JPS6131795Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a device that presses a workpiece against an axial positioning stopper when chucking the workpiece to the tip of the spindle. or an unloader arm), the pressing member is movable in the axial direction and is inserted together with an elastic member that biases toward the workpiece, and a detent ball mechanism is embedded in the outer periphery of the holding member. The present invention provides a workpiece positioning device characterized by the following features.

As described above, the workpiece positioning device of this invention is incorporated into the workpiece inner diameter holding member provided on the loading arm, so that the structure is simple and inexpensive, and the workpiece can be reliably pressed against the axial positioning stopper for accurate positioning.

In the conventional device, a positioning mechanism is incorporated into the rotation drive mechanism of the loading arm to regulate the longitudinal position of the loading arm itself when the rotation is completed. However, it has been extremely difficult to achieve highly accurate positioning and stopping due to the inertial weight of the loading arm.

There is also a device in which the loading arm is bent in the direction of the main axis to press the workpiece against the positioning stopper, but it is difficult to keep the pressing force constant, and the direction of the pressing force is Since it is difficult to align the center accurately, the positioning accuracy has not always been good.

The present invention solves the above-mentioned conventional problems.An embodiment of this invention will be explained below with reference to the drawings.In the first embodiment shown in Fig. 1, an unprocessed workpiece _W1 is The work loader 4 carries the work loader 4 from the rear toward the front through the center hole of the guide tube 3 inserted into the center hole of the guide tube 3, and brings it into the collection chuck 2 at the front. At this time, the machined workpiece W ₀ held by the collection chuck 2 is pushed out by the unprocessed workpiece W ₁ and is fitted into the workpiece inner diameter holding member 6 provided on the unloader arm 5 . The work loader 4 is stroked left and right by a fluid pressure cylinder (not shown), and at the rightmost position shown in the drawing, it also serves as a stopper for axial positioning of the workpiece _W1 . That is, by pressing the bottom surface 15 of the unprocessed workpiece _W1 against the end surface 14 of the work loader 4, the workpiece _W1 is positioned in the axial direction.

Now, a pressing member 8 and a spring 9 are inserted into the center hole 7 of the workpiece inner diameter holding member 6. code 1
7 is a retaining ring. Further, a detent ball mechanism 10 is embedded in the outer periphery of the holding member 6. The detent ball mechanism 10 consists of a ball 11 and a spring 12, and is embedded in a radially bored hole 13 as shown in the figure, and locks the workpiece _W0 to the holding member 6.

In the first embodiment with the above configuration, when the processed workpiece W ₀ is pushed out by the unprocessed workpiece W ₁ and fitted into the holding member 6 as described above, the processed workpiece W ₀
has its inner bottom surface 16 pressed by the pressing member 8 and spring 9 and is biased toward the left in the figure, pushing the unprocessed workpiece W ₁ to the left and pushing its bottom surface 15 against the end surface of the work loader 4. 14 from beginning to end, the unprocessed workpiece _W1 is positioned in the axial direction as described above, and is chucked into the collect chuck 2 in this state. However, the above-mentioned both end surfaces 14, 15
Since they are pressed against each other statically without jumping, and with a substantially constant appropriate force determined by the spring 9, highly accurate and stable positioning can be expected.

FIG. 2 shows a different embodiment from the above, in which an unprocessed workpiece W ₂ is held at its inner diameter by a holding member 28 provided on a loader arm 27 and is attached to a collect chuck 22 at the tip of the main shaft 21 of the machine tool. is supplied to Reference numeral 23 is a sleeve for reducing the diameter of the collector chuck 22, and a bolt 25 is attached to the piston rod 24 of the chuck cylinder installed in the center hole of the main shaft.
It is fixed in place. A stopper member 26 is also attached to the front end of the main shaft. The stopper member 26 has a tip 36 projecting into the pocket of the sleeve 23 through a groove 35 formed at the tail of the sleeve 23, and the rear end surface 37 of the workpiece _W2 is brought into contact with the tip 36 for positioning. It's starting to feel like it's being done.

The holding member 28 is a washer-shaped pressing member 2.
9. Loader arm 2 as shown in the figure via spring 30
7, and a detent ball mechanism 31 similar to that of the first embodiment is embedded in holes 34 radially bored on the outer periphery of the holding member 28. Reference numeral 32 is a ball, and 33 is a spring.

In the embodiment shown in FIG. 2, the workpiece W ₂ is shaped like a bottomless pipe, and is brought to the front end of the main spindle with its inner diameter held by the holding member 28 of the loader arm 27 in the direction of arrow A of the loader arm 27. The movement inserts it into the collector chuck 22 in a known manner. At this time, the end surface 37 of the workpiece W ₂ comes into contact with the end surface 36 of the stopper member 26, and is further pressed with a constant force so as to deflect the spring 30 by a required amount.
Accurate positioning is possible.

The present invention has the structure and operation as explained above, and has a loading arm (the unloader arm 5 or the loader arm 27 of the above embodiment) that incorporates both a pressing member and an elastic member. Therefore, the structure is simple and inexpensive,
However, the workpiece can be statically pressed against the axial positioning stopper to ensure accurate positioning. It can also be expected to shorten the loading cycle of machine tools.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing another embodiment. Explanation of symbols, 1...Main shaft, 2...Collection chuck, 4...Work loader (also stopper), 5...
...Unloader arm, 6... Holding member, 8... Pressing member, 10... Detent ball mechanism, 21...
Main shaft, 22...Collection chuck, 23...Sleeve, 26...Stopper member, 27...Loader arm, 28...Holding member, 29...Pushing member, 3
1... Detent ball mechanism, W ₀ , W ₁ , W ₂ ... Workpiece.

Claims (1)

[Scope of utility model registration request] a loading arm having a holding member that is inserted into the inner diameter surface of the workpiece to hold the workpiece; a collection chuck that chucks the outer diameter surface of the loaded workpiece; and a positioning arm that abuts against the end surface of the loaded workpiece. In a workpiece positioning device for a machine tool comprising a stopper and a main shaft having the above-mentioned collect chuck at its tip, when chucking the above-mentioned workpiece with a pressing member inserted into the above-mentioned holding member so as to be freely movable in the axial direction,
A workpiece positioning device comprising: an elastic member built into the holding member in a pressable manner; and a detent ball mechanism comprising a spring and a ball embedded in the outer periphery of the holding member.