JP6834377B2 - Multi-axis machine tool - Google Patents

Description

The present invention relates to a multi-axis machine tool equipped with a plurality of processing axes.

Machine tools such as machining centers are equipped with multiple machining axes parallel to each other in order to improve production volume and reduce installation space, and tools held on each machining axis are used between the machining axes on a jig on the table. It is known that a plurality of workpieces fixed according to the pitch of the above can be processed at the same time.
In such a multi-axis machine tool, when the machining time is long, the pitch between the machining shafts fluctuates due to heat generated from the motor, bearings, and the like. On the other hand, on the jig side, since the cutting fluid is applied to the machining area, the temperature of the jig is substantially equal to that of the cutting fluid. As a result, a difference occurs between the pitch between the machining shafts and the fixed pitch of the workpieces on the jig side, and an error occurs in the dimensional accuracy between the workpieces.
In order to suppress the occurrence of such an error due to heat generation, Patent Document 1 describes a displacement generator in which a temperature sensor is provided between a plurality of headstocks and has a heat generating means inside, and a position detection rod is extended. The invention of a multi-axis lathe erected perpendicular to the spindle is disclosed. Here, when the position of the headstock is displaced, the position detection rod detects the displacement amount of the position detector incorporated in the headstock, and when the displacement amount exceeds the reference value, the displacement amount becomes 0. It is heated or cooled, and the displacement generator is operated with the detection temperature detected by the temperature sensor as a target value at that time.
On the other hand, in Patent Document 2, a cooling fluid passage for lubricating the cooling fluid is formed along the heat generating portion between the spindle of the spindle head body and the base of the machine tool, and the base is provided with the cooling fluid circulating in the passage. An invention that reduces thermal deformation at the sliding portion on the side is disclosed. Therefore, even in a multi-screw machine tool, it is conceivable to adopt such a cooling structure across a plurality of spindle heads.

Japanese Unexamined Patent Publication No. 62-94202 Jikkenhei 5-74749

Since the invention described in Patent Document 1 is a technique for suppressing only the displacement between a plurality of headstocks, the difference between the pitch between the headstocks and the fixed pitch of the work cannot be suppressed. Also in the invention of Patent Document 2, since only the displacement on the head side of the spindle is suppressed by the cooling fluid passage, the difference from the fixed pitch of the work cannot be eliminated.

Therefore, the present invention provides a multi-axis machine tool capable of effectively suppressing the difference between the pitch between machining axes and the fixed pitch of the workpiece and improving the dimensional accuracy of the workpieces to be simultaneously machined. It is intended for.

In order to achieve the above object, the invention according to claim 1 uses a pair of left and right vertical machining axes arranged so that their axes are parallel to each other at a predetermined pitch, and works at the same fixed pitch as the pitch. and securable jig, and cutting fluid supply means capable of supplying machining fluid to the machining area of the work, Ri name includes a cooling means, the cooling of the machining axis cutting fluid,
A pair of left and right machining shaft housings that individually support each machining shaft are provided, and a Z-axis table that is connected across the machining shaft housings and is controlled to move in the vertical direction is provided.
Inside the Z-axis table, the cutting fluid supplied from the cutting fluid supply means flows to the upper center of the Z-axis table, separates from the upper center to the left and right, and then moves to the left and right outside of the Z-axis table. , A pair of left and right cooling paths are formed that rise on the left and right outside to reach the upper end of the Z-axis table.
By passing the cutting fluid through each cooling path, a cooling means for cooling each machining shaft is formed via the Z-axis table and each machining shaft housing .
The invention according to claim 2 is characterized in that, in the configuration of claim 1 , the cutting fluid used in the cutting fluid supply means is filtered and reused in the cooling means.

According to the first aspect of the present invention, by cooling the machining shaft with the cutting fluid supplied to the machining region, the pitch between the axes of the machining shaft and the fixed pitch of the workpiece are irrespective of the heat generated during machining. The difference between the above and the above can be effectively suppressed. Therefore, the dimensional accuracy of the workpieces to be simultaneously machined can be improved.
Further, since the cooling means is a pair of left and right cooling paths formed in the Z-axis table connected across the machining shaft housings and through which the cutting fluid passes, the machining shaft is used by using the Z-axis table. The housing and machining shaft can be cooled indirectly and rationally.
According to the second aspect of the invention, in addition to the effect of the first aspect , the cutting fluid used in the cutting fluid supply means is filtered and reused in the cooling means, which leads to the saving of the cutting fluid.

It is explanatory drawing from the front of a machining center. It is explanatory drawing from the side surface of a machining center. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 2 (however, only the Z-axis table is shown). FIG. 2 is a cross-sectional view taken along the line BB of FIG. 2 (however, only the connecting plate is shown).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view from the front of a 2-axis type machining center which is an example of a multi-axis machine tool, and FIG. 2 is an explanatory view from the side.
The machining center 1 has a column 3 at the upper rear side of the bed 2 that can be moved in the Y-axis direction (direction orthogonal to the paper surface in FIG. 1) by a guide portion and a feed shaft mechanism (not shown), and the front surface of the column 3 has a column 3. A Z-axis table 5 as a connecting body is provided via the guide portion 4. The Z-axis table 5 is moved and controlled in the Z-axis direction (vertical direction in FIGS. 1 and 2) by a feed axis mechanism (not shown).

A pair of left and right spindle heads 6 and 6 are fixed to the front surface of the Z-axis table 5. Each spindle head 6 drives the spindle motor 8 by supporting the spindle 9 as a machining shaft downward through a bearing (not shown) in the spindle housing 7 as a machining shaft housing having a spindle motor 8 at the upper end. The spindle 9 is rotated with. A holder 10 for mounting the tool T is provided at the lower end of the spindle 9. On the lower surface of each spindle housing 7, on the left and right outer sides of the holder 10, replacement arms 11 for exchanging the tool T with a tool magazine (not shown) are provided.

On the other hand, on the bed 2, an X-axis table 12 whose movement is controlled in the X-axis direction (left-right direction in FIG. 1) by a guide portion and a feed axis mechanism (not shown) is provided, and an X-axis table 12 is provided on the upper surface of the X-axis table 12. A jig plate 14 as a jig is provided via the cover 13. The jig plate 14 is provided with positioning pins 15 and 15 for positioning the two workpieces W and W, respectively, below the spindle heads 6 and 6, and is provided with a clamp (not shown) for fixing the workpieces W and W, respectively. Here, the pitch P1 between the axes of the main shafts 9 and 9 parallel to each other is set to be equal to the fixed pitch P2 (pitch between the centers of the positioning pins 15 and 15) of the works W and W.

The installation surface of the X-axis table 12 on the bed 2 is an inclined surface 16 that inclines downward toward the rear, and a cutting fluid supply device 18 is connected to the end of the inclined surface 16 via a recovery pipe 17. ing. The supply device 18 includes a pump 19 that delivers the cutting fluid stored in the internal tank at a predetermined supply pressure, and a delivery pipe 20 to which the cutting fluid is delivered is connected to the tank. The first branch pipe 22 and the second branch pipe 23 are connected to the downstream end of the delivery pipe 20 via a bifurcated branch pipe portion 21. Of these, the first branch pipe 22 is connected to the upper left side of the Z-axis table 5, and the second branch pipe 23 passes between the left and right spindle heads 6 and 6 and between the front surfaces of the spindle housings 7 and 7. It is connected to the upper back surface of the connecting plate 24 as an erected connecting body.

As shown in FIG. 3, the Z-axis table 5 to which the first branch pipe 22 is connected is formed by connecting the upper block 25 and the lower block 26, which are vertically divided, with bolts 27 and 27, and Z Inside the shaft table 5, there is a first horizontal hole 28 extending horizontally from the upper side of the left side surface to which the first branch pipe 22 is connected to the central portion, and a horizontal direction extending from the lower side of the left and right side surfaces to the central portion. A pair of left and right second horizontal holes 29, 29 are formed so as to extend to and close the side surface side. Further, in the central portion of the Z-axis table 5, a pair of left and right first vertical holes 30 and 30 whose upper ends intersect with the first horizontal holes 28 and whose lower ends intersect with the ends of the second horizontal holes 29 on the same side, respectively. A pair of left and right second vertical holes that extend downward from the lower position of the first horizontal hole 28 on the left and right outer sides of the first vertical holes 30 and 30 and whose lower ends intersect with the intermediate portions of the second horizontal holes 29 on the same side. Holes 31 and 31 are formed.

Therefore, in the Z-axis table 5, the cutting fluid sent from the first branch pipe 22 is divided into the left and right first vertical holes 30 and 30 in the central portion through the first horizontal hole 28, and then descends to the left and right. The first cooling passage 32 as a pair of left and right inverted F-shaped cooling means, which moves from the second horizontal holes 29, 29 to the left and right outside, rises from the middle portion to the second vertical holes 31, 31 and reaches the upper end. 32 will be formed. The front surface of the Z-axis table 5 is connected to the upper ends of the second vertical holes 31 and 31, and the internal pipes 33 and 33 are connected to the chambers 34 and 34 provided at the lower ends through the left and right spindle housings 7 and 7. Is provided. Cleaning nozzles 35, 35 ... With their tips directed toward the replacement arm 11 are provided on the lower surface of each chamber 34.

On the other hand, as shown in FIG. 4, the connecting plate 24 has a substantially rectangular shape in front view in which the upper portion is tapered upward and has a concave portion 37 formed on the rear surface excluding the outer peripheral portion. , The flat plate-shaped rear plate 38 is connected with the bolts 39, 39 ... At the four corners. Here, by screwing the left and right bolts 39 and 39 into the front surface of the main shaft housing 7 on the same side, the connecting plate 24 is connected so as to straddle both at the center of the left and right main shaft housings 7 and 7. .. The second branch pipe 23 is connected to the upper center of the rear plate 38, extends in the left-right direction below the connection portion of the second branch pipe 23 in the recess 37 of the front plate 36, and is interrupted in front of the outer peripheral portion. A horizontally elongated trapezoidal ridge 40 is formed and is in contact with the front surface of the rear plate 38. Therefore, in the connecting plate 24, a second cooling passage 41 is formed as a cooling means to reach the lower end after the cutting fluid sent from the second branch pipe 23 is divided into left and right by the ridge 40.

At the lower end of the front plate 36, six cutting fluid supply nozzles 42, 42 ... Are provided downward at equal intervals, and three left and right supply nozzles 42, 42 ... Are on the same side, respectively. It corresponds to work W. However, here, of the three supply nozzles 42, 42 ..., the two outer supply nozzles 42, 42 are directed to the region including the machining point by the tool T, respectively, and the one inner supply nozzle 42 is It is directed to the jig plate 14 side. Therefore, a cutting fluid supply means is formed here from the supply device 18 to the supply nozzle 42 via the delivery pipe 20, the branch pipe portion 21, the second branch pipe 23, and the connecting plate 24, and the cutting fluid supply means is formed. A second cooling passage 41, which is one of the cooling means, will be incorporated into the room.

In the machining center 1 configured as described above, the same tools T and T are mounted on the holders 10 and 10 of the left and right spindles 9 and 9, the spindles 9 and 9 are rotated, and the Z-axis table 5 is rotated on the Y-axis and the Z-axis. While the movement is controlled in the direction, the two same workpieces W and W are fixed to the jig plate 14 at a fixed pitch P2, and the X-axis table 12 is controlled to move in the X-axis direction. Further, by exchanging the tools T and T with the tool magazine (not shown) via the exchange arms 11 and 11 at a predetermined timing, the predetermined machining can be performed.

During processing, the pump 19 of the supply device 18 is driven to send the cutting fluid in the tank from the delivery pipe 20 to the first and second branch pipes 22 and 23 via the branch pipe portion 21, respectively. As described above, the cutting fluid from the first branch pipe 22 passes through the left and right first cooling passages 32 and 32 of the Z-axis table 5 and reaches the chambers 34 and 34 from the internal pipes 33 and 33, and from each cleaning nozzle 35. The chips that are ejected and adhere to the replacement arm 11 are removed. On the other hand, the cutting fluid from the second branch pipe 23 passes through the second cooling passage 41 of the connecting plate 24 and then is ejected from each supply nozzle 42 to cool the tool T and the work W, and also the jig plate 14. Cooling.
The cutting fluid ejected from the cleaning nozzle 35 and the supply nozzle 42 flows backward on the inclined surface 16 together with the chips, is collected by the supply device 18 via the collection pipe 17, is filtered by a filter (not shown), and then returns to the tank. .. Therefore, it is sent from the delivery pipe 20 to the Z-axis table 5 and the connecting plate 24 again and circulates.

In this way, the cutting fluid passes through the first cooling passage 32 of the Z-axis table 5 and the second cooling passage 41 of the connecting plate 24, so that the Z-axis table 5 and the connecting plate 24 are cooled to a temperature close to that of the cutting fluid. The left and right spindle housings 7 and 7 connected to these and the spindles 9 and 9 inside the housings 7 and 7 are also cooled to the same temperature. On the other hand, the jig plate 14 also becomes the same temperature as the cutting fluid when the cutting fluid is applied.
Therefore, even if the pitch P1 between the spindles 9 and 9 fluctuates due to heat generated from the motor, bearing, or the like, the displacement is close to that of the cutting fluid. Similarly, even if the fixed pitch P2 fluctuates due to the heat generated by the workpieces W and W, the displacement is the same as that of the cutting fluid. Therefore, the difference between the two pitches P1 and P2 becomes small, and the dimensional error between the left and right workpieces W and W can be suppressed.

As described above, according to the machining center 1 of the above-described embodiment, the work W is fixed by a pair of spindles 9 and 9 arranged so that their axes are parallel to each other at a predetermined pitch P1 and a fixed pitch P2 which is the same as the pitch P1. A possible jig plate 14, a cutting fluid supply means (supply nozzle 42 from the supply device 18) capable of supplying the cutting fluid to the machining area of the work W, and a cooling means (first) for cooling the spindles 9 and 9 with the cutting fluid. By including the cooling passage 32 and the second cooling passage 41), the difference between the pitch P1 between the axes of the spindles 9 and 9 and the fixed pitch P2 of the workpieces W and W is effective regardless of the heat generated during machining. Can be suppressed. Therefore, the dimensional accuracy of the workpieces W and W that are simultaneously machined can be improved.

In particular, here, the second cooling passage 41 is incorporated in the cutting fluid supply means from the supply device 18 to the supply nozzle 42, and the cutting fluid used in the second cooling passage 41 is used in the supply nozzle 42 for cutting. The cooling means can be rationally formed by using the liquid supply means, and even if the cooling means is provided, the cost increase can be suppressed. Further, since the same cutting fluid cools the spindle housing 7, the work W, and the jig plate 14, the temperatures of the two are likely to be close to each other, and the effect of suppressing the difference between the pitches P1 and P2 is enhanced.
Further, since the cutting fluid used in the cutting fluid supply means is filtered and reused in the first cooling passage 32 and the second cooling passage 41, the cutting fluid can be saved.

Further, a spindle housing 7 that individually supports each spindle 9 is provided, and a Z-axis table 5 and a connecting plate 24 that are connected across the spindle housings 7 and 7 are provided to provide cooling means. , The first cooling path 32 formed in the Z-axis table 5 through which the cutting fluid passes and the second cooling path 41 formed in the connecting plate 24 through which the cutting fluid passes, so that the Z-axis table 5 and the connecting plate 24 can be used to indirectly and rationally cool the spindle housings 7, 7 and the spindles 9, 9.

The configuration of the cooling path in the Z-axis table is not limited to the above form, and can be appropriately changed as long as the left and right spindle housings can be cooled evenly, such as by forming the cooling path in a meandering shape. The structure of the Z-axis table itself is not limited to that consisting of upper and lower blocks, and may be formed from three or more blocks, or may be a combination of front and rear plates such as connecting plates.
Similarly, the configuration of the cooling path in the connecting plate is not limited to the above form, and the form of the ridges can be changed (for example, triangular shape) to increase the number of ridges, or the ridges can be eliminated to form a cooling path such as a Z-axis table. It can be changed as appropriate as long as the left and right spindle housings can be cooled evenly and the cutting fluid can be evenly distributed to the supply nozzles. The structure of the connecting plate itself is not limited to that of the front and rear plates, and a combination of upper and lower blocks such as a Z-axis table may be used.
Further, the structure is not limited to a structure in which a cooling path is provided in the connecting body such as a Z-axis table or a connecting plate to indirectly cool the processed shaft housing such as the spindle housing, and the cooling path is provided in the processed shaft housing such as the spindle housing. It is also possible to adopt a structure in which the machined shaft housing is directly cooled by forming the above.

In the above embodiment, the first cooling path of the Z-axis table is provided on the upstream side of the cleaning nozzle that supplies the cutting fluid to the replacement arm. However, if the cleaning nozzle is not provided, the internal pipe is connected to the connecting plate. The cutting fluid may be merged at the connecting plate so that the cutting fluid is supplied to the machining area only from the supply nozzle. On the contrary, a supply nozzle may be provided in the chamber, the connecting plate and the chamber may be connected by a pipe, the cutting fluid may be merged with the chamber side, and the cutting fluid may be supplied to the machining area from the supply nozzle on the rear side.
However, it is possible to provide cooling means only on one of the front and rear without using cooling means on the front and rear connecting bodies of the connecting plate and the Z-axis table as in the above embodiment.

On the other hand, in the above embodiment, cooling means (first cooling path and second cooling path) are incorporated in the cutting fluid supply path from the supply device to the cleaning nozzle and the supply nozzle, respectively, but they are independent of the cutting fluid supply path. It is possible to form a cooling means by connecting the supply device with the first cooling passage and the second cooling passage by a route.
In addition, the present invention is applicable not only to a vertical machining center but also to a horizontal machining center, and a machine tool such as a lathe or a multi-tasking machine other than the machining center may be used. Further, the present invention in which the machining shaft is cooled by the cutting fluid can be adopted even in a multi-axis machine tool equipped with three or more machining shafts, not limited to the one provided with a pair of machining shafts as in the above embodiment. ..

1 ... Machining center, 2 ... Bed, 3 ... Column, 5 ... Z-axis table, 6 ... Spindle head, 7 ... Spindle housing, 9 ... Spindle, 12 ... X-axis table, 14 ... Tool plate, 15 ... positioning pin, 16 ... inclined surface, 17 ... recovery pipe, 18 ... supply device, 19 ... pump, 20 ... delivery pipe, 22 ... 1st branch pipe, 23 ... 2 branch pipes, 24 ... connecting plate, 32 ... 1st cooling path, 35 ... cleaning nozzle, 41 ... 2nd cooling path, 42 ... supply nozzle, P1 ... pitch between spindles 9 and 9 , P2 ... Work W, W fixed pitch.

Claims (2)

A pair of left and right vertical machining axes arranged so that their axes are parallel to each other at a predetermined pitch.
A jig that can fix the work at the same fixed pitch as the above pitch,
A cutting fluid supply means capable of supplying the cutting fluid to the machining area of the workpiece,
Ri Na includes a cooling means for cooling each said machining axis cutting fluid, and
A pair of left and right machining shaft housings that individually support each of the machining shafts is provided, and a Z-axis table that is connected across the machining shaft housings and is controlled to move in the vertical direction is provided.
Inside the Z-axis table, the cutting fluid supplied from the cutting fluid supply means flows to the upper center portion of the Z-axis table, and after being divided into left and right and descending from the upper center portion, the Z-axis table A pair of left and right cooling paths are formed by moving to the left and right outside, rising the left and right outside, and reaching the upper end of the Z-axis table.
A multi-axis machine tool characterized in that, when a cutting fluid passes through each of the cooling paths, the cooling means for cooling each of the machining shafts is formed via the Z-axis table and the machining shaft housings. The multi-axis machine tool according to claim 1 , wherein the cutting fluid used in the cutting fluid supply means is filtered and reused in the cooling means.

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