece W indicated by a one-dot chain line penetrates into the interior of the chuck body 12. A collet chuck mechanism 13 for gripping the workpiece W is assembled to the chuck body 12 at its inside, and a counter metal 15 is provided at the tip.

  The workpiece W targeted by the chuck 10 has a shaft portion 101 as a grip portion and a disk-shaped flange portion 102 which is expanded in the radial direction. The flange portion 102 has a surface formed in a truncated cone shape as a tapered surface. Therefore, the seating surface 151 of the counter metal 15 is a tapered surface having an inverted frusto-conical shape so as to coincide with the tapered surface. In the chuck, generally, the workpiece W is received in a plane orthogonal to the rotation axis O. However, in the case of the work W, since the orthogonal plane is only at the tip end 103, even if the counter metal is provided at the back of the chuck 10, it becomes difficult to stably sit the posture of the work W. Therefore, a winning metal 15 is formed on the chuck 10 so as to be in contact with the flange portion 102 and to be seated.

  Then, a detection hole 11 opened to the seating surface 151 is formed in the winning metal 15, and the detection flow passage 2 (secondary side flow passage 202) passing through the operation rod 17 and the chuck body 12 is formed in the detection hole 11 Are in communication. Therefore, in the workpiece seating detection device 1 in the chuck 10, an air pressure confirmation master corresponding to the workpiece seating surface 151 having the tapered surface is used. FIG. 3 is a perspective view showing the air pressure confirmation master of the present embodiment. And FIG. 4 is the figure which showed the state which made the air pressure confirmation master sit on the counter metal 15 of the chuck | zipper 10. As shown in FIG.

  The air pressure confirmation master 20 has a shape corresponding to the work W, and is formed with a flange portion 21 in contact with the seating surface 151 of the hit metal 15 and a shaft portion 22 gripped by the collet chuck mechanism 13. As shown in a sectional view in FIG. 4, the flange portion 21 is formed with a truncated conical tapered surface in contact with the seating surface 151 of the counter metal 15 at the peripheral edge portion, and the annular first adjustment surface 211 and the first adjustment surface 211 A two adjustment surface 212 is configured. The flange portion 21 on which the first and second adjustment surfaces 211 and 212 are formed has the shape of the front and back surfaces and the shaft portion 22 protruding on both surfaces relative to a center line C1 orthogonal to the central axis C shown in FIG. It is formed symmetrically.

  In the flange portion 21, annular first adjustment grooves 25 and second adjustment grooves 26 are formed in the first and second adjustment surfaces 211 and 212. Further, in the flange portion 21, notch portions 215 having a step-like shape are respectively formed on the first adjustment surface 211 side and the second adjustment surface 212 side on a part of the peripheral portion. Mark surfaces 27 and 28 are formed on the side surfaces of the peripheral portion orthogonal to the radial direction in the notch portion 215, and a mark to distinguish the first and second adjustment grooves 25 and 26, for example, a groove depth described later A numerical value etc. are displayed.

  The first and second adjustment grooves 25 and 26 are overlapped at the position of the detection hole 11 and virtually create a gap G when the work W is seated on the counter metal 15. The depth of the first adjustment groove 25 is 0.03 mm, and the depth of the second adjustment groove 26 is 0.05 mm. In these two values, a gap of 0.03 mm means a proper seating condition, and a gap of 0.05 mm means an improper seating condition. Accordingly, in the back pressure adjustment using the air pressure confirmation master 20, if the dimensions of the first and second adjustment grooves 25 and 26 are not accurate, the detection result in the work seating detection device 1 becomes inaccurate. Get

  Therefore, in the air pressure check mask 20, the first adjustment groove 25 and the second adjustment groove 26 are formed in the circumferential direction (in particular, in the present embodiment, in an annular shape), so that dimension control of the groove depth can be accurately performed. ing. That is, if it is conventional, the adjustment groove of the air pressure confirmation master 20 is a linear groove extending in the radial direction from the central axis C. However, in the case of the present embodiment, the workpiece W and the seating surface 151 of the counter metal 15 are tapered surfaces, and accordingly, the first and second adjustment surfaces 211 and 212 are also tapered surfaces. Therefore, in the case of a linear groove in the radial direction, the groove becomes a linear groove along the slope of the tapered surface, so that dimensional control of the groove depth is difficult and becomes uncertain. Here, FIG. 5 is a view showing a cross section of a part of the air pressure check master 30 and the counter metal 15 when the adjustment groove is a linear groove in the radial direction.

  The air pressure check master 30 has linear adjustment grooves 31 and 32 formed in the radial direction with respect to the inclined adjustment surfaces 33 and 34 in accordance with the conventional structure. Then, at the time of back pressure adjustment in the work seating detection device 1, the adjustment surface 33 is applied to the seating surface 151 of the counter metal 15, for example, so that the adjustment groove 31 matches the position of the detection hole 11. Therefore, the compressed air sent through the detection flow path 2 is discharged from the detection hole 11 through the adjustment groove 31. The back pressure adjustment is performed in the same manner for the opposite adjustment groove 32 as well. At this time, the discharge flow rate of the compressed air in the adjustment grooves 31 and 32 in which the gap G is assumed depends on the size of each groove cross-sectional area, but the groove cross-sectional area is controlled by the groove depth.

  In FIG. 5, a cross section in which the angle is changed in the longitudinal direction of the adjustment groove 31 (the inclination direction of the adjustment surface 33) is shown in a partially enlarged round frame. The adjustment surfaces 33 and 34 formed on both the front and back sides are each frusto-conical, and the surface, which is tapered, is curved in the left-right direction as shown in the round frame when viewed in the inclined direction It is a curved surface. Therefore, when it overlaps on the seating surface 151 which has the same curved surface, the cross section of the discharge path 35 which consists of the adjustment groove 31 is the curved shape which bulged upwards. In such a case, the height from the bottom of the adjustment groove 31 to the seating surface 151 can be determined as the groove depth in the drawing, but the actual measurement can not accurately measure the groove depth.

  The dimensional control of the adjustment grooves 31 and 32 is performed by measurement using a dial gauge or the like after the processing. At this time, the groove depth N in the vicinity of the groove side surface can be measured by using the adjustment surfaces 33 and 34 as a reference. However, since the height of the discharge path 35 changes in the width direction of the adjustment grooves 31 and 32, reference can not be taken at other positions, and for example, the groove depth M of the central portion can not be accurately measured. . In the work seating detection device 1, two different clearances are created by dimensional control of the groove depth, and back pressure adjustment is performed to determine the suitability of seating. Therefore, if the dimension control of the adjustment groove is not appropriate, the back pressure adjustment may not be accurate, which may result in deterioration of the processing quality due to the seating determination of the work W.

  So, in this embodiment, the structure which can carry out exact dimension control about the adjustment groove in case the adjustment surface is a taper surface is taken. That is, the first adjustment groove 25 and the second adjustment groove 26 of the air pressure confirmation master 20 are annularly formed as described above. The cross section which looked at the adjustment groove 31 in the circumferential direction in the round frame which expanded the part by FIG. 4 is shown. The first adjustment groove 25 (also the second adjustment groove 26) formed in the circumferential direction is formed at an angle at which the width direction is the radial direction of the flange portion 21 and the bottom surface matches the inclination of the adjustment surface 211 . As a result, the groove depth L of the first and second adjustment grooves 25 and 26 with respect to the seating surface 151 of the counter metal 15 becomes constant. Therefore, the first and second adjustment grooves 25 and 26 can be performed with reference to the adjustment surfaces 211 and 212 in measurement using a dial gauge performed after the processing.

  By the way, in the detection holes 11 formed at three locations, when adjusting the back pressure, a gap by the first or second adjustment groove 25 or 26 is made only in one detection hole 11, and the other two detection holes 11 are closed. It must have been done. However, if the three detection holes 11 exist on the same circumference as the first and second adjustment grooves 25 and 26 formed in an annular shape as in the present embodiment, gaps will be formed in all. Therefore, only one of the three detection holes 11 is formed at a position overlapping the first and second adjustment grooves 25 and 26, and the other two detection holes 11 are formed at positions shifted in the radial direction. It is done. In the present embodiment, the detection hole 11 shown on the lower side of the drawing is formed at a position closer to the center line C side, and is closed by the first adjustment surface 211.

  Subsequently, the operation of the work seating detection device 1 incorporated in the machine tool will be described. In order to process the workpiece W in the machine tool, the workpiece W is held by the chuck 10 of the spindle. In the work seating detection device 1, compressed air is constantly fed from the air supply source 3 into the detection flow path 2 and discharged from the detection hole 11. When the workpiece W is properly gripped by the chuck 10, the detection hole 11 is closed by the workpiece W seated on the seating surface 151 of the counter metal 15, and the discharge of the compressed air is blocked, thereby the detection flow path 2 Internal pressure increases. Then, the back pressure of the secondary flow passage 202 is increased, the pressure switch 8 is switched, the second contact point 88 is turned on, a detection signal is transmitted, and the proper seating state is confirmed.

  However, if the work W is inclined and a gap G is generated between the work W and the seating surface 151, the compressed air leaks from there and the value of the back pressure in the secondary side flow passage 202 becomes low. When the gap G exceeds the allowable value, no detection signal is sent from the pressure switch 8, and the machine tool is judged to be improper seating, and predetermined processing such as warning is performed. On the other hand, if the gap G is within the allowable range, the processing of the workpiece W by the machine tool is executed even if the gap is generated. In the work seating detection device 1, since the allowable value of the gap G is 0.05 mm, back pressure adjustment using the air pressure confirmation master 20 is performed so that the pressure switch 8 operates properly within the allowable range.

  In the back pressure adjustment, as shown in FIG. 4, the air pressure confirmation master 20 is held by the chuck 10 in a state where the shaft portion 22 is inserted, and the flange portion 21 is brought into contact with the seating surface 151 of the counter metal 15. At this time, although the air pressure confirmation master 20 has a symmetrical shape, the insertion of the chuck 10 is performed in the correct direction by the operator confirming the marks on the mark surfaces 27 and 28. In the back pressure adjustment operation, a first adjustment for seating the first adjustment surface 211 on the seating surface 151 and a second adjustment for seating the second adjustment surface 212 are sequentially performed. At this time, the first adjustment groove 25 creates a state where it is determined that the clearance is 0.03 mm, and the second adjustment groove 26 determines that the clearance is 0.05 mm. State is created.

  In the first adjustment, the compressed air is discharged from the detection hole 11 into the first adjustment groove 25, and the back pressure in the secondary flow passage 202 is increased in this situation. At this time, the flow rate and pressure of the compressed air are adjusted so that the back pressure gauge 7 rises to the first set value within a predetermined time. In the back pressure adjustment, the throttling amount of the metering orifice 4 is changed by the flow control valve 5, and the pressure decrease or pressure increase in the secondary side flow passage 202 is adjusted. In this way, the back pressure rises to the first set value within a predetermined time by the first adjustment groove 25 which creates a gap of 0.03 mm, and the second contact 88 of the pressure switch 8 is turned on. Complete.

  On the other hand, if the pressure of the compressed air fed into the secondary side flow passage 202 is too high at this time, the second contact 88 may be switched to the ON state even if the gap G is 0.05 mm or more. is there. Therefore, the adjustment in which the second adjustment groove 26 is superimposed on the detection hole 11 is subsequently performed. At this time, a gap of 0.05 mm is formed at the opening of the detection hole 11, and more compressed air is discharged from the detection hole 11. Therefore, adjustment is performed so that the back pressure in the secondary side flow passage 202 becomes a second set value lower than the first set value. At the back pressure of the second set value, the pressure switch 8 does not switch the second contact point 88 and remains in the OFF state.

  Therefore, according to the present embodiment, even if the first and second adjustment surfaces 211 and 212 of the air pressure confirmation master 20 are tapered surfaces having a truncated cone shape, the first and second adjustment grooves 25 and 26 can be used. By forming in the circumferential direction, dimensional control of the groove depth L can be performed accurately. Moreover, by forming in an annular shape, the first and second adjustment surfaces 211 and 212 can be aligned with the detection hole 11 without particularly aligning. On the other hand, since the detection holes 11 other than one target detection hole 11 are on the circumference different in diameter, appropriate back pressure adjustment is performed even if the first and second adjustment surfaces 211 and 212 are annular. be able to. In addition, since the air pressure confirmation master 20 has a symmetrical shape based on the center line C1, the direction of the back pressure is likely to be wrong in the first adjustment and the second adjustment, but when the operator picks it up Since the marking surfaces 27 and 28 are formed at positions that can be the front, it is possible to avoid mistakes.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the embodiment described above, the first and second adjustment surfaces 211 and 212 are shown as one air pressure confirmation master 20 in which both front and back surfaces are formed, but the first adjustment surface and the second adjustment surface are formed in each of them. The two masters for air pressure confirmation may be used.
Moreover, although the 1st and 2nd adjustment groove | channels 25 and 26 are cyclic | annular in the said embodiment, it may be an arc-shaped groove | channel of predetermined length.
Further, in the above embodiment, the marking surfaces 27 and 28 are provided on the step surface of the notch 215, but with the peripheral portion of the flange portion 21 as the circumference as it is, the first and second side surfaces are the marking surfaces. A mark may be attached to distinguish the adjustment grooves 25 and 26.
Furthermore, although both the first and second adjustment grooves 25 and 26 are marked, only one may be marked.

1 ... Workpiece seating detection device 2 ... Flow path for detection 3 ... Air supply source 8 ... Pressure switch 10 ... Chuck 11 ... Detection hole 15 ... Matching metal 20 ... Master for air pressure check 21 ... Flange part 22 ... Shaft part 25 ... No. 1 Adjustment groove 26 ... 2nd adjustment groove 27, 28 ... Mark surface 151 ... Seated surface 202 ... Secondary side channel 211 ... 1st adjustment surface 212 ... 2nd adjustment surface

Claims (5)

  A master for checking air pressure, comprising: a frusto-conical adjustment surface corresponding to a work seating surface; and an adjustment groove formed circumferentially with respect to the adjustment surface. The adjustment surface has a first adjustment surface having a frusto-conical shape corresponding to the work seating surface, and a second adjustment surface formed on the back side of the first adjustment surface and corresponding to the work seating surface. And
The adjustment groove is formed in a circumferential direction with respect to a first adjustment groove formed in a circumferential direction with respect to the first adjustment surface and with respect to the second adjustment surface, and a depth different from the first adjustment groove The air pressure confirmation master according to claim 1, further comprising: a second adjustment groove.   The air pressure confirmation master according to claim 1, wherein the adjustment groove is formed in an annular shape. The first adjustment surface and the second adjustment surface are formed in a disk-shaped flange portion having symmetrical shapes on both the front and back sides,
The air pressure confirmation master according to claim 2 or 3, wherein the flange portion is marked with a side surface portion of the peripheral edge to distinguish the first adjustment surface side and the second adjustment surface side. . A counter metal with an inverted frusto-conical workpiece seating surface formed on a chuck for gripping the workpiece;
A plurality of air discharge detection holes formed at positions away from the same circumference on the same circumference;
A detection flow path that connects an air supply source that supplies air at a predetermined pressure and the detection hole;
A pressure switch for detecting the secondary pressure of the throttling portion formed in the detection flow path;
A pressure regulator for adjusting the secondary pressure;
A workpiece seating detection device comprising: a frusto-conical adjustment surface corresponding to a workpiece seating surface; and an air pressure confirmation master including an adjustment groove formed circumferentially with respect to the adjustment surface.

Images