JPH0258048B2 - - Google Patents

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Application Field The present invention provides a support device for a tool drive unit in a machine tool, in particular, a support device for a tool drive unit that moves up and down with respect to a column. It is lifted and lowered along a pair of left and right guide rails extending in the vertical direction on the front side of the elevator frame, and on the front side of this lifting frame, the elevator frame is rotated around an axis in a direction inclined with respect to the front-rear direction in a horizontal plane. This invention relates to a support device for a tool drive unit in a machine tool in which a leaning tower type turret head is supported.

(2) Prior art Machine tools equipped with tool changing turrets have been known for a long time, as seen in Japanese Patent Publication No. 47-32112 and Japanese Patent Application Laid-open No. 52-122976. The lifting frame of the tool drive unit that moves up and down is raised and lowered along a guide rail that extends vertically on the front side of the column. Devices for supporting tool drive units in machine tools are also known, such as the one shown in FIG. 5, in which a leaning tower turret head is supported which is pivoted about an axis.

In FIG. 5, a pair of left and right guide rails 91 and 92 are provided on the front side of a column 90 of the machine tool and extend in the vertical direction, and a vertical feed screw The guide rail 9 receives a moving force in the vertical direction from the guide rail 94.
Go up and down along 1,92. At the tip of the cylindrical support part 95 formed in the front part of the elevating frame 93, there is a leaning tower type turret head 96 that rotates around an axis in a direction inclined with respect to the front-rear direction in a horizontal plane.
The outer periphery of the cylindrical connecting portion 97 of the turret head 96 is rotatably supported on the inner periphery of the cylindrical support portion 95 of the lifting frame 93 via a bearing 98. The outer peripheral flange 93f at the outer end of the cylindrical support part 95 and the outer peripheral flange 96f at the connecting part of the turret head 96 can be slid into contact with each other on their opposing surfaces, and a tapered surface is formed on the back side. An annular clamp 99 is fitted to the outer circumferential surfaces of these outer circumferential flanges 93f and 96f to prevent the turret head 96 from pivoting relative to the elevating frame 93 as necessary.

A gear 100 is integrally fixed to the end surface side of the cylindrical connecting portion 97 of the turret head 96, and a bevel gear 102, a bevel gear 102,
A bevel gear 103 and a gear 105 that are rotationally driven via a gear shaft 104 are meshed with each other.

The rotational driving force of the tool rotation motor 106 disposed on the lifting frame 93 is generated by the tool rotation motor 106.
A joint 107, a gear 108, connected to the output shaft of
109, 110, a spline 111 on the gear shaft of the gear 110, and a drive-side engaging member 113 of the clutch 112, which is fitted onto the spline 111 and is operated to move in the axial direction via a bearing 114 by a clutch operation cylinder 115. is transmitted to the base end of a spindle 117 rotatably fitted into the inner circumferential side of the spindle head 116 of the turret head 96. A tool holder 120 that holds a tool shaft 119 of a tool 118 is held at the tip of the spindle 117 so as to be able to rotate integrally with the spindle 117.

The turret head 96 is connected to the spindle head 11.
In addition to the tool holder 6, there is another turret head 121, and a spindle 122 that holds a tool holder 123 at its tip is rotatably fitted into this spindle head 121. Each spindle head 116, 121 has a corresponding spindle 1
17 and 122 are formed so that their central axes are at different levels so that they do not interfere with each other, and during operation, they are in the position of the spindle head 116 shown by the solid line and are in line with the spline 111. During a tool change, the turret head 96 pivots to occupy the position of the spindle head 121, which is shown in phantom.

(3) Problems to be Solved by the Invention In the conventional tool drive unit support device shown in FIG.
Since both are arranged in the same vertical plane in the left and right direction, the distance from the guide rail 92 to the connection part of the turret head 96 is much longer than the distance from the guide rail 91 to the connection part of the turret head 96. The amount of overhang from the rail 92 is large. For this reason, the mechanical rigidity of the tool drive unit A' is not sufficient, which tends to cause vibrations due to the cutting load during cutting with the tool and a decrease in the horizontal accuracy of the spindle 117. The amount of thermal displacement of A' was also not small, which was inconvenient in improving machining accuracy.

Therefore, the present invention provides a support device for a tool drive unit in a machine tool that prevents vibrations caused by cutting loads and a decrease in the horizontal precision of the spindle, reduces the amount of thermal displacement of the tool drive unit, and further improves machining accuracy. The main purpose is to obtain.

B. Structure of the Invention (1) Means for Solving Problems According to the present invention, the elevating frame of the tool drive unit that moves up and down with respect to the column has left and right sections extending vertically on the front side of the column. The tool drive unit is lifted and lowered along a pair of guide rails, and on the front side of this lifting frame supports a leaning tower type turret head that is rotated around an axis that is inclined with respect to the front-rear direction in a horizontal plane. In the supporting device, one of the pair of guide rails is disposed relatively forward of the other guide rail so that both of the guide rails are located close to the turret head. A support device for a tool drive unit in a machine tool is obtained.

(2) Function One guide rail of the pair of left and right guide rails is located relatively forward of the other guide rail so that each guide rail is located close to the leaning tower type turret head. As a result, the amount of overhang of the tool drive unit from each guide rail is extremely small compared to conventional equipment.
The mechanical rigidity of the tool drive unit is increased, suppressing vibrations caused by cutting loads and deterioration of horizontal accuracy of the spindle, and the amount of thermal displacement of the tool drive unit is also reduced, resulting in further improvement of machining accuracy.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIGS. 1 and 2, a horizontal moving table 3 is mounted on the machine tool bed 1 and is moved horizontally by a feed motor 2. motor 4
A back-and-forth moving table 7 is mounted which is moved back and forth along a pair of guide rails 5 and 6. A column 8 is erected on this back-and-forth direction movable table 7, and a tool drive unit A is moved up and down by a feed screw 10 which is rotationally driven by a feed motor 9.
The lifting frame 11 has a pair of left and right guide rails 12, 1 extending vertically on the front side of the column.
3 relative to the column 8.
A leaning tower type turret head 17 is supported on the front side of the lifting frame 11 and is pivoted around an axis in a direction inclined with respect to the front-rear direction in a horizontal plane. 66 is formed. The center axis of each spindle head 16, 66 is set at the first axis in order to avoid mutual interference of the internal mechanisms of the tool drive unit A.
They are in a twisted relationship with each other as shown in the figure.
As shown in FIG. 2, when the tool is in cutting operation, the center axis of the spindle head is directed in the longitudinal direction with respect to the column 8, and when changing the tool, as the turret head 17 rotates, the center axis of the spindle head is Head left and right with respect to column 8. In Figure 2, spindle head 1
6 is in the cutting position, and the spindle head 66 is in the tool changing position. Also, as shown in Figure 2,
The guide rail 13 is arranged in front of the guide rail 12, and the distances from each guide rail 12, 13 to the turret head 17 are both short.

In FIG. 3, the cylindrical support part 1 of the lifting frame 11 is
The outer circumferential side of the cylindrical connecting portion 18 of the turret head 17 is rotatably supported on the inner circumferential side of the turret head 17 via a bearing 15, and the outer circumferential flange 11f of the lifting frame 11 and the outer circumferential flange 17f of the turret head 17 are supported on the inner circumferential side of the turret head 17. The opposing surfaces are configured to be able to come into sliding contact with each other. and each outer periphery flange 11
The back sides of f and 17f are tapered surfaces 11t and 17f, respectively.
17t, and the outer surfaces of the pair of outer circumferential flanges 11f, 17f are surrounded by an annular clamp 19 for restraining the rotation of the turret head 17 as required.

A gear 20 is integrally fixed to the end surface side of the cylindrical connecting part 18, and a turret rotation motor 21 mounted on the elevating frame 11 is attached to the gear 20. The bevel gear 23 and the gear 28 at the other end of the gear shaft 26 which are rotatably driven via the bevel gear 27 at one end of the gear shaft 26 which is rotatably supported on the cylindrical support part 14 by bearings 24 and 25 mesh with each other. It's on.

The rotational driving force of the tool rotation motor 29 mounted on the lifting frame 11 is transmitted through the output shaft 30 and the lifting frame 11.
A gear 34 on a gear shaft 33 rotatably supported by the elevator frame 11 via bearings 31 and 32, a gear 38 on a gear shaft 37 rotatably supported by the elevator frame 11 via bearings 35 and 36, and an elevator. The signal is transmitted to the spline 43 on the outer peripheral surface of the forward projection of the gear shaft 41 via the gear 42 on the gear shaft 41 which is rotatably supported by the frame 11 via bearings 39 and 40.

The spline 43 is engaged with a spline on the inner circumferential surface of the drive-side engaging member 44a of the clutch 44. The drive-side engagement member 44a has a cylindrical shape as a whole, and has an engagement portion on its front edge that engages with the driven-side engagement member 44b, and has an engagement portion on its outer peripheral surface near the rear end. A clutch operation wheel 45 having an annular groove 46 formed on the outer peripheral surface thereof is fixed.

The base end of a rod 47 that protrudes forward in parallel with the spline 43 is fixed to the lifting frame 11, and a clutch operation cylinder 49 is attached to a fixed piston 48 formed in the center of the rod 47.
are mated. Both end walls of the clutch operating cylinder 49 are slidable along the outer peripheral surface of the rod 47, and a clutch operating pawl 50 fixed on the outer peripheral surface near the rear end of the clutch operating cylinder 49 is fitted into an annular groove of the clutch operating wheel 45. 46. As shown in FIG.
Clutch operation cylinder 4 is located on the upper surface of the rear end of 9.
The base end of a sliding member 73 that protrudes in a direction perpendicular to the axial direction of the sliding member 73 is fixed, and the sliding member 73 has a base end fixed on the elevating frame 11 and a stopper nut at the distal end. Rod 4 with 75 screwed together
7 and is slidably fitted into a guide rail 74 parallel to the guide rail 74. Along this guide rail 74, the sliding contact member 73
(Fig. 4), the clutch operation cylinder 49 slides along the rod 47 while always maintaining a constant orientation. When the pressure fluid is conducted to the pressure fluid path 51 in the rod 47, the clutch operation cylinder 49 is moved back and the clutch 44 is in the disengaged state, and the pressure fluid path 51 in the rod 47 is
2, the clutch operating cylinder 49 moves forward and the clutch 44 becomes engaged.

In FIG. 3, a hollow spindle 55 is rotatably supported on the inner circumference 17 of the spindle head 16 via a bearing 53 and a bearing group 54, and a clutch is mounted on the outer circumferential surface of the rear end of the hollow spindle 55. An annular driven-side engagement member 44b constituting 44
is fixed. Therefore, when the clutch 44 is in the engaged state, the rotational driving force on the spline 43 side is transmitted to the hollow spindle 55 via the clutch 44.

A tapered surface 55t that expands toward the front is formed on the inner peripheral surface side of the front end of the hollow spindle 55, and a tool holder 57 is formed on this tapered surface 55t.
A tapered surface 57t formed on the outer periphery of the plate is in close contact with the tapered surface 57t. The tool holder 57 has a tapered surface 5
In the state in which the hollow spindle 55 is fitted into the 5t section, the rotational driving force of the hollow spindle 55 is applied to the engagement pin 56 fixed to the front end surface of the hollow spindle 55 and the engagement pin 56 formed on the outer peripheral surface of the front end of the tool holder 57. By engaging with the recessed portion, the force is transmitted to the tool holder 57 via the engagement pin 56.

A tool holder shaft 58 having an enlarged portion at the rear end protrudes rearward from the rear end surface of the tool holder 57, and this tool holder shaft 58 extends in the axial direction within the hollow portion of the hollow spindle 55. It is adapted to fit into a cylindrical portion 60 formed at the front end of the drawbar 59. The cylindrical portion 60 has a plurality of, for example, three, radially penetrating ball holding holes formed at intervals in the circumferential direction, and the balls 61 are held in each ball holding hole so that they do not come off. has been done. A cylindrical member 62 having a tapered surface that expands forward is held at a position corresponding to the cylindrical portion 60 in the hollow portion of the hollow spindle 55 on the inner peripheral portion of the front end side. A nut 63 is screwed to the rear end of the drawbar, and the spring biasing force of a large number of annular leaf springs 64 interposed between the nut 63 and the shoulder on the inner peripheral side of the hollow spindle 55 causes The drawbar 59 is constantly receiving a backward tensile force, and due to this spring biasing force, each ball 61 moves along the tapered surface on the inner circumferential side of the cylindrical member 62, tightens the tool holder shaft 58, and tightens the tool holder 57. is securely held within the tapered surface 55t.

When removing the tool holder 57 from the hollow spindle 55, the turret head 17 is rotated to position the spindle head 16 at the tool exchange position, and then the base end surface of the draw bar 59 is pressed by a spring by a pressing device not shown in FIG. While pressing against the biasing force, the tool holder 57 is pulled out to the outside of the hollow spindle 55 by engaging the gripping claw in the annular engagement groove 65 formed on the outer peripheral surface of the tip end of the tool holder 57. This allows the tool holder 57 to be removed from the hollow spindle 55.

A pressurized air introduction hole 59c is formed in the drawbar 59 so as to penetrate in the axial direction, and when the tool holder 57 is removed from the hollow spindle 55 during tool exchange, pressurized air can be introduced into the pressure air introduction hole 59c. The pressurized air is transferred to the tapered surface 55.
The tapered surface 55t can be cleaned by spraying toward the t side.

In FIG. 4, the spindle head 16 is in the operating position and the tool holder 57 holds the tool shaft 12.
The tool 124, which is held in five parts, is in a cutting operation. In contrast, the spindle head 66 is in the tool change position. A hollow spindle 69 is rotatably supported on the inner peripheral side of the spindle head 66 via a bearing 67 and a bearing group 68, and the hollow spindle 69 holds a tool holder 71 that holds a tool shaft 70. There is.

The hollow spindle 69 has exactly the same structure as the hollow spindle 55, and the driven side engagement member 72 of the clutch 44 is fixed on the outer peripheral surface of the proximal end of the hollow spindle 69. An engagement groove 83 is formed adjacent to the engagement member 72. On the other hand, a bracket 79 protruding from the proximal end of the hook 80 is pivotally supported by a pivot portion 78 of a bracket 77 fixed to the elevating frame 11.
A forked engagement claw 82 that engages with the engagement groove 83 of the hollow spindle 69 is formed at the distal end of the hook 80, and a forked engagement claw 82 that engages with the engagement groove 83 of the hollow spindle 69 is formed at the center of the hook 80. A long hole 81 that is elongated toward
An engaging pin 76 protruding from the upper surface of the outer peripheral portion of the clutch operation cylinder 49 is loosely fitted into the elongated hole 81 . Therefore, when the turret head 17 is rotated by the operation of the turret rotation motor 21, the clutch operating cylinder 4
9 retreats and the clutch 44 is in the disengaged state, the hook 80 swings around the pivot portion 78 toward the lifting frame 11, and the engagement claw 82 moves into the engagement groove 83.
However, when one of the pair of spindle heads, e.g., spindle head 16, is positioned at the operating position, the other spindle head, e.g., spindle head 66, is positioned at the tool change position, and the clutch operating cylinder 49 is moved forward. When the clutch 44 is engaged, the hook 80 swings forward about the pivot portion 78, and the engagement pawl 82 engages the engagement groove 83, so that the hook 80 is engaged in the axial direction of the hollow spindle 69. Part of the force is shared to reduce the burden on the bearing 67 and the bearing group 68.

C. Effects of the Invention As described above, according to the present invention, one guide rail of a pair of guide rails is relatively closer to the turret head so that each guide rail is located closer to the turret head. Since it is located in the front position, the amount of overhang from each guide rail of the tool drive unit is small, which increases the mechanical rigidity of the tool drive unit and reduces the vibration and spindle caused by the cutting load during cutting with the tool. This further improves machining accuracy by suppressing deterioration in horizontal accuracy and by reducing the amount of thermal displacement of the tool drive unit starting from the guide rail.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of a machine tool equipped with a support device for a tool drive unit according to an embodiment of the present invention, FIG. 2 is a plan view of the machine tool shown in FIG. 1, and FIG. FIG. 4 is a plan sectional view of the main part taken along the - line in the figure, FIG. 4 is a plan sectional view of the main part taken along the - line in FIG. 1, and FIG. 5 shows a conventional tool drive unit support device. It is a plane sectional view of the main part. A...Tool drive unit, 8...Column, 11
... Lifting frame body, 12, 13 ... Guide rail, 17
...Tall head.

Claims (1)

[Claims] 1. The lifting frame 11 of the tool driving unit A that moves up and down with respect to the column 8 is moved up and down along a pair of left and right guide rails 12 and 13 that extend in the vertical direction on the front side of the column 8, and the lifting frame body 11
In the support device for the tool drive unit, each of the guide rails 1 is supported on the front side of the tool drive unit, in which a leaning tower type turret head 17 is supported, which is rotated around an axis in a direction inclined with respect to the front-rear direction in a horizontal plane.
2 and 13 are the pair of guide rails 12 and 1 so that both are located close to the turret head 17.
3. A support device for a tool drive unit in a machine tool, wherein one of the guide rails 13 is disposed at a position relatively forward of the other guide rail 12.