KR20070054102A - Spindle device - Google Patents

Abstract

Provided is a spindle device capable of miniaturizing the device, and capable of easily determining the spring life of the tool holding of the collet chuck. The pressure reducing valve 32 is adjusted so that the pressing force of the piston 22 is the minimum pressing force satisfying the specification. The push rod is turned on at the position where the three-port solenoid valve 30 and the three-port solenoid valve 31 are turned on and the piston 22 is stopped, that is, the pressing force of the piston 22 and the reaction force of the spring 8 are balanced. The dog 71 is arrange | positioned in the position which the sensor 72 of 20 turns ON. When the sensor 72 does not turn on when the three-port solenoid valve 30 and the three-port solenoid valve 31 are turned on, it is determined that the spring 8 is a service life.

Spindle, Collet Chuck, Push Rod, Actuator, Solenoid Valve, Pressure Reducing Valve, Dog

Description

Spindle unit {SPINDLE DEVICE}

1 is a front sectional view of a main spindle device according to a first embodiment of the present invention.

2 is a front sectional view of a main shaft device according to a second embodiment of the present invention.

3 is a front sectional view of a main shaft device according to a third embodiment of the present invention.

4 is a front sectional view of a main shaft device according to a fourth embodiment of the present invention.

5 is a view showing the relationship between the operation frequency of the push rod and the pressure sensor output voltage.

Fig. 6 is a front sectional view of a conventional spindle device in a printed board punching machine.

※ Explanation of symbols for main parts of drawing

1: spindle 1t: tapered surface

2: collet chuck 2t: tapered surface

8: Spring (loading means) 20: Push rod (rod-shaped member)

22: piston (pneumatic actuator)

30: 3 port solenoid valve 31: 3 port solenoid valve

32: pressure reducing valve (predetermined pressure applying means)

30A, 30P, 42, 90: Pneumatic supply passage

71: dog 72: sensor (measuring means)

81: piezoelectric sensor (measuring means) 95: judging device (judgment means)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle device in machine tools such as a printed board puncher, and more particularly, to a spindle device in which a tool is held in a collet chuck having a slit.

Fig. 6 is a front sectional view showing a conventional spindle device in a printed board punching machine. In the same figure, the main shaft 1 is arrange | positioned at the center part of the case 10. As shown in FIG. The center of the main shaft 1 in the axial direction is connected to the bottom mounting hole 7 and the center of the bottom surface of the bottom mounting hole 7 and expanded to the tip side (lower side in the drawing). The tapered surface 1t of a female type is formed.

The outer periphery of the collet chuck 2 is formed with a male tapered surface 2t having the same angle as the data surface 1t, and a hole 4 for engaging the drill (tool 3) in the center portion is provided. It is perforated to extend in the axial direction. In addition, the collet chuck 2 has a plurality of cutting grooves (slits) (not shown) formed so as to extend from the tapered surface 2t to the hole 4 and at equal angle intervals in the circumferential direction. In addition, the diameter of the shank portion (part held by the collet chuck 2) of the tool 3 used in the printed board processing machine is formed with the same diameter irrespective of the nominal diameter of the tool 3.

The rod 5 is fixed to the rear end side of the collet chuck 2 (upper side in the drawing), and the guide bush 6 is fixed to the outer periphery of the rod 5. The plate spring 8 is compressed between the bottom face of the bottom attachment hole 7 and the guide bush 6 so as to push the collet chuck 2 upward in the drawing. Then, the tapered surface 2t comes into close contact with the tapered surface 1t so that the collet chuck 2 is elastically deformed and closed in the inner direction, and the drill 3 is driven by the friction force between the inner surface of the hole 4 and the surface of the drill 3. Firmly held.

 The case 10 is formed with a hole 11 to which the main shaft 1 fits freely and slidably. The coil (stator) 12 is arrange | positioned in the position which opposes the rotor 9 of the substantially center part of this hole 11 in the axial direction. The coil 12 is connected to an inverter power supply (not shown).

In the portion facing the hole 11 of the case 10, a plurality of air supply holes 13 constituting the journal gas bearing of the orifice throttle type are spaced in the radial direction and spaced at a predetermined interval in the axial direction (○). It is installed. The direction in which the air supply hole 13 discharges gas (here, compressed air) is a direction orthogonal to the axis (○), and in the case of illustration, two rows are arranged above and below the coil 12. The air supply hole 13 is connected (communicated) to the supply port which omits illustration (1st), respectively.

On the rear end side of the hole 11 (upper side in the drawing), an annular recess 11d formed to accommodate the flange 1f disposed on the rear end side of the main shaft 1 is provided. A plurality of air supply holes 15 are formed in the circumferential direction on the upper and lower surfaces of the annular recess 11d that face the flange 1f. The plurality of air supply holes 15 constitute a thrust machine body retainer in a form connected to a (second) supply port in which the air supply direction is directed toward the axis (○) direction, which is not shown.

The cylinder 25 is fixed to the upper part of the case 10. One end (the upper end of the figure) of the push rod 20 is fixed to the piston 22. The piston 22 is arrange | positioned in the chamber 25a of the cylinder 25, and these pistons and a cylinder comprise a pneumatic actuator. The chamber 25a on the upper side of the piston 22 is a cylinder port 30A of the three-port solenoid valve 30 by a supply port 23 formed in the cylinder 25 and a conduit 40 connected to the supply port 23. Is connected to. The chamber 25a under the piston 22 communicates with the hole 11 by the through hole 24 and the hole 25b formed in the lower part of the cylinder 25. A spring 26 disposed in the chamber 25a biases the piston 22 upwards in the figure.

The supply port 30P of the three-port solenoid valve 30 is connected to the compressed air source 90 by the conduit 41, and the discharge port 30R is opened. The coil 30C of the three-port solenoid valve 30 is connected to an NC device 100 that controls the entire printed board processing machine.

Next, the operation of the conventional spindle device having the above configuration will be described.

When replacing the drill 3, the three-port solenoid valve 30 is turned on, that is, electric power is supplied to the coil 30C. Then, the supply port 30P and the cylinder port 30A communicate with each other, the compressed air from the compressed air source 90 is supplied from the supply port 23 into the chamber 25a, and the piston ( 22) is lowered. In response to the lowering of the piston 22, the push rod 20 moves downward in the drawing to press the rod 5, and the collet chuck 2 moves downward in the drawing against the counter force of the disc spring 8. Let's do it.

When the tapered surface 2t of the collet chuck 2 is separated from the tapered surface 1t, the force acting in the inner diameter direction of the collet chuck 2 is lost, so that the drill 3 is easily removed from the collet chuck 2. I can make it. Next, when another drill 3 is inserted into the collet chuck 2 and the three-port solenoid valve 30 is turned off, the cylinder port 30A and the discharge port 30R communicate with each other, and the chamber 25a is connected. Compressed air is opened, and the piston 22 is raised by the biasing force (restoring force) of the spring 26. Following this, the push rod 20 moves upward in the drawing, the tapered surface 2t is pressed against the tapered surface 1t by the negative force of the dish spring 8, and the collet chuck 2 is closed. The drill 3 is thus strongly held on the main shaft 1.

Next, compressed air is supplied from a supply port (not shown). Then, the main shaft 1 is supported in the radial direction by aligning its axis with the axis ○ of the hole 11 by the function of the journal gas bearing, and in the direction of the axis (○) by the function of the thrust gas bearing. Supported. When a current is supplied to the coil 12 in this state, a rotating torque is generated in the rotor 9 by the magnetic field generated in the coil 12, and the main shaft 1 rotates.

Hereinafter, the NC apparatus 100 moves the case 10 to the axis line ((circle)) direction by means of omission of illustration, and processes a workpiece | work by the drill 3. As shown in FIG.

However, when dust adheres to the inner surface of the collet chuck 2 which is a tool holding means, or when the spring 8 has reached the end of its life, the force that the collet chuck 2 holds the tool 1 (hereinafter referred to as "tool holding force") Decreases. When the tool holding force is lowered, the drill 3 slips in the radial direction and / or the axial direction with respect to the collet chuck 2 at the time of machining, resulting in poor machining.

Therefore, there is a processing apparatus in which a tool holding force inspection device for inspecting a tool holding force is arranged on a table supporting a work, and the processing is performed after the tool holding force is inspected (Patent Document 1).

According to this technique, since the operator does not need to check the tool holding force, maintenance and maintenance can be facilitated, and processing quality and work efficiency can be improved.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-130502

However, the processing apparatus has to be large because the tool holding force inspection device must be placed on the table. In addition, when the spring has reached the end of its life, it takes time to specify that the decrease in tool holding force is due to the life of the spring.

SUMMARY OF THE INVENTION An object of the present invention is to provide a spindle device which can solve the above problems, can reduce the size of the device, and can easily specify the spring life.

As a result of investigating the cause of the decrease in the tool holding force, the present inventors pay attention to the fact that it takes time to identify the cause when the spring has reached the end of its life. It was also conceived to specify the spring life based on the reaction force of the spring.

In a first aspect of the present invention, a portion of the outer circumferential surface in the axial direction is formed on the tapered surface, and the main shaft includes a collet chuck having slit in the axial direction on the tapered surface, and a tapered surface engaged with the tapered surface. And a urging means for biasing the collet chuck against the main shaft so that the collet chuck hangs the tool, and a rod-shaped member for pushing down the collet chuck against the urging means to release the locking of the tool of the collet chuck. A spindle device comprising: a predetermined pressure imparting means capable of biasing the rod-shaped member with a predetermined force, a measuring means for measuring an amount of movement of the rod-shaped member, and the rod-shaped member by the predetermined pressure imparting means When the amount of movement of the rod-shaped member when pressing down exceeds a predetermined value, it is provided with a determination means for determining that the tax-paying means is a lifetime. And that is characterized.

The rod-shaped member is moved by a pneumatic actuator to release the collet chuck against the biasing means, and the predetermined pressure applying means is a pressure reducing valve interposed in the pneumatic pressure supply path of the pneumatic actuator.

Moreover, in the 2nd aspect of this invention, a part of an outer peripheral surface of an axial direction is formed in a taper surface, and the main shaft provided with the collet chuck which has a slit of an axial direction in this taper surface, and the taper surface which engages with the said taper surface, And a urging means for biasing the collet chuck against the main shaft so that the collet chuck hangs the tool, and a rod-shaped member for pushing down the collet chuck against the urging means to release the locking of the tool of the collet chuck. A spindle device comprising: measuring means for measuring a pressure acting on the rod-shaped member from the biasing means; and determining means for determining that the biasing means is a life if the measured pressure does not satisfy a predetermined value. It characterized by having a.

The measuring means is a piezoelectric element provided at the tip of the rod-shaped member, and is made by measuring the pressure from the biasing means in contact with the rod that supports the biasing means and moves with the deformation of the biasing means.

The rod-shaped member is moved by a pneumatic actuator to release the collet chuck against the biasing means, and the measuring means is measured by the movement of the rod-shaped member by the pneumatic actuator.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated, referring drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front sectional view of a main shaft device according to a first embodiment of the present invention, and the same reference numerals as those in Fig. 6 or the same functions will be omitted.

A three-port two-position switching solenoid valve 31 and a pressure reducing valve 32 are disposed in the conduit 41 connected to the outlet of the compressed air source 90. The supply port 31P of the three-port solenoid valve 31 is connected to the inlet of the compressed air source 90 and the pressure reduction valve 21. The cylinder port 31A of the three-port solenoid valve 31 is connected to the supply port 30P of the three-port solenoid valve 30 via the conduit 42. The discharge port 31R of the three-port solenoid valve 31 is connected to the outlet of the pressure reducing valve 32. The coil 31C of the three-port solenoid valve 31 is connected to the NC device 100 together with the coil 30C of the solenoid valve 30. The pressure reducing valve 32 communicates the inlet side with the air source, and outputs a predetermined predetermined pressure regardless of the inlet side pressure, and constitutes the predetermined pressure applying means.

The sensor 72 is disposed at the upper end of the case 10. The sensor 72 turns ON when facing the dog 71 provided on the push rod (rod-shaped member 20), and constitutes measuring means for measuring the movement amount of the rod-shaped member (rod). The sensor 72 is connected to the determination device 95. The determination device 95 outputs a signal to the NC device 100 that the sensor is in operation when the sensor 72 is turned on. When the sensor 72 is turned OFF, the determination device 95 indicates that the sensor 72 is turned OFF. The signal is output to the NC device 100. The dog 71 is fixed to the push rod 20. In addition, the dog 71 is positioned as follows.

That is, the pressure reducing valve 32 is adjusted so that the pressing force of the piston 22 may be the minimum pressing force satisfying the specification. In this state, the 3 port solenoid valve 30 and the 3 port solenoid valve 31 are turned on, and the piston 22 is lowered. Then, the sensor 71 is turned on at the position where the piston 22 is stopped, that is, the position where the pressing force of the piston 22 and the repulsive force of the spring 8 are balanced, and moves downward from the sensor 72. In one case, the sensor 72 is fixed to the push rod 20 at a position where the sensor 72 is not turned on.

Next, the operation of this embodiment will be described.

Prior to processing or whenever a predetermined time elapses, the 3 port solenoid valve 30 and the 3 port solenoid valve 31 are turned on. Then, the compressed air of the pressure determined by the pressure reducing valve 32 is supplied to the chamber 25a, and the piston 22 is lowered. When the predetermined time elapses, the determination device 95 checks the output of the sensor 72.

When the spring 8 has not reached the end of its life, the dog 71 faces the sensor 72 at the position where the piston 22 has stopped, and the sensor 72 is turned on. The judging device 95 confirming that the sensor 72 is turned on, outputs a processable signal to the NC device 100. The NC device 100 which has confirmed that the processable signal, i.e., the spring 8 has not reached its end of life, turns off the three-port solenoid valve 30 and the three-port solenoid valve 31, and waits for the next work start command. .

In addition, when the spring 8 has reached the end of its life, the push rod 20 is further lowered, so that the dog 71 deviates from the position facing the sensor 72 and no detection signal is output. Therefore, the determination device 95 outputs an unprocessable signal to the NC device 100, and activates an alarm device, for example, not shown. In addition, the NC device 100 that has received a non-machinable signal does not execute subsequent work until the spring 8 is replaced.

However, in this embodiment, since the main shaft 1 moves in the axial direction (up and down direction) accompanying the movement of the case 10, it is necessary to increase the capacity of the moving means for moving the main shaft 1, When the main shaft 1 is configured to be movable with respect to (10), the response speed of the main shaft 1 can be increased.

FIG. 2 is a diagram showing a second embodiment of the present invention, in which the same or the same functions as those in FIGS. 1 and 6 are denoted by the same reference numerals, and redundant description thereof will be omitted.

50 d of annular recessed parts which can accommodate the flange 1f of the main shaft 1 are provided in the flange part 50f provided in the lower part of the spindle holder 50. As shown in FIG. A plurality of air supply holes 15 are formed in the circumferential direction on the upper and lower surfaces of the annular recess 50d that face the flange 1f. The plurality of air supply holes 15 constitute a thrust gas bearing in a form connected to a (second) supply port in which the air supply direction is in the axial line (○) direction and not shown.

The flange part 50f is arrange | positioned inside the space 10k formed in the case 10, and is free to move to the axial direction ((circle)) direction. The length of the space 10k in the axis (○) direction is longer by the height G than the length of the flange portion 50f. The notch 50a which notched the spindle holder 50 in the axial direction is provided in the position which opposes the sensor 72 of the spindle holder.

The main shaft holder 50 is supported by the bearing 51 and is free to move in the direction of the axis (○). The bearing 51 is held in the case 10. The upper end of the main shaft holder 50 is fixed to the lower end of the mover 52 by a bolt (not shown).

The magnet 53b which forms the linear motor 53 with the coil 53a is arrange | positioned at the side of the movable body 52. As shown in FIG. The coil 53a is disposed on the base 54 that faces the magnet 53b. When the current is supplied to the coil 53a, the mover 52 moves along the axis ○. A spring 55 is disposed between the magnet 53b and the base 54. The spring 55 urges the mover 52 upward through the magnet 53b. As a result, when the linear motor 53 is OFF, a gap of height G is formed between the lower end of the flange portion 50f and the bottom portion of the space 10k.

The base 54 is fixed to the plate 56. In this embodiment, the case 10 is fixed to the supporting member of the plate 56, which is not shown. The cylinder 15 is fixed to the top of the base 54. The push rod 20 fixed to the piston 22 penetrates the movable body 52 and the spindle holder 50, and the lower end opposes the upper end of the rod 5. The sensor 72 is disposed above the case 10.

The attachment position of the dog 71 with respect to the push rod 20 is determined similarly to the case of the said 1st Embodiment in the state which positioned the main shaft 1 in the upper end side (in the case of illustration) of a movement. Moreover, you may determine the attachment position with respect to the push rod 20 of the dog 71 in the state which positioned the main shaft 1 in the lower end side of a movement.

In the present embodiment, the linear shaft 53 moves the movable member and the main shaft holder 50 integrally therewith in the vertical direction to move the main shaft 1 upward and downward through the flange portion 50f and the flange 1f. Go to.

Then, the three-port solenoid valve 30 is turned on, and the piston 22 and the push rod 20 are moved downward by supplying compressed air of a predetermined pressure determined by the pressure reducing valve 32 to the chamber 25a. When the tip of the push rod 20 moves while deforming the spring 8 in contact with the rod 52 and the dog 71 moves to a position deviating from the position facing the sensor 72, the determination device 95 Determines that the spring 8 is reaching the end of its life.

In the second embodiment, however, the structure is complicated because the push rod 20 penetrates the mover 52 and the spindle holder 50.

3 is a view showing a third embodiment of the present invention, and the same or similar functions as those in FIGS. 1, 2, and 6 are assigned the same reference numerals, and description thereof will be omitted.

The cylinder 60 is fixed in parallel with the base 54 on the plate 56. A guide 61 is fixed to the tip of the piston rod 60a of the cylinder 60. The shaft 62 is fixed to the guide 61. One end of the lever 63 is formed with a long hole 63a. This long hole 63a is engaged with the shaft 62. The lever 63 is free to rotate around the shaft 64. The shaft 64 is supported by a block 65 supported by the plate 56. The other end of the lever 63 faces the push rod 20.

A stopper 66 is fixed to the push rod 20. A spring 67 is disposed between the stopper 66 and the spindle holder 50. A gap is formed between the front end (lower end) of the push rod 20 and the upper end of the rod 5 by the spring 67.

In this embodiment, the 5-port solenoid valve 33 is used instead of the 3-port solenoid valve 30 in FIG. When the five-port solenoid valve 33 is OFF, compressed air is supplied above the cylinder 60, and the tip of the lever 63 is separated from the push rod 20 at this time. When a current is supplied to the coil 33c of the 5-port solenoid valve 33, the piston 60p is raised, the lever 63 is rotated counterclockwise, and the push rod 20 is pushed down.

In this embodiment, the push rod 20 is moved through the lever 63 instead of being moved directly by the piston, and since the operation is substantially the same as in the second embodiment, the detailed description is omitted.

By the way, the air pressure supplied to the chamber 25a above the piston 22 is not changed normally. Hereinafter, the case where no predetermined pressure applying means is provided will be described.

FIG. 4 is a view showing a fourth embodiment of the present invention, and the same reference numerals as those in FIG. 1 and FIG. 6 or the same functions will be omitted.

The recessed part 20a is arrange | positioned at the front-end | tip part of the push rod 20. As shown in FIG. In the recess 20, a pressure sensor 81 made of a piezo element (piezoelectric element) is arranged. The tip (lower part in the figure) of the pressure sensor 81 protrudes from 0.5 to 1 mm from the tip of the push rod 20. One end of the L-shaped hole 20b formed in the push rod is opened in the concave portion 20a, and the other end is opened in the hole 25b formed in the cylinder case 25. The signal line 84 of the pressure sensor 81 passes through the hole 20b and is connected to the determination device 95 through a through hole 83 provided in the case 25. The output voltage value E1 described later is input to the determination device 95 in advance.

5 is the reaction force of the number of operations of the push rod 20 (ie, the number of operations of the dish spring 8) and the output voltage E output from the piezoelectric element installed in the pressure sensor 81, and the counter spring 8. Is a tool holding force. As shown in the same drawing, when the number of times the operation of the push rod 20 reaches a certain number of times, the output voltage E gradually decreases, and the output voltage E is lower than the predetermined value E1 indicated by the dotted line in the drawing. You cannot hold (3) firmly. Thus, the output voltage value E1 is input to the determination device 95 as the minimum value of the voltage. That is, the pressure sensor measures the pressure acting on the push rod 20 from the spring 8, and detects the reaction force (stress) from the spring 8 as long as the air pressure acting on the chamber 25a is constant. When the degree of fatigue is detected and the output power E becomes less than or equal to the predetermined value E1, it is determined that the lifetime has been reached.

Next, the operation of this embodiment will be described.

When the push rod 20 is lowered to open the collet chuck 2, the pressure sensor 81 is pressed against the rod 5, and as a result, the reaction force of the dish spring 8 accompanies the lowering of the push rod 20. It is applied to the pressure sensor 81. Thus, when the push rod 20 is operated, the output voltage E of the pressure sensor 81 is monitored. When the value of the output voltage E when the push rod 20 is moved to a desired amount (usually, the total amount of movement of the push rod 20 is about 3 mm) becomes less than E1, the disc spring 8 It is determined that the service life has expired, and the determination device 95 outputs an unprocessable signal to the NC device 100, and operates an alarm device, for example, not shown. In addition, the NC device 100 that has received a non-machinable signal does not execute subsequent work until the spring 8 is replaced.

In the case of this embodiment, since the moving means of the push rod 20 when replacing the collet chuck 2 is substituted for the predetermined pressure applying means required in the case of the first to third embodiments, The predetermined pressure imparting means required in the embodiment becomes substantially unnecessary, and the structure is simple. In addition, since the tool holding force is checked every time the push rod 20 is operated, the tool holding force can be repaired immediately. Therefore, compared with the case of the said 1st-3rd embodiment, work efficiency can be improved further.

In addition, in the case where the NC device 100 has the function of the judgment device 95, the dedicated judgment device 95 may not be provided.

Since the tool holding force inspection device does not need to be placed on the table, the device can be made compact and the life of the spring can be immediately determined, thereby improving work efficiency.

Claims (5)

A collet chuck having a portion of the outer circumferential surface in the axial direction formed on the tapered surface, the tapered surface having slit in the axial direction; A main shaft having a tapered surface engaged with the tapered surface, Biasing means for biasing the collet chuck against the main shaft such that the collet chuck hangs and secures a tool; In the spindle device having a rod-like member for pressing the collet chuck against the biasing means to release the locking of the tool of the collet chuck, Predetermined pressure imparting means capable of biasing the rod-shaped member with a predetermined force; Measuring means for measuring an amount of movement of said rod-shaped member; And a judging means for judging that the biasing means is a life when the moving amount of the rod-shaped member when the rod-shaped member is pushed down by the predetermined pressure applying means exceeds a predetermined value. . The method of claim 1, The rod-shaped member is moved by a pneumatic actuator to release the collet chuck against the biasing means, And said predetermined pressure applying means is a pressure reducing valve interposed in the air pressure supply passage of said pneumatic actuator. A collet chuck having a portion of the outer circumferential surface in the axial direction formed on the tapered surface, the tapered surface having slit in the axial direction; A main shaft having a tapered surface engaged with the tapered surface, Biasing means for biasing the collet chuck against the main shaft such that the collet chuck hangs and secures a tool; In the spindle device having a rod-like member for pressing the collet chuck against the biasing means to release the locking of the tool of the collet chuck, Measuring means for measuring the pressure acting on the rod-shaped member from the biasing means; And a judging means for judging that the biasing means is a life when the measured pressure does not satisfy a predetermined value. The method of claim 3, wherein The measuring means is a piezoelectric element provided at the tip of the rod-shaped member, characterized in that made by measuring the pressure from the biasing means in contact with the rod supporting the biasing means and moving with the deformation of the biasing means. Spindle system. The method according to claim 3 or 4, The rod-shaped member is moved by a pneumatic actuator to release the collet chuck against the biasing means, And the measuring means is measured by the movement of the rod-shaped member by the pneumatic actuator.

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