KR100308228B1 - Pallet Changer - Google Patents

Abstract

The present invention relates to a pallet changer, wherein a pallet is used to shorten the exchange time between a finished workpiece and a workpiece before using one driving means and a plurality of cam members for moving up / down and rotating the main shaft by the driving force. It relates to an exchange device.

According to the configuration of the present invention, in the automatic pallet changer of the machining center, the output speed is reduced by the gearbox 10a, and the extension shaft 12 in the axial direction rotates at the output shaft 10b end. A drive motor 10 to be installed; An up / down cam 20 which is axially coupled to the inside and the outside of the extension shaft 12 and has a constant cam curve 21a, 21b formed around the extension shaft 12; The main shaft 15 is operated by operating the lifting mechanism 17 axially coupled to the upper portion of the main shaft 15 by the phase change of the cam curves 21a and 21b of the lifting / lowering cam 20 by cloud contact. Link means for moving up / down; And a cam follower 16a of the cam shaft 16 for rotation after the main shaft 15 is lifted up on the extension shaft 12 between the lifting and lowering cams 20. It is to include a rotary cam 23 to rotate the main shaft 15 by 180 ° while being guided to move.

Description

Pallet changer

The present invention relates to a pallet exchanger, and more particularly, to a single workpiece and a plurality of cam members for moving up / down and rotating the main shaft by the driving force. An apparatus for changing a pallet for shortening.

In general, NC machine tools, including NC lathes and machining centers, are basically capable of controlling three to five axes, making it easy to machine any complex workpiece.

Machine tools with horizontal spindles, such as NC lathes or horizontal machining centers, are machined by rotating at high speed while clamping workpieces with small volume or weight, while vertical machining centers hold the tool while It is mainly used for machining by clamping the spindle. Therefore, the vertical machining center is a machine tool which is mainly advantageous for the machining of large-weight workpieces.

Therefore, vertical machining centers must be equipped with a pallet changer that exchanges the finished workpieces and the pallets on which the workpieces are prepared.

One example of a conventional pallet changer is that the central gear 33 is rotated in a predetermined rotational direction by the driving force of the hydraulic motor 39 as shown in FIGS. 1A and 1B, and this rotational force causes the center gear 33 to rotate. The driven gears 35a, 35b, 35c, and 35d meshed with the external gears 34a and 34b and the external gears 34a and 34b, which are circumscribed to the center, respectively, and the gears selectively engage with each other. While rotating, the guide plates 36a, 36b, 36c and 36d are moved by 90 °, respectively, to clamp the pallet.

When this operation is completed, the piston 37 is raised by the inflow of the hydraulic oil to the hydraulic port 38a, and the pallet supported by the guide plates 36a, 36b, 36c and 36d is raised. Thereafter, the pinion 32 is rotated by the rack 31 which rotates in conjunction with the driving force of the hydraulic cylinder (not shown) to replace the pallet while moving the pallet by 180 °.

However, in the conventional pallet changer, since the operation for moving the guide plate, the operation for raising the pallet from the pallet table, and the operation for exchanging the pallet are all driven by separate operation means, noise between operations is reduced. It is uncomfortable and assembly is inconvenient, and the delay time due to each driving means (waiting time until pallet lifting / lowering operation and waiting time to rotate pallet after completion of lifting / lowering operation) decreases productivity. In addition, the production cost of the machine is raised, the problem that the charm is lowered.

Accordingly, the present invention has been made to solve the above-mentioned problems, the object of which is to finish the workpiece and before processing using a plurality of cam members for raising and lowering and rotating the main shaft by one driving means and its driving force. An object of the present invention is to provide a pallet exchange device for shortening the replacement time of a workpiece.

In order to achieve the above object, the present invention, in the automatic pallet changer of the machining center for exchanging the pallet by continuously raising / lowering and rotating the main shaft spline-coupled to the celebration housing,

A drive motor which outputs at a reduced speed by the gear box and is provided such that an extension shaft in the axial direction is rotated at the output shaft end thereof;

An up / down cam axially coupled to the inside and the outside of the extension shaft and having a constant cam curve formed around the extension shaft;

Link means for moving the main shaft up and down by operating an elevating mechanism coupled to an upper portion of the main shaft by a phase change due to a rolling contact with the cam curve of the elevating / lowering cam; And

It is installed on the extension shaft between each of the lifting and lowering cams, and after the main shaft rises the cam follower of the shaft housing is guided to the cam groove to move the main cam to rotate the main shaft 180 ° Has

1A is a plan view showing a conventional pallet changer.

FIG. 1B is a cross-sectional view taken along the line BB of FIG. 1A. FIG.

Figure 2 is a side cross-sectional view showing a pallet exchange apparatus according to the present invention.

3 is an enlarged cross-sectional view of the main portion of FIG.

4 is a cross-sectional view taken along the line A-A of FIG.

5 is a schematic perspective view illustrating a coupling relationship between a rotating cam and a cam follower.

Figure 6 is a cam curve characteristic diagram of the up / down cam and the rotary cam of the present invention.

* Explanation of symbols for main parts of the drawings

10: drive motor 10a: gearbox

11: torque limiter 12: extension shaft

14: cam housing 15: main shaft

16: rotating cam shaft 16a: rotating cam follower

17 lifting mechanism 17a: flange

17b: collar 17c: bearing

17d: Locknut 18: Bearing

19: Spline 20: Up / Down Cam

21a, 21b: Cam curve 22: Up / down cam link

22a: Hinge shaft 22b: Cam follower for one-stage lifting

22c: two-stage lifting cam follower 23: rotating cam

23a: cam yo groove 24: dog

25: proximity switch

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail based on attached drawing.

Figure 2 is a side cross-sectional view showing a pallet changer according to the present invention, Figure 3 is a planar cross-sectional view showing an enlarged main portion of the upper part of Figure 2, Figure 4 is a cross-sectional view taken along line A-A of FIG.

The configuration of the present invention, in the automatic pallet changer of the machining center to exchange the pallet by continuously raising / lowering and rotating the main shaft 15 splined to the rotary cam shaft 16,

Torque is increased by gear coupling of a plurality of reduction gears (not shown), and output at a reduced speed, and an axial extension shaft 12 is rotated by a bearing 13 at the output shaft 10b end thereof. Bolting the drive motor 10 to the cam housing 14 to be installed to be supported. In other words, the drive motor 10 is a geared motor.

In addition, a torque limiter 11 is coupled between the output terminal 10b from the gearbox 10a and the extension shaft 12 to shut off power when the driving motor 10 is overloaded. .

On the other hand, the main shaft 15 is installed vertically for the lifting / lowering and rotation of the pallet (B) (B '), the lower portion of the main shaft 15 is a free end on one side of the pallet table (PT) The lifting mechanism 17 is installed to be rotated, and the upper part of the main shaft 15 is larger than the diameter of the shaft 15 and the plurality of members are organically coupled, and the lower end of the lifting mechanism 17 is axially coupled. The rotating camshaft 16 in the form enclosed on the outer side of the main shaft 15 is supported by the bearing 18 from the cam housing 14 to be rotated. In addition, the installation position of the cam housing 14 is installed on the upper side of the splash guard 40, not the bottom of the pallet table.

Specifically, the elevating mechanism 17 is a flange 17a loosely fitted to the main shaft 15 and positioned to engage the up / down cam link 22, and the main shaft 15 above the flange 17a. Lock 17 is screwed to fix the position of the collar 17b and the collar 17b tightly interposed in the space between the flange 17a and the collar 17b. It consists of 17d.

The bearing 17c provided between the flange 17a and the collar 17b is a member in which the flange 17a does not interlock with the main shaft 15, while the collar 17b is formed of the main shaft 15. Since it is a member that interlocks when rotating, the bearing 17c is specifically configured to have an upward force of the up / down cam link 22 described later as a thrust bearing from the flange 17a to the main shaft 15. There is also a reason for installation.

On the other hand, the main shaft 15 is spline shaft-coupled to the interlocking camshaft 16 in the up and down directions, but hung in the rotational camshaft 16 in the rotational direction, interlocked, On the outer periphery of the dedicated camshaft 16, the cam follower 16a for rotation is provided radially from an axial center, at equal intervals. Detailed description of the rotating cam follower (16a) will be described later.

On the other hand, the extension shaft 12 is provided with a cam member having two purposes, one of which is axially coupled by the spline 19 in the inner, outer sides of the extension shaft 12 and the portion is different in diameter than the other portion The cam curves 21a and 21b are formed on the up / down cams 20, and the other one is axially coupled by the spline 19 between the up / down cams 20 and has a constant depth and curved trajectory cam on the outer circumferential surface. That is the rotary cam 23 having the groove 23a.

One side end is pivotally coupled by the hinge shaft 22a at the rear end of the cam housing 14 and the other end is provided with a one-step lifting cam follower 22b at the upper end of the lifting / lowering cam 20. The lifting / lowering cam link 22 provided with the two-stage lifting cam follower 23c is provided in the center part in contact with the cam curve 21a, 21b of the lifting / lowering cam 20.

That is, the lifting / lowering cam link 22 is the axial direction of the main shaft 15 while the two-stage lifting cam follower 22c moves along the cam curves 21a and 21b of the lifting / lowering cam 20. To increase / decrease by

On the other hand, the rotary cam follower 16a radially divided on the rotary cam shaft 16 is movably coupled in the cam recess 23a of the rotary cam 23 so that the rotary cam shaft 16 is rotated. In order to rotate the camshaft 16 for rotation including the main shaft (15) while being sequentially coupled to the cam groove (23a) having a cam characteristic of the direction to rotate).

In addition, the cam curves 21a and 21b of the up / down cam 20 and the cam recesses 23a of the rotary cam 23 are first moved by the up / down cam links 22 passing through the circular cam curve 21a. Rotating camshaft including the main shaft 15 in succession after the main shaft 15 is lifted vertically so that the pallets B and B 'at each position are separated from the pallet table PT and PT'. 16 is rotated by 180 ° by the cam follower 17a which is fitted into the cam recess 23a of the rotary cam 23 and slides. In addition, when the rotation is completed by the cam recess 23a, the main shaft 15 is lowered while passing through the elliptical cam curve 21b formed in the up / down cam 20 again, so that the pallet B (B ') is removed. It should be formed so that it can descend.

As shown in FIG. 5, the cam cam groove 23a curve characteristic of the rotary cam 23 includes the main shaft 15 including the rotary cam shaft 16 at a 90 ° to 270 ° rotational position of the rotary cam 23. Rotate 180 °, and the cam curve of the up / down cam 20 raises the pallet by raising (UP) the up / down cam link 22 at a rotational position of 5 ° to 115 °, and 245 ° to 355 The pallet is seated by descending at the rotational position of °.

On the other hand, the dog 24 is provided at the end of the extension shaft 12, the cam housing 14 side opposite to the dog (at the time when the completion of one stroke in parallel with the vertical and rotational movement as described above) A proximity switch 25 is installed to detect the power supply 24 and control the power of the driving motor 10.

Referring to the operation of the present invention configured as described above are as follows.

When power is applied to the drive motor 10, the output of the motor 10 rotates the extension shaft 12 by reducing the rotational force instead of increasing the torque through the gearbox 10a.

At this time, the two-stage elevating cam follower 22c of the elevating / lowering cam link 22 is the first of the cam means axially coupled to the extension shaft 12 in the order of pallet exchange flow. After moving along the elliptical cam curve 21 b), it moves upward in a range (5 °) that folds into the circular cam curve 21 a. During its operation, the lifting / lowering cam link 22 starts to rise around the hinge shaft 22a, and the first-stage lifting cam follower 22b configured at the end pushes the lifting mechanism 17 while the main shaft ( 15) upwards.

In addition, the pallet table PT (PT ') integrally configured to interlock with the main shaft 15 and seated on the pallet is moved upward with the main shaft 15 from each pallet base 1a and 1b. Departure.

After that, when the cam recess 23a of the rotary cam 23 axially coupled to the rotating shaft 12 reaches a rotational position of 90 °, a plurality of cams radially fixed to the rotating cam shaft 16 are provided. Rotating the rotating camshaft 16 supported while rotating the follower 17a in turn, and when it reaches a rotational position of 270 °, the main shaft 15 is splined with the rotating camshaft 16. ) Is rotated 180 ° so that the pallet table PT (PT ') in the up-movement state is reversed while being interlocked with it.

In the above process, the two-stage elevating cam follower 22c of the elevating / lowering cam link 22 is rotated while rolling from the circular cam curve 21a to the elliptical cam curve 21b. Pallet (B) mounted on pallet table (PT) (PT ') with 180 ° of pallet base (1a) (1b) by moving the main shaft (15) downward while moving downward at a rotational position of 245 °. Seat (B '). At the same time, the dog 24 installed at the end of the extension shaft 12 is powered by the proximity switch 25 installed at the cam housing 14 when one stroke of the extension shaft 12 is completed. The operation of 1 stroke for changing pallet is completed, blocking.

The present invention described above is not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those who have

Applying the present invention as described above, since the time for changing the pallet is shortened by about half (15 seconds → 8 seconds) compared with the conventional, the productivity is increased, and the power transmission is continuously performed by the cam, so the noise In addition, it provides a stable structure that minimizes vibration, and most importantly, since there is only one power driving means for driving a pallet changer, it is not only excellent in assembly and maintainability compared to the conventional one which requires a plurality of power sources. The low price of the device allows consumers to inspire purchasing power.

Claims (5)

In the automatic pallet changer of the machining center, the drive motor 10 is outputted at a speed reduced by the gearbox 10a, and the extension shaft 12 in the axial direction is rotated at the output shaft 10b. ; An up / down cam 20 which is axially coupled to the inside and the outside of the extension shaft 12 and has a constant cam curve 21a, 21b formed around the extension shaft 12; The main shaft 15 is operated by operating the lifting mechanism 17 axially coupled to the upper portion of the main shaft 15 by the phase change of the cam curves 21a and 21b of the lifting / lowering cam 20 by cloud contact. Link means for moving up / down; And a cam camer 16a for rotating the cam shaft 16 of the rotary cam shaft 16 after the main shaft 15 is lifted up. And a rotating cam (23) for rotating the main shaft (15) by 180 ° while being guided and moved by 23a). The pallet exchanger according to claim 1, further comprising a torque limiter (11) which cuts off the overload of the drive motor (10) between the output shaft (10b) and the extension shaft (12) of the gearbox (10a). Device. 2. The linking device according to claim 1, wherein the link means includes a lift / lower cam link (22) whose one end is hinged to the fixed body (14a) on the cam housing (14) and the other end is hooked to the bottom surface of the lift mechanism (17). And a two-stage elevating cam follower 22c installed in the center of the elevating / lowering cam link 22 and making a cloud contact on the cam curves 21a and 21b of the elevating / lowering cam 20. Pallet changer characterized in that. The lift mechanism (17) according to claim 1, wherein the elevating mechanism (17) is loosely fitted to the main shaft (15) and positioned to engage the elevating / lowering cam link (22) and the upper portion of the flange (17a). A collar 17b axially coupled to the main shaft 15, a bearing 17c interposed in the space between the flange 17a and the collar 17b, and screwed to fix the position of the collar 17b. A pallet changer comprising a lock nut (17d). 5. Pallet exchange device according to claim 4, characterized in that the bearing (17c) is a thrust bearing.