JP4190083B2 - Pallet clamp structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clamp structure suitable for a pallet that can be attached to and detached from a spindle of a machine tool.
[0002]
[Prior art]
In order to facilitate the processing of the workpiece or the transfer of the workpiece, the workpiece is conventionally fixed to a pallet, and the pallet is attached to the processing table or sent out on a conveyor.
[0003]
In this way, the pallet is provided with clamp claws for fixing the workpiece during processing or conveyance. As disclosed in Japanese Patent Publication No. 4-60772 and the like, this clamping claw clamping structure has a piston inserted into a cylinder and a rod having one end attached to the piston, and is attached to the tip of the rod protruding outside the cylinder. A clamp claw is attached, and a strong elastic member such as a disc spring is arranged between the piston and the inner wall of the cylinder, and the clamp claw is always urged in the closing (clamping) direction to work during processing and conveyance. Safety is ensured so that the work does not fall off the pallet due to carelessness of the worker.
[0004]
And in order to make an unclamped state, compressed fluid is supplied to the chamber on the opposite side to the chamber in which the elastic member is stored among the chambers defined in the cylinder by the piston, and resists the elastic member. The clamp pawl is moved in the opening direction.
By the way, in Japanese Patent Publication No. 4-60772, the rod screw with a clamp pawl attached to one end and the piston are separated so that the resistance during opening operation can be reduced and the amp lamp can be smoothly operated. It has the structure which connected these through.
[0005]
On the other hand, in a processing station, a prior art in which a pallet is automatically attached to and detached from a processing table using an accurate positioning function by numerical control (NC) of a machine tool is disclosed in Japanese Patent Application Laid-Open No. 55-70543. And JP-A-55-112753.
[0006]
[Problems to be solved by the invention]
When a compressed fluid such as compressed air is used to apply a force in the unclamping direction to the clamp pawl, it takes time until the pressure of the fluid chamber in the cylinder overcomes the elastic force of the elastic member.
[0007]
Therefore, it is conceivable to use incompressible hydraulic oil (oil) instead of the compressed fluid. However, if this idea is applied as it is to the apparatus proposed in Japanese Patent Laid-Open Nos. 55-70543 and 55-112753, a working oil passage for opening and closing the clamp pawl is provided in the machine tool. There must be.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a pallet clamping structure that includes a clamp claw that is constantly urged in a clamping direction by a resilient member and is detachable from a spindle of a machine tool. A fluid chamber for forming a coolant channel connected to a coolant (cutting fluid) channel formed on the main shaft of the cylinder and causing the coolant channel to act on the clamp pawl against the elastic member in the unclamping direction. Further, pressure increasing means (booster) for supplying a force in the unclamping direction larger than the elastic force of the elastic member to the fluid chamber was connected to the coolant channel.
[0009]
With such a configuration, the responsiveness of the unclamping operation is improved, and it is not necessary to perform special processing on the spindle of the machine tool, and the pallet clamping claw can be opened and closed with the existing spindle. it can.
[0010]
In addition, a check valve that is opened by a member on the machine tool side when the pallet is mounted on the spindle of the machine tool and closed when the pallet is removed from the spindle of the machine tool is installed in the coolant channel formed on the pallet side. It is preferable to provide it.
[0011]
By setting it as such a structure, it waits in the state with which the coolant flow path in the pallet and the fluid chamber were filled. And since it is connected to the main spindle of the machine tool from this state, when the pressure is increased by the pressure increasing means (booster), the coolant is already filled in the pallet, so the pressure is immediately transmitted, and almost the same as the start of the operation of the pressure increasing means. At the same time, it can be in an unclamped state.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a schematic perspective view of an entire processing station incorporating a machine tool having a pallet holding structure according to the present invention, FIG. 2 is a plan view of the processing station, FIG. 3 is a side view of the processing station, and FIG. FIG. 5 is a plan view of a processing station according to another embodiment, FIG. 6 is a side view showing a pallet stocker of the processing station according to another embodiment, and FIG. 7 is a side view of the machine tool. FIG. 8 is a side view of the machine tool as viewed from the opposite side to FIG. 7, FIG. 9 is a view showing the connection structure between the spindle tip of the machine tool and the pallet, and FIG. 10A is the spindle of the machine tool. (B) is an enlarged view of a state in which a machining tool is held by the spindle of the machine tool, FIG. 11 is a diagram showing a hydraulic circuit for opening and closing the pallet clamping pawl, and FIG. For processing table device FIG. 13 is a side view showing a state where the machine tool is processing a workpiece, FIG. 14 is a side view showing a balance mechanism of the processing table device, and FIG. FIG. 16 is a view similar to FIG. 14 showing another embodiment, FIG. 17 is a sectional view taken along the line CC of FIG. 16, and FIG. FIG. 19 is an enlarged view of FIG. 18, and FIG. 20 is a cross-sectional view taken along line AA of FIG.
[0013]
As shown in FIGS. 1 to 4, the processing station is provided with a base 1, a machine tool 100 and a processing table device 200 are placed on the base 1, and the machine tool 100 is surrounded outside the base 1. A pallet stocker 300 is disposed on the machine tool 100, and an auto tool changer (ATC) 400 is disposed above the machine tool 100.
[0014]
In the machine tool 100, a turn block 101 can be swiveled in a horizontal plane around a vertical axis with respect to a base 1, and the pallet stocker 300 includes a plurality of pallet receiving frames 301. These pallet receiving frames 301 and the processing table device 200 is arranged substantially radially around the turning center of the machine tool 100, and the tip of the transfer line L <b> 1, which serves as both loading and unloading of the workpiece W, faces the workpiece supply position 500. It is said.
As a result, the machine tool 100 faces the processing table device 200, the pallet stocker 300, and the workpiece supply position 500.
[0015]
In the machine tool 100, a support portion 103 is attached to the turn block 101 around a horizontal axis 102 so as to be tiltable in a vertical plane by driving a motor 104. A main bearing 105 is attached to the support portion 103 with a motor 106. Further, a main shaft (spindle shaft) 107 that is rotated at a high speed by a motor (not shown) is supported in the main bearing 105.
[0016]
As shown in FIGS. 12 and 13, the main bearing 105 is attached to a male screw rod 110 extending rearward from the support portion 103 via a nut member 111, and the male screw is driven by the motor 106. By rotating the rod 110, the nut member 111 moves along the guide rod 112, and the main bearing 105 moves forward and backward together with the nut member 111.
[0017]
As the support portion 103 tilts in the vertical plane, the main shaft 107 faces a direction that matches the height of the processing table device 200, the pallet stocker 300, or the auto tool changer 400 as shown in FIG. 3 or FIG. .
[0018]
Further, as shown in FIG. 8, the base end of the lever 108 is attached to the end of the horizontal shaft 102 opposite to the motor 104, and the rod of the balance cylinder 109 is attached to the tip of the lever 108, so that the main bearing It absorbs the imbalance of the weight accompanying the forward / backward movement of 105.
[0019]
The structure of the tip of the main shaft 107 is a structure that can be selectively held by a pallet P on which the workpiece W is mounted and a machining tool T that performs machining such as cutting and drilling on the workpiece.
[0020]
The holding structure of the pallet P and the processing tool T by the main shaft 107 will be described with reference to FIGS.
A through hole 107a is formed in the main shaft 107 in the axial direction, and a tip portion of the through hole 107a is a receiving recess 113. The receiving recess 113 is, as shown in FIG. 10, a female tapered portion 113a and a female tapered portion 113a. When holding the pallet P, the straight shank portion 601 of the outer block 600 of the pallet P is connected to the straight portion 113b of the receiving recess 113 as shown in FIG. When fitting and holding the processing tool T, the tapered cone portion 700 of the processing tool T is fitted to the female tapered portion 113a of the receiving recess 113 as shown in FIG.
[0021]
In the present invention, the main shaft 107 holds the pallet P and the processing tool T. In this case, if the pallet P and the processing tool T are held at the same portion of the receiving recess 113, the pallet P becomes a heavy weight when the work W is attached, and the surface of the receiving recess 113 may be damaged. When the machining tool T is held in the receiving recess 113 whose inner surface is damaged, the main shaft 107 rotates at a high speed during machining, so that the rotational axis of the machining tool T is shaken or the backlash machining accuracy is deteriorated.
[0022]
Therefore, as described above, the shape of the receiving recess 113 is not a simple female taper shape, but a straight portion 113b is provided continuously to the female taper portion 113a, and the straight shank portion 601 of the pallet P is held by the straight portion 113b. A part of the pallet P was prevented from contacting the female taper portion 113a.
[0023]
An annular convex portion 602 is formed on the surface of the outer block 600 of the pallet P facing the main shaft 107, and this convex portion 602 is in contact with the end surface of the main shaft 107 in the holding state.
[0024]
If the entire opposing surface of the outer block 600 is brought into contact with the end surface of the main shaft 107, the contact area is large, and there is a risk of rattling. However, by causing the convex portion 602 with a small area to contact, Can be prevented. Further, since the annular convex portion 602 contacts the end surface of the main shaft 107, the pallet can be accurately held even if a slight gap or the like occurs in the straight portion 113b and the straight shank portion 601 due to deformation or twisting. .
[0025]
Further, as shown in FIG. 9, a clamping sleeve 115 that is advanced and retracted (moved left and right in the figure) by a cylinder (not shown) faces in a through hole 107 a formed in the main shaft 107, and outside the clamping sleeve 115. A gripper 116 having a slit in the axial direction is provided, and the inside of the clamping sleeve 115 is a coolant flow path 117.
[0026]
Thus, when the clamping sleeve 115 is located on the left side of the state of FIG. 9, the gripper 116 is reduced in diameter, and the straight portion 601 of the pallet P can be received and pulled out from the recess 113. When a cylinder (not shown) is driven from such a state, the clamping sleeve 115 is pulled to the right side in the drawing. Then, the male taper portion of the clamping sleeve 115 enters the gripper 116, expands the gripper 116, receives the straight portion 601 of the pallet P, and firmly holds it between the straight portion 113 b of the recess 113.
[0027]
Further, as shown in FIG. 9, the structure of the holding part of the pallet P is such that the shank part 600 is fixed to the main body of the pallet P via a fixing member 603. A common through hole is formed in the fixing member 603 and the shank portion 600, and a check valve 604 is inserted into the through hole.
[0028]
The check valve 604 is urged in a protruding direction by a spring 605 provided between the main body of the pallet P, and a valve seat surface 606 in which a land portion of the check valve 604 is formed on the fixing member 603 when not being held by the main shaft 107. Abuts closely.
[0029]
A passage 607 is formed in the check valve 604, and this passage 607 is connected to a coolant (cutting fluid) supply source via a coolant passage 117 in the clamping sleeve 115.
[0030]
As shown in FIGS. 9 and 11, the coolant from the supply source unclamps the clamp claws 608 via the coolant channel 607 in the check valve 604, the coolant channel 611 in the pallet P, and the coolant pipe 612. The fluid is supplied to the fluid chamber 610.
[0031]
The pallet P is provided with four clamp claws 608 for fixing the workpiece W. The clamp pawl 608 is attached to one end of the rod 613, and the other end of the rod 613 is inserted into the cylinder 614 and connected to the piston 615. The piston 615 defines the inside of the cylinder 614 as the fluid chamber 610 and another chamber 616, and the clamp pawl 608 is always in the clamping direction by a strong resilient member 609 such as a disc spring provided in the chamber 616. It is energized. In FIG. 9, reference numeral 618 denotes a stopper.
The clamping / unclamping operation of the clamp pawl 608 will be described below.
[0032]
First, in a state where the pallet P is not held by the main shaft 107, the coolant passage 609 and the coolant pipe 610 in the pallet P are closed by the check valve 604 as described above. The fluid chamber 610 that applies a force in the unclamping direction to the clamp pawl 608 is filled with a coolant. However, since the force of the elastic member 609 is larger than the force applied from the coolant in the fluid chamber 610, the clamp pawl 608 maintains the clamped state.
[0033]
On the other hand, FIG. 9 shows a state in which the pallet P is held by the main shaft 107. In this state, the check valve 604 is pushed inward by the clamping sleeve 115 against the elastic force of the spring 605, and the check valve The land portion of 604 is separated from the valve seat surface 606 formed on the fixing member 603, and the coolant flow path communicates.
[0034]
Even if the coolant flow path communicates, the force of the resilient member 609 is large, so that the clamp pawl 608 maintains the clamped state. In order to enter the unclamped state against the force of the elastic member 609, as shown in FIG. Thereby, the pressure in the chamber 610 becomes larger than the elastic force of the elastic member 609, and the clamp pawl 608 is in an unclamped state.
[0035]
As described above, the coolant is used as the fluid for operating the clamp claw 608 without using hydraulic oil. The coolant is necessary when cutting or drilling with a machine tool. By using this coolant as the working fluid, piping for supplying hydraulic oil is unnecessary and the structure of the main spindle is used as it is. be able to.
[0036]
Further, since the coolant and the passage formed in the pallet P are always filled with the coolant, the pressure transmission when the booster 617 is pressurized in order to unclamp the clamp claw 608 is instantaneously performed. Clamp operation can be switched reliably and without delay.
[0037]
On the other hand, in the processing table apparatus 200, the support block 201 can be swiveled in a horizontal plane around the vertical axis with respect to the base 1, and a horizontal shaft 202 is attached to the support block 201. One end of the horizontal shaft 202 is provided with a motor 203 (see FIG. 2) for rotating the horizontal shaft 202.
[0038]
The horizontal shaft 202 is provided with a balance mechanism on the other end side of the horizontal shaft 202 in order to rotate the processing table together with the processing table, which is a heavy object, and the pallet P to which the workpiece W is attached.
[0039]
As shown in FIGS. 14 and 15, this balance mechanism is provided with brackets 204a and 204b on a support block 201, a base portion of a cylinder unit 205 is attached to the bracket 204a, and one end of a rod 204c is attached to the bracket 204b. The lower end of the plate 206 is fixed to the bracket 204a by welding or the like, and the tip of the rod 204c is attached to the tip of the plate 206 via a nut so that the position can be adjusted.
Further, a shaft 207 is rotatably supported on the plate 206, a crank 208 is attached to one end of the shaft 207, a gear 209 is attached to the other end, a rod of the cylinder unit 205 is connected to the crank 208, and A timing belt 211 is stretched between the gear 210 provided on the other end of the horizontal shaft 202 and the gear 209.
Here, when the machining table 212 is stopped in a state where it is in a lateral position with respect to the horizontal axis 202 and is in a position where a torsional force is applied to the horizontal axis 202, the upper side or lower side of the timing belt 211 (gears 209, 210 ) Is in a tension state, and a force in the direction of falling (rightward force in FIG. 14) acts on the plate 206. In this state, an excessive force acts on the lower end mounting portion of the plate 206, and the rod 204c prevents the tension plate 206 from falling down.
[0040]
A rotary joint 213 (see FIG. 17) is provided outside the gear 210 of the horizontal shaft 202. Since this rotary joint 213 is attached to the end of the horizontal shaft 202, a general balance mechanism as applied to a machine tool cannot be adopted, and the above-described structure is adopted.
[0041]
Thus, since the machining table 212 is attached to the horizontal shaft 202, the weight of the machining table 212 acts as a torsional moment on the horizontal shaft 202, but the cylinder unit 205 is driven and this driving force is applied. By applying a force in a direction opposite to the torsional force to the horizontal shaft 202 via the crank 208, the shaft 207, the gear 209, the timing belt 211, and the gear 210, the horizontal shaft 202 is canceled and the balance is maintained. This balance can be maintained even when the processing table 212 is located at any position of 360 ° around the horizontal axis 202.
[0042]
FIGS. 16 and 17 are views similar to FIGS. 14 and 15 showing another embodiment of the balance mechanism. In this embodiment, a gear 214 is used instead of the timing belt 211, and other members are described. It is the same as the embodiment shown in FIGS.
[0043]
In the above-described machine tool 100, the lever 108 is attached to the horizontal shaft, and the rod 100 of the balance cylinder 109 is attached to the tip of the lever 108. If it cannot be attached, as described above, the movement of the shaft may be transmitted to the balance cylinder via a lever or a crank provided at a location separated via a timing belt or a gear train.
[0044]
Next, the structure of the processing table 212 will be described with reference to FIGS. Claws 215 for clamping the pallet P are provided at the four corners on the mounting surface side of the processing table 212, and sensors 216 for confirming the seating of the pallet P are provided at positions inside the clamp claw 215. As a structure of the sensor 216, for example, air is constantly ejected, and when the pallet P is seated, the pallet P closes the air ejection port and detects this.
[0045]
Further, on the back side of the processing table 212, a turning motor 217 for turning the pallet (90 °) in a state in which the clamp by the claw 215 is released is provided, and a chuck 218 for preventing the pallet P from dropping in the state in which the clamp is released. Is provided at the center on the mounting surface side of the processing table 212.
The chuck 218 opens and closes by combining a cylinder unit (not shown) and a link mechanism.
[0046]
The machining table 212 is provided with an arm 219 that pivots integrally with the pallet P by the turning motor 217. Proximity switches 220 and 221 that regulate the turning position of the arm 219 are 90 ° on the machining table 212 side. In addition, a triangular plate 222 is attached to the arm 219, and the rotation of the pallet P is stopped without impact by applying the plate 222 to the dampers 223 and 224 provided on the processing table 212 in this turning limit. I have to.
[0047]
The dampers 223 and 224 have external threads engraved on the outer periphery and are attached to the support plate 227 via nut members 225 and 226 so that the position of the dampers 223 and 224 can be adjusted. Yes.
[0048]
In addition, two lifting cylinders 228 and 229 are provided at positions away from the center on the back side of the processing table 212, and locating pins 230 and 231 for positioning the pallet P by the operation of the lifting cylinders 228 and 229 are provided. It appears on the mounting surface side of the processing table 212.
[0049]
Next, the pallet stocker 300 will be described. In the pallet stocker 300, a plurality of pallet receiving frames 301 are arranged so as to surround the machine tool 100 as shown in FIG. Each pallet receiving frame 301 stores one pallet P.
[0050]
By the way, in the present invention, it is possible to machine the six surfaces (entire surface) of the workpiece W. When processing the workpiece W while the workpiece W is fixed to the pallet P, the processing table 212 is rotated, or the pallet P is rotated while being held on the processing table 212 to process up to five surfaces. Can do. However, the remaining one surface, that is, the surface attached to the pallet P cannot be processed because the pallet P itself becomes an obstacle.
[0051]
Therefore, in the present invention, as will be described later, when the workpiece W is processed to a predetermined surface, another pallet P is prepared, the workpiece W is transferred to the pallet P, and the remaining unprocessed surface is transferred to the pallet P. I try to process.
[0052]
Therefore, in order to process the entire surface of the workpiece W, two types of pallets P are required, and in the example shown in FIG. 2, six pallet receiving frames 301 are arranged. Can do.
[0053]
As shown in FIGS. 1 and 3, the pallet receiving frame 301 is structured such that the pallet mounting portion 302 is inclined forward and upward toward the horizontal axis 102 of the machine tool 100, and a stopper 303 of the pallet P is provided at the rear end. In order to receive the pallet P from the pallet placing part 302, the main bearing 105 is made parallel to the pallet placing part 302 by the tilting movement of the support part 103 of the machine tool 100, and the main bearing 105 is placed on the pallet in this state. As shown in FIG. 9, the straight portion 601 of the pallet P is fitted into the receiving recess 113 of the main shaft 107, and the clamping sleeve 115 is pulled in to expand the gripper 116. Open and hold the pallet P with the main shaft 107.
[0054]
1 to 4, the pallet stocker 300 surrounds about 180 ° around the machine tool 100, and the workpiece carry-in line L1 also serves as a workpiece carry-out line.
By adopting such a configuration, it is possible to cope with the machining of the three types of workpieces W as described above. However, since the workpiece carry-in line L1 also serves as the carry-out line, the machining procedure is restricted.
[0055]
Therefore, an example in which the carry-in line and the carry-out line of the work W are separated is shown in FIGS. 5 and 6. Here, FIG. 5 is a plan view of a processing station according to another embodiment, and FIG. 6 is a side view showing a pallet stocker of the processing station according to another embodiment.
[0056]
In this embodiment, the workpiece carry-in line L1 and the workpiece carry-out line L2 are provided on a straight line, and the machine tool 100 is positioned between them. The pallet stocker 300 is located on one side of the line, and the machining table device 200 is located on the other side. The layout is designed so that the left and right objects are arranged as a whole, and the degree of freedom increases in consideration of the balance with the arrangement of other devices.
[0057]
On the other hand, since the workpiece carry-in line L1 and the workpiece carry-out line L2 are provided on a straight line, the space for arranging the pallet stocker 300 is reduced. Therefore, in this embodiment, the pallet receiving section 301 is provided with two upper and lower pallet mounting portions 302 so that two types of pallets P are stocked on one pallet receiving frame 301.
[0058]
The lower pallet placing part 302 is the same as described above, but the upper pallet placing part 302 is inclined downward toward the horizontal axis 102 of the machine tool 100, and a stopper 303 of the pallet P is provided at the front end. Provided.
[0059]
Further, as shown in FIG. 1, an auto tool changer (ATC) 400 disposed above the machine tool 100 includes a tool stocker 401 in which a number of machining tools T are held in a gun belt shape, and the tool stocker 401 and the spindle. And an exchange device 402 for exchanging the tool T with the machine 107.
[0060]
The tool stocker 401 is movable in an annular shape, and the exchange device 402 is provided with tool holders 405 at both ends of an arm 404 that pivots about an axis 403 as shown in FIG. 4, and a tool holder 405 is attached to one of these two tool holders 405. The tool to be returned from the machine 100 to the tool stocker 401 is held on the other side, and the tool T newly attached to the spindle 107 of the machine tool 100 is held from the tool stocker 401, and exchange is performed by combining turning and forward / backward movement.
[0061]
Next, a procedure for machining 6 surfaces (entire surface) of the workpiece W such as a cylinder block in the machining station having the above configuration will be described with reference to FIGS. 21 to 34, FIGS. 21 to 23, 25, 26, 30, 31, 31, 33, and 34 are schematic plan views of the processing station, and the remaining drawings are schematic side views. .
[0062]
First, as shown in FIG. 21, the machine tool 100 is turned around the vertical axis, the main shaft 107 of the machine tool 100 is directed to the pallet P1 as shown in FIG. 22, and then the pallet P1 is held by the main shaft 107. This state is also shown in FIG.
[0063]
Then, the machine tool 100 is swung around the vertical axis in the opposite direction as described above, and the spindle 107 is directed to the workpiece supply position 500 and the spindle 107 is placed above the workpiece W as shown in FIG. The pallet P1 held in the state 107 is exposed.
[0064]
Thereafter, the clamping claw 608 is opened by the clamping / unclamping mechanism using the coolant as the working fluid, and when the workpiece W is positioned, the workpiece W is fixed to the pallet P1 by the clamping claw 608.
[0065]
Next, as shown in FIGS. 23 and 24, while the workpiece W is fixed to the pallet P1, the main shaft 107 is tilted upward and the machine tool 100 is turned about the vertical axis to hold the pallet P1 held on the main shaft 107. Is positioned below the processing table 212 facing downward, and the main shaft 107 is further tilted upward to press the back surface of the pallet P1 (the side opposite to the workpiece holding surface) against the mounting surface of the processing table 212, and the pallet P1 is moved. Delivered to the processing table 212 side.
[0066]
Thereafter, the machining tool T is attached to the spindle 107 from which the pallet P1 has been removed, and a predetermined surface of the workpiece W is machined by the machining tool T as shown in FIG.
When the machining in the state shown in FIG. 13 is completed, the pallet P1 is turned 90 ° to the right, the right side is turned 90 ° to the left, and the left side is machined, and further, the machining is performed about the horizontal axis 202. The table 212 is rotated 90 ° in the vertical plane to process the upper surface of the workpiece.
[0067]
Thus, the processing of the front surface, the left and right side surfaces, and the upper surface of the workpiece W is completed. At this time, the four surfaces of the workpiece W are processed, and the rear surface and the bottom surface (the mounting surface to the processing table 212) of the workpiece W remain unprocessed.
[0068]
Therefore, as shown in FIG. 25, the main shaft 107 is retracted, the tool T held at the tip of the main shaft 107 is returned to the tool stocker 401, and the tip of the main shaft 107 is emptied in the direction of the second pallet P2. The machine tool 100 is turned. Here, the pallet P2 is provided with a positioning hole or the like for attaching the upper surface of the workpiece W.
[0069]
If the machine tool 100 is directed in the direction of the second pallet P2, as shown in FIG. 26, the pallet P2 is held by the main shaft 107, and the machine tool 100 is swung in the opposite direction as shown in FIG. As shown in FIG. 27, the pallet P2 is positioned above the work W fixed to the pallet P1.
[0070]
Thereafter, the pallet P2 is attached to the upper surface of the workpiece W. At this time, the workpiece W is sandwiched between the pallet P1 and the pallet P2. Thereafter, the holding state of the pallet P1 by the processing table 212 is released, and only the processing table 212 is rotated about 180 ° around the horizontal axis, and the processing table 212 is positioned above the pallet P2.
[0071]
Next, as shown in FIG. 28, the pallet P <b> 2 is held on the processing table 212. In this state, the pallet P2 is held on both the machining table 212 and the main shaft 107.
Thereafter, the main shaft 107 is removed from the pallet P2, the support block 201 is rotated 180 ° around the vertical axis, the holding portion of the pallet P1 is directed to the main shaft 107, and the pallet P1 is held by the main shaft 107 as shown in FIG. Then, the engagement state between the workpiece W and the pallet P1 is released. In order to hold the pallet P1 with the main spindle 107, the holding of the pallet P2 by the main spindle 107 is released from the state of FIG. 28, and then the processing table 212 is rotated about 180 ° around the horizontal axis, and the holding section of P1 is moved to the main spindle 107. Alternatively, the pallet P1 may be held by the main shaft 107 and the pallet P1 may be removed from the workpiece W, and the processing table 212 may be rotated about 180 ° around the horizontal axis again so that the workpiece W faces downward.
[0072]
Thereafter, as shown in FIG. 30, the machine tool 100 is turned around the vertical axis, and the pallet P1 held at the tip of the main shaft 107 is returned to the pallet stocker. And as shown in FIG. 31, the tool T is attached to the front-end | tip of the main axis | shaft 107, and the surface left in the unprocessed year with this tool T is processed.
[0073]
After the six surfaces of the workpiece W have been machined in this way, the tool T is removed again from the tip of the spindle 107, and the pallet P2 is held at the tip of the spindle 107 as shown in FIG. And the machine tool 100 is turned around the vertical axis while holding the pallet P2 at the tip of the main spindle 107, and the processed workpiece W is returned to the workpiece supply position 500 as shown in FIG.
[0074]
Then, as shown in FIG. 34, the pallet P2 is returned to the original position of the pallet stocker, and a series of operations is completed.
[0075]
【The invention's effect】
As described above, according to the present invention, the coolant flow path is formed in the pallet that can be attached to and detached from the spindle of the machine tool, and the coolant is generated in the fluid chamber that generates the pressure for unclamping via the spindle of the machine tool. First, the response speed is faster than the conventional unclamping mechanism using compressed fluid, and the coolant is used as the working fluid, so there is no need to change the main shaft. Free.
[0076]
Also, by providing a check valve, the coolant flow path and the fluid chamber in the pallet are maintained filled with the coolant when the pallet is removed from the machine tool. Therefore, the pallet is mounted on the spindle of the machine tool. At this point, it is not necessary to distribute the coolant to the coolant flow path and the fluid chamber in the pallet, so that unclamping is possible immediately.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a processing station to which a pallet clamping structure according to the present invention is applied. FIG. 2 is a plan view of the processing station. FIG. 3 is a side view of the processing station. FIG. 5 is a plan view of a processing station according to another embodiment. FIG. 6 is a side view showing a pallet stocker of the processing station according to another embodiment. FIG. 7 is a side view of a machine tool. FIG. 9 is a side view of the machine tool as viewed from the opposite side to FIG. 7. FIG. 9 is a view showing a coupling structure between the spindle tip of the machine tool and the pallet. FIG. Fig. 11B is an enlarged view of the state in which the machining tool is held by the spindle of the machine tool. Fig. 11 is a diagram showing a hydraulic circuit that opens and closes the clamp pawl of the pallet. Palette FIG. 13 is a side view showing a state where the machine tool is processing a workpiece. FIG. 14 is a side view showing a balance mechanism of the processing table device. FIG. FIG. 16 is an enlarged view with a part cut away. FIG. 16 is a view similar to FIG. 14 showing another embodiment. FIG. 17 is a cross-sectional view taken along the line CC of FIG. FIG. 19 is an enlarged view of FIG. 18. FIG. 20 is a cross-sectional view taken along the line AA in FIG. 19. FIG. 21 is a plan view showing a work procedure at the processing station. FIG. 23 is a plan view showing the procedure of work at the processing station. FIG. 24 is a plan view showing the procedure of work at the processing station. FIG. 25 is a plan view showing the procedure of work at the processing station. Fig. 26 Hands working at the processing station FIG. 27 is a plan view showing the work procedure at the processing station. FIG. 28 is a plan view showing the work procedure at the processing station. FIG. 29 is a plan view showing the work procedure at the processing station. 30 is a plan view showing a procedure of work at the processing station. FIG. 31 is a plan view showing a procedure of work at the processing station. FIG. 32 is a plan view showing a procedure of work at the processing station. [Figure 34] Plan view showing work procedure at the work station [Fig. 34] Plan view showing work procedure at the processing station [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Base, 100 ... Machine tool, 101 ... Turn block, 102 ... Horizontal shaft, 103 ... Support part, 104 ... Motor, 105 ... Main bearing, 106 ... Motor, 107 ... Main shaft, 108 ... Lever, 109 ... Balance cylinder, DESCRIPTION OF SYMBOLS 110 ... Male screw rod, 111 ... Nut member, 112 ... Guide rod, 113 ... Receiving recessed part, 113a ... Female taper part, 113b ... Straight part, 115 ... Clamping sleeve, 116 ... Gripper, 117 ... Coolant flow path, 200 ... Processing table device, 201 ... support block, 202 ... horizontal shaft, 203 ... motor, 204a, 204b ... bracket, 205 ... cylinder unit, 206 ... plate, 207 ... shaft, 208 ... crank, 209, 210, 214 ... gear, 211 ... Timing belt, 212 ... Processing table, 213 ... Rotor -Joint, 215 ... Clamp claw, 216 ... Sensor, 217 ... Motor for rotation, 218 ... Chuck, 219 ... Arm, 220, 221 ... Proximity switch, 222 ... Plate, 223, 224 ... Damper, 225, 226 ... Nut member, 227 ... support plate, 228, 229 ... elevating cylinder, 230, 231 ... locate pin, 300 ... pallet stocker, 301 ... pallet receiving frame, 302 ... pallet placing part, 303 ... stopper, 400 ... auto tool changer (ATC), DESCRIPTION OF SYMBOLS 401 ... Tool stocker, 402 ... Tool changer, 500 ... Work supply position, 600 ... Outer block, 601 ... Straight shank part, 602 ... Convex part, 603 ... Fixing member, 604 ... Check valve, 605 ... Spring, 606 ... Valve Seat surface, 607 ... passage 608 ... Clamp claw, 609 ... Elastic member, 610 ... Fluid chamber, 611 ... Coolant flow path in pallet, 612 ... Coolant piping, 613 ... Rod, 614 ... Cylinder, 615 ... Piston, 616 ... Houses the elastic member Chamber in cylinder, 617 ... Booster, 700 ... Taper cone portion of machining tool T, L1 ... Work carry-in line, L2 ... Work carry-out line, P, P1, P2 ... Pallet, T ... Work tool, W ... Work.

Claims (2)

A clamp claw always biased in the clamping direction by a resilient member ;
The pawl provided with a clamp structure for operating the clamping and unclamping direction, Oite the clamp structure with palette which is detachable to the main spindle of a machine tool,
In the clamp structure, a coolant flow path connected to a coolant flow path formed on the spindle of the machine tool is formed,
The coolant channel formed on the pallet side communicates with a fluid chamber for applying a force in the unclamping direction to the clamp pawl against the elastic member ,
A check valve is provided that opens when a pallet is mounted on the machine tool spindle, and closes when the pallet is removed from the machine tool spindle.
A pallet with a clamp structure , wherein the clamp structure is filled with a coolant . A pallet with a clamp structure according to claim 1 ;
In a machine tool comprising the pallet with a clamp structure detachably attached to a main shaft, connected to a coolant passage formed on the pallet, and a coolant passage formed on the main shaft.
Further, a pressure increasing means for supplying a force in the unclamping direction larger than that of the elastic member to the fluid chamber is connected to the coolant channel.
A machine tool characterized by

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