JPH0524208U - Booster mechanism for spindle tool lifting device - Google Patents

Abstract

(57) [Abstract] [Purpose] The contact area between the roller and the taper of the booster mechanism for increasing the spring force of the tool pulling device for machine tools such as machining centers to raise the tool is increased to improve wear resistance. To improve the pulling power of. [Structure] An R groove 8 having an approximate radius R2 of a taper 4a of a pull rod 4 is formed at the center of an outer peripheral axial direction of a via barrel roller 8 formed on an arc surface 8a of an approximate radius R1 of a tapered hole 5a on a main shaft 1 side.
b is provided, the taper hole 5a, the roller outer circumference 8a, and the taper 4a
And the contact area of each of the R groove 8b of the roller and
The structure will improve wear resistance and withstand a strong pulling force.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a booster mechanism for a spindle tool lifting device of a machine tool such as a machining center.

[0002]

[Prior Art]

 Conventionally, in a spindle tool lifting device for a machine tool such as a machining center, as shown in FIG. 5, a pull stud 103 of a tool 102 inserted in a tapered hole 101a of a spindle 101 is gripped by a collet 104 and pulled up by a disc spring 105. The system is usually used, and recently, it has become common to install a booster mechanism to increase the pulling force of the tool to improve the performance of the tool and the horsepower of the machine. In this booster mechanism, a via-barrel roller 107 as shown in an enlarged view of FIG. 4, which is an approximate arc of a tapered hole of the ring 106 on the spindle side, comes into contact with the tapered hole and the taper 108a on the tool pull rod 108 side, and the wedge effect is obtained. Is used to increase the spring force as the movement of the tool pulling shaft 109 becomes slower than the movement of the pull rod 108.

[0003]

[Problems to be solved by the device]

 In the booster mechanism described in the conventional technology, the outer circumference of the roller is formed in a similar arc to the taper hole on the spindle side, so a certain contact area is secured, but the taper on the tool tension bar side is Since it is in point contact with the outer circumference of the roller, there is a problem that a very large load cannot be applied due to Hertzian stress. The present invention has been made in view of the above problems of the prior art, and the purpose thereof is to increase the contact area between the roller and the taper on the tool pull rod side to endure a large tool pulling force. It is intended to provide a boosting mechanism designed to be obtained.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the boosting mechanism of the spindle tool lifting device according to the present invention is equipped with holes at equal intervals on the circumference of the tool lifting shaft of the tool lifting device provided in the spindle of a machine tool such as a machining center. In the boosting mechanism in which the via barrel roller rotatably fitted is in contact with the taper hole on the main shaft center hole side and the taper on the pull rod side to increase the spring force acting on the pull rod by the wedge effect, The via groove formed in the approximate circular arc of the tapered hole is provided with the R groove of the approximate circular arc of the taper at the center in the outer peripheral axial direction of the roller.

[0005]

[Action]

 When a tool is inserted into the spindle and the pull rod is pulled up by the spring, the tool pulling shaft holds the pull stud with the collet and is pulled up, and the via barrel roller fitted in the hole of the pull rod is the spindle. When the side taper is reached, the arcuate surface of the roller outer periphery abuts the taper on the spindle side, the R groove of the roller abuts the taper of the tension rod, and the wedge effect increases the spring force to pull up the tool.

[0006]

【Example】

 Examples will be described with reference to FIGS. 1 to 3. The center hole of the spindle 1 which is rotatably supported by the spindle head (not shown) of the machining center has a tapered end 1a, and the tool pulling shaft 2 is attached to the stepped holes 1b and 1c following the tapered hole 1a. It is inserted so that it can move in any direction. A collet 3 that holds the pull stud Ta of the tool T is attached to the front end of the tool pulling shaft 2, and the tip end of the pull rod 4 is inserted into the center holes 2a and 2b at the rear end of the tool pulling shaft 2. It is inserted so that it can move in any direction. A ring 5 having a taper 5a constituting a booster mechanism is fitted in a large diameter hole 1d following the stepped hole 1c of the main shaft 1, and a plurality of disc springs 7 are fitted via a collar 6. The tension rod 4 is constantly biased by the disc spring 7 without any tension, and the tension rod 4 is formed with a taper 4a forming a booster mechanism at a position near the tip end thereof. An escape groove 4b for 8 is formed.

Further, square holes 2c are formed at equal intervals on the circumference at positions near the rear end of the tool pull-up shaft 2, and the rollers 8 are fitted in the square holes 2c so as to be rotatable along the pull-up shaft concentric circles. It is equipped. As shown in FIG. 3, the roller 8 is formed in the shape of a via barrel having a similar arc surface 8a with a radius R1 slightly larger than the taper hole 5a, and an R groove 8b with an approximate radius R2 of the taper 4a is formed in the axial center. It is set up. The tool pulling shaft 2 holds the pull stud Ta with the collet 3 and pulls up the tool T so that the arcuate surface 8a of the roller 8 fitted in the square hole 2c contacts the taper of the ring 5. The axial dimension of the pull rod 4 is adjusted by the disc spring 7, and the pull rod 4a is brought into contact with the R groove 8b of the roller to transmit the pull force. Therefore, the axial movement amount of the tool pulling shaft 2 is smaller than the axial movement amount of the pull rod 4, and this reduction ratio increases the spring force, so that the tool T can be strongly pulled up. .

Next, the operation of this embodiment will be described. When the tool T is inserted into the main shaft taper hole 1a by the tool exchange arm of the ATC (not shown), the piston of the hydraulic cylinder (not shown) retracts, and the tension bar 4 is pulled by the force of the disc spring 7. When the tool pull-up shaft 2 holding the pull stud Ta with the collet 3 is pulled to a predetermined position, the arcuate surface 8a of the roller 8 abuts the tapered hole 5a, and the R-groove 8b further has the taper 4a of the pull rod. Upon contact, the roller pulls up the tool pulling shaft 2 through the inner wall of the square hole 4a by the wedge effect. At this time, since the outer circumferential arc surface 8a of the roller 8 is formed with a radius R1 slightly larger than the radius of the tapered hole 5a, a wide contact area with slightly strong axial end portions is obtained, and the R groove 8b of the roller 8 is obtained. Is formed with an approximate radius R2 of the taper surface 4a, so that a wide contact area can be obtained over almost the entire surface. Next, when removing the tool T, when the tension rod 4 is pushed out against the force of the disc spring 7 by the hydraulic cylinder, the roller 8 retreats into the groove 4b and the tool pulling upper shaft 2 moves. Becomes free and the tip of the pull rod 4 comes into contact with the inner wall of the center hole 2a at the rear end of the tool pull-up shaft 2 and the tool pull-up shaft 2 is pushed out, the collet 3 opens and the tip of the tool pull-up shaft 2 pulls the pull stud Ta. Hit the end face to push out the tool T.

[0009]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. An R groove with an approximate radius of the taper of the pull rod is provided in the axial center of the via barrel roller of the booster mechanism of the spindle tool pulling device, so the contact area of the taper between the roller and the pull rod is increased. Therefore, the wear resistance is improved, and a stronger tool pulling force can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a tool lifting device with a boosting mechanism of the present embodiment.

FIG. 2 is an enlarged view of the booster mechanism portion of FIG.

FIG. 3 is a side view of a roller of a booster mechanism.

FIG. 4 is a side view of a roller of a conventional booster mechanism.

FIG. 5 is a cross-sectional view of a conventional tool lifting device with a booster mechanism.

[Explanation of symbols]

1 spindle 2 tool pulling shaft 3 collet 4 pull rod 4a taper 5 ring 5a taper hole 7 disc spring 8 roller 8a arc surface 8b R groove

Claims (1)

[Scope of utility model registration request] 1. A via barrel-shaped roller rotatably fitted in holes at equal intervals on the circumference of a tool lifting shaft of a tool lifting device provided in a spindle of a machine tool such as a machining center is located at the spindle central hole side. In the booster mechanism that abuts against the tapered hole of the pull rod and the taper on the pull rod side to increase the spring force acting on the pull rod by the wedge effect, the outer peripheral shaft of the via barrel roller formed in the approximate arc of the tapered hole. A booster mechanism for a spindle tool lifting device, characterized in that an R-shaped groove having an approximately circular arc of the taper is provided at the center of the direction.