JP5876366B2 - Work indexing jig and machine tool using the jig - Google Patents

Description

  The present invention relates to a jig used to fix a workpiece to a table of a machine tool so that the workpiece can be indexed and rotated, and a machine tool that performs processing while indexing and rotating the workpiece by the jig.

  A machine tool that performs drilling or plane machining, such as a drilling machine, a milling machine, or a machining center, includes a table that fixes a workpiece and a tool shaft that rotates with a tool mounted on the tip. The tool axis and the table are provided so as to be relatively movable in a two-dimensional plane parallel to or orthogonal to the table surface, and the tool axis is provided so as to be movable back and forth in the axial direction.

  In order to perform 4-sided and 5-sided machining of workpieces with this type of machine tool, a jig equipped with an indexing table that rotates around an axis parallel to the table surface (work indexing axis. "Jig" or "jig"). The indexing jig includes a housing fixed to the table of the machine tool, an indexing base that rotates around the axis parallel to the table surface, that is, parallel to the bottom surface of the housing, and the indexing base around the axis. And a fitting pair fixed at every predetermined angle. As this fitting pair, a two-piece or three-piece surface gear pair called a Kirbic coupling or a hearth coupling is widely used. This fitting pair must be disengaged when the index table is rotated to change the posture of the workpiece. Therefore, this type of work indexing jig requires a driving means for rotating the indexing base and a driving means for fitting / removing the fitting pair.

  With an indexing jig that manually rotates the indexing base and mates the mating pair, unattended machining of the workpiece is not possible. In a tool indexing turret or table indexing / rotating device provided in a machine tool itself, the turret or table is generally rotated by an electric motor, and the mating pair is fitted / removed by a hydraulic piston. However, connecting an electric cable or hydraulic piping to an indexing jig that is frequently attached to or detached from the table causes a problem that the attaching / detaching work of the jig becomes troublesome. Further, it becomes impossible to turn the workpiece by rotating the table.

  Therefore, there has been proposed a workpiece indexing jig having a structure in which a handle for rotating the indexing base and a lever for fitting / removing the mating pair are operated by an operating tool mounted on the tool shaft. The workpiece indexing jig with such a structure prevents the indexing table from rotating and deviating from the indexing position due to unbalance of the workpiece attached to the indexing table when the mating pair is fitted and removed with the operation tool. For this purpose, a transmission system having a self-holding function such as a worm wheel or a cross bevel gear is used for the rotation drive system of the index base, or a brake device for suppressing the rotation of the index base is provided (Patent Documents 1 and 2). 3).

  In addition, fixing of the indexing base by a mating pair such as a pair of surface gears and a knock pin can firmly fix the indexing base with high accuracy, but the indexing base is fixed at a free angle shifted from the fitting position. Can not do it. In Patent Documents 4 and 5, a split piston provided with a fixed piston for fixing the coupling on the rotating side in a state where the coupling is disengaged in an indexing table using a three-piece Kirvic coupling as a fitting pair. A dispensing device has been proposed.

JP-A-7-323395 Japanese Utility Model Publication No. 6-42047 Japanese Patent No. 2974631 JP 2000-254836 A Japanese Patent No. 4339440

  This invention is a workpiece indexing jig that is mounted on a table of a machine tool and performs indexing rotation and fixing of the indexing table with an operating tool mounted on the tool axis of the machine tool, and the structure of the jig itself is simple. Thus, it is easy to control the rotation and fixing operation of the indexing table by the NC device, and when necessary, the workpiece indexing process can fix the indexing table at a free angle away from the fitting position of the fitting pair. The challenge is to provide ingredients.

  The workpiece indexing jig according to the present invention includes a main body 1 having a housing 11 fixed to a table of a machine tool and a rotary indexing base 2 for fixing the workpiece, and an operating tool with a rack 41 attached to a tool axis of the machine tool. 4 is provided.

  The index table 2 is supported by the housing 11 so as to be freely rotatable. The main body 1 includes a wheel gear 21 that is provided integrally with the index base and meshes with the rack 41 during operation, and a fitting pair 12 that fixes the wheel gear at a rotation angle for each predetermined angle.

  The index table 2 or the wheel gear 21 is disposed so that its back surface is in contact with a contact surface 17 formed on one end surface of the housing 11 and rotates. A pressing frame 31 is arranged on the outer peripheral side of the index base 2 or the wheel gear 21 on the side opposite to the housing, and a screw block 32 that biases the pressing frame toward the housing 11 is provided. The fitting pair 12 and the screw block 32 include engaging portions 52 and 37 (37a and 37b) that engage with and disengage from the operation tool 4.

  The screw block 32 moves the pressing frame 31 back and forth in the axial direction by the swinging motion of the indexing table 2 around the axis a, and moves or biases the pressing frame 31 toward the housing 11, thereby The back surface of the gear 21 is pressed against the contact surface 17 to fix the index table 2 by frictional force.

  A preferable structure is that the screw block 32 is screwed, that is, a movement by a screw action in a direction in which the pressing frame 31 is urged toward the housing, and the rear frame 33 provided on the rear side of the housing 11, the rear frame and the pressing frame 31. Is transmitted to the pressing frame 31 via a tie rod 34 connecting the two. The tie rod 34 is provided with a plurality of portions that protrude outward from the outer periphery of the wheel gear 21 on the outer peripheral portions of the pressing frame 31 and the rear frame 33, and connects the rear frame 33 and the pressing frame 31 at the protruding portions.

  The fitting pair 12 can be formed by a fitting pin 13 provided in the housing 11 so as to be able to advance and retreat, and a large number of fitting holes 23 provided in the index base 2 with a pitch angle that equally divides the circumference. In this case, a plurality of fitting pins 13 are provided, and the fitting pins are fitted at an angular interval obtained by adding an angular difference obtained by equally dividing the plurality of pitch angles of the fitting holes 23 to the pitch angle. The indexing base 2 can be fixed for each angle obtained by dividing the pitch angle of the joint hole 23 by the number of the fitting pins 13.

  The workpiece indexing jig according to the present invention performs a rotation operation of the wheel gear 21 of the main body, a fitting / removing operation of the fitting pair 12 and a swinging operation of the screw block 32 by the operation tool 4 with a rack mounted on the tool shaft of the machine tool. Then, the angle of the index table 2 is set and fixed to an angle specified by the workpiece machining program.

  A machine tool that processes a workpiece by attaching the workpiece indexing jig of the present invention to the table is indexed to the tool axis by an automatic tool changer when the indexing angle of the indexing table 2 is specified by the machining program. After the operation tool 4 is mounted, the rack 41 moves to a position where it engages with the wheel gear 21, and the index table 2 is rotated to a specified angle by one or more vertical movements in the axial direction of the tool shaft. When the indexing table rotating means and the set indexing angle are predetermined angles, that is, when the tool axis is a multiple of a unit angle that can be fixed by the fitting pair 12, the tool axis is fitted to the fitting pair 12. Indexing table fixing means for performing the fixing operation of the indexing table by the friction body 17 when the indexing table is fixed and the tool shaft is not a multiple.

  When the indexing jig fitting pair 12 includes a plurality of fitting pins 13, the indexing table fixing means performs the predetermined angle of the predetermined angle when performing the fixing operation of the indexing table by the fitting. The moving position of the tool axis is changed every angle that is an integral multiple of the set number. The predetermined integer is the number of fitting pins 13.

  According to the present invention, it is possible to rotate the indexing base of the detachable workpiece indexing jig fixed to the table of the machine tool to the specified angle and to fix at the angle with the operation tool 4 mounted on the tool axis. Therefore, the rotation and fixing of the indexing jig can be automated without using an electric cable or hydraulic piping. The indexing base can be fixed with high precision and firmness by fitting pairs in a predetermined angle unit, and can be fixed at a free angle by friction, and the posture of the workpiece can be set freely, and 15 degrees There is a feature that a general processing angle every 30 degrees can be held with high accuracy and strength.

  Moreover, the workpiece indexing jig of the present invention has a simple and compact structure of the jig itself, and the operation when rotating and fixing the indexing base with the tool axis can be performed by a combination of linear movement. Therefore, it is possible to simplify the macro program to be registered in the NC device in order to perform the operation, and it is possible to perform the operation in a short time.

Cross-sectional side view of workpiece indexing jig body Front view Rear view Front view of index stand Rear view Rear view of the main housing Front view Side view of the operation tool Flow chart showing the procedure of indexing operation FIG. 9 is a flowchart of the shortcut angle calculation step.

  A workpiece indexing jig according to the present invention includes a housing 11 fixed to a table of a machine tool, and an indexing tool attached to be rotatable about an axis parallel to a bottom surface of the housing, that is, a surface fixed to the table of the machine tool. A stand 2 and a fitting pair 12 for fixing the index stand for each predetermined angular position are provided. The index table 2 is configured such that a bearing 25 fitted in a bearing hole 24 provided on the back surface is fitted to a boss 18 projecting from the axial center portion of the housing 11 so as to be freely rotatable, and the back surface is formed on the end surface of the housing. It is attached so as to be in contact with the contact surface 17. An O-ring 26 is attached to the bearing hole 24 so as to be in sliding contact with the end face of the inner ring of the bearing 25, and provides resistance to the rotation of the index base 2.

  On the front side of the index table 2, that is, on the work mounting surface 3 side, a pressing frame 31 that sandwiches the index table 2 with the contact surface 17 is disposed. The pressing frame 31 has an opening at the center, and the front surface of the portion of the indexing table 2 that passes through the opening is the work mounting surface 3. A wheel gear 21 is formed on the outer periphery of the portion sandwiched between the abutment surface 17 of the index base 2 and the pressing frame 31.

  A shallow cylindrical recess is provided on the back surface of the housing 11, that is, on the end surface opposite to the contact surface 17, and a short cylindrical screw block 32 whose center is the axis of the indexing base is swingable in this cylindrical recess. Is fitted. The screw block 32 is provided with a male screw 35 on a part of the outer periphery thereof, and a female screw 36 provided in a center hole of the back frame 33 that closes the back side of the housing 11 is screwed to the male screw. Engagement levers 37 a and 37 b extending on both sides of the housing 11 are fixed to the screw block 32.

  The outer corners of the housing 11, the back frame 33, and the pressing frame 31 protrude to the outside of the wheel gear 21, and are provided with coaxial through-holes that penetrate in the axial direction of the four-part divided base. Yes. The pressing frame 31 and the back frame 33 are connected by a tie rod 34 through the through hole. The tie rod in the figure is a long bolt, and the pressing frame 31 and the back frame 33 are connected by a bolt head and a nut.

  An axial pin hole 14 is provided in the upper part of the housing 11, and a knock pin 13 is inserted into the pin hole. The pin holes 14 are opened in the contact surface 17, and knock holes 23 are provided on the back surface of the indexing base 2 at a constant pitch angle, in the illustrated example, at intervals of 15 degrees. A bracket 15 extending upward is fixed to the base end of the knock pin 13, that is, the end on the side opposite to the indexing base. At the upper end of the bracket 15, a cover plate 51 that closes the recess 16 provided to allow the bracket 15 to move in the axial direction is fixed by a bolt 52. The head of this bolt protruding from the cover plate 51 serves as an engaging portion for operating the knock pin.

  A sleeve 53 is fitted in the pin hole 14. The pin hole 14 is further provided with a single circumferential groove, and an O-ring 54 is fitted into the circumferential groove. The knock pin 13 has a shallow circumference at an advanced position, that is, a position where the tip of the knock pin 13 is inserted into the fitting hole 23 of the indexing base, and a retracted position, ie, a position where the tip of the knock pin 13 is inserted into the pin hole 14. A groove is provided, and the advance position and the retracted position of the knock pin 13 are held by fitting the O-ring 54 into the circumferential groove.

  In the illustrated apparatus, 24 fitting holes 23 of the indexing base 2 are provided with a pitch angle of 15 degrees, and three knock pins 13 are provided to be fitted and removed. The knock pins 13b and 13c on both sides are provided at positions where the angle around the rotation center axis a of the index base 2 is 20 degrees with respect to the center knock pin 13a. This 20 degrees is an angle obtained by adding 5 degrees to the pitch angle of the knock holes of the indexing base, and 5 degrees is an angle obtained by dividing the pitch angle 15 degrees into three equal parts. That is, the right knock pin 13b is the right-hand fitting hole at the position where the indexing base is rotated 5 degrees clockwise in FIG. 6 from the position where the central pin 13a is fitted in one fitting hole 23 of the indexing base. The left knock pin 13c is a position where it is fitted into the left adjacent fitting hole at a position rotated 5 degrees counterclockwise. Thus, the fitting hole provided in the indexing base is provided by providing the housing 11 with a pitch angle obtained by adding the angle obtained by dividing the pitch angle by n to the pitch angle of the knocking hole provided with n knock pins in the indexing base. It is possible to fix the index base 2 with the knock pin 13 for every 1 / n of the pitch angle.

  Since the back frame 33 cannot rotate around the axis, when the screw levers 32 are swung by alternately pushing down the engagement levers 37a and 37b, the rear frame 33 approaches and moves toward the housing 11 due to the forward and backward movement of the male screw 35 and the female screw 36. Move in the direction of separation. The length of the tie rod 34 is adjusted so that the pressing frame 31 firmly presses the back surface of the index base 2 against the contact surface 17 when the back frame 33 moves in a direction away from the housing 11.

  When fixing the index base 2 at a free angle at which the knock pin 13 does not fit, the engaging lever 37a on the side where the rear frame 33 is separated from the housing 11 is pushed down. At this time, the screw block 32 pushes the rear frame 33 away from the housing 11, and the pressing frame 31 connected by the tie rod 34 sandwiches the indexing table 2 between the contact surface 17 and the indexing table. 2 is fixed.

  As shown in FIG. 8, the operating tool 4 for operating the indexing jig having the above structure is a rod-shaped operating tool 4 including a rack 41 that meshes with the wheel gear 21. The operating tool is mounted on the tool shaft by the automatic tool changer of the machine tool, the rack 41 is engaged with the wheel gear 21, and the tool shaft is moved upward or downward in the axial direction, thereby rotating the index base 2. In the illustrated apparatus, the indexing base 2 rotates 30 degrees by moving the tool axis upward or downward with a set full stroke. When the index base 2 is rotated at an angle exceeding 30 degrees, after the tool shaft is moved by a full stroke, the wheel gear 21 and the rack 41 are disengaged by the lateral movement of the tool shaft, and the remaining angle is returned to the stroke origin. Move the minute in the tool axis direction. If the rotation angle of the index base 2 is 60 degrees or more, the full stroke movement of the tool axis is performed twice or more.

  If the indexing angle of the indexing base 2 is the position where one of the knock pins 13 is fitted, the tool shaft 42 moves above the housing 11 and the tip of the operation tool 4 is engaged with the engaging portion 52 of the corresponding knock pin. Then, the knock pin 13 is inserted into the opposing fitting hole 23 by the lateral movement of the tool shaft 42 to fix the rotation of the index base 2. If the indexing angle is an angle that cannot be fixed by the knock pin, the screw shaft 32 is swung to move the tool shaft 42 above the engaging lever 37a and descend, and the pressing frame 31 is used to squeeze the indexing table 2. The index base 2 is fixed by pressing the outer peripheral portion against the contact surface 17 of the housing. Next, when the index table 2 is rotated, the fixing is released by pushing down the opposite engagement lever 37b.

  The operation of the workpiece indexing jig by the NC device is performed by inserting a command including an indexing angle set in the machining program. FIG. 9 is a diagram showing a procedure of a macro program executed by the command. This macro program rotates the index table 2 by the difference in the index angle commanded from the current index angle of the index table, and when the angle difference exceeds 180 degrees, the macro program starts from 360 degrees. The index base is rotated at a short-cut angle obtained by subtracting the angle difference. If the set angle is a multiple of 5 degrees, the indexing base 2 is fixed by fitting the knock pin 13 and the fitting hole 23, and if it is any other angle, the indexing base 2 is fixed by the pressing frame 31. The index table 2 is fixed by pressing and frictional force.

  In the preparation step of FIG. 9, when the indexing of the index table is commanded by the machining program, the command angle θ is read to obtain the angle difference Δθ from the current angle stored in the NC device, and the angle difference is 0 degrees. If so, exit without doing anything.

  If the angle difference Δθ is not 0 degree, the tool is replaced with an operation tool, and the current angle is released in the current angle fixing release step. The release of the fixing is an operation of depressing the knock pin 13 fitted with the operation tool 4 by moving the tool shaft or pushing down the engaging lever 37b in a direction in which the rear frame 33 is brought closer to the housing. Which of these is performed can be determined by storing which fixing means was used at the time of the previous indexing.

Next, in the meshing inspection step, it is inspected whether the rack 41 and the wheel gear at the current angle can be meshed at the origin position of the rack 41. If there is a pitch deviation Δp between the two, the origin position is corrected at the first stroke of the rack 41, and the correction Δp is added to the angle difference Δθ. Δp is
Δp = current angle- (p * int (current angle / p))
It can be calculated by Here, p is a pitch angle of the wheel gear, and if Δp = 0, meshing can be performed without correction. int () is a function that returns the integer value of the quotient.

  Next, in the shortcut angle calculation step, when the angle difference Δθ exceeds 180 degrees in the plus or minus direction, the shortcut angle in the opposite direction is set as the angle difference Δθ ′. The angle difference Δθ ′ is a positive or negative angle of 180 degrees or less. The step of calculating the shortcut angle in the embodiment is performed according to the procedure shown in FIG. Where abs is a function that returns an absolute value.

  Next, in the rotation direction setting step, if the new angle difference Δθ ′ (both 180 degrees or less) is positive, the rack 41 is moved to the upper end of the full stroke that is the origin of the positive rotation, and if negative, the rack is reversed. The rack 41 is moved to the lower end of the full stroke that is the origin of rotation. When Δp is not zero, the rack 41 is moved upward by Δp from the set full stroke origin to ensure meshing between the rack 41 and the wheel gear 21. Engagement at the second and subsequent strokes is ensured by making the full stroke of the rack 41 an integral multiple of the pitch p of the wheel gear 21.

  If the angle difference Δθ ′ exceeds an integer multiple of the rotation angle (30 degrees in the embodiment) of the wheel gear 21 corresponding to the full stroke of the rack, the full stroke of the tool shaft 42 is moved up and down by that integer. Repeat and stroke the last remaining angle to rotate the index table 2 to the set angle. When the vertical movement is repeated, the movement of the tool axis is such that the rack 41 meshes with the wheel gear 21 and moves up or down, moves laterally away from the wheel gear 21 at the stroke end, disengages the rack, and returns to the origin. This is a movement that draws a rectangular trajectory of returning to the wheel gear 21 side and meshing the rack 41.

  Next, the angle determined in the fixing operation step is fixed. When the set angle θ is a multiple of an angle (5 degrees in the embodiment) that can be fixed by the knock pin 13, the index table 2 is fixed by fitting the knock pin 13 and the fitting hole 23. In the embodiment, since the pitch of the fitting holes 23 is 15 degrees and the number of the knock pins 13 is three and the fixation is possible every 5 degrees, the knock pins to be used are also selected. That is, if the set angle θ is divided by 15 degrees and the remainder is 0, the indexing base 2 is fixed with the center knock pin 13a, and if the remainder is 5 degrees, the right knock pin 13b is fixed. The index table 2 is fixed at 13c. Therefore, after the index table 2 is rotated to the set angle θ by the rack 41, the tool shaft 42 is lifted and moved horizontally to the position of the engagement portion 52 of the knock pin corresponding to the remainder angle divided by 15 degrees. By moving, engaging the engaging part and the tip of the operation tool 4 and moving in the axial direction of the indexing table 2, the corresponding knock pin is fitted into the fitting hole to fix the indexing table 2. .

  On the other hand, when the remaining angle obtained by dividing the set angle θ by 15 degrees is neither 0, 5, nor 10 degrees, after the index base 2 is indexed to the set angle, the tool axis is located above the fixed engagement lever 37a. The pressure frame 31 is moved to the abutment surface 17 side by the screw block 32, and the index base 2 is sandwiched and fixed between the press frame 31 and the abutment surface 17.

  In the last storing step, the set angle θ is stored in the NC device as the current angle, information on whether or not the index base is fixed by the screw block 32 is stored in the NC device, and the process is terminated. When the index angle is fixed with any knock pin, it can be determined by the remainder obtained by dividing the current angle by 15 degrees at the next index, so the corresponding knock pin may be degenerated to release the fixation. .

1 Main body 2 Rotating index table 4 Operating tool with rack
11 Housing
12 Mating pair
13 Mating pin
17 Contact surface
21 Wheel gear
23 Mating hole
31 Press frame
32 Screw block
33 Rear frame
34 Tie Rod
37 (37a, 37b) Engagement lever
41 racks
52 bolt a axis

Claims (5)

A main body having a housing fixed to the table of the machine tool, and an operation tool with a rack attached to the tool axis of the machine tool,
The body is
An index base supported by the housing so as to be freely rotatable;
A wheel gear provided integrally with the indexing base and meshing with the rack during operation;
A fitting pair for fixing the wheel gear at a predetermined rotation angle;
A pressing frame that presses the rear surface of the index table or wheel gear against the end surface of the housing;
A screw block that moves the pressing frame back and forth in the axial direction by a swinging motion around the axis of the indexing base,
The fitting pair and the screw block include an engaging portion that engages and disengages with the operation tool.
Work tool indexing jig for machine tools. In a workpiece indexing jig comprising a housing fixed to a machine tool table, a rotary indexing table for fixing a workpiece, and a fitting pair for fixing the indexing table at a predetermined angular position,
A wheel gear integral with the indexing table;
A pressing frame that is located on the outer side of the index table on the side opposite to the housing and whose rear surface faces the end surface of the housing with the index table or wheel gear interposed therebetween;
A rear frame disposed on the counter indexing side of the housing;
A screw block that is interposed between the rear frame and the housing, and that is screwed back and forth in the axial direction by swinging around the central axis of the index base;
A tie rod connecting the pressing frame and the back frame at a plurality of locations protruding outside the outer periphery of the wheel gear at the outer peripheral portion of the pressing frame and the back frame,
A workpiece indexing jig for a machine tool, which performs a rotation operation of the wheel gear, a fitting / removing operation of a fitting pair, and a swinging operation of a screw block by an operation tool with a rack mounted on a tool axis of the machine tool.   The fitting pair is provided in the housing so as to be movable back and forth, and a plurality of fitting pins that are fitted into and removed from fitting holes provided at a pitch angle that equally divides the circumference of the index table by the back and forth operation. The indexing jig according to claim 1, wherein the plurality of fitting pins are arranged at an angular interval obtained by adding an angular difference obtained by equally dividing the pitch angle to the pitch angle.   When the indexing angle of the indexing base is specified in the machining program, the indexing base is set to the specified angle by one or more vertical movements in the axial direction after attaching the indexing jig operation tool to the tool axis. Rotating index table rotating means, and when the set index angle is a multiple of a predetermined angle, the index table is fixed by fitting the index table, and when it is not a multiple, the index table is fixed by the friction body A machine tool comprising index table fixing means for performing an operation.   The indexing table fixing means changes the moving position of the tool axis at every predetermined integer multiple of the predetermined angle when performing the fixing operation of the indexing table by fitting. Item 5. The machine tool according to Item 4.

Images