JP2013094915A - Machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool whose chatter vibration can be effectively suppressed even if using not an expensive tool such as a cemented carbide tool and a vibration-proof tool but a tool formed of a general steel material.SOLUTION: The chatter vibration generated in a tool T during processing an inner diameter by processing the inner diameter by a pressing member 12 which is pressed against a surface of a tool T is absorbed by the elasticity of the pressing member 12, the slight vertical motion of a piston 11, and the elasticity of a spring member 14, and the flow of oil filled in first and second oil chambers 16, 17, thus reducing chatter vibration in the tool T. Accordingly, the expensive tool such as a cemented carbide tool and a vibration-proof tool are not necessary to be used, thus reducing a machine tool in cost.

Description

  The present invention relates to a machine tool that performs internal diameter processing such as an NC lathe.

  2. Description of the Related Art Conventionally, various machine tools for performing inner diameter machining have been devised, including a machine tool disclosed in Patent Document 1, for example. When performing the inner diameter machining, it is common to use a tool having a longer tool length as the machining depth becomes deeper. However, when a tool having a long tool length is used, chatter vibration is likely to occur during the inner diameter machining, and the tool may be damaged or the accuracy of the machined surface may be lowered. Therefore, conventionally, the steel material of the tool is made of cemented carbide, or a vibration isolating tool provided with a vibration isolating mechanism is used.

JP 2011-0779069 A

  However, cemented carbide tools and vibration isolating tools are very expensive tools, and depending on the product, there is a problem in that the cost is lost when a cemented carbide tool or vibration isolating tool is prepared.

  Therefore, the present invention has been made in view of the above problems, and chatter vibrations are generated even when a tool formed of a general steel material is used instead of an expensive tool such as a cemented carbide tool or a vibration isolating tool. It is an object of the present invention to provide a machine tool that can be effectively suppressed.

In order to achieve the above object, the invention according to claim 1 of the present invention is a machine tool for performing an inner diameter machining on a workpiece, wherein the abutting member and the tool for inner diameter machining are described above. A vibration reduction device having a moving mechanism for moving the contact member, and a holder for holding the tool or the tool by moving the contact member by the moving mechanism when the inner diameter is processed by the tool It is possible to reduce chatter vibration generated during inner diameter processing by abutting on the surface.
According to a second aspect of the present invention, in the first aspect of the present invention, the first tool base on which the tool can be mounted via the holder, and the second tool that can be moved separately from the first tool base. And the moving mechanism is the second tool rest.
According to a third aspect of the present invention, the piston according to the first or second aspect is provided with a piston movable in a predetermined direction and one end of the piston, and the piston is moved in one direction along the predetermined direction. An urging member for urging is provided, and the abutting member is provided on the other end side of the piston.
The invention according to claim 4 is the invention according to claim 3, wherein the piston is provided in such a posture that the one end side is housed in the casing member and the other end side protrudes from the casing member. A flange portion provided with a throttle that opens across the front and back is formed on one end side of the piston in a bowl shape, and the internal space of the casing member in which the one end side is accommodated is divided into two chambers sandwiching the flange portion. The two chambers are filled with fluid, and the urging member is housed in one of the two chambers.

According to the present invention, when machining the inner diameter, the contact member is moved by the moving mechanism, and the contact member is brought into contact with the surface of the tool or the holder holding the tool, thereby contacting chatter vibration generated during the inner diameter machining. It can be absorbed by the member, and as a result, chatter vibration generated in the tool can be effectively reduced. Therefore, it is not necessary to use an expensive tool such as a cemented carbide tool or a vibration isolating tool, and the cost of the machine tool can be reduced.
Moreover, according to the invention of Claim 2, it can comprise only by installing a vibration reduction apparatus in a 2nd tool stand. Therefore, it can be retrofitted to an existing machine tool and is highly versatile.
Furthermore, according to the third aspect of the present invention, chatter vibration can be absorbed by using the movement of the piston and the elastic force of the biasing member, and the chatter vibration generated in the tool can be reduced more effectively. it can.
In addition, according to the invention described in claim 4, it is possible to prevent the piston from largely moving due to chatter vibration due to the fluid existing across the flange portion, and to prevent chatter vibration from coming into contact. Since it can absorb while diffusing to a member, a piston, a biasing member, and a fluid, chatter vibration can be reduced very effectively.

It is explanatory drawing which showed a part of NC lathe which is an example of a machine tool. It is explanatory drawing which showed the internal structure of the vibration reduction apparatus.

  Hereinafter, a machine tool according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view showing a part of an NC lathe 1 which is an example of a machine tool, and FIG. 2 is an explanatory view showing an internal structure of a vibration reducing device 2 which is a main part of the present invention. The X axis, the Y axis, and the Z axis are orthogonal to each other. The vertical direction in FIG. 1 is the X axis direction, the horizontal direction is the Z axis direction, and the front and rear direction is the Y axis direction.
The NC lathe 1 includes a chuck having a spindle device (not shown), a first tool base 3 provided so as to be movable in the X1 axis direction parallel to the X axis and the Z1 axis direction parallel to the Z axis, and a first tool base. 3 and a second tool base 4 provided to be movable in the X2 axis direction parallel to the X axis and the Z2 axis direction parallel to the Z axis. A tool T (in this case, a boring bar formed of a general steel material) for machining the work gripped by the chuck has a fixing holder 5 for holding the tool T at the tip of the tool table 3. Is mounted through. A second tool base 4 is positioned below the tool T, and a vibration reducing device 2 described later is installed at the tip of the second tool base 4. The NC lathe 1 includes an NC device (not shown), and the first tool table 3 and the second tool table 4 move in the respective axial directions under the control of the NC device.

Here, the vibration reducing device 2 which is a main part of the invention will be described.
The vibration reducing device 2 includes a piston 11 that can move up and down along the Z-axis direction, a pressing member 12 that is pressed against the tool T, a casing member 13 that houses a base end portion of the piston 11, and the piston 11 that moves upward. And a spring member 14 for urging the spring. The piston 11 is provided such that a tip portion protrudes upward from the upper surface of the casing member 13, and a pressing member 12 is fixed to the tip portion. Further, a flange portion 15 is provided in the base end portion of the piston 11 in a bowl shape, and a first oil chamber 16 above the flange portion 15 and an inner space of the casing member 13 below the flange portion 15. The second oil chamber 17 is partitioned. Further, the flange portion 15 is provided with a throttle 18 that opens across the front and back, and the first oil chamber 16 and the second oil chamber 17 communicate with each other through the throttle 18. In addition, the first oil chamber 16 and the second oil chamber 17 are filled with oil, which is a fluid, and a spring member 14 is accommodated in the second oil chamber 17, and the spring member 14 has a flange. The lower surface of the portion 15, that is, the piston 11 is urged upward. On the other hand, the pressing member 12 is formed by forming a metal member into an inverted L shape so that the tip portion formed in a convex shape functions as a pressing portion 12a pressed against the surface of the tool T. It has become. Reference numeral 19 denotes a seal member provided on the flange portion 15 to prevent excess oil from going back and forth between the first oil chamber 16 and the second oil chamber 17, and 20 denotes the first oil chamber 16. It is a seal member which prevents oil from leaking through the peripheral surface of a piston.

  In the NC lathe 1 equipped with the vibration reducing device 2 as described above, when the inner diameter machining of the workpiece is performed with the tool T, the second tool rest 4 is moved in the X2 axis direction and the Z2 axis direction. The pressing portion 12a is directly pressed against the surface of the tool T mounted on the first tool base 3 that has been moved to the machining position by moving in the Z1 axis direction. Then, the inner diameter machining with the tool T may be started by rotating the workpiece in the state. Then, although chatter vibration is generated in the tool T during machining, the chatter vibration is caused by the elasticity of the pressing portion 12a, the slight vertical movement of the piston 11, the elasticity of the spring member 14, and the first oil chamber 16 and the second oil chamber 16. It is absorbed by the flow of oil filled in the oil chamber 17. Therefore, chatter vibration generated in the tool T is reduced. The oil also has a function as a brake that prevents the piston 11 from moving up and down greatly by chatter vibration. Further, as the inner diameter machining progresses, when the tool T is moved, the second tool table 4 may be moved in synchronization with the movement of the tool T (first tool table 3).

According to the NC lathe 1 provided with the vibration reducing device 2 having the above-described configuration, the inner diameter is processed while the inner diameter is processed while the pressing portion 12a of the pressing member 12 is pressed against the surface of the tool T. Since chatter vibration generated in the tool T is absorbed by the pressing member 12, chatter vibration generated in the tool T can be effectively reduced. Therefore, it is not necessary to use an expensive tool such as a cemented carbide tool or a vibration isolating tool, and the cost of the machine tool can be reduced.
Further, the vibration reducing device 2 having the pressing member 12 is configured only by being installed on a second tool table (tool table in a state in which the tool T is not mounted) provided in a general NC lathe 1. be able to. Therefore, it can be retrofitted to an existing NC lathe and is highly versatile.

Further, the pressing member 12 is fixed to the tip of the piston 11 that can move up and down and is urged upward by the spring member 14, and is configured to press the pressing portion 12a against the tool T from below. Yes. Therefore, chatter vibration generated in the tool T can be more effectively absorbed and reduced.
In addition, a flange portion 15 provided with a throttle 18 that opens across the front and back sides is provided in the base end portion of the piston 11 in a bowl shape, and the internal space of the casing member 13 in which the base end portion of the piston 11 is accommodated is defined as the flange portion 15. A spring member that divides the first oil chamber 16 above and the second oil chamber 17 below, fills both the oil chambers 16 and 17, and biases the piston 11 toward the second oil chamber 17. 14 is housed. Therefore, when chatter vibration occurs, the piston 11 can be prevented from greatly moving up and down by the oil filled in the oil chambers 16 and 17, and the chatter vibration can be prevented from being applied to the pressing member 12, the piston 11, Since it can absorb while diffusing in the spring member 14 and oil, chatter vibration can be reduced extremely effectively.

  In addition, the machine tool according to the present invention is not limited to the aspect of the above embodiment, and the configuration of the vibration reduction device, the configuration related to the installation of the vibration reduction device, and the like are within the scope of the present invention. These can be changed as necessary.

For example, in the above-described embodiment, the vibration reducing device 2 is installed on the second tool base 4. However, for example, the vibration reducing device 2 itself is moved in a direction of approaching / separating from the moving mechanism such as a hydraulic cylinder and the tool T. If a movable mechanism is provided, it is not necessary to install the second tool base 4.
Further, the configuration is such that chatter vibration is absorbed only by the elastic force of the pressing member 12, that is, the pressing member 12 is installed not on a member that can move in a predetermined direction like the piston 11 but on a fixed member that does not move. There may be no problem even if it is configured so that oil or the like is not used. On the other hand, in the above embodiment, the pressing member 12 is made of metal, but it may be made of synthetic resin instead of metal, and if it is installed on a member that can move in a predetermined direction, such as the piston 11, Whether the contact member 12 is made of metal or synthetic resin, chatter vibration can be effectively absorbed and reduced.

Further, the shape and the like of the pressing member 12 can be changed as appropriate, and the position at which the pressing portion 12a is pressed is further pressed to the position on the tip side of the tool T than the position shown in FIG. Alternatively, it may be pressed against the fixing holder 5.
Furthermore, even if the pressing force is not applied to the tool T and the pressing portion 12a is in contact with the surface of the tool T or the fixing holder 5, that is, as long as the pressing portion 12a is in contact with the tool T, the chatter vibration can be reduced. A certain effect can be recognized.

Furthermore, by attaching a roller to the pressing member 12, when the position of the tool T is moved along with the inner diameter machining, the pressing portion 12a is in contact with the tool T without moving the position on the vibration reducing device 2 side. It is also possible to configure so that the above can be maintained.
Moreover, in the said embodiment, although the spring member 14 is accommodated in the 2nd oil chamber 17, even if another spring member is accommodated in a 1st oil chamber, the structure which show | plays the same function is possible. Instead of the spring member 14, a block body such as rubber may be employed as the biasing member.
In addition, in the above embodiment, an NC lathe which is an embodiment of a machine tool is described. However, the machine tool is not limited to an NC lathe as long as it is a machine tool that performs inner diameter machining. The present invention can also be suitably applied to other machine tools such as machines.

  1 .... NC lathe 2 .... Vibration reduction device 3 .... first tool stand 4 .... second tool stand (moving mechanism) 5 .... fixing holder 11, 11. piston, 12 ... Member (abutting member), 12a ··· Pressing portion, 13 ·· Casing member, ··· Spring member (biasing member), 15 · · Flange portion, ··· First oil chamber, ··· Second Oil chamber, 18 ... throttle, 19, 20 ... seal member.

Claims (4)

A machine tool that performs internal machining on a workpiece,
A vibration reducing device having a contact member and a moving mechanism for moving the contact member relative to a tool for machining an inner diameter;
When the inner diameter is machined by the tool, the contact member is moved by the moving mechanism, and the contact member is brought into contact with the surface of the tool or the holder holding the tool, thereby preventing chatter vibration generated during the inner diameter machining. A machine tool characterized in that it can be reduced.   A first tool table on which the tool can be mounted via the holder; and a second tool table that can be moved separately from the first tool table, wherein the moving mechanism is the second tool table. The machine tool according to claim 1, wherein the machine tool is provided.   A piston that is movable in a predetermined direction, and a biasing member that is provided on one end side of the piston and biases the piston in one direction along the predetermined direction, are provided on the other end side of the piston. The machine tool according to claim 1, wherein a member is provided. The piston is provided in such a posture that the one end side is housed in the casing member and the other end side protrudes from the casing member,
A flange portion provided with a throttle that opens across the front and back is formed on one end side of the piston in a bowl shape, and the internal space of the casing member in which the one end side is accommodated is divided into two chambers sandwiching the flange portion. The machine tool according to claim 3, wherein the machine tool is partitioned, the two chambers are filled with a fluid, and the biasing member is housed in one of the two chambers.

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