JPS6343008Y2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a compact defective workpiece detection device capable of detecting poor fitting between a drawbar and an annular workpiece in a puller-type fixture.

In recent years, numerical control of gear cutting machines such as hobbing machines has progressed, and with this, complete automation of gear cutting operations is also being planned. For this reason, there is a need for the gear cutting machine itself to automatically detect defects in pre-processing and setting of the workpiece, and to continue automatic operation.

For example, in a puller-type fixture that holds an annular workpiece to be subjected to gear cutting, etc., there is a risk that the workpiece cannot be fixed if the workpiece is in a bad position or the inner diameter of the workpiece is too small. In this case, it is desirable to immediately detect the poor fit between the drawbar and the workpiece and correct the position of the workpiece or replace it with a new one, but conventional methods require an independent workpiece position detector or workpiece inner diameter measuring device. had to be installed separately from the machine tool, which caused many problems in terms of equipment cost and space.

Based on this knowledge, it is an object of the present invention to provide a defective workpiece detection device for a puller-type fixture that is compact and does not require special installation space.

The configuration of the defective workpiece detection device in the puller-type fixture of the present invention that achieves this purpose includes a base having an annular lower holder at the upper end on which an annular workpiece is placed, and a base that can be raised and lowered above the base. A support arm is provided, a drawbar is held by the support arm so as to be slidable up and down and penetrates the workpiece and is tightly fitted with the workpiece; an upper holder that can be press-fixed to the lower holder; a hollow clamp rod that is installed in the base so as to be slidable up and down and into which the lower end of the drawbar is fitted; and a hollow clamp rod that is slidably held in the clamp rod in the radial direction. A puller-type fixture having a plurality of fingers that can be locked to the lower end of the drawbar and pull down the drawbar as the clamp rod is lowered, the cylinder being fixed to the support arm; a compression spring that is interposed between the upper end of the drawbar and always applies a downward spring force to the drawbar; a detection rod whose lower end faces the upper end of the drawbar with a gap in between; It is equipped with a limit switch that raises the support arm.

Therefore, according to the present invention, the drawbar is held slidably up and down relative to the support arm, and when the support arm is inserted into the annular workpiece, the drawbar is not pushed up due to poor fitting. Since the movement of the drawbar is detected by a limit switch attached to the support arm, the detection device itself can be installed on the support arm at the upper end of the drawbar.
No special installation space is required. Furthermore, by detecting a poor fit between the drawbar and the work, it is possible to determine whether the work is in a poor position or has an insufficient inner diameter, and there is no need to use an expensive inner diameter measuring device.

Below, Fig. 1 shows the overall structure of an embodiment of the defective work detection device for a puller-type fixture according to the present invention, and Fig. 2 shows an enlarged view of its main parts.
This will be explained in detail with reference to Figure a and Figure 2 b, which shows the planar shape thereof.

An annular holder 14 having an annular lower holder 13 at the upper end is integrally attached to a truncated conical base 12 fixed on the work table 11. The annular workpiece 15 placed therein is carried in and out by a transport device 17 via a workpiece magazine 16. A support arm 18 that is raised and lowered by a drive mechanism (not shown) has a drawbar 19 that projects vertically downward and is held so as to be able to slide vertically within a certain range with respect to the support arm 18. This drawbar 19 whose lower end can penetrate into the receiver 14 has an upper holder 20 that can press and fix the workpiece 15 to the lower holder 13.
It is attached via 1. The pusher 21 is supported by a presser block 22 fixed to the drawbar 19 via an annular holder 23, and in this embodiment, the contact surface between the presser 21 and the presser block 22 is spherical. A hollow clamp rod 24 whose upper end is fitted to the receiver 14 so as to be slidable up and down is connected to a hydraulic cylinder (not shown) so that it can move up and down, and into which the lower end of the drawbar 19 is inserted. A plurality of fingers 26 are housed in the clamp rod 24 so as to be able to reciprocate in the radial direction of the clamp rod 24, the inner peripheral side of which can be engaged with a small diameter portion 25 formed at the lower end of the drawbar 19. Also, a finger 26 is provided on the inner circumference of the money receiver 14.
A retraction groove 27 is formed to allow the drawbar 19 to move up and down relative to the finger 26 by retracting the outer peripheral side of the drawbar 19 .

Therefore, when the clamp rod 24 is located at the rising end of the right half in FIG. Alternatively, extraction can be performed freely. However, when the drawbar 19 is inserted into the clamp rod 24, the clamp rod 24
When the clamp rod 24 is lowered, the finger 26 is pushed out of the retraction groove 27 and locked in the small diameter portion 25, as shown in the left half of FIG. 20 strongly presses the workpiece 15 to clamp the workpiece 15.

On the other hand, a cylindrical cylinder 28 into which the upper end of the drawbar 19 can penetrate is fixed to the support arm 18. The upper end of this cylinder 28 is coaxial with the drawbar 19, and its lower end is connected to the upper end of the drawbar 19. Detection rods 30 that can face each other across the gap 29
A rod holder 31 is integrally attached to the rod holder 31 for holding the rod so as to be slidable up and down. This rod holder 31
A compression coil spring 3 is provided between the detection rod 30 and the detection rod 30 to constantly apply a downward spring force to the detection rod 30.
A sensitivity adjustment nut 33 is screwed into the upper end of the detection rod 30 to adjust the amount of the gap 29 by setting the lowering end of the detection rod 30 relative to the rod holder 31. Furthermore,
Together with this sensitivity adjustment nut 33, the detection rod 30
A disc-shaped dog 35 is fixed to the detection rod 30 by a lock nut 34 screwed into the upper end.
A limit switch 36 that can detect, via this dog 35, the upward movement of the detection rod 30 against the spring force of the compression coil spring 32 is opposed to and in contact with. This limit switch 36, which is supported by the cylinder 28 via a bracket 37, converts the upward movement of the detection rod 30 into an electrical signal and sends it to a control device (not shown), thereby immediately stopping the downward movement of the support arm 18. On the contrary, a system is set up to raise the workpiece 15, correct the position of the workpiece 15, or replace it with a new workpiece 15. A compression coil spring 38 is interposed between the rod holder 31 and the upper end of the drawbar 19, which always presses the drawbar 19 downward, so that the drawbar 19 will not move unless an upward force is applied.
Due to its own weight and the spring force of the compression coil spring 38, the pin 40, which engages with the lifting guide groove 39 carved in the drawbar 19, comes into contact with the upper end of the lifting guide groove 39 and is suspended from the support arm 18. It's summery.

Therefore, when lowering the support arm 18 and inserting the drawbar 19 into the workpiece 15, if the workpiece 15 is incorrectly positioned or has an insufficient inner diameter, the drawbar 19 cannot be lowered, and relatively only the support arm 18 is lowered. , the upper end of the drawbar 19 pushes up the detection rod 30 so that an abnormality can be detected immediately.

It should be noted that various structures other than the present example can be considered as the structure of the puller-type fixture and the specific structure of the workpiece defect detection device, but in short, it is sufficient as long as it has the structure described in the scope of the utility model registration claim. .

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a schematic structure of one embodiment of the defective work detection device for a puller-type fixture according to the present invention, Fig. 2a is an enlarged sectional view of its main part, and Fig. 2b is a plan view thereof. 12 is the base, 13 is the lower holder, 15 is the workpiece, and 18 is the code in the figure.
is a support arm, 19 is a drawbar, 20 is an upper holder, 24 is a clamp rod, 25 is a small diameter part,
26 is a finger, 27 is a retraction groove, 28 is a cylinder, 30 is a detection rod, 32 and 38 are compression coil springs, 35 is a dog, 36 is a limit switch,
39 is a lifting guide groove, and 40 is a pin.

Claims (1)

[Scope of utility model registration request] A base having an annular lower holder at the upper end on which an annular workpiece is placed; a support arm provided above the base so as to be movable up and down; a drawbar that penetrates and fits tightly with the drawbar; an upper holder that is integrally attached to the drawbar and that can press and fix the workpiece to the lower holder; and an upper holder that is attached to the base so as to be slidable up and down. and a hollow clamp rod into which the lower end of the drawbar is fitted, and a hollow clamp rod that is slidably held in the radial direction by the clamp rod and can be locked to the lower end of the drawbar, and the drawbar is moved as the clamp rod is lowered. In a puller type fixture having a plurality of fingers for pulling down, the cylinder is fixed to the support arm, and the cylinder is interposed between the cylinder and the upper end of the drawbar to constantly apply a downward spring force to the drawbar. a compression spring that is slidably held in the cylinder up and down, a detection rod that is always applied with a downward spring force and whose lower end faces the upper end of the drawbar across a gap; and a detection rod that is attached to the cylinder. a limit switch that detects thrusting up of the detection rod via the drawbar and raises the support arm when the drawbar does not penetrate the workpiece.