JPH0333460B2 - - Google Patents

Description

Detailed Description of the Invention A. Object of the Invention (1) Industrial Field of Application The present invention provides a structure in which a leaning tower type turret head rotatably supports a plurality of tool rotation spindles and is rotatably supported with respect to a frame. This invention relates to a clamping device for a turret head of a machine tool of the type described above.

(2) Prior Art A machine tool of the type in which a leaning tower type turret head rotatably supports a plurality of tool rotation spindles is rotatably supported on a frame body was developed in Japanese Patent Application Laid-open No.
This is already known as seen in Japanese Patent No. 52-122976.

(3) Problems to be Solved by the Invention At the same time when the turret head is rotated to position one of the plurality of spindles at the processing position,
Conventionally, when fixing the turret head to the frame after at least one of the other spindles has been positioned at the tool changing position, the turret head is fixed using an index pin that responds to a detection signal of the rotational position of the turret head. However, fixing with index pins does not sufficiently fix the turret head to the frame, so vibrations are likely to occur in the turret head, especially during high-speed cutting, making it difficult to perform highly accurate machining.

Therefore, the main object of the present invention is to provide a machine tool turret head clamping device that can securely fix the turret head to the frame, has a simple structure, and is reliable in operation. .

B. Structure of the Invention (1) Means for Solving the Problems In the machine tool turret head clamping device according to the present invention, a leaning tower type turret head that rotatably supports a plurality of tool rotation spindles is attached to a frame body. A clamping device for a turret head of a machine tool, which is rotatably supported by a turret head, comprising an outer periphery flange formed on the outer peripheral side of an end edge of the cylindrical support portion of the frame body and a cylindrical connecting portion of the turret head. The outer peripheral flanges formed on the outer peripheral side of the end edge face each other on the same axis, and the back side of each of the outer peripheral flanges is formed as a tapered surface so as to cooperate with each other to form an annular wedge. A pair of semicircular clamp pieces are pivotally supported on the frame via a first pivot portion at the proximal end of each clamp piece so as to fit into the tapered surface portion of each of the outer peripheral flanges. At the same time, a clamp operation cylinder for swinging the tip of each of the clamp pieces in a plane parallel to each of the outer peripheral flanges is supported at a position between the tips of the pair of clamp pieces, The clamp operation cylinder includes a cylinder body attached to the frame body, a pair of pistons disposed opposite to each other in the cylinder body to define a common pressure fluid chamber, and a pair of pistons facing oppositely to each other in the cylinder body. A pair of piston rods are provided in a protruding manner so as to extend in the opposite direction, and are pivotally supported at the distal ends of the corresponding two clamp pieces via second pivot parts, and both pistons and both piston rods have their axes aligned with each other. It is characterized in that it is arranged along an imaginary circle centered on the first pivot and passing through both second pivots.

(2) Action After rotating the turret head to position one of the multiple spindles at the machining position and at the same time positioning at least one of the other spindles at the tool changing position, actuate the clamp operation cylinder to When the distal ends of the clamp pieces are drawn together, each clamp piece tightens each outer periphery flange from the outside in the radial direction while being fitted into the tapered surface portion of the pair of outer periphery flanges. At this time, a wedge effect is created between each clamp piece and the tapered surface of each outer periphery flange, and the turret head is securely fixed to the frame in a stable state. When machining and tool exchange are completed and the turret head is rotated relative to the frame, the clamp operation cylinder is actuated to press and move the tips of each clamp piece away from each other. Since it is pulled away from the tapered surface of the flange, the turret head is free to pivot relative to the frame.

Further, since both pistons are disposed with a common pressure fluid chamber in between, the pistons can be actuated equally and both clamp pieces can be oscillated evenly.

Furthermore, both pistons and both piston rods are
Since their axes are arranged along the imaginary circle, the directions of movement of the piston and piston rod and the swinging directions of both the second pivot parts substantially coincide with each other, so that when the piston and piston rod move back and forth, Bending stress generated in them is suppressed as much as possible.

(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 have tapered surfaces 11t and 17f, respectively, so as to cooperate with each other to form a circular wedge.
7t, and the outer surfaces of the pair of outer circumferential flanges 11f and 17f are surrounded by an annular clamp 19 for restraining the turret head 17 from pivoting as necessary.

A gear 20 is integrally fixed to the end surface side of the cylindrical connecting portion 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 is rotatably driven via the bevel gear 27 at one end of the gear shaft 26 which is pivotally 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 is fitted. 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 contact member 73 that protrudes in a direction perpendicular to the axial direction of the sliding contact member 73 is fixed. - Rod 4 with nut 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 periphery 17 of the spindle head 16 via a bearing 53 and a bearing group 54, and a clutch is mounted on the outer periphery 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, rotate the turret head 17 to position the spindle head 16 at the tool exchange position, and then press the base end of the drawbar 59 against the spring biasing force with a push rod (described later). At the same time, the tool holder 57 is made hollow by engaging the gripping claw with the annular engagement groove 65 formed on the outer peripheral surface of the tip end of the tool holder 57 and pulling the tool holder 57 out of the hollow spindle 55. It can be removed from the 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 Figures 4 to 7, spindle head 1
6 is in the machining position, and the tool 124 with its tool shaft 125 held by the tool holder 57 is in a cutting operation state. In contrast, the spindle head 66 is in the tool change position. This spindle head 66
A hollow spindle 69 is rotatably supported on the inner peripheral side of the tool 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.

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 machining position, the other spindle head, e.g., spindle head 66, is positioned at the tool changing position, and the clutch operating cylinder 49 moves 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. against force,
This prevents excessive force from being applied to the bearing 67 and the bearing group 68.

In particular, in FIGS. 6 and 7, a cylinder 90 is integrally formed within the hook 80, and the tip of a push rod 92 that is integral with the piston rod of a piston 91 that slides in the cylinder 90 is connected to the tip of the hook 80. It can stick out to the side.
A flow path 93 is formed in the push rod 92, and when pressure fluid is introduced into the port 95 as shown in FIG. However, as shown in FIG.
When pressure fluid is introduced into the port 94 while the piston 91 is engaged with the proximal end of the drawbar 94, the piston 91 moves toward the distal end of the hook 80, and the push rod 92 presses the proximal end surface of the drawbar 97.
The drawbar 97 is moved toward the tip of the spindle 69 against the spring force of the leaf spring 98. At the same time, the flow passage 93 communicates with the port 96, and pressurized air passes through the port 96, the flow path 93, and the pressure air introduction hole 97c formed by the hollow part of the drawbar 97, and connects to the tapered surface 69t of the tip of the spindle 69. It is introduced into the annular gap between the tool holder 71 and the tapered surface 71t.

As a result, the engagement between the drawbar 97 and the tool holder 71 is released, and the tool holder 71 can be detached from the spindle 69.
The tapered surface 69t of is cleaned by pressurized air.
During this time, since the hook 80 is engaged with the base end of the spindle 69, the spindle 69 is not pressed toward the distal end, and no unreasonable force is applied to the bearings 67, 68.

In FIGS. 8 to 10, the annular clamp 19
is constituted by a pair of semicircular clamp pieces 19a and 19b whose respective proximal ends are pivoted on a first pivot 99 on the elevating frame 11.
A clamp operation cylinder 100 supported by the elevating frame 11 is disposed between the tips of the clamp pieces 19a and 19b. The clamp operation cylinder 100 has a cylinder body 100a attached to the lifting frame 11, and the cylinder body 1
Cylinder chambers 101a and 101b integral with 00a are formed so as to face each other. A pair of pistons 10 are provided in the cylinder chambers 101a and 101b.
2a and 102b are arranged to face each other, and a common pressure fluid chamber P is defined between these pistons 102a and 102b. Both pistons 102a, 102b
A pair of piston rods 103a, 103b are provided in a protruding manner so as to extend in opposite directions, respectively.
are pivotally supported via second pivot parts 105a, 105b to brackets 104a, 104b formed at the tips of the corresponding clamp pieces 19a, 19b. Further, both pistons 102a, 102b and both piston rods 103a, 103b are arranged so that their axes lie along an imaginary circle C centered on the first pivot 99 and passing through both the second pivots 105a, 105b. A port 106 communicating with a pressure fluid source opens in the pressure fluid chamber P, and each piston 102
a, 102b and piston rods 103a, 103
A leaf spring 10 is provided between each end wall through which b passes through.
7 is interposed.

Therefore, each piston 102a, 102b is always biased by the corresponding leaf spring 107 in the direction of approaching each other, and no pressure fluid is introduced from the port 106 during machining or tool exchange. Each piston 102a, 102b receives a force in the direction of approaching each other by the spring biasing force of the corresponding leaf spring 107, and the inner circumferential surface of each clamp piece 19a, 19b is shaped as shown in FIGS. 3 and 4. are pressed against the tapered surfaces 11t, 17t of the respective outer peripheral flanges 11f, 17f, and the turret head 17 is reliably moved into the lifting frame 11 by a wedge action.
Fixed against.

When the turret head 17 rotates, pressure fluid is introduced from the port 106, so that
Each piston 102a, 102b moves in a direction away from each other, and as a result, each clamp piece 19a, 1
The turret head 17 can be pivoted relative to the lifting frame 11 since the turret head 9b swings outward about the pivot portion 99 away from the outer peripheral flanges 11f and 17f, respectively.

C. Effects of the Invention As described above, according to the present invention, the outer peripheral flange of the cylindrical support portion of the frame body and the outer peripheral flange of the cylindrical connecting portion of the turret head cooperate with each other to form an annular wedge. The turret head is formed as a tapered surface, and a pair of semicircular clamp pieces are configured to swing around the pivot portion and press into contact with these tapered surfaces, so that the outer peripheral flange of the turret head is The wedge action can be used to securely tighten and fix the turret head over a long distance, and the mechanical rigidity of the connection between the turret head and the frame body can be maintained at a high level, which prevents vibrations in the turret head even during high-speed cutting. It is possible to prevent this and perform highly accurate machining.

In addition, a clamp operation cylinder for swinging the tip of each clamp piece is provided between the tips of the pair of clamp pieces, so the clamp can be operated reliably with a simple configuration. Can be done.

Furthermore, since both pistons are arranged with a common pressure fluid chamber in between, these pistons are actuated equally to cause both clamp pieces to swing evenly, thereby tightening and releasing the outer peripheral flange of the turret head. can be done smoothly.

Furthermore, since both pistons and both piston rods are arranged at positions specified based on the virtual circle, the bending stress generated in these pistons and piston rods is suppressed as much as possible when they move back and forth. can be moved smoothly.

[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 Fig. 1, Fig. 5 is a plan sectional view of the main part taken along the - line in Fig. 4. FIG. 6 is a sectional view of the main part of FIG. 4, FIG. 7 is a sectional view of the main part similar to FIG. 6 in a different operating state from FIG. Figure 9 is a sectional view of the main part taken along the - line in Figure 3, and Figure 9 is the - line in Figure 8.
FIG. 10 is a side view of the main part taken along the line, and FIG. 10 is a sectional view of the main part taken along the line - in FIG. 11... Frame, 11f... Outer flange, 11
t... Tapered surface, 14... Cylindrical support part, 17...
Turret head, 17f...Outer flange, 17
t... Tapered surface, 18... Cylindrical connecting portion, 19a,
19b... Clamp piece, 55, 69... Spindle, 99... First pivot portion, 100... Clamp operation cylinder, 100a... Cylinder body, 102
a, 102b...piston, 103a, 103b
...Piston rod, 105a, 105b...Second pivot portion, C...Virtual circle, P...Pressure fluid chamber.

Claims (1)

[Claims] 1. A clamping device for a turret head of a machine tool in which a leaning tower type turret head 17 rotatably supports a plurality of tool rotation spindles 55, 69 is rotatably supported on a frame 11, The outer peripheral flange 11f formed on the outer peripheral side of the end edge of the cylindrical support portion 14 of the frame 11 and the outer peripheral flange 17f formed on the outer peripheral side of the end edge of the cylindrical connecting portion 18 of the turret head 17 are coaxial with each other. The outer peripheral flanges 11f, 17f have tapered surfaces 11t, 17 so as to cooperate with each other to form an annular wedge.
t, and on the frame 11,
Tapered surface 1 of each outer peripheral flange 11f, 17f
A pair of semicircular clamp pieces 19a and 19b are provided on each clamp piece 19 so as to fit into the 1t and 17t parts.
A, 19b are pivotally supported at the proximal end portions via a first pivot portion 99, and at a position between the distal end portions of these pair of clamp pieces 19a, 19b,
A clamp operation cylinder 100 is supported for swinging the tip of each of the clamp pieces 19a, 19b in a plane parallel to each of the outer peripheral flanges 11f, 17f, and the clamp operation cylinder 10
0 includes a cylinder main body 100a attached to the frame 11, a pair of pistons 102a and 102b disposed opposite to each other in the cylinder main body 100a to define a common pressure fluid chamber P, and both pistons 102a and 102b. A pair of piston rods 103a protrude from the pistons 102a, 102b so as to extend in opposite directions, and are pivotally supported at the tips of the corresponding clamp pieces 19a, 19b via second pivots 105a, 105b, respectively. , 103b, both pistons 102a, 102b and both piston rods 103a, 103b have their axes centered on the first pivot 99 and both second pivots 105.
A clamping device for a turret head for a machine tool, characterized in that it is arranged along an imaginary circle C passing through a and 105b.