JP7173754B2 - Work holding bracket - Google Patents

Description

TECHNICAL FIELD The present invention relates to a work holding bracket that prevents a work from falling off even when a chuck device is in an unclamped state.

In a machine tool such as a lathe, a workpiece is transferred to a spindle chuck by a workpiece transfer device, and after processing such as cutting, the workpiece is picked up from the spindle chuck by the workpiece transfer device and transferred to the next machine tool or the like. 2. Description of the Related Art In a chuck device of a machine tool, for example, chuck claws are opened and closed via a cylinder that expands and contracts by air pressure to clamp and unclamp a workpiece. By the way, there are cases where a machine tool comes to a stopped state while gripping a workpiece due to an emergency stop due to an abnormal signal or a nighttime cycle stop. If the non-operating state continues for a long time, the work will drop out of the chucking device due to air leakage. In this respect, Patent Document 1 below discloses a chuck for a work transfer device, which has a structure in which the biasing force of a spring always acts in the closing direction so that the work can be held for a long time. .

JP-A-7-178643 JP 2016-168633 A

The conventional example of Patent Document 1 is intended to be able to hold a workpiece for a long time, but for that purpose, it is necessary to add a special configuration, and improvements etc. will increase the cost. On the other hand, in order to prevent the work from falling off, the worker should remove the work without leaving it in the chuck device. However, the issue here is safety. That is, when removing a workpiece from a machine tool that has stopped operating, the operator must open the door of the machine tool body, put his/her hand into the processing section, and operate the chuck device while gripping the workpiece.

At that time, it is conceivable that the chuck device is operated to unclamp the work, and then the door is opened so that the operator can take out the work. However, in this case, the work may fall off before the operator can take it out, and the work itself may be damaged or the internal equipment of the machine tool may be damaged. As another method, it is conceivable to use a work conveying device to take out the work instead of taking it out directly by the operator. However, in the work carried out by the work conveying device, the work can only be taken out by operating each processing section out of the plurality of processing sections, so the take-out work takes time.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a workpiece holding bracket that prevents the workpiece from falling off even when the chuck device is in an unclamped state.

A workpiece holding bracket according to the present invention includes a fitting member that is fitted to the outer periphery of a device body of a chuck device that clamps and unclamps a workpiece by the operation of a gripping portion, and is integrally formed with the fitting member. and a support member for supporting the held workpiece.

According to the above configuration, the work holding bracket is attached by fitting the fitting member to the outer peripheral portion of the main body of the chuck device, and the support member formed integrally with the fitting member holds the work held by the chuck device. To support. Therefore, even if the chuck device is in an unclamped state, the work is supported by the work holding bracket and is maintained in a state of being held by the chuck device.

FIG. 4 is a side cross-sectional view showing a state in which the workpiece holding bracket of the first embodiment is attached to the chuck device; FIG. 2 is a front view showing a state in which the workpiece holding bracket of the first embodiment is attached to the chuck device; It is a side cross-sectional view showing a modification of the work holding bracket of the first embodiment. FIG. 11 is a side cross-sectional view showing a state in which the workpiece holding bracket of the second embodiment is attached to the chuck device; FIG. 11 is a front view showing a state in which the workpiece holding bracket of the second embodiment is attached to the chuck device;

Next, one embodiment of a work holding bracket according to the present invention will be described below with reference to the drawings. In this embodiment, a work holding bracket used when taking out a work from a chuck device in a machine tool will be described. 1 and 2 are diagrams showing a first embodiment of a work holding bracket. In particular, FIG. 1 is a side cross-sectional view showing a state in which a workpiece holding bracket is attached to a chuck device. 2 is a front view of the workpiece holding bracket from the right side of FIG. 1 (the front side of the chuck device).

First, the illustrated chuck device 8 has a cylindrical device body 11 with a center line O as a rotation axis, and a collet 12 radially cut from the center side protrudes from the device body 11 . The device body 11 is also provided with a contact 13 for axially receiving the workpiece W, and the like. In this chuck device 8, as shown in FIG. 1, the end face of the work W is abutted against the abutment 13 to position the work W in the direction of the rotation axis, and the collet 12 expands radially outward to move the work W inward. It is clamped so that it can be grabbed from.

The work holding bracket 1 of this embodiment is designed to prevent the work W from falling off from the chuck device 8 even when the collet 12 is in an unclamped state. The workpiece holding bracket 1 has a fitting member 21 fitted to the outer peripheral portion of the apparatus main body 11 , and a support member 22 directly supporting the workpiece W held by the chuck device 8 is fixed to the fitting portion 21 . It is one. For example, the fitting member 21 and the support member 22 are made of metal and joined by welding. The fitting member 21 is in the shape of a ring with a constant width so as to be fitted around the entire outer circumference of the cylindrical device main body 11 . A support member 22 is provided so as to be positioned at the lower end when the fitting member 21 is fitted to the device main body 11 .

As shown in FIGS. 1 and 2, the support member 22 extends in a direction perpendicular to the radial direction of the substantially circular fitting member 21, that is, when the workpiece holding bracket 1 is attached to the chuck device 8, the center line O The arm portion 221 extends in a direction along the . A receiving portion 222 is formed at the tip portion of the arm portion 221 so as to be perpendicularly bent upward. The support member 22 is a plate material having a predetermined width, and the fitting member 21 has a flat portion 211 formed on the outer peripheral surface of the lower end portion thereof, to which the ends of arm portions 221 are fixed. The receiving part 222 is formed wider than the arm part 221, and a receiving surface 225 cut in a V-shape at an angle corresponding to the outer diameter of the corresponding part of the work W is formed at the upper end part that contacts the work W. It is

The ring-shaped fitting member 21 has an inner diameter slightly larger than the outer diameter of the main body 11 of the chuck device 8 . Therefore, a slight gap is generated between the chuck device 11 and the fitting member 21, as indicated by the dashed line in FIG. This gap facilitates attachment and detachment of the workpiece holding bracket 1 with respect to the chuck device 8 . On the other hand, since the gap causes backlash, the stability of the holding state of the workpiece W is also lowered. Therefore, the fitting member 21 is provided with ball plungers 23 (23a, 23b, 23c) at three locations.

The ball plunger 23 has a male thread formed on the outer peripheral surface of the main body and is screwed into a threaded hole formed in the fitting member 21 as shown. A lock nut 24 is screwed onto the ball plunger 23 from the outer peripheral side of the fitting member 21 to position the fitting member 21 in the radial direction. The ball plunger 23 is formed with a recess opening on the inner peripheral side of the fitting member 21, and the ball is incorporated therein so as to be biased outward by a coil spring. When the workpiece holding bracket 1 is attached to the chuck device 8, the balls of the ball plunger 23 come into contact with the outer peripheral surface of the device main body 11, and the coil spring is compressed, thereby radially outwardly with respect to the fitting member 21. spring force acts.

The ball plungers 23 are provided at three locations on the fitting member 21. As shown in FIG. Two ball plungers 23b and 23c are provided at symmetrical positions. Since the ball plungers 23b and 23c are positioned higher than the center line O, the spring force in the radial direction toward the center line O stabilizes the workpiece holding bracket 1 in the same direction by the component force in the left and right width directions. The work holding bracket 1 is further maintained in its attached state by the component force that pulls it up.

Next, use of the workpiece holding bracket 1 will be described. First, the chuck device 8 receives and clamps the work W from the work conveying device when processing the work. That is, the center hole of the work W is fitted into the collet 12, and the work W is clamped from the inside by expanding the collet 12 radially outward. Then, if the operation of the machine tool stops for some reason, the operator has to take out the workpiece W directly from the chuck device 8 . At that time, if the chuck device 8 is unclamped, the workpiece W may fall off because the center of gravity of the workpiece W is distant from the clamping position of the collet 12 . Therefore, the workpiece holding bracket 1 of the present embodiment is attached.

When the machine tool stops operating, the operator opens the door of the machine tool body, puts his/her hand into the processing section, and attaches the work holding bracket 1 to the chuck device 8 holding the work W as shown in the figure. is done. For example, an operator who holds the support member 22 fits the fitting member 21 through which the workpiece W is passed to the outer peripheral portion of the apparatus main body 11, and moves the receiving portion 222 (receiving surface 225) of the support member 22 in the direction of the center line O. It is positioned so as to hit the vicinity of the end of the work W seen from above. In the work holding bracket 1, the fitting state of the fitting member 21 is maintained by the biasing force of the ball plunger 23, and the support member 22 supports the work W at a position away from the clamping position of the collet 12.

Next, the operator puts his/her hand out of the processing section to confirm a safe state, and then manually operates the chuck device 8 to bring the collet 12 into an unclamped state. At this time, the work W is supported by the collet 12 at one end side as viewed along the center line O, and is supported by the work holding bracket 1 at the other end side, so that the state of being held by the chuck device 8 is maintained. be. Then, the operator puts his/her hand into the processing section of the machine tool again, removes the work holding bracket 1 together with the work W from the chuck device 8, and takes out the work.

Therefore, by using the work holding bracket 1, it is possible to prevent the work W from coming off during unclamping. Therefore, the operator does not have to put his/her hands into the working portion of the machine tool when driving the chuck device 8, and the safety of the work can be ensured. In addition, since the work holding bracket 1 is a simple one in which the ring-shaped fitting member 21 is integrated with the L-shaped plate member 22, the above effects can be obtained at a low cost. In addition, the workpiece W can be held by a simple operation of fitting the fitting member 21 to the outer peripheral portion of the device main body 11 .

Here, FIG. 3 is a side cross-sectional view showing a modification of the work holding bracket of the first embodiment. This workpiece holding bracket 1A is provided with a ball plunger 23d at a position just below the center line O in addition to the three ball plungers 23a, 23b and 23c. When the workpiece W is supported as shown in FIG. 1, the load F1 of the workpiece W acts on the receiving portion 222 as shown in FIG. works.

Therefore, the ball plunger 23d is farther from the receiving part 222 than the others when viewed in the direction of the center line O so that the spring force F2 acts on the workpiece holding bracket 1A in the direction of canceling the force of the load F1. placed in position. Therefore, in the work holding bracket 1A that supports the work W, the posture of holding the work W can be maintained by applying the spring force F2 by the ball plunger 23d on the opposite side of the load F1 that tilts the support member 22. can. In other words, it is possible to stabilize the holding state of the workpiece W when the chuck device 8 is unclamped.

Next, FIGS. 4 and 5 are diagrams showing a state in which the second embodiment of the work holding bracket is attached to the chuck device. In particular, this embodiment is a work holding bracket for a long work, and FIG. 4 is a side cross-sectional view thereof, and FIG. 5 is a front view thereof. The workpiece holding bracket 2 is intended for a long workpiece LW that is rotatably supported by the centers 33 and 34 of the first headstock 31 and the second headstock 32, respectively. A chuck device 35 is provided on the first headstock 31 , and the long work LW is positioned by abutting an end portion in the direction of the center line O against a contact metal 351 and clamped by chuck claws 352 . The long work LW is rotatably supported by the centers 33 and 34 so that its axis is aligned with the center line O. As shown in FIG.

In the work holding bracket 2 of the present embodiment, a support member 42 for directly supporting the long work LW held by the chuck device 35 is provided with respect to a fitting member 41 fitted to the outer peripheral portion of the device main body 355 of the chuck device 35. It is fixed and united. For example, the fitting member 41 and the support member 42 are also made of metal and joined by welding. The fitting member 41 is a C-shaped member with a constant width as shown in FIG. Ball plungers 43 are provided at both ends of the fitting member 41, respectively, and their positions are higher than the center line O. As shown in FIG.

A support member 42 is provided so as to be positioned at the lower end portion when the fitting member 41 is fitted to the device main body 355 . As shown in FIG. 4, the support member 42 has an arm portion 421 extending horizontally along the center line O, and two receiving plates 423 and 424 are fixed to the arm plate 421 . One end of two rods 425 is fixed to the receiving plate 424, and a screw hole is formed in the other end. A tip portion of the arm plate 421 is bent upward so as to be orthogonal, and a through hole is formed there. Through holes are also formed in the receiving plate 423 , bolts 426 are passed through both through holes, and the screw holes of the rod 425 are tightened to be integrally attached to the arm plate 421 .

In this embodiment as well, the workpiece holding bracket 2 is used to take out the workpiece W when the machine tool stops operating for some reason. An operator opens the door of the machine tool main body, puts his/her hand into the processing section, and attaches the workpiece holding bracket 2 to the chuck device 35 holding the workpiece W as shown in the figure. The fitting member 41 is fitted to the device main body 355 so that the long work LW supported by the centers 33 and 34 passes between the separated ends of the C shape.

The workpiece holding bracket 2 is maintained in the fitted state of the fitting member 21 by the biasing force of the ball plunger 43 . The receiving plates 423 and 424 support, at two points, the long work LW placed against the V-shaped surface cut at a predetermined angle. After confirming a safe state by reaching out from the processing section, the operator manually operates the chuck device 35 to bring it into an unclamped state. At this time, the long work LW is maintained in a state of being held by the work holding bracket 2, so the operator puts his/her hand into the processing section of the machine tool again and pushes the work holding bracket 2 together with the long work LW. 1 and the second headstocks 31 and 32 and take them out.

Therefore, by using the work holding bracket 2, it is possible to prevent the long work LW from coming off during unclamping. Therefore, the operator does not have to put his/her hands into the working portion of the machine tool when driving the chuck device 35, and the safety of the work can be ensured. In addition, since the work holding bracket 2 is formed mainly by integrating the support member 42 with the fitting member 41, the above effect can be obtained at a low cost. In addition, the workpiece W can be held by a simple operation of fitting the fitting member 21 to the outer peripheral portion of the device main body 11 . In particular, by using the C-shaped fitting member 41, both ends of the long work LW can be easily attached to the centers 33 and 34 as well.

Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.
For example, in the above embodiment, the fitting member 21 (41) and the support member 22 (42) are integrally formed by welding, but they may be detachable by bolting or the like. Furthermore, although the support member 22 is one member in the first embodiment, the arm portion 221 and the receiving portion 222 may be configured as separate members so that they can be attached and detached by bolting or the like.

DESCRIPTION OF SYMBOLS 1... Work holding bracket 8... Chuck device 11... Apparatus main body 12... Collet 21... Fitting member 22... Support member 23... Ball plunger 24... Lock nut 221... Arm part 222... Receiving part

Claims (4)

a fitting member that fits onto the outer periphery of a device body of a chuck device that clamps and unclamps a workpiece by the action of the gripping portion;
A workpiece holding bracket having a support member integrally formed with the fitting member for supporting the workpiece held by the chuck device. The fitting member is formed in an annular shape to match the outer peripheral shape of the device main body, and the support member is fixed to the lower portion of the fitting member fitted to the device main body to support the work downward. 2. The work holding bracket according to claim 1, wherein the work holding bracket supports from. The fitting member has two or three positioning members that are elastically deformed by receiving a reaction force when pressed against the fitted device main body. 3. The work holding bracket according to claim 1, wherein the work holding bracket is arranged at a position higher than the shaft so as to be left-right symmetrical. The positioning member is a plunger, and when viewed in the direction of the central axis of the chuck device, the lower plunger, which is the positioning member arranged directly below the central axis , is positioned above the upper plunger, which is the positioning member. 4. The work holding bracket according to claim 3, wherein the work holding bracket is fixed at a position apart from the work.

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