JPH0866866A - Grinding head - Google Patents

Abstract

PURPOSE: To reduce the clogging of a grinding wheel due to grinding and to enhance the efficiency of grinding by providing a grinding head with the function of vibrating the grinding wheel in the direction of the rotation axis of the grinding wheel, in addition to the function of rotating the grinding wheel. CONSTITUTION: This grinding head can vibrate a grinding wheel 5 axially by vibrating a spindle 4 by means of both a cam 12 rotated by a rotary drive source 13 and an elastic member 14, the spindle 4 being mounted on the front end of the spindle 4. The spindle 4 has an air turbine 7 serving as a rotary drive means and can rotate the grinding wheel 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding head for carrying out grinding by being attached to a spindle of a machine tool such as a milling machine, a grinding machine or a machining center.

[0002]

2. Description of the Related Art Conventionally, a grinding head has been known as an apparatus for performing a grinding process. The grinding head is equipped with a spindle to which a grindstone is detachably mounted at the front end, and a rotation driving means such as a micromotor or an air turbine that rotates this spindle, and grinding can be performed by rotating the grindstone mounted on the spindle. . Normally, the grinding head is used by being attached to the main spindle of a machine tool. For example, when grinding is performed after cutting with a milling machine, etc., the work is transferred to the grinding machine by attaching the grinding head to the main spindle. It is possible to perform the grinding process without using the milling machine, and to insert the boring mill between the main spindle and the grinding head and rotate the main spindle to grind the inner surface of the hole.

[0003]

By the way, generally, there is a problem that the grindstone is clogged in the grinding process. Since the clogging of the grindstone reduces the efficiency of the grinding process, when the clogging becomes severe, it is necessary to remove the clogging by dressing or replace the grindstone with a new one. As described above, the above work related to clogging is troublesome and expensive.

An object of the present invention is to pay attention to the above-mentioned problems, and to provide a grinding head having a function of reducing clogging of a grindstone and capable of efficient grinding.

[0005]

According to the present invention, a spindle for removably mounting a grindstone on a front end thereof and a rotation driving means for rotating the spindle are provided, and the spindle is mounted on a main shaft portion of a milling machine, a machining center or the like for use. In the grinding head, a cam for reciprocating the spindle in the axial direction and a urging force in one direction at all times against the reciprocating movement of the spindle in accordance with the rotation from a rotation driving source separate from the rotation driving means. A grinding head is provided, which comprises an elastic member.

Further, according to the present invention, the cam may be a disk having a circular engaging side surface, and an eccentric shaft eccentric from the center of the disk may be connected to the rotary drive source.

Further, according to the present invention, the cam has a contact surface for contacting the tilted upper end of the spindle with an inclined substantially elliptical engaging cross section, and the tip of the contact surface. A grinding head is provided in which the spindle is moved up and down by rotating the spindle around the substantially elliptical shape by the rotary drive source.

Here, as the rotation driving means, a micromotor, an air motor and an air turbine are preferable. Further, as the rotary drive source, an air motor or a micromotor is preferable. Any elastic member such as a metal spring or a non-metal spring may be used as the elastic member. As the cam, in addition to the above, a tangential cam, a flat cam such as a triangular cam, a solid cam such as a cylindrical cam, a conical cam, and a spherical cam or a positive cam may be used.

[0009]

According to the grinding head of the present invention, the grindstone mounted on the front end of the spindle is rotated by the rotation driving means, and the spindle is rotationally driven while being constantly urged in one axial direction by the elastic member. Since the cam rotated by the source gives the displacement to the spindle in the direction opposite to the direction in which the elastic member urges the spindle, grinding can be performed while the spindle vibrates. As a result, compared with the case of using a conventional grinding head in which the spindle does not vibrate, the grinding resistance applied to the grindstone is reduced and clogging of the grindstone can be reduced, so that the life of the grindstone is extended and Since the cutting depth of grinding can be increased as the resistance is reduced, efficient grinding can be performed.

[0010]

Embodiment 1 A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a grinding head according to the present invention. The constituent elements will be described below.

The grinding head 1 is used by being attached to a jig grinder, a milling machine, or a main shaft portion of a machining center. In this embodiment, the taper shank 2 is used to fix the grinding head 1 to the main shaft portion 3. The grinding depth of the work can be determined by lowering the main spindle 3.

The spindle 4 rotates the cam receiving portion 16 that directly receives the bias of the cam 12, the elastic member receiving portion 17 that receives the bias of the elastic member 14, the mounting tool 6 for mounting the grindstone 5, and the grindstone 5. It is composed of an air turbine 7 which is a rotation driving means for performing the operation. In this embodiment, the air turbine 7 is used as the rotation driving means, but a micromotor or the like may be used.

The air turbine 7 is composed of a rotor 22, a nozzle 10 and a bearing 18. The operation of the air turbine 7 is from a compressed air supply source (not shown) to an air supply port 8, an air supply passage 9 and a nozzle 10. Through the rotor 22
By supplying compressed air to the rotor 22, the rotor 22 rotates and a rotational force can be obtained. The compressed air, after giving a rotational force to the rotor 22, is discharged to the outside of the grinding head 1 through the exhaust passage 11 and an exhaust port (not shown).

The cam 12 is for energizing the vibration of the spindle 4, and is rotated by fixing the rotary shaft of the rotary drive source 13 at a position eccentric from the center of the disk of the cam. A disc cam, which is one of the flat cams, is used as the cam in this embodiment, but other types of cams may be used.

The elastic member 14 is interposed between the elastic member receiving portion 17 of the spindle 4 and the bearing means 15, and always urges the spindle 4 in the axial direction of the main shaft portion 3.
In this embodiment, a coil spring is used for the elastic member 14, but other metal springs, rubber, non-metal springs such as air springs may be used.

The bearing means 15 is for supporting the vibration of the spindle 4 while preventing its core runout. In this embodiment, an air bearing is used.

The air bearing is a device for supporting compressed air by injecting compressed air from a nozzle arranged on the circumference of the shaft to suspend the shaft in the circumference.

The air bearing of this embodiment has a compressed air supply source, an air supply port 8, an air supply passage 24, and an air supply groove 2 which are not shown.
3, the nozzle 21 is provided, and compressed air is jetted from the nozzle 21 through the air supply port 8, the air supply passage 24 and the air supply groove 23 by the compressed air source, and the spindle 4 can be suspended and supported. .

As shown in FIG. 2, the nozzles 21 are arranged radially, and the pressure of the compressed air injected by each nozzle is set to be equal, so that the bearing means 15 which is an air bearing is vibrated. The spindle 4 can be supported while preventing center runout. 2 is shown in FIG.
II is a sectional view taken along line II-II of FIG.

Further, as shown in FIG. 3, the upper portion of the bearing means 15 has a square shape, which serves as a detent for the spindle 4. Note that FIG. 3 is a sectional view taken along the line III-III in FIG.

Next, the operation of vibration of the spindle 4 of the grinding head in this embodiment will be described.

A cam 12 rotated by a rotary drive source 13.
Urges the spindle 4 via the cam receiving portion 16 to a displacement corresponding to the amount of eccentricity, so that the spindle 4 is pushed downward. Then, the spindle 4 is temporarily pushed downward, but the cam 12 is caused by the elastic member 14 interposed between the elastic member receiving portion 17 which is one of the constituent elements of the spindle 4 and the bearing means 15 (which does not vibrate, of course). Since it is always urged in the direction opposite to the urging force of the cam 12,
Is returned to its original position when the bias is lost due to its rotation. Since the cam 12 naturally rotates continuously, the spindle 4 can vibrate by repeating the above operation. Since the spindle 4 is supported by the bearing means 15 in the vibration thereof, it is possible to perform a smooth vibration without any center runout.

The grindstone 5 mounted on the front end of the spindle 4 is given a rotational force by the air turbine 7 and can perform grinding while accompanied by the vibration of the spindle 4 described above.

The stroke of the vibration is determined by the amount of eccentricity of the cam 12, but is preferably 0.1 to 1.0 mm. Also,
The frequency of the vibration is determined by the rotation speed of the rotary drive source 13, and is preferably about 3 Hz. Also, the rotary power source 1
3 is preferably an air motor or a micromotor.

[0026]

Embodiment 2 FIG. 4 shows another embodiment of the grinding head of the present invention.

In this embodiment, the grinding head 50 of the present invention is supported by utilizing the outer case 51a of the main shaft portion 51. The grinding head 50 is not directly attached to the main spindle portion 51 because the main spindle portion 51 is used as a rotary drive source for rotating the cam 52. At the tip of the main shaft portion, there is a cam 52 whose cross section obtained by obliquely cutting the main shaft portion has a substantially elliptical shape, and this cam 52 serves as a driving node in the cam mechanism.

The spindle 54 is a subordinate cam 53 having a substantially elliptical cross section, the upper end of which is in contact with the cam 52 of the main shaft as shown in the drawing. Also, spindle 5
Although not shown, 4 is provided with a rotation stop by a known means such as a bearing having a rectangular cross section. Further, the spindle 54 does not have a rotation driving means for rotating the grindstone,
Instead, it has a mounting tool 55 to which a jig grinder 58 can be mounted.

The jig grinder 58 has substantially the same structure as the grinding head in the above-mentioned conventional example, has a function of rotating a grindstone, and is an apparatus for mounting a grindstone 59 at the tip to perform grinding.

The bearing means 57 is a device for supporting the spindle 54 as in the first embodiment. Although a ball slide is used in this embodiment, an air bearing may be used as in the first embodiment.

Next, the operation of vibration of the spindle 54 will be described.

The spindle 54, which has a cam 53 as a subordinate node and is provided with a rotation stop, is displaced in the direction of the grindstone 59 in the axial direction when the cam 52 is rotated by being urged by the main shaft portion 51. Since the coil spring 56, which is an elastic member, constantly urges the spindle 54 toward the main shaft portion 51 in the axial direction as in the first embodiment, the spindle 54 vibrates as the cam 52 rotates.

The jig grinder 58 mounted on the spindle 54 also naturally vibrates. As described above, the jig grinder 58 has a function of mounting and rotating a grindstone, so that the grindstone 59 can perform grinding while vibrating the spindle 54.

[0034]

As described above, according to the grinding head of the present invention, in addition to the function of rotating the grindstone, the grindstone can be vibrated in the rotational axis direction of the grindstone to perform the grinding process. It is possible to reduce the grinding resistance applied to, and to reduce the clogging of the grindstone. As a result, the life of the grindstone can be extended and the number of times the grindstone is dressed can be reduced, which is economical and efficient.

Further, by reducing the grinding resistance as described above,
Since the cutting depth of grinding can be increased, there is an advantage that work efficiency is increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a grinding head according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view of a grinding head according to the present invention.

[Explanation of symbols]

1 ... Grinding head, 4 ... Spindle, 5 ... Grinding stone, 7 ... Air turbine, 12 ... Cam, 13 ...
.... Rotation driving means, 14 ... Elastic member, 15 ... Bearing means, 50 ... Grinding head, 52 and 53 ...
Cam, 54 ... Spindle, 57 ... Bearing means, 5
8 ... Jig grinder, 59 ... Whetstone

Claims (3)

[Claims] 1. A grinding head equipped with a spindle for removably mounting a grindstone on a front end thereof, and a rotation driving means for rotating the spindle, the grinding head being used by being attached to a main shaft portion such as a milling machine or a machining center. Is a cam that reciprocates the spindle in the axial direction with the rotation from a separate rotary drive source,
A grinding head comprising: an elastic member that constantly urges in one direction against the reciprocating motion of the spindle. 2. The cam is a disk having a circular engagement side surface, and an eccentric shaft eccentric from the center of the disk is connected to the rotary drive source.
The grinding head described in. 3. The cam has an abutment surface for abutting an inclined elliptical engagement cross-section of the rotation-stopped spindle upper end, and the tip of the abutment surface is caused by the rotary drive source. 2. The spindle is moved up and down by rotating the spindle around the substantially elliptical shape.
Grinding head as described.