JPH0325879Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a tool mounting attachment that is attached to a tool mounting part of an NC machine tool, such as a tool post, by a manipulator of an automatic tool changer, to the tool post. This invention relates to a tool clamping device for firmly clamping.

(Prior art and its problems) For example, a tool mounting attachment that is mounted on a tool post of a numerically controlled turret lathe by a manipulator of an automatic tool changer has a tool mounting attachment that fits tightly into a tapered hole in the tool post. A tapered protruding shaft portion is provided. The clamp of the tool attachment attachment pulls the tapered protruding shaft portion fitted into the tapered hole inward to closely fit the two, and the clamp of the tool attachment attachment can be used as needed. This is done by bringing the annular end surfaces formed around the axis on the attachment side and the tool post side into surface contact with each other.

A conventional tool clamping device of this kind has a retracting shaft that can be freely engaged with and disengaged from the tip of the protruding shaft, and a retracting shaft that is inserted into the tool as a means for inwardly retracting the tapered protruding shaft of the tool mounting attachment. It used a multi-stage disc spring that pulled in the opposite direction. Such a conventional clamp device using a disc spring is suitable for machine tools that perform heavy cutting or machining with a large overhang where the cutting force of the cutting tool attached to the tool mounting attachment exceeds the biasing force of the disc spring. When applied to a tool, there is a risk that the clamp for the tool attachment may loosen unexpectedly, which poses a safety problem. In addition, since the retraction shaft and disc spring group are arranged on the center line, it is difficult to apply it to a tool mounting attachment that has a tool drive shaft passing through the center. This method could only be applied to machine tools in which the attachment itself is rotationally driven, that is, a machine tool equipped with a rotationally driven tool post.

(Means for Solving the Problems) The present invention proposes a tool clamping device that can solve the above-mentioned conventional problems, and its features are as follows:
The tapered protruding shaft part 3 is connected to an engaging shaft part 4 that protrudes coaxially from the protruding shaft part and has an engaging circumferential flange 5 protruding from its tip.
and the engaging shaft portion 4, and the tool mounting portion 2 on the machine tool side is provided with a tapered fitting hole portion 11 into which the protruding shaft portion 3 can fit. At the same time, a mounting hole 12 is provided on the inner side of the fitting hole, and a mounting hole 12 is formed between the mounting hole and the fitting hole 1.
A large-diameter hole 13 is provided concentrically between the mounting hole 12 and the clamping cylindrical body 14 having an end that fits externally into the engagement shaft 4. A driving rotary body 15 is installed inside the clamping body, and is interlocked with the clamping cylindrical body 14 through a screw mechanism, and draws the cylindrical body inward when rotating in the normal direction and pushes it outward when rotating in the reverse direction. The end of the clamping cylindrical body has an engaging periphery flange 5 that engages with the engaging flange 5 when the cylindrical body is pulled in to prevent the attachment from coming off, and when the cylindrical body is pushed out.
The clamping means 50, 50a is provided with clamping means 50, 50a that is detached from the clamp and displaced toward the large-diameter hole 13 to release the retainer, so that the clamping means 50 and 50a penetrate through the driving rotary body 15 and can be freely connected to and detached from the tool drive shaft 7 on the attachment side. The main shaft 16 for driving a tool is internally equipped with a clutch mechanism.

Further, as an embodiment of the present invention, the clamping means 50 includes a plurality of ball holding holes 21 which are provided through the front end portion of the clamping cylindrical body at intervals in the circumferential direction.
When the holding hole 21 is recessed into the mounting hole 12 by pulling in the clamping cylindrical body 14, it protrudes inward from the holding hole and engages with the engaging circumferential flange 5, thereby preventing the attachment from coming off. , the holding hole 2 is opened by extruding the clamping cylindrical body 14.
1 faces the large-diameter hole 13, the clamp ball 22 projects outward into the large-diameter hole and releases the engagement with the engaging circumferential flange 5.

Furthermore, as another embodiment of the present invention, the clamping means 50a has an inner end thereof screwed onto the driving rotating body 15, and a plurality of grooves 21a extending in the axial direction, leaving the inner end. At the outer end thereof, an inward engaging circumferential collar 22a is fitted onto the engaging shaft portion 4 and engages with the outward engaging circumferential collar 5 from the outside to prevent the attachment from coming off. This configuration employs a split collet 14a for clamping.

(Function) According to the tool clamping device of the present invention as described above, when the tool mounting attachment 1 is in a state where the clamping means 50, 50a is exposed to the large diameter hole 13, the tapered protruding shaft portion 3 is machined. It fits into the tapered fitting hole 11 of the tool attachment part 2 on the machine side, and the engagement circumferential flange 5 at the tip of the engagement shaft 4 pushes aside the clamping means 50, 50a and is used for clamping on the machine tool side. After being fitted so as to fit into the cylindrical body 14, the clamping cylindrical body 14 is rotated in the normal direction by driving the driving rotary body 15 in the forward direction.
The clamping means 50, 50a is recessed into the mounting hole 12 by pulling the clamping means 50, 50a inwardly through the screw mechanism, whereby the clamping means 50, 50a is inserted into the engaging periphery 5.
The tool mounting attachment 1 is then pulled inward through the clamping means 50, 50a, and the tapered protruding shaft portion 3 of the tool mounting attachment 1 is inserted into the tapered fitting hole of the tool mounting portion 2. The attachment can be fixed by a tight fit to the part 11.

When the driving rotating body 15 is reversed, the clamping cylindrical body 14 is pushed outward and the clamping means 50, 50a are exposed to the large diameter hole 13, whereby the clamping means 50, 50a are engaged. Shutsuba 5
Since the engagement with the tool mounting part 1 is released and the tool mounting attachment 1 is disengaged from the tool mounting part 2, the tool mounting attachment 1 can be removed from the tool mounting part 2.

(Example) An example of the present invention will be described below based on the attached illustrative drawings.

In FIG. 1, 1 is an attachment for mounting a tool, and 2 is a tool post on the machine tool side.
At the inner end of the tool mounting attachment 1, a tapered protruding shaft portion 3 and a small-diameter engagement shaft portion 4 that protrudes further than the protruding shaft portion 3 are coaxially arranged, At the tip of the engagement shaft portion 4, an engagement peripheral flange 5 protruding outward in the radial direction is provided. Also, a bearing 6 is included in the attachment 1.
The tool drive shaft 7 is supported concentrically through the
A tool gripper 8 for gripping the tool T is attached to the outer end of the tool drive shaft 7, and a clutch pawl 9 is formed at the inner end of the tool drive shaft 7 protruding from the engagement shaft portion 4. There is. Reference numeral 10 denotes a manipulator grip portion formed on the tool mounting attachment 1.

The tool post 2 is provided at its outer end with a tapered fitting hole 11 that can be closely fitted with the tapered protruding shaft 3 of the tool mounting attachment 1, and further includes: This fitting hole 11
There is a mounting hole 12 inside the mounting hole 1.
2 and the fitting hole 11, a large diameter hole 13 having a larger inner diameter than these is provided concentrically,
A clamping cylindrical body 14 and a driving rotating body 15 are fitted into the mounting hole 12, and a tool driving main shaft 16 is inserted and supported within the driving rotating body 15. Reference numeral 17 denotes a rotation stopper pin protruding from the annular end surface 18 of the tool post 2, and a recess 20 formed in the inner annular end surface 19 of the manipulator grip part 10 of the tool mounting attachment 1.
Fits in.

The clamping cylindrical body 14 has an outer end that can be fitted onto the engagement shaft portion 4 including the engagement circumferential flange 5 on the tool mounting attachment 1 side, and a clamp is attached to this outer end. A plurality of ball holding holes 21 serving as means 50 are provided through the cylindrical body 14 in the radial direction at regular intervals in the circumferential direction, and each holding hole 21
A clamp ball 22 having a diameter larger than the length of the holding hole 21 (that is, the thickness of the cylindrical body) is held in the holding hole 21 . Note that each holding hole 21 has an inner diameter slightly larger than the diameter of the clamp ball 22 so that the clamp ball 22 can easily come in and out from the outer end opening and the inner end opening. The inner end opening is narrowed to a diameter slightly smaller than the diameter of the clamp ball 22 so that the clamp ball 22 does not slip out from the inner end opening. Also,
The outer peripheral surface of the inner end of the clamping cylindrical body 14 engages with a stopper pin 23 protruding from the inner peripheral surface of the tool post 2 to prevent the clamping cylindrical body 14 from rotating. A concave groove portion 24 is provided in the axial direction to guide the axial movement thereof, and a female screw portion 25 is further formed on the inner circumferential surface of the inner end.

The driving rotating body 15 is rotatably supported within the tool post 2 via a needle bearing 26 and a thrust ball 27, with the outer end protruding into the clamping cylindrical body 14. The driving rotating body 15 is connected to the clamping cylindrical body 15 through a screw mechanism consisting of a male threaded portion 28 formed on the outer peripheral surface of the central portion and the female threaded portion 25.
The forward rotation of the drive rotary body 15 pulls the clamping cylindrical body 14 inward along the axial direction, and the reverse rotation pulls the clamping cylindrical body 14 outward. It's starting to push out. The driving rotary body 15 can be rotationally driven by a drive gear 29 shown by a two-dot chain line in the figure via a gear 30 provided at the inner end of the rotary body 15.

The tool driving main shaft 16 is connected to the driving rotating body 1
The rotating body 15 is supported by a ball bearing 31 and a needle bearing 32 while penetrating through the interior of the rotating body 5, and a clamping mechanism is installed inside the distal end side. This clamp mechanism is concentrically fitted into the driving rotating body 15 via a transmission key 33 and a stopper 34 for preventing removal, and is movable only in the axial direction within a certain range. Clutch claw 3 that engages with side clutch claw 9
5 and a coil spring 37 that urges the movable body 36 outward. The tool drive main shaft 16 can be rotationally driven by a driving shaft 38 indicated by a two-dot chain line in the figure. Reference numeral 39 denotes a positioning guide rod that penetrates the center of the movable body 36 so as to be able to slide in the axial direction and protrudes from the distal end surface of the movable body 36, and this protruding end is coaxial with the opposite end of the tool drive shaft 7. The rod 39 is fitted into a guide hole 40 provided in the rod 39, and the rod 39 is urged outward by a coil spring 41.

Next, to explain how to use it, the driving rotor 1
5 is reversely driven in advance, the clamping cylindrical body 14 is pushed outward from the mounting hole 12, and the ball holding hole 21 at the outer end is completely closed to the large diameter hole 13.
From this state, the tool mounting attachment 1 is placed so that its annular end surface 19 faces the annular end surface 18 on the tool post 2 side, and the tool mounting attachment 1 is placed in the recessed state. It is attached to the tool post 2 so that the rotation stopper pin 17 on the tool post 2 side fits into the rotation stopper pin 17 on the tool post 2 side. During this installation, insert the guide hole 40 on the tool drive shaft 7 side into the movable body 3.
Positioning guide rod 39 protruding from the 6 side
The work can be done quickly and easily by fitting the parts. By attaching the tool mounting attachment 1 to the tool post 2 in this manner, the tapered protruding shaft portion 3 is fitted into the medium tapered fitting hole 11 of the tool post 2, and the engaging peripheral flange is fitted. 5 pushes aside the clamp ball 22 protruding from the inner end opening side of the ball holding hole 21 and enters into the clamping cylindrical body 14.

In such a state, the driving rotating body 1 is rotated by the driving gear 29.
When 5 is rotated in the normal direction, the external threaded portion 28 on the rotating body 15 side and the clamping cylindrical body 1 that can only move in the axial direction are connected to each other.
The clamping cylindrical body 14 is drawn inward through a screw mechanism consisting of the female threaded portion 25 on the fourth side. As a result, as shown in FIG. 1, each ball holding hole 21 at the outer end of the clamping cylindrical body 14 is recessed into the mounting hole 12 of the tool post 2, while the engagement circumference on the tool mounting attachment 1 side is inserted into the mounting hole 12 of the tool post 2. The tool mounting attachment 1 is engaged with the collar 5, and the tool mounting attachment 1 is drawn inward through the clamp hole 22.
The attachment 1 for attaching a tool is inserted into the tapered fitting hole 11, which is tapered in the middle.
At the same time, the annular end surface 18 on the tool post 2 side and the tool mounting attachment 1 are brought into close contact with each other.
The side annular end surfaces 19 are brought into surface contact with each other. In this state, normal rotation driving of the drive rotor 15 is stopped, but by interposing a torque limiter in the drive system of the drive gear 29 or using a torque motor, the timing of stopping the drive of the drive rotor 15 can be determined. It is desirable to configure the system so that overload can be automatically avoided even if there is a delay.

In addition, when the tool mounting attachment 1 is provided with the tool drive shaft 7 that drives the tool gripping tool 8 as shown in the figure, when the tool mounting attachment 1 is attached to the tool post 2, the tool drive shaft 7 on the tool post 2 side The main shaft 16 and the tool drive shaft 7 are automatically connected via the clutch mechanism. That is, the clutch pawl 9 on the tool drive shaft 7 side
The clutch pawl 35 on the tool driving shaft 16 side engages with the clutch pawl 35 on the tool driving shaft 16 side, but even if the two are out of phase, the movable body 36 of this clutch mechanism is pushed by the clutch pawl 9 on the tool driving shaft 7 side and the spring is released. 37, and when both clutch pawls 9, 35 are brought into phase with each other by the rotation of the tool driving main shaft 16, the movable body 36 moves forward by the biasing force of the spring 37, and both clutch pawls 9, 35 are automatically moved. to bite.

By rotating the tool driving main shaft 16 through the driving shaft 38, the rotational force is transmitted to the tool driving shaft 7 on the tool mounting attachment 1 side through the clutch pawls 35 and 9, and the tool gripping tool 8 is It can be rotated.

When the tool mounting attachment 1 is to be detached from the tool post 2, the driving rotating body 15 is driven in the reverse direction. As a result, the clamping cylindrical body 14 is pushed out via the screw mechanism interposed between the rotating body 15 and the clamping cylindrical body 14. As a result, each ball holding hole 21 at the outer end of the clamping cylindrical body 14 comes out from the mounting hole 12 of the tool post 2 into the large diameter hole 13, and each clamp ball 22 opens at the outer end of the ball holding hole 21. It becomes possible to protrude outward from the part. In this state, when the reverse rotation of the drive rotating body 15 is stopped and the tool attachment attachment 1 is pulled outward by the manipulator, each clamp ball 22 is moved outwardly in the axial direction of the engagement circumference 5. is pushed out from the outer end opening into the large diameter hole 13, whereby the attachment 1 can be pulled out from the tool post 2.

In the embodiment described above, the screw mechanism for moving the clamping cylindrical body 14 in the axial direction by the rotation of the driving rotary body 15 is connected to the external threaded portion 28 provided on the driving rotary body 15 side and the clamp. Although the female threaded portion 25 is provided on the side of the cylindrical body 14, other screw mechanisms may be used, such as the one shown in FIG. 2, for example. That is, the screw mechanism shown in FIG. 2 is fixedly protruded from the inner circumferential surface of the clamping cylindrical body 14 which can only be moved in the axial direction by means of a stopper pin 43 protruding from the tool post 2 side. The engaging pin 45 and the driving rotating body 15
A spiral grooved cylinder block 48 is provided on the outer peripheral surface of the cylinder block 48, and the engaging pin 4 is engaged with the spiral grooved cylinder block 48 by forward and reverse rotation of the rotating body 15.
5 is guided by this groove, and the clamping cylindrical strip 1
4 can reciprocate in the axial direction.

Figure 3 shows another embodiment of the present invention.
The tool clamping device of this embodiment has the same structure as the embodiment shown in FIG. 1, except that it uses a split collet-type clamping cylindrical body 14a. Only the differences will be explained, and the same members will be denoted by the same reference numerals. That is, as is clear from FIG. 4, the clamping cylindrical body 14a is provided with a plurality of grooves 21a extending in the axial direction except for the inner end, so that the diameter of the outer end can be expanded. and this cylindrical body 1
The outer end of 4a is provided with an inward engaging flange 22a serving as a clamping means 50a that protrudes inwardly in the radial direction on the inner circumferential side thereof, and this inward engaging flange 22a When the end portion is fitted into the mounting hole 12 of the tool post 2, it fits onto the engagement shaft portion 4 including the outward engagement flange 5 on the tool attachment attachment 1 side, and the outward engagement flange 5 and prevents the attachment 1 from coming off, and when the cylindrical body 14a is pushed outward, the outer end protrudes from the mounting hole 12 into the large diameter hole 13 side. and the tapered engagement surface 22 at the tip.
a ₁ is the tapered engagement surface 3 on the attachment 1 side
By fitting into the large-diameter hole portion 13 while slidingly contacting the outer end portion a, the diameter of the outer end portion expands as shown by the dashed line in FIG. The engagement of the circumferential collar 22a is disengaged. The inner end of the clamping cylindrical body 14a is screwed into the driving rotary body 15 and is biased in the drawing direction by the rotary body, and the outer end thereof is inserted into the mounting hole 12. They are fitted and the diameter is reduced.
In this diameter-reduced state, the inward engaging circumferential flange 22a engages with the outward engaging circumferential flange 5. From this state, when the cylindrical body 14a is pushed outward by reversing the drive rotary body 15, its outer end is attached as shown by the dashed line in FIG. Hole 1
2 and fits into the large-diameter hole 13, thereby releasing the attachment 1 from coming off.
In the embodiment shown in FIG. 3, in order to expand the diameter of the outer end of the clamping cylindrical body 14a, a tapered engagement surface _22a1 is provided on the tip side of the outer end, and this is also necessary. A tapered engagement surface 3a is provided at a required part on the opposing tool mounting attachment 1 side, and when the outer end protrudes outward as the cylindrical body 14a is pushed out, the taper on the cylindrical body 14a side Although the diameter of the shaped engagement surface _22a1 is expanded while slidingly contacting the tapered engagement surface 3a on the attachment 1 side, and the outer end thereof is fitted into the large diameter hole 13, there are other methods. is a split collet-type cylinder in which the outer end, where the inward engaging flange is provided, has a larger diameter than the intermediate part and the inner end, and the outer end has an expanded diameter in advance. When the outer end of this cylindrical body is fitted into the mounting hole 12 of the tool post 2, the diameter of the outer end is reduced. It is in elastic contact with the inner circumferential surface, and the outer end is connected from the mounting hole 12 to the large diameter hole 1.
When pushed out into the large-diameter hole 13, the diameter may be expanded by the restoring force and fit into the large-diameter hole 13.

(Effects of the invention) According to the tool clamping device of the present invention, which can be implemented as described above, the tool mounting attachment is not clamped by the tensile force of the spring.
Since the clamping is performed using a forced tensile force using a screw mechanism, extremely strong clamping can be achieved. Therefore, it can be safely used as a clamping device for a tool attachment in a machine tool that performs heavy cutting or machining with a large overhang.

In addition, compared to a method in which a movable clamping body that is rotatably and axially movable and is installed in a tool mounting hole on the machine tool side is engaged with a thread formed on the tool mounting attachment side, the clamping action is smoother and more efficient. Not only can it be done quickly, but it also has a long service life because there is no risk of teeth becoming loose at the end of the threaded part.

Furthermore, the clamping device of the present invention can be easily applied to a rotary tool mounting attachment provided with a tool drive shaft. In the present invention, a rotating tool mounting attachment is fixed to a tool mounting part (tool post 2 in the embodiment) on the machine tool side that does not rotate even though the tool drive shaft provided on the tool mounting attachment rotates. Therefore, there is no need to stop the tool drive shaft in a fixed position (orientation) during automatic tool change work, and the tool drive system can be easily controlled and carried out at low cost. In the embodiment, the tool post 2) can be used both for a rotating tool and a fixed tool.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing one embodiment of the present invention, Fig. 2 is a partially longitudinal cross-sectional side view showing a modification of the screw mechanism, and Fig. 3 is a longitudinal cross-sectional view showing another embodiment of the present invention. , FIG. 4 is a perspective view of the same essential parts. 1... Attachment for mounting tools, 2...
Tool post (tool attachment part), 3...Tapered protruding shaft portion, 4...Engagement shaft portion, 5...Engagement circumferential flange, 11...Medium tapered fitting hole portion, 1
2...Hole mounting hole part, 13...Large diameter hole part, 14,1
4a... Clamping cylindrical body, 15... Driving rotating body, 50, 50a... Clamping means.

Claims (1)

[Claims for Utility Model Registration] 1. An attachment for attaching a tool, including a tapered protruding shaft portion and an engaging shaft portion that protrudes coaxially from the protruding shaft portion and has an engaging peripheral flange protruding from its tip. and a tool drive shaft that extends through the tapered protruding shaft portion and the engagement shaft portion, and a tool mounting portion on the machine tool side has a taper shaft into which the protruding shaft portion can fit. A shaped fitting hole is provided, a mounting hole is provided on the inner side of the fitting hole, and a large diameter hole is provided between the mounting hole and the fitting hole. The clamping cylindrical body, which has an end that fits externally on the engagement shaft part, is fitted so as to be able to move in and out only in the axial direction, and is operatively connected to the clamping cylindrical body through a screw mechanism. A driving rotating body is installed inside the cylinder for pulling the cylindrical body inward by rotation and pushing it outward by reversing the cylinder, and the end of the cylindrical body for clamping engages with the engaging periphery when the cylindrical body is drawn in. and a clamping means which prevents the attachment from coming off and which disengages from the engaging periphery when the cylindrical body is pushed out and displaces toward the large diameter hole to release the stopper. A tool clamping device comprising a tool drive main shaft which is provided with a clutch mechanism that penetrates through the tool drive shaft and can be freely connected to and detached from the tool drive shaft on the attachment side. 2. The clamping means includes a plurality of ball holding holes extending through the front end of the clamping cylindrical body at intervals in the circumferential direction, and the holding holes sink into the mounting hole when the clamping cylindrical body is pulled in. When the clamping cylindrical body is pushed out, the holding hole protrudes inwardly from the holding hole and engages with the engaging circumferential flange to prevent the attachment from coming off. A tool clamping device according to claim 1, which is a utility model, and comprises a clamp ball that projects outwardly to release the engagement with the engagement periphery. 3. The clamping means has an inner end screwed onto the driving rotor, and has a plurality of grooves extending in the axial direction, leaving the inner end, and is externally fitted onto the engagement shaft. Scope of Utility Model Registration Claim No. 1 comprising a split collet for a clamp having an inward engaging circumferential flange at its outer end that engages with the outward engaging flange from the outside to prevent the attachment from coming off. Tool clamping device as described in section.