JP4637217B2 - Tool shank and machine tool - Google Patents

Description

The present invention relates to a tool shank and machine tools having a through-spindle coolant function.

In machine tools, there is a through-spindle coolant system that supplies coolant liquid to the machined part of a drill or end mill, forming a flow path from the machine tool spindle to the tool edge, and supplying coolant directly to the tool edge. . It is more efficient than the conventional method of spraying the coolant liquid from the outside toward the processing part, and has the effect of extending the tool life and improving the quality of the processing part. Further, in a machine tool having the same configuration, there is a case in which a machining tool such as a drill is not provided and a washing machine is used to remove burrs and curls by spraying a washing liquid on the machining portion.
However, in a machine tool having an automatic tool change function, since the tool shank is changed each time with respect to the main shaft, the flow path of coolant liquid and cleaning liquid (hereinafter collectively referred to as fluid) is divided. It is necessary to prevent liquid leakage from the joint portion, which is particularly problematic when supplying a high-pressure fluid. As an example of a conventional tool shank and spindle, FIG. 3A shows a general BT standard, and FIG. 3B shows a general HSK standard. However, in each figure, the upper side shows a clamped state, and the lower side shows an unclamped state. Further, Patent Document 1 proposes a spindle device in which a slidable cutting fluid communication pipe is provided inside the spindle and is pressed against a pull stud.
JP 2001-322050 A

  However, in the case of the BT standard tool shank S1 and the main shaft M1 shown in FIG. 3A, in the clamped state, there is a gap d between the pull stud 103 and the clamp unit 122, and the fluid leaking from the gap d is space 125. Since the pressure is applied in the direction in which the entire tool shank S1 is pushed out from the main shaft M1, the high-pressure fluid cannot be supplied. Further, in the case of the tool shank S2 and the spindle M2 of the HSK standard shown in FIG. 3 (b), the structure is complicated, so it is good to use a coolant for processing, but to use a cleaning liquid with poor lubricity. Was unsuitable. Further, the fluid does not enter the space 225 by the O-ring 208 provided in the clamp unit 222, but the tool collides with the O-ring 208 every time the tool is changed, and the O-ring 208 is worn out early. It was also a problem. Further, the spindle device of Document 1 is resistant to wear because the seal member 9 is always in contact with the cutting fluid communication pipe 11, but by providing a sliding mechanism for the cutting fluid communication pipe 11 inside the spindle device 1. If the spindle device 1 has a large diameter and the moment of inertia increases, the basic performance of the machine tool is impaired, the bearing diameter increases and the cost increases. There is no choice but to make the main shaft thin, which is disadvantageous for increasing the pressure of the supply fluid. In addition, when replacing the seal member, it is necessary to stop the apparatus and disassemble the main shaft, and the maintainability is poor.

The present invention has been made in view of the above circumstances, withstand the supply of high pressure fluid, and to provide a good tool shank and machine tools for maintenance in a simple and compact construction.

  The invention according to claim 1 of the present invention is a tool shank that is mounted on a tool mounting portion having a tapered hole shape provided at the tip of a spindle of a machine tool, and fluid is supplied through a flow path communicating with the flow path provided on the spindle. A tapered portion that fits into the tool mounting portion, a center hole formed on the rotation shaft, a pull stud, a joining pipe, and an elastic member, and the pull stud is proximal to the center hole. Inserted from the side and fixed, has a through hole on the rotating shaft, and the joining tube is formed as a tube head with the outer diameter of the distal end side larger than the other part, and is inserted into the through hole from the distal end side And is slidable in the axial direction, and includes a seal member on the outer periphery of the tube head, the seal member is in contact with the inner peripheral surface of the center hole, and the elastic member is disposed in the center hole and The joint pipe and the center hole are flow paths. Characterized in that it comprises.

A second aspect of the present invention is a machine tool comprising the tool shank according to the first aspect and a main shaft on which the tool shank is mounted, wherein the main shaft clamps the tool shank inside. The clamp unit includes a substantially cylindrical barrel portion and a clamp claw extending from the outer periphery of the barrel portion to the distal end side. When the clamp claw is engaged with the pull stud and clamps the tool shank, The proximal end of the joining tube and the distal end of the barrel are joined to form a flow path.

  According to the present invention, the seal member provided on the pipe head is always in contact with the inner surface of the center hole, and deformation of the seal member is suppressed during the clamping / unclamping operation of the tool. Can withstand supply. In addition, the joining pipe is urged to the proximal end side by an elastic member in a state where the hydraulic pressure of the fluid is not applied, and has a large-diameter pipe head at the distal end side in a state where the fluid is supplied and the hydraulic pressure is applied Since the area of the distal end side end surface is larger than the proximal end side end surface, the proximal end side is biased by water pressure, and the proximal end end is pressed against the distal end end of the body of the clamp unit. Therefore, since the fluid is joined with a stronger force as the pressure becomes higher, liquid leakage does not occur. Furthermore, by providing a slidable joint tube on the tool shank instead of the main shaft, the main shaft is prevented from increasing its diameter, and the tool shank is tapered, so it can be formed thick even if various mechanisms are provided inside. This is advantageous for increasing the pressure of the supply fluid. Further, when the seal member is worn, only the tool shank needs to be maintained, and the maintainability is good.

The specific configuration of the tool shank and machine tools of the present invention will be described with reference to the drawings. 1 and 2 are sectional views of the machine tool, FIG. 1 is an enlarged view of a tool shank and a main shaft portion at the tip, and FIG. 2 shows the whole. However, in FIG. 1, (a) shows a clamped state, (b) shows an unclamped state, and in FIG. 2, the upper side shows a clamped state and the lower side shows an unclamped state. In the drawing, the right side is the distal end side, and the left side is the proximal end side.
The tool shank S includes a tapered portion 1 formed on the base end side, a center hole 2 formed on the rotation shaft, a pull stud 3, a joining tube 4, and an elastic member 5. The pull stud 3 is fixed by being inserted into the center hole 2 from the base end side and screwed together, and a through hole 6 is formed on the rotating shaft. The joining pipe 4 has a larger outer diameter at the end on the tip end side than the other part and is formed thick, and this thick part is referred to as a pipe head 7. The joining tube 4 is inserted into the through-hole 6 from the distal end side and is slidable in the axial direction. The tube head 7 is locked to the distal end side end of the pull stud 3, thereby 4 is prevented from falling off the pull stud 3. A seal member 8 made of an O-ring is provided on the outer periphery of the pipe head portion 7 and is in contact with the inner peripheral surface of the center hole 2. Further, an elastic member 5 made of a coil spring is inserted on the distal end side of the tube head 7 of the center hole 2 to urge the joining tube 4 toward the proximal end side. The center hole 2 is opened on the tip side of the tool shank S, and a fluid discharge port 9 is formed in the opening, which functions as a washing machine that sprays fluid to the processing part to remove burrs and turns. To do.
On the other hand, the spindle M has a tapered hole-shaped tool mounting portion 21 formed at the tip end portion, a space portion 25 communicating with the tool mounting portion 21, and a main shaft hole 26 communicating with the proximal end side of the space portion 25. The space 25 is formed to have a larger diameter than the main shaft hole 26. The main shaft M is rotatably held by the housing 28 via a bearing 27. A clamp unit 22 for clamping the tool shank S is provided in the main shaft hole 26. The clamp unit 22 has a substantially cylindrical body portion 23 and a clamp claw 24 extending from the outer periphery of the body portion 23 to the front end side. With. The clamp claw 24 has an engaging projection 29 formed on the inner side of the distal end side end, a distal end convex portion 30 formed on the outer side of the distal end side end portion, and a proximal end convex portion 31 formed on the outer side of the proximal end side end portion. In addition, a convex portion 26 a is formed at a position corresponding to the base end convex portion 31 on the inner peripheral surface of the main shaft hole 26. A hollow draw bar 32 is connected to the proximal end side of the clamp unit 22, and a multi-layer disc spring 33 is extrapolated to the draw bar 32 to urge the draw bar 32 toward the proximal end side. A hollow hydraulic cylinder 34 is connected to the base end side of the draw bar 32 so that the draw bar 32 can be moved in the axial direction. Further, a fluid supply device 36 is connected to the proximal end side of the hollow hydraulic cylinder 34 via a rotary joint 35. A motor 37 is provided on the side of the housing 28. The shaft of the motor 37 is orthogonal to the main shaft M, and a bevel main shaft side gear 38 provided on the main shaft M meshes with a bevel motor side gear 39 provided on the shaft of the motor 37. Rotation drive.

Next, the clamping and unclamping operation of the tool and the fluid flow path in the tool shank and the main shaft formed as described above will be described. First, in the clamped state (FIG. 1A), the draw bar 32 is urged to the proximal end side by the disc spring 33, so that the tip convex portion 30 of the clamp claw 24 comes into contact with the inner peripheral surface of the main shaft hole 26. Thus, the tip end side of the clamp claw 24 is closed inward. As a result, the engagement protrusion 29 engages with the pull stud 3 to clamp the tool shank S. At this time, the joining tube 4 is urged to the proximal end side by the elastic member 5, and the proximal end side end portion of the joining tube 4 is pressed against the distal end side end portion of the body portion 23 of the clamp unit 22. Thus, a flow path is formed. And when the fluid flows through the flow path, the water pressure is applied to each part, but the joining pipe 4 has the pipe head part 7, and the area of the distal end side end face is larger than the area of the proximal end side end face. The joining pipe 4 is pressed to the base end side by water pressure. Therefore, as the hydraulic pressure of the fluid increases, the force that presses the joining pipe 4 toward the proximal end increases, and even when a high-pressure fluid is supplied, leakage of fluid from the joining portion is prevented. In addition, the outer peripheral part of the base end side end part of the joining pipe 4 and the inner peripheral part of the front end side end part of the body part 23 are each chamfered, and the degree of adhesion is further increased by bringing the double-sided part into contact. . In this state, a flow path from the fluid supply device 36 to the discharge port 9 via the rotary joint 35, the hollow hydraulic cylinder 34, the draw bar 32, the body portion 23 of the clamp unit 22, the joining pipe 4 and the center hole 2. Is formed.
On the other hand, in order to unclamp the tool (FIG. 1B), the hollow hydraulic cylinder 34 moves the draw bar 32 to the tip side against the urging force of the disc spring 33. Then, the base end convex portion 31 of the clamp claw 24 engages with the convex portion 26 a formed on the inner peripheral surface of the main shaft hole 26, and the distal end convex portion 30 escapes from the main shaft hole 26 to the larger diameter space portion 25. Thus, the tip end side of the clamp claw 24 opens outward. As a result, the engagement protrusion 29 releases the pull stud 3 and enters an unclamped state.
In this series of clamping and unclamping operations, the seal member 8 provided on the pipe head portion 7 is always in contact with the inner peripheral surface of the center hole 2, so that the deformation is small and it is resistant to wear. In addition, when a seal member is provided on the main shaft side, the same seal member continues to function even if the tool is replaced, so wear is fast. However, if a seal member is provided on the tool side as in the present invention, the seal member Will only work while the tool is in use, resulting in slow wear and a longer period before replacement is required. Furthermore, when replacing the tool, only the tool shank needs to be maintained, and the maintainability is good. Since the tool shank has a tapered shape, it can be formed thick even if various mechanisms such as a joining pipe are provided therein, which is advantageous for increasing the pressure of the supply fluid.

The present invention is not limited to the above embodiments. In the embodiment, a cleaning machine having a discharge port is shown, but a tool such as a drill having a flow path or an end mill may be attached to the tip of the tool shank. Further, the overall configuration of the machine tool as long as it has the above tools shank and spindle may be of any type.

Is a cross-sectional view of the tool shank and main shaft of the machine tool of the present invention, (a) shows the clamped state, the (b) is unclamped state. It is sectional drawing of the whole machine tool. It is sectional drawing of the conventional tool shank and a main axis | shaft, (a) is a thing of BT standard, (b) shows the thing of a HSK standard.

DESCRIPTION OF SYMBOLS 1 Tapered part 2 Center hole 3 Pull stud 4 Joint pipe 5 Elastic member 6 Through hole 7 Pipe head 8 Seal member 21 Tool mounting part 22 Clamp unit 23 Trunk part 24 Clamp claw

Claims (2)

  A tool shank mounted on a tool mounting portion (21) having a tapered hole shape provided at the tip of a spindle of a machine tool and supplied with fluid through a flow path communicating with a flow path provided on the spindle, the tool mounting section ( 21) includes a tapered portion (1), a center hole (2) formed on the rotating shaft, a pull stud (3), a joining pipe (4), and an elastic member (5), The pull stud (3) is inserted into and fixed to the center hole (2) from the base end side, and has a through hole (6) on the rotating shaft. The pipe head (7) is formed to have a diameter larger than that of the other part. The pipe head (7) is inserted from the distal end side into the through hole (6) and is slidable in the axial direction. ), The seal member (8) is in contact with the inner peripheral surface of the center hole (2), and the elastic member (5) A tool shank arranged in a hole (2) and biasing the joining pipe (4) toward the proximal end, and the joining pipe (4) and the central hole (2) serve as a flow path. . It is a machine tool provided with the tool shank of Claim 1 , and the main axis | shaft which mounted | wore with this tool shank , Comprising : The said main axis | shaft is equipped with the clamp unit (22) which clamps the said tool shank inside, This clamp unit (22) ) Includes a substantially cylindrical body portion (23) and a clamp claw (24) extending from the outer periphery of the body portion (23) to the distal end side, and the clamp claw (24) is engaged with the pull stud (3). When the tool shank is clamped together, the base end side end portion of the joining pipe (4) and the tip end side end portion of the trunk portion (23) are joined to form a flow path. machine tools.

Images