JPS58126007A - Tool machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a machine tool having an elongated tool holder fixed at one end and having a tool weight attached to the other end, the tool holder being fixed at one end and having a tool holder attached to the other end. It relates to objects of a type that can be rotated relative to each other in order to perform

In conventional machine tools, the movement of the tool holder is produced by moving a cross slide, on which the tool holder is mounted, by means of a motor via a guide screw. Such a machine tool can satisfactorily machine rotating workpieces with a constant circular cross section over their entire length. A similar mounting for a tool holder can be used to hold the workpiece stationary and rotate the tool to create a hole in the workpiece. Furthermore, such a machine tool is capable of producing holes with a constant circular cross section over the entire length of the hole.

The disadvantage of both said machine tools is that the mounting does not allow rapid changes in the position of the tool during machining due to the inertia of the part, guide screw and motor, and therefore only at extremely low speeds in order to produce non-circular cross-sections. Another disadvantage is that it cannot be used to create steps on the machined surface of a workpiece.

According to an embodiment of the invention, there is provided a machine tool of the type which is fixed at one end and has separate parts, in which the workpiece and the tool can be rotated relative to each other in order to carry out machining operations on the workpiece. In order to deflect the tool holder during machining to change the position of the tool relative to the fixed end by a predetermined value, The holder deflection member is working.
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According to an advantageous embodiment, the tool holder deflection element is constituted by a magnetic field generating element which generates a magnetic field around the tool holder, and the tool holders are made of dissimilar materials which are joined together side by side. It is formed by two elongated members and the material of the elongated members is such that a magnetostrictive length change in the elongated members caused by the magnetic field generating member causes a deflection of the tool holder.

Further in accordance with an embodiment of the invention, the tool holder is rotatable about its own axis, and further the tool holder deflection member is connected to the fixed end and the tool mounting for causing deflection of the tool holder during rotation. is an eccentric weight attached to the tool holder between the part and the tool mount is radially inwardly rotated around the tool holder in an offset trajectory of motion to define the trajectory traced by the part. and a force supplying member for applying a predetermined force.

Further advantageously, an elongated flexible boring bar is provided for machining the inner surface of a stationary workpiece, and a drive member that engages the boring bar at one end of the boring bar for rotating the boring bar. , a tool holder provided at the other end of the boring bar, and a member for applying a controlled force to the boring bar is provided between the two ends to bend the boring bar while the boring bar is rotating. This allows the position of the tool attached to the boring bar to be changed by a predetermined value relative to the workpiece.

The invention will now be explained with reference to the illustrated embodiment.

As can be seen from the machine tool of FIG. 1, the machine tool has a headstock 10 with a chuck 11 for holding and rotating an elongated tool holder 12. - The cross slider 13 of the machine tool supports the workpiece 14. Tools-
The holder 12 is fixed at one end to the chuck 11 and at the other end supports a diamond P or another suitable tool 15 in a tool mounting member 16'. The tool holder/12 is located parallel to the axis of the hole in the workpiece to be machined,
It is arranged so that

The tool holder 12 consists of two strips 12a of different materials joined side to side in a plane perpendicular to the direction required by the tool movement.

12b. There are two connections.

The tight bonding of the strips 12a, 12b to one another can be carried out by gluing or by melting or, if desired, by diffusion bonding.

The metal of said strips 12a, 12b is selected such that the length of one of said strips can be varied in a magnetic field by a different amount than the change in length of the other strip in the same magnetic field. There is. This effect is called magnetostriction. Advantageously, the length of one strip increases while the length of the other strip decreases.

A suitable pair of metals is nickel and pure iron, nickel and 50%
an alloy of 50% iron and 50% nickel, an alloy of nickel and 50% conoquilt and 50% iron, and an alloy of nickel and 70% iron, 6% iron and 30% iron. All are percentages of weight. Naturally, this table is not exhaustive and other suitable pairs of materials may be used.

The tool holder 12 is surrounded by an electrical coil 17 between the fixed end and the tool mounting portion 16 . The coil 17 can be wound directly onto the tool holder 12 or, if sufficient play is provided between the tool holder 12 and the molded body considering the movement of the tool holder, on a separate molded body. It can be wrapped around. The coil 17 is connected to a current supply 18 to which an alternating or direct current of variable frequency and amplitude can be applied. For example, the variable frequency oscillator 19 is connected to the coil 17 via the power amplifier 20.
It can be used by connecting with.

Since only the part of the tool holder within the area of the coil 17 exhibits a magnetostrictive effect, only this part of the tool holder need be made of the selected magnetostrictive metal.

The tool supporting end of tool holder 12 may be formed from mild steel.

The tool holder 12 can be clamped to reduce or prevent undesirable vibrations such as chucks. Such a damping member may take the form of a thin steel strip placed on either side of the tool holder.

The machine tool is operated as follows. The tool holder 12 is rotated in the headstock 10 and the workpiece 14 is moved onto the cross slide 13 to a reference position relative to the tool. A predetermined current is applied to the coil 17 and the magnetostrictive effect in the two metal parts of the tool holder 12 causes the tool holder 12 to have two metal strips 12a, 12.
This results in an offset perpendicular to the plane of the joint between b. The amount of deflection is proportional to the strength of the magnetic field produced by the coil 17, so that the desired amount of deflection can be obtained by controlling the variable frequency oscillator 19. The yoke tool 15 inserts a circular surface with a desired radius of curvature into the workpiece in this manner.
It can be manufactured by

The position of the tool 15 can be changed several times during the machining operation to produce finished workpieces of different circular cross-sections over the entire length of the workpiece, or can be kept constant throughout the machining operation. good. Furthermore, the position of the tool 15 can also be changed during one rotation of the workpiece in order to produce workpieces with non-circular cross-sections. The current changes necessary to produce these various cross-sections are controlled by computer 21.

Furthermore, it is not necessary to rotate the tool holder 12.

As an alternative to this, the workpiece can be rotated,
The tool holder 1 is designed to act on the outer surface of the workpiece like a rounding tool by rotating the tool holder over 90 degrees.
2 can be arranged in a plane perpendicular to the axis of rotation of the workpiece.

Surfaces of various cross-sections can be fabricated on the gills described above. - The excursion of the tool holder 12 is temperature related and for this reason a cooling mechanism 22 can be provided in order to maintain the temperature of the tool holder almost constant. A mechanism such as computer 21 may be provided to compensate for the effects of temperature changes over time.

As is clear from FIGS. 2, 3 and 4, the machine tool is a bellows RA equipped with a headstock 3.1.

The chuck 33 is rotatable on the headstock 31. A workpiece 34, such as a piston, into which a piston pin hole 35 is to be machined, is attached to a movable slider 4'2 at the end of the bed opposite the headstock 31.

A tool holder in the form of an elongated boring bar 36 of circular cross-section (see FIG. 3) is held fixedly in the chuck 33 at one end, and a tool 37 is mounted in a section 38 at the other end of the tool holder. is attached to. A weight 39 is eccentrically attached to the boring bar 36 between its ends.

A fluid bearing member 40 surrounds the boring bar 36 between its ends and is adjacent to the eccentric weight 39 and fixed to the bed 30. The fluid bearing member 40 is fitted snugly around the boring bar 36, as is clear from FIG. has eight pairs of orifices 41 which are spaced apart in the axial direction and equally spaced in the circumferential direction around the boring bar, as is clear from FIG. each pair of orifices is connected to a supply of pressurized fluid, e.g. pressurized liquid or air, so that the supply of fluid to each pair of orifices can be controlled separately; The pressure of the fluid exiting the orifice 41 can be varied by the same value or by a different value.

Such control may be provided by a sertor valve under computer 430 control.

Additionally, a foot nosec control mechanism 44 may be provided for comparing the actual trajectory of the tool 37 with the desired trajectory and adjusting the radially inward force in accordance with the comparison.

The machine tool according to FIGS. 2, 3 and 4 is operated as follows. The chuck 33 rotates, and therefore the boring bar 36 rotates about its own axis. Biased jσ weight 3
9, the axis of the boring bar is displaced.

In other words, a curved conical surface of rotation is created around the rotation axis of the headstock. The maximum diameter of the cone occurs at the end of the tool holder supporting the tool 37, whereas the end of the tool holder 36 held by the chuck 33 does not deflect at all.

The fluid bearing member 40 acts to control the rotational excursion by applying a controlled radially inward force on the boring bar 36. If the fluid pressure exiting the orifice 41 is the same fluid pressure for all orifices, the tool 37 will draw a perfect circle, and the radius of curvature of this perfect circle will be related to the fluid pressure (FIG. 3). reference).

However, if the fluid pressures exiting the orifice 41 are not equal, the tool will follow a non-circular trajectory, the shape of which is controlled by controlling the fluid supply to the orifice.

In this manner, the tool is used to form the piston pin hole 35 of the piston 34 over its entire length to the desired cross section. The cross section can be perfectly circular or elliptical or another desired shape. The fluid bearing member thus acts like a cam whose shape can either change during the machining process or remain constant during the machining process.

It does not have to be applied by a radially inwardly directed fluid bearing member. For example, the force can be applied by a number of hydraulic springs 45 (see FIG. 5) of variable dynamic stiffness and spaced circumferentially around the tool holder. Furthermore, said force can be applied by a cam surface 46 that is engaged by the boring bar 36 to give the tool holder 36 the desired trajectory. The cam surface has a shape that can be changed during the machining operation.

Furthermore, the tool mounting can be provided with a wide variety of elements for deflecting the part during machining so as to change the position of the tool relative to the holding end by a predetermined value. For example piezoelectric forces can be used, or magnetic and/or mechanical effects other than those described above in connection with the figures can be used.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side view of a machine tool that uses magnetostrictive effect to position the tool holder of the machine tool, and Fig. 2 is a side view of a machine tool for positioning the tool holder. a side view of a machine tool having a tool holder that uses a fluid bearing member and supports an eccentric weight;
3 is a cross-sectional view of the fluid bearing member surrounding the tool holder of the machine tool shown in FIG. 2, FIG. 4 is a longitudinal sectional view of the fluid bearing member of FIG. 3, and FIG. A hydraulic spring is shown, and FIG. 6 shows an eccentric cam for positioning the tool holder. 10.31... Headstock, 11.33... Chuck,
12... Tool holder, 12a, 12b... Strip, 13... Cross slider, 14.34... Workpiece, 15° 37... Tool, 16.38... Tool mounting part , 17... Coil, 18... Current supply section, 19.
...Variable frequency oscillator, 20...Power amplifier, 21.
... Computer, 22 ... Cooling mechanism, 30 ... Bed, 35 ... Piston pin hole, 36 ... Boring rod, 39 ... Weight, 40 ... Fluid support member, 41 ...
- Orifice, 42... Slider, 43... Computer, 44... Fee P notch control mechanism, 45.
...Spring, 46...Cam surface

Claims (1)

[Claims] 1. A machine tool having an elongated tool holder fixed at one end and having a tool mounting section at the other end, the workpiece and the tool being connected to each other to perform a machining operation on the workpiece. In the type that can be rotated relatively, the tool (15
, a7) during machining to change the position of the tool holder (1).
2, 36), the tool holder deflection member (17, 39, 40, 45, 46)
A machine tool characterized by the fact that 2. The tool holder deflection member is composed of a magnetic field generating member (17) for generating a magnetic field around the tool holder, and the tool holder comprises two elongated members (12a) made of different materials that are juxtaposed and joined to each other. , 12b) and the elongated members (12a, 12b).
2. The machine tool according to claim 1, wherein the material of item b) is such a material that a change in length due to magnetostrictive action in the elongated member produced by the magnetic field generating member causes a deflection of the tool holder. 3. The magnetic field generating member is a coil (1) arranged around the tool holder between the fixed end of the tool holder and the tool mounting section.
7) The machine tool according to claim 2, which is formed from the following. 4. The metal of the tool holder (12) is pure iron for one part and nickel for the other part, or nickel for one part and (
an alloy of 50% nickel (by weight) and 50% iron (by weight), or nickel for one part and 50% K (by weight) for the other part. An alloy consisting of iron and 50% (by weight) Conort or nickel for one part and 30% (by weight) iron and (by weight) for the other part. Claim 2 or 3, which is an alloy consisting of 70% Co, S and
Machine tools listed in section. 5 The tool holder (12) during machining is rotated about its own axis and the workpiece (14) is not rotated, or the tool holder during machining is not rotated and the workpiece is rotated. A machine tool according to any one of claims 1 to 4. 6. The tool holder (36) is rotatable about its own axis, and the tool holder deflection member is arranged between the fixed end and the tool mounting section in order to cause the tool holder to deflect during rotation. Eccentric weight attached to tool holder (39
), a force supply member (4o) for applying a predetermined radially inward force around the tool holder rotating in an offset trajectory of motion to define a trajectory traced by the tool mounting section. A machine tool according to claim 1, comprising: 7. The tool holder (36) has a circular cross section, and the force supply member for applying a radially inward force is connected to the tool in order to adapt to the deflection of the tool holder. It consists of an air bearing placed around the tool holder with a gap between the air bearing and the holder.
7. The machine tool of claim 6, wherein the air for the bearing is adapted to apply said force around the tool holder so that the tool mounting section follows the desired trajectory. A number of dynamically variable stiffness hydraulic springs (4) spaced circumferentially around the tool holder (36) to apply a force therearound.
5) The machine tool according to claim 6, comprising: 9. The force supply member for applying a radially inward force is formed from a cam surface (46) that is engaged by the tool holder to impart the desired trajectory to the tool holder, the shape of the cam surface being 7. The machine tool according to claim 6, wherein the tool mounting is variable during rotation of the tool holder in order to change the part locus. A control mechanism (18°, 19, 20, 21
, 43, 44) are provided in order for the bearing pressure control mechanism to produce a constant amount of deflection throughout the machining operation in the workpiece and/or to control the relative rotation between the workpiece and the tool. 10. A machine tool according to claim 1, wherein the tool holder deflection member is controlled to produce a deflection variable within one revolution. 11. The machine tool according to claim 10, wherein the control mechanism is adapted to control the tool holder deflection member to displace the workpiece within the machining range. 12 an elongated flexible boring bar for machining the inner surface of a stationary workpiece; a drive member that engages the boring bar at one end to rotate the boring bar; and a boring bar; a tool holder provided at the other end, and a member (12°36) for applying a controlled force to the boring bar (12°36).
7, a9. sq, 4s, 4s) is placed between both ends to bend the boring bar while it is rotating, and this allows it to be attached to the boring bar by a predetermined value relative to the workpiece. Machine tool 0 according to claim 1, wherein the position of the tool (15, 37) can be changed.