JPH058032Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a tool head for attaching tools such as drills and end mills to the main spindle of machine tools such as machining centers, drilling machines, and milling machines.
More specifically, the present invention relates to a tool head that has a built-in speed increasing mechanism and enables high-speed machining.

Conventional technology As a tool head attached to the main spindle of a machine tool, a speed increasing mechanism is incorporated to enable high-speed machining of workpieces with excellent machinability such as free-cutting steel, aluminum alloy, and plastic. There is something I did.

In such a tool head, as shown in FIG. 2, the proximal end of a tool head main body 120 is fitted and connected to the main shaft 101 of a machine tool, and the distal end of the tool head main body 120 is formed into a cylindrical shape. This tip portion is surrounded and rotatably supported by a housing 130 that is fixedly supported by the machine tool via a support member 150.

A tool drive shaft 160 that rotatably supports a tool (not shown) such as a drill is provided at the tip of the tool head body 120.

A gear 136 is provided on the outer peripheral surface of the base end side of the tool drive shaft 160, and a planetary gear 1 meshes with the gear 136.
26 is rotatably provided at the tip of the tool head body 120. This planetary gear 126 is rotatably supported by a pin installed in a mounting hole 140 provided in the tool head body 120, and is supported by an inner surface provided on the inner circumferential surface of a housing 130 that is prevented from rotating in the machine tool. It meshes with the gear 138, increases the rotation speed of the tool head body 120, and rotates the tool drive shaft 160.
It functions as a planetary gear that rotates.

Problems to be Solved by the Invention In the tool head having such a configuration, the mounting hole 140 should be opened at the distal end of the tool head main body 120 from the distal end face toward the proximal end using, for example, a drill. However, since the hole is deep, the cutting resistance causes the drill etc. to vibrate, and even if the finishing process is performed afterwards by boring, reaming, etc., the machining accuracy deteriorates due to the poor machining accuracy of the previous machining. Therefore, there is a risk that the pin 139 may be attached with its axis eccentric to the axis of the tool head body 120.

For this reason, the planetary gear 126 is the gear 136,
This results in uneven contact with the internal gear 138, resulting in damage, noise, and shortened lifespan. Further, since the tool vibrates, there is a problem that the life of the tool is shortened and accurate cutting cannot be performed. Also, tool head 1
When the mounting hole 140 is machined in the axial direction of the tool head body 120, the hole axially passes through the cylindrical tip of the tool head body 120, and the cylindrical tip becomes thicker. The cylindrical end of the tool head body 120 supports the tool drive shaft 160 and the housing 130 via bearings inside and outside. These bearings are
It is a standard product and can only be increased in size in stages. Further, the number of teeth of the planetary gear 126 is also increased only in stages according to the tooth number formula of the planetary gear. Under such circumstances, if the cylindrical end of the tool head body 120 becomes thicker, the bearing and the planetary gear 126 will become larger than the thickening, resulting in a significant increase in the size of the tool head.

The present invention was developed in view of the above circumstances, and is compact and allows the pin to be mounted with the pin axis accurately aligned with the axis of the cylindrical body such as the tool head body. The purpose of the present invention is to provide a tool head that prevents deterioration and extends the life of tools, gears, etc., and has excellent cutting accuracy without noise and vibration.

Means for Solving the Problems The tool head according to the present invention supports a tool drive shaft via a bearing inside the cylindrical part of the tool head body which is connected to the main shaft of a machine tool, and supports the tool drive shaft via a bearing on the outside of the tool head body. In addition, a plurality of planetary gears that mesh with the internal gear provided on the inner surface of the housing are meshed with the gear provided on the outer surface of the tool drive shaft, thereby increasing the rotation speed of the tool head body and driving the tool drive shaft. In the tool head to be rotated, the planetary gear is rotatably supported by a support pin attached to a mounting hole opened from the outer peripheral surface of the cylindrical portion of the tool head main body.

Effects In the present invention, since the mounting hole is opened from the outer peripheral surface of the cylindrical part of the tool head body, deterioration of machining accuracy is prevented, and as a result, the axis of the pin is aligned with the axis of the cylinder. The pin should be installed in the mounting hole while being accurately aligned, and even if the mounting hole should be eccentric to the axis of the tool head body,
You can prevent the support pin from becoming eccentric by placing shims, etc.

Embodiment Hereinafter, one embodiment of the tool head according to this invention will be described based on the drawings. FIG. 1 is a sectional view showing a tool head attached to the main shaft of a machine tool.

This tool head 10 includes a tool head main body 20 provided on the proximal end side located on the left side in the figure, a housing 30 connected to the distal end (right end) side, and a support member 50 provided on the outer peripheral surface of the housing 30. Consisting of

In the figure, 1 is the main shaft of a machine tool to which a tool head 10 is attached. This attachment is performed by fitting the taper shank 20a provided at the proximal end of the tool head body 20 into the taper hole 2 of the main spindle 1.

At this time, the positioning pin 51 of the support member 50 is simultaneously pushed into the pin groove (or hole) 4 of the positioning block 3 of the machine tool, and the housing 30 is reliably prevented from rotating. That is, the tool head 44 chucked (held) at the tip of the tool head 10 is now positioned with respect to the workpiece (not shown).

As shown, the tip 21 of the tool head body 20 is cylindrical, and is fitted into a cylindrical housing 30 to connect the two. Specifically, two ball bearings 32a are arranged in parallel on the base end side of the inner peripheral surface of the housing 30,
At 32b, the tip 21, that is, the tool head main body 20
It is configured to rotatably support the

These ball bearings 32a and 32b are installed on the inner circumferential surface of the housing 30 and the tip end 21.
Fit the ball bearings 32a and 32b in this order into the bearing seat 33 formed on the outer peripheral surface of the
This is done by locking with a snap spring 35.

A tool drive shaft 40 is provided on the tip side of the inner peripheral surface of the tip portion 21.
Three ball bearings 2 that rotatably support the
2a, 22b, and 22c are fitted. To install these ball bearings 22a, 22b, 22c, first fit the ball bearing 22a into the bearing seat 23, then insert the sleeves 24a, 24.
b. The ball rings 22b and 22c are fitted in this order, and the annular presser member 25 is attached to the tip of the tip portion 21.

Also, with this installation, the tool drive shaft 40
is supported by the tip portion 21 via ball bearings 22, 22b, and 22c.

The reason why the two ball bearings 22b and 22c are arranged in parallel inside the tip 21 is to receive the thrust force from the tool 44.

3 in the circumferential direction corresponding to a position of the distal end portion 21 that is slightly offset toward the proximal end from the bearing seat 23.
A planetary gear 26 is attached to the position using a pin 27. (Only one planetary gear 26 is visible in the drawing). The planetary gear 26 has ball bearings 28a and 28 fitted to the corresponding outer circumferential surface of the pin 27.
It is rotatable by b.

The planetary gear 26 is attached to a mounting hole 2 that is long in the axial direction by milling, electric discharge machining, etc. from the outer peripheral surface of the tip 21 toward its axis.
9a, and a planetary gear insertion hole 29b is opened orthogonally to this mounting hole 29a, and the planetary gear 2
Insert the pin 27 into the axial center of the pin 27.
This is done by inserting it into the mounting hole 29a.

An internal gear 36 that meshes with the planetary gear 26 is formed on the inner peripheral surface of the housing 30 that corresponds to the planetary gear 26.
It is meshed with 6. Therefore, the planetary gear 26 and the pin 27 are prevented from coming off by the internal gear 36, that is, the housing 30.

On the other hand, a gear 4 that meshes with the planet gear 26 is provided on the outer peripheral surface of the tool drive shaft 40 facing the planet gear 26.
1 is formed.

In such a gear mechanism, when the main shaft 1 is rotated, the planetary gear 26 rolls on the internal gear 36 in the opposite direction to the rotation direction of the main shaft 1, and the gear 41 is rotated in the same direction as the main shaft 1. In other words, this gear mechanism constitutes a planetary gear train in which gear 41 is a sun gear. This planetary gear train causes the tool drive shaft 40 to rotate at an increased speed relative to the main shaft 1 as described above.

Thus, the rotation of the tool drive shaft 40, which is accelerated relative to the main shaft 1 by the planetary gear train described above, is transmitted to a tool, such as a drill or an end mill, which is chucked at its tip.

The present invention can also be applied to a so-called angle head in which the tool drive shaft is inclined at a predetermined angle with respect to the main axis, and is suitable for machining a workpiece having an inclined machining surface. That is, in this case, the outer periphery of a cylindrical body that is connected to the power transmission shaft connected to the tool head body via an intermediate power transmission shaft tilted, for example, 90 degrees, and rotatably supports the tool drive shaft at its tip. A mounting hole similar to that described above is provided in the surface, and a pin planetary gear provided therein is rotatably supported. In this case, the internal gear is formed on the inner circumferential surface of a housing that rotatably supports the cylindrical body.

Effects of the invention In the case of this invention as described above, since the mounting hole is formed by opening from the outer peripheral surface of the cylindrical part of the tool head body, the pin axis is aligned with the axis of the tool head body or cylinder. This allows the pin to be installed in an accurately aligned state, which prevents uneven contact between the gear 41 of the planetary gear and the internal gear 36, prolonging their life, and reducing the vibration of the tool held on the tool drive shaft. It has excellent effects such as no vibration, which makes it possible to extend the life of the machine, and also enables high-precision cutting without vibration. In addition, since the mounting hole for attaching the support pin of the planetary gear can be avoided from penetrating the cylindrical part of the tool head body in the axial direction, the thickness of the cylindrical part can be made thinner, and the bearing can be made one or more smaller. and allows the use of planetary gears. Therefore, the tool head can be made smaller in size by making the cylindrical portion of the tool head body thinner.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a tool head according to this invention attached to a spindle, and FIG. 2 is a cross-sectional view of a conventional tool. 1... Spindle, 20... Tool head body, 21...
...Tip, 26...Planetary gear, 27...Pin, 2
9a...Mounting hole, 30...Housing, 36...
... Internal gear, 40 ... Tool drive shaft, 41 ... Gear.

Claims (1)

[Scope of utility model registration request] The tool drive shaft is supported via a bearing inside the cylindrical part of the tool head body connected to the main shaft of the machine tool, and a housing is provided outside via the bearing, and meshes with an internal gear provided on the inner surface of the housing. In a tool head in which a plurality of planetary gears are meshed with gears provided on the outer surface of the tool drive shaft to increase the rotation speed of the tool head body and rotate the tool drive shaft, from the outer circumferential surface of the cylindrical portion of the tool head body. A tool head characterized in that the planetary gear is rotatably supported by a support pin attached to an opened attachment hole.