KR940003945B1 - Spindle clamping device for machine tool - Google Patents

Abstract

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Description

Spindle clamping machine tool

1 is a cross-sectional view of a spindle clamping device constituting an embodiment of the present invention.

2 is a cross-sectional view of the clamp ring consisting of an inner and outer ring.

FIG. 3 is an enlarged fragmentary sectional view of the device of FIG. 1 showing the first and second spindles clamped together.

4 is an enlarged partial sectional view of the apparatus of FIG. 1 showing the first and second spindles being unclamped to each other.

5 is a cross-sectional view of the spindle clamping device of another embodiment of the present invention.

6 is a cross-sectional view of the spindle clamping device of another embodiment of the present invention.

7 is a cross-sectional view of the spindle clamping device of another embodiment of the present invention.

8 is a graph showing the amount of cutting of a machine tool with a spindle clamping device and a milling cutter provided according to the invention, compared to the amount of cutting of a machine tool with a milling cutter and a conventional spindle clamping device.

9 is a graph showing the amount of cut of a machine tool with an end mill and a spindle clamping device provided in accordance with the present invention, compared to the amount of cutting of a machine tool with an end mill and a conventional spindle clamping device.

* Explanation of symbols for main parts of the drawings

1: milling spindle 2: spindle head

4: Boring Spindle 13, 14: Clamp Ring

12: disc spring 19: constant pressure chamber

The present invention relates to a spindle clamping device for a machine tool, and more particularly to a device for clamping two coaxial axes of a machine tool such as horizontal boring and boring and milling spindle of a milling machine.

Various spindle clamping devices are used for the spindle of a machine tool, wherein the hollow first spindle is rotatably supported in the main head and the second spindle is rotatable in the hollow first spindle to move back and forth in its axial direction. Supported.

In the case of horizontal boring and milling machines, the first spindle is the milling spindle and the second spindle is the boring spindle, and the clamping device for machine tools can be classified into two types (1) and (2) as follows. .

(1) A thin shell between a milling spindle rotatably supported on the spindle head and a boring spindle rotatably supported on the milling spindle so as to be movable back and forth in the axial direction of the boring spindle (Japanese Patent Application No. 62-43684). Similar to the clamping ring described in), to clamp the boring spindle to the milling spindle.

When the compressed oil is released from the thin shelling, the two main spindles are de-clamped.

(2) The function of the self-maintaining compressed oil is provided in the second spindle, that is, the boring spindle, to clamp the milling and boring ejections with each other as disclosed in the above-mentioned publication.

More specifically, a thin shelling is provided between the milling spindle rotatably supported by the main head and the boring spindle rotatably supported in the milling spindle so as to be movable back and forth in the axial direction of the boring spindle.

Accumulators are provided to supply pressurized oil to the shelling.

An oil spray nozzle unit is provided to the accumulator, and a hydraulic oil supply unit is provided to supply oil to the spray nozzle.

For form (1), the pressurized oil must always be supplied or maintained during the rotation of the spindle.

For this reason, if the milling spindle is rotated rapidly during machining, a lot of heat is generated in the positive pressure pocket during the rotation, and the boring spindle is stretched by this thermal expansion, which adversely affects the precision of machining.

For form (2), leakage of pressurized oil cannot be prevented during the rotation of the spindle, and therefore the machine tool cannot be operated for a long time.

For this reason, the machining must be stopped, the boring spindle must be repositioned at the prescribed angle, and the oil spray nozzle unit and the hydraulic oil supply unit are mutually spaced before the operation to supply the compressed oil into the thin shelling is achieved. Must match.

In the case of pressurized oil leakage, the oil pressure to be applied to the thin shelling is low, making it difficult to firmly clamp the spindles firmly to each other.

Moreover, the working rate of the machine tool is lowered because some time is required to take the work for feeding the compressed oil into the thin shelling.

The present invention addresses the above mentioned problem.

An object of the present invention is to be able to clamp firmly and reliably and to be rotatable on a first spindle such that the first spindle is rotatably supported by the spindle head and the second spindle is movable back and forth in the axial direction of the second spindle. The present invention provides a spindle clamping device for a first and a second spindle of a machine tool in a supporting form.

According to the present invention, the object is a work having a main head, a hollow first spindle rotatably supported by the main head and a second spindle rotatably supported on the first spindle to move back and forth in the axial direction thereof. Obtained by a spindle clamping device in the machine, the spindle clamping device comprising means for forming an annular space between the first spindle and the second spindle, the inner and outer clamping rings being not movable in the axial direction of the spindle and the other The clamping ring is axially movable relative to one clamping ring and has at least one set of radially inner and outer clappling, each having an inner and outer conical surface and in sliding contact with each other, said Axially to push the slideable clamping ring disposed in the space on one side of the sliding clamping ring in the axial direction Exerting a force on the slidable clamping ring to produce a wedge effect due to the conical surface, and accordingly an annular between the spring means for clamping the first and second spindles to each other, and the axial axis on the other side of the slidable clamping ring. Means for forming a pressure chamber of the apparatus, connected to a hydraulic source, exerting an axial force opposite the axial force of the spring means as the hydraulic pressure enters, and thus moving the slidable clamping ring to release the clamping; It consists of a pressure chamber.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

1 shows a spindle clamping device 10 according to the invention for clamping a spindle of a machine tool.

The machine tool shown is a horizontal boring and milling machine with a hollow milling spindle 1 as the first spindle and a boring spindle 4 as the second spindle.

The milling spindle 1 is rotatably supported by a bearing 3 in the spindle head 2. The boring spindle 4 is rotatably supported on the used milling spindle 1 in such a way that the boring spindle 4 can be moved back and forth in the axial direction by a drive mechanism not shown in the drawing. The boring spindle 4 has a socket 5 at the end of the spindle.

The tool can be inserted into the socket 5 and replaced by another tool depending on the type of machining operation to be achieved by the machine tool.

As shown, the spindle clamping device 10 includes an annular space 11, a disk spring 12, a clamp ring 13 and 14, a collar 15, a seal member 18A and 18B and an O-ring. 18a, the static pressure chamber 19, the oil passage 20, the oil pressure bush 21, the coupling 23, the hydraulic source not shown in the figure, the compressed air source 26 and the cylindrical closing member 33 It includes. These elements will be described in detail below.

The annular space 11 is formed in the milling spindle 1 so as to open radially inward and is located between the boring spindle 4 and the milling spindle.

The disc spring 12 is provided as an elastic means in the annular space 11 for clamping the milling and boring spindles 1, 4 together.

Clamp rings 13 and 14 are inserted at both sides of the assembly of the disc spring 12.

The clamp rings 13 and 14 consist of tapered outer rings 13A and 14A and tapered inner rings 13B and 14B, which differ from each other by opposing inclined tapered or conical surfaces.

The inner rings 13B and 14B can be moved in the axial direction of the boring spindle 4, but the outer rings 13A and 14A are restrained in the axial movement by the installation of the collar 15.

Clamp rings 13, 14 are used to clamp the milling and boring spindles 1, 4 through the action of the disk springs 12, as will be described in detail below.

The clamp rings 13 and 14 are identical in shape and structure. Therefore, only the clamp ring 13 will be described in detail below with reference to FIG.

The clamp rings 13, 14 consist of an outer ring 13A and an inner ring 13B which face in contact with the conical tapered surface and which are movable relative to each other in the axial direction of the boring spindle 4.

The inner surface of the inner ring 13B has an oil removal groove 16 extending spirally along the circumferential surface.

The inner ring 13B has slits 17 provided at equal intervals along the circumference of the ring and extend respectively along one axis toward one side of the ring.

The outer ring 13A is restrained in the annular space 11 to be immovable in the axial direction of the boring spindle 1, but the inner ring 13B is movable in that direction.

The collar 15 is provided between the outer rings 13A and 14A to adjust the force of the disc spring 12 when the clamp rings 13 and 14 are inserted into the annular space 11.

The seal member 18 is provided in the annular space 11 and is in constant contact with the milling and boring spindles 1, 4 via an O-ring.

The seal member 18 is in contact with the inner rings 13B and 14B on one side of each seal member and in contact with the static pressure chamber 19 on the other side of each seal member.

The static pressure chamber 19 is provided in the milling spindle 1 and communicates with the oil passage 20 provided in the spindle. The oil inlet port of the oil passage 20 is in sliding contact with the oil pressure bushing 21 fastened to the spindle head 2.

The positive pressure pocket 22 is provided on the inner circumferential surface of the oil pressure bush 21 and is connected to the oil transfer port of oil pressure through the coupling 23. The positive pressure pocket 21 has an air hole 22a for supplying pressurized air into the pocket. The air hole 22a is connected to a pressurized air source 26 that intermittently supplies the compressed air through the air hole 22a into the pocket 22.

The closing member 33 is fastened to the milling spindle 4 at its front end by bolts 34.

The operation of the spindle clamping device 10 will be described in detail below.

In order to clamp the milling and boring spindles 1 and 4 to each other, the supply of hydraulic oil from the hydraulic source through the oil passage 20 to the constant pressure chamber 19 is stopped to prevent the pressure of the oil from acting in the chamber. .

As a result of this, the force of the disc spring 12 displaces the inner rings 13B and 14B in the direction of moving the inner rings apart from each other as indicated by the arrows in FIG. For this reason, a wedge effect is generated on the outer and inner rings 13A, 14A, 13B, 14B due to the tapered surface so that the milling and boring spindles 1, 4 are clamped to each other.

As a result of this clamping, the slits 17 of the inner rings 13B and 14B are circumferentially compressed and the tapered surfaces of the inner and outer rings are pushed against each other.

Since the inner surfaces of the inner rings 13B and 14B have oil removal grooves 16, oil on the outer circumferential surface of the boring shaft 4 is removed from the surface during the movement of the inner ring so that the inner rings clamp both spindles together. The boring spindle is in contact with the metal-to-metal so as not to slip against the boring spindle.

The milling and boring spindles 1, 4 are movably connected together with the clamping rings 13, 14, and their assemblies remain in a very rigid state.

In order to de-clamp the milling and boring spindles 1 and 4 from each other, hydraulic oil is supplied from the hydraulic source to the constant pressure chamber 19 through the coupling 23, the positive pressure pocket 22 of the bush 21 and the oil passage 20. Supplied, as shown in FIG. 4, against the force of the disc spring 12 via the seal member 18 disposed with the axial external force in contact with the main shaft via the O-ring 18a. It acts on the inner rings 13B and 14B.

As a result, the inner rings 13B and 14B are moved toward each other against the force of the disc spring 12 by the hydraulic pressure in the static pressure chamber 19, as shown in FIG. The push against the rings 13A, 14A is eliminated. For this reason, the clamping force is released because no clamping force acts on the milling and boring spindles 1, 4.

If the hydraulic pressure is present in the hydrostatic pocket 22 during the rotation of the milling spindle 1 clamped to the boring spindle 4, heat is generated due to the shear stress of the oil between the milling spindle and the oil pressure bushing 21.

For this reason, compressed air is intermittently supplied from the compressed air source 26 through the air hole 22a during the operation of the machine tool to the positive pressure pocket 22, so that the constant pressure oil is discharged from the positive pressure pocket to prevent the generation of heat. Remove to lower the thermal expansion of the spindle (1,4).

5 shows a spindle clamping device 30 according to another embodiment of the invention for clamping the milling spindle 1 and the boring spindle 4 to each other.

The device 30 is formed in the milling spindle 1 and annular space 11 located between the boring spindle 4 and the milling spindle 1, the annular space 11 for acting to clamp the migration axes to each other. It consists of a disk spring 12 provided within and an outer and inner ring 14, 15 and a clamp ring 13 arranged on one side of the assembly of the disk spring to act to clamp the main shafts to each other.

The collar 31 is used to immobilize the outer ring 14 nonmovably.

Because of the above-described configuration, the number of components of the spindle clamping device 30 is smaller than that of the spindle clamping device 10.

Since the tapered surface of the clamp ring 13 is tapered low toward the right as shown in FIG. 5, the clamping state of the spindle clamping device 30 is on the right side of the spindle clamping device with respect to FIG. Sufficiently resist the working force.

The spindle clamping device 30 is the same as the spindle clamping device 10 described above in this respect and will not be described further.

6 shows a spindle clamping device 30 for clamping a milling spindle 1 and a boring spindle 4 to each other by the use of clamping rings 13, 14, according to another embodiment of the invention. have.

Since the spindle clamping device 30 is a modification of the spindle clamping window 10 described above, the common corresponding parts are denoted by the same reference numerals in the drawings.

With respect to the spindle clamping device 30, each of the O-rings 18a on the seal members 18A and 18B prevents the resistance from affecting the movement of the boring spindle 4, which resistance accurately positions the spindle. Makes it impossible to let.

The spindle clamping device 30 includes an annular space 11, a disk spring 12, a clamp ring 13 and 14, a seal member 18A and 18B, a static pressure chamber 19, an oil passage 20 and an oil pressure. Composed of bush 21, positive pressure pocket 22, coupling 23, sleeves 31 and 32, cylindrical closing member 33, hydraulic source not shown in the figure and pressurized air source not shown in the figure It is.

An annular space 11 is formed in the milling spindle 1 and is located between the boring spindle 4 and the milling spindle.

The disc spring 12 is inserted around the annular space 31 fixed on the boring spindle 4. The clamp rings 13 and 14 consist of the outer rings 13A and 14A and the inner rings 13B and 14B and are inserted at both sides of the assembly of the disc spring 12.

The seal members 18A and 18B are inserted at both sides of the assembly of the clamp rings 13 and 14 and the disk spring 12. The seal member 18A is in contact with the O-ring 18 with the spacer sleeve 32 inserted on the boring spindle 4.

One side of the sealing member 18A is in a state of being connected to the outer ring 14A.

The other side of the sealing member 18A is in contact with the constant pressure chamber 19.

The other seal member 18B is in contact via another O-ring 18a with an extension 33a of the cylindrical closure member 33 inserted into the boring spindle 4.

The closing member 33 is fastened to the milling spindle 1 with a bolt 34 at the front end thereof.

One side of the seal member 18B is in contact with the outer ring 13A.

The other side of the seal member 18B is in contact with the positive pressure pocket 19.

The clamp rings 13 and 14 are formed similarly to the spindle clamping device 10 shown in Figs. 1 and 2, except that the inclination of the tapered surface is reversed. The inner rings 13B and 14B are restrained in the annular space 11 so as not to be movable, but the outer rings 13A and 14B can be moved in the axial direction of the boring spindle 4.

The static pressure chamber 19 communicates with the oil passage 20 provided in the milling spindle 1. The oil inlet port of the oil passage 20 is in sliding contact with the oil pressure bush 21 fastened to the head head 22 supporting the milling and boring spindles 1, 4. The inner circumferential surface of the bush 21 has a positive pressure pocket 22 connected to the hydraulic source through the coupling 23.

When the compressed oil is supplied from the hydraulic source to the positive pressure pocket 19 through the coupling 23, the positive pressure pocket 22 and the oil passage 20, the assembly of the disc spring 12 is sealed member 18A, 18B. And compressed by the pressure of the oil through the action of the outer rings 13A and 14A, thereby releasing the clamping of the milling and boring spindles 1 and 4 together with the clamping rings 13 and 14.

The operation of the spindle clamping device 30 shown in FIG. 6 will be described in detail below.

In order to clamp the milling and boring spindles 1 and 4 to each other, the supply of pressurized oil from the hydraulic source to the positive pressure pocket 19 is stopped so that the pressure of the oil does not act on the pocket.

As a result, the outer rings 13A, 14B are spaced apart from each other in the axial direction of the main shaft 4 by the force of the disk springs 12, so that the outer and inner rings 13A, 14A, 13B due to the tapered surface. And milling and boring spindles 1, 4 are clamped to each other.

At this time, the slits 17 of the inner rings 13B and 14B are pressed in the circumferential direction and the tapered surfaces of the outer rings 13A and 14A push the tapered surfaces of the inner ring.

Since the outer circumferential surfaces of the outer rings 13A and 14A have oil removal grooves 16 for removing oil to the inner circumferential surface of the milling spindle 1 during the movement of the outer ring, the ring is a result of the movement of the ring. The milling spindle and boring spindle 4 are clamped to each other because they are in metal-to-metal contact with the milling spindle so that the reel does not slip on the milling spindle.

Pressurized oil is supplied from the hydraulic source to the constant pressure chamber 19 through the coupling 23, the constant pressure ford 22, and the oil passage 90 to release the milling and boring spindles 1, 4 from each other. An axial external force acts on the outer ring by oil through the action of the seal member 18 against the force of the disk spring 12.

At this time, the oil pressure in the static pressure chamber 19 moves the outer rings 13A and 13A toward each other against the force of the disc spring 12 so that the spindle clamping force is removed from the clamp rings 13 and 14. The spindles 1, 4 are unclamped with respect to each other.

7 shows a spindle clamping device 40 for clamping the milling spindle 1 and the boring spindle 4 in accordance with another embodiment of the present invention. Since the spindle clamping device 40 is a modification of the spindle clamping device 30 shown in FIG. 5, the mutually corresponding parts of these devices are denoted by the same reference numerals in the drawings.

For the spindle clamping device 40, each O-ring on the seal member 18 prevents the resistance from affecting the movement of the milling spindle 1, which resists the precise positioning of the spindle through the movement. Make it impossible.

The spindle clamping device 40 includes an annular space 11, a disc spring 12, a clamp ring 13, a seal member 18, an O-ring 18a, a constant pressure chamber 19, and an annular spacer 31. And 32). An annular space 11 is formed in the milling spindle 1 and is located between the boring spindle 4 and the milling spindle.

The disc spring 13 is inserted between the milling spindle 1 and the annular spacer 31 inserted on the boring spindle 4.

The clamp ring 13 consists of an outer ring 13A and an inner ring 13B and is provided on one side of the assembly of the disc spring 12 to act to clamp the milling spindle 1 and the boring spindle 4 to each other. have.

The seal member 18 is provided in an annular space 11 and has an O-ring 18a, one of which is on a spacer slave 32 inserted on the boring spindle 4.

One side of the seal member 18 is in contact with the outer ring 13A.

The other side of the seal member 18 is in contact with the mating pocket 19.

The spindle clamping device 40 performs the same operation as the spindle clamping device 30 shown in FIG.

8 shows the amount of cutting of a machine tool with a milling cutter and a spindle clamping device provided according to the invention, compared to the amount of cutting of a machine tool with a milling cutter and a conventional spindle clamping device.

9 shows the amount of cutting of a machine tool with an end mill and a spindle clamping device provided according to the present invention, compared to the amount of cutting of a machine tool with an end mill and a conventional spindle clamping device.

The abscissa in each of FIGS. 8 and 9 shows the amount of cutting by the machine tool.

The ordinate in each of FIG. 8 and FIG. 9 has shown the ratio L / D of the length L of the boring spindle of a machine tool, and the diameter D of the boring spindle from the end of a milling spindle.

The amount of cutting of a machine tool with a milling cutter and a spindle clamping device provided in accordance with the present invention is about twice as much as that of a machine tool with a milling cutter and a conventional spindle clamping device, with an end mill and a clamping device provided according to the invention. It will be appreciated from FIGS. 8 and 9 that the cutting amount of a machine tool is four times the cutting amount of a machine tool with an end mill and a conventional spindle clamping device. Therefore, this good result is obtained in both cases by the use of the spindle clamping device according to the invention.

While the invention is not proposed in the embodiments described above, it can be embodied or embodied in other ways without departing from the scope or essential characteristics of the invention.

Claims (10)

A work machine having a spindle head 2, a hollow first spindle 1 rotatably supported in the spindle head, and a second spindle 4 rotatably supported in the first spindle so as to be moved back and forth in the axial direction thereof. A spindle clamping device in a machine, the spindle clamping device comprising: an annular space (11) formed between a first spindle (1) and a second spindle (4); One of the inner and outer clamping rings is immovable in the axial direction of the main shaft and the other clamping ring is axially slidable relative to one clamping ring, formed in the space and having a conical outer and inner surface. At least one set of radially inner and outer clamping rings 13A, 13B; 14A, 14B; 14, 15 in sliding contact with each other; An axial force on the slidable clamp ring disposed in the space on one side of the clamp ring that is slid relative to the axial direction and for sliding the slidable clamp ring axially to produce a wedge effect due to the conical surface. A spring means 12 for clamping the first and second spindles accordingly; It is formed between the main shafts on the other side of the slidable clamping ring and is connected to a hydraulic source and applies an axial force opposite the axial force of the spring means as the hydraulic pressure flows in, thereby clamping the main shaft. An annular pressure chamber 19 for displacing the slidable clamp ring to release; Spindle clamping device, characterized in that consisting of. 2. The spindle clamping device according to claim 1, wherein the annular space (11) is formed on the inner surface of the hollow first spindle (1). 2. A spindle clamping device according to claim 1, wherein the spring means is a set of disc springs. 2. A spindle clamping device according to claim 1, wherein the immovable clamping ring is immovably fixed in an axial direction by a collar (15,31) inserted into the annular space. The pressure chamber (19) according to claim 1, wherein the pressure chamber (19) is fitted on the outer surface of the axially slidable second spindle (4) and transmits the force generated by the pressure in the chamber to the slidable clamping ring. And a sealing member (18) inserted between the sliding clamp ring and the slideable clamping ring. 6. The spindle clamping according to claim 5, further comprising a sleeve (32) fitted to the inner surface of the hollow first spindle (1) for separating the seal member and the pressure chamber from the second spindle. Device. 2. A spindle clamping device according to claim 1, further comprising an oil passage (20) formed in the first spindle (1) for connecting the pressure chamber (19) to the hydraulic source. 8. An oil pressure bush (21) surrounding the first spindle (1) in sliding sealing contact with the first spindle, wherein the bush is in constant contact with the oil passage (20) in the first spindle. A spindle clamping device, characterized in that it is in communication and has a pressure pocket (22) connected to a hydraulic source. 9. The air conditioner as claimed in claim 8, further comprising an air hole (22a) provided in the bush (21) for supplying compressed air into the pressure pocket (22), thereby removing the pressure oil from the pressure pocket to reduce heat generation. Spindle clamping device comprising a. 2. The inner clamp ring according to claim 1, wherein the inner clamp ring has an axial slit 17 disposed in parallel with the oil removal groove 16 extending in the circumferential direction of the inner clamp ring. Spindle clamping device characterized in that.