JP2003094218A - Work press-down device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work press-down device which prevents problems that a work W1 is damaged by resided cutting chips near the machining section for the work W1, the hole position accuracy of the work W1 is spoiled, or the like. SOLUTION: The work press-down device is provided with an inner cylindrical section 30a having a through hole 30d through which a drill 25 mounted on the spindle 14 goes and an outer cylindrical section 30b located on the outside, and the inner cylindrical section 30a and the outer cylindrical section 30b are integrated as a work press-down bushing 30 through a bridge section 30c as a unit. The inner cylindrical section 30a is provided with link grooves 30f on the bottom circumferential edge, which communicates with a clearance between the inner/outer cylindrical sections 30a and 30b and the hole 30d. A mounting base 32 which constitutes a pressure body 35 is provided with a slot hole 47 open outward so that it communicates with the clearance between the inner/outer cylindrical sections 30a and 30b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work holding device used in a machine tool for punching a work such as a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, in this type of machine tool,
In order to prevent the work from slipping and floating during drilling, a work holding bush with a through hole is provided on the lower end surface of the pressure foot located below the spindle to allow the tool mounted on the spindle to pass through in the vertical direction. The configuration is, for example, Japanese Patent Laid-Open No. 1-306146, and Japanese Utility Model Laid-Open No. 4-112.
No. 725 and Japanese Utility Model Publication No. 4-29926.

FIG. 16 and FIG. 17 show an example of an automatic (NC control) machine tool equipped with a work holding device of this type. As shown in FIG. 16, the spindle device 91 arranged so as to be movable up and down above the table 98 for mounting the work W'is
A main shaft 92 rotatable by a main shaft motor (not shown) is provided, and a drill 93 as a drilling tool is attached to the lower end of the main shaft 92.

A pressure foot 94 having a hollow portion is disposed below the main spindle device 91 so as to be able to move up and down via rods 95, 95 of actuators provided on both left and right sides of the main spindle device 91. At the other end of the flexible hose 96 connected to the side surface of the pressure foot 94,
A pump (not shown) as a dust collecting device for forcibly sucking and removing chips is connected and connected.

On the lower surface of the pressure foot 94, a shaft hole 94a through which the drill 93 can pass in the vertical direction is bored, and a bushing 97 made of synthetic resin for holding the work is fixed by screws 99, 99. The bush 97 is formed with a through-hole 97a having an upper and lower opening that communicates with the shaft hole 94a on the lower surface of the pressure foot 94. Around the through hole 97a on the lower surface of the bush 97, a plurality of ventilation grooves 97 communicating with the through hole 97a and opening outward.
b (four in FIG. 17) are formed radially in a bottom view.

Drilling by the machine tool of this example is carried out as follows, for example. The operation of each component is controlled by a known NC control device according to a predetermined program.

That is, when the spindle device 91 and the pressure foot 94 are lowered toward the work W'on the table 98, the work W'is pressed by the lower surface of the bush 97. Then, the tip of the rotating drill 93 passes through the through hole 97a of the bush 97 and comes into contact with the work W ',
A processed hole is formed at a predetermined position of the work W '.

In this case, by operating a pump (not shown) as a dust collector to forcibly suck the air in the pressure foot 94, the outside air flows in from each ventilation groove 97b of the bush 97. However, it flows into the pressure foot 94 through the through hole 97a.
Due to the pressure of the air, chips generated during the drilling process are suctioned and removed from the periphery of the drill 93.

[0009]

However, in the above-mentioned conventional structure, the chips generated from the previously drilled holes remain on the workpiece W'where a large number of holes are formed and cannot be completely collected. If this happens, when the bush 97 is pressed against the next processing location located in the vicinity of the above-described processing hole, chips will be caught between the work W ′ and the lower surface of the bush 97. If the surface is scratched with cutting chips, or if there is cutting chips on the next processed portion, the tip of the drill 93 slips with cutting chips and the hole position accuracy of the work W ′ deteriorates.

Therefore, it is a technical object of the present invention to provide a work holding device which solves the above problems.

[0011]

In order to solve this technical problem, a work pressing device according to a first aspect of the present invention has an inner cylinder portion having a through hole through which a tool mounted on a main shaft is inserted, and an outer side thereof. The outer cylinder part located at, is a work pressing device provided with a work pressing bush integrally connected continuously via a bridge part, in the peripheral edge of the inner cylinder part abutting the work, A communication groove that connects the gap between the inner and outer tubular portions and the through hole is formed, and an intake portion that opens outward is formed in the pressure body to which the bush is attached or the outer tubular portion of the bush, and the inner and outer tubular portions. It is formed so as to communicate with the gap between them.

According to a second aspect of the invention, in the work holding device according to the first aspect, a plurality of the communication grooves are provided radially when viewed from the axial direction of the main shaft.

Further, according to the invention of claim 3, in the work pressing device according to claim 1 or 2, an air supply source such as a blower is connected in communication with the outward opening end of the intake portion. .

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. 1 to 9 show a first embodiment in which the present invention is applied to a work holding device provided in a machine tool (printed board punching machine). In the machine tool 1 of the first embodiment, four adjuster bolts 3 are attached to the lower end of the base 2 made of cast iron or the like so that the machine tool 1 is horizontal when installed (see FIG. 1).

A gate-shaped column 4 which is long in the left-right direction (the X-axis direction in FIGS. 1 and 2) is erected on the rear side of the upper surface of the base 2, while the front side of the column 4 has a left-right longitudinal direction. Thus, a pair of upper and lower X-axis guide rails 7, 7 are arranged. For both X-axis guide rails 7, 7, the spindle block 6
A head 5 provided with a ball screw shaft 8 arranged on the front surface of the column 4 and an X-axis motor 9 driving the ball screw shaft 8 are arranged so as to be movable left and right.

The spindle block 6 is a Z-axis motor 11 and a ball screw shaft 12 attached to the head 5,
It is configured to be vertically movable along a Z-axis guide rail 10 which is attached to the front surface of and is long in the vertical direction (Z-axis direction in FIG. 1).

A spindle motor 13 provided at the upper end of the spindle block 6 rotates a spindle 14 (see a chain double-dashed line in FIG. 3) to make a drill 25 (a tool attached to the lower end of the spindle 14). 3, FIG. 6, FIG. 7 and FIG. 9) is adapted to perform drilling such as cutting.

As shown in FIGS. 1 and 2, a pair of left and right Ys that are long in the front-rear direction (Y-axis direction in FIG. 2) are provided on the upper surface of the base 2.
Axial guide rails 17, 17 are arranged, and a table 16 for attaching and fixing a work W1 (see FIGS. 6 and 9) such as a printed circuit board to these Y-axis guide rails 17, 17 is provided. Both Y-axis guide rails 17,
A ball screw shaft 18 arranged in parallel with 17 and a Y-axis motor 19 arranged at the rear of the base 2 are arranged so as to be movable back and forth.

An image pickup means 20, such as a CCD camera, is attached to the head 5 through a mount 21 with the optical axis parallel to the Z-axis direction (see FIG. 1).
The position deviation of the work W1 can be corrected by imaging and recognizing the image recognition mark formed on the surface of the work W1 on the table 16.

Although not shown in detail, the table 16
A large number of open air passage grooves are formed on the upper surface of the plate 26, and the plate 26 (FIGS. 6 and 9) mounted on the upper surface is formed.
A large number of small-diameter through holes (not shown) penetrating vertically are formed in the four corners of the reference (see).

In this case, the plate 26 is superposed on the upper surface of the table 16, the work W1 is placed thereon, and the air is sucked through the suction hose and the pump which are connected to the air passage groove of the table 16 in communication. , When drilling,
The work W1 is prevented from coming off the table 16 or being displaced.

A left and right longitudinal mounting table 28 on which a plurality of tool magazines 27 are removably mounted is provided so as to project forward from the front edge of the table 16 (see FIG. 2) and moves back and forth integrally with the table 16. Is configured to. In each tool magazine 27, a plurality of drills having different diameters or the same diameter are erected so that the tips of the drills can face down and can be inserted and removed.

A work holding bush (which will be described in detail later) consisting of a bush body 30 and a holder body 31 is pulled out from a mounting base body 32, which will be described later, and temporarily placed and stored on the mounting table 28. The holder base 29 is disposed on the side of the tool magazine 27 or the like (see FIGS. 1 to 3).
reference).

As shown in FIGS. 1 and 2, the tool changer 22 installed upright on the upper surface of the base 2 outside the range of movement of the table 16 has a horizontal plane of 180 when driven by an actuator (not shown). It is composed of a reversing table 23 that is configured to rotate at every angle, and two cylindrical tool posts 24, 24, etc., which are vertically movable on support blocks provided on both ends of the upper surface of the reversing table 23, respectively. The old drill 25 and the new drill 25 to be replaced are inserted into the respective tool posts 24 with their tips facing downward.

In this case, the distance from the vertical axis of each tool post 24 to the rotation axis of the reversing table 23 is set to be equal, while the axis of the spindle 14 and the tool pickup device 33 arranged on the spindle block 6 are moved up and down. The distance from the axis of the shaft is set to be equal to the distance between the tool posts 24, 24.

When exchanging tools, first, the shank portion of the new drill 25 is grasped and lifted from the tool magazine 27 by the tool pickup device 33, and the new drill 25 is positioned on one tool post 24 of the tool exchanging device 22. As described above, the head 5 is moved in the lateral direction (X-Y direction).

Then, the used drill 25 mounted on the lower end of the main spindle 14 is positioned on the other tool post 24, so that the main spindle block 6 is lowered to release the grip between the old and new drills 25, 25. Accordingly, the corresponding drill 25 is inserted into and supported by each tool post 24.

Next, after raising the spindle block 6, the reversing table 23 is rotated by 180 °, whereby each drill 2 for the spindle 14 and the tool pickup device 33 is rotated.
Swap the positions of 5.

Then, the spindle block 6 is lowered, and the shank portion of the new drill 25 is gripped by a plurality of collets (not shown) incorporated in the spindle 14, while the tool pick-up device 33 shank the drill 25 after use. Grab the part and lift it. After that, the head 5 is moved to the tool magazine 27.
The drill 25 is horizontally moved upward and the used drill 25 is stored in the tool magazine 27.

Next, the structure of the work holding device according to the present invention will be described. As shown in FIGS. 3 to 5, metal pressure bodies (pressure feet) 35 are provided below the spindle block 6 on rods 34 a, 34 a of air cylinders 34, 34 arranged on both left and right sides of the spindle block 6. Further, it is arranged so as to be vertically movable via guide shafts 34b, 34b connected thereto.

The pressure body 35 includes a dust collecting case 36 having a hollow portion 36a, and a mounting base body 32 having a substantially rectangular shape in plan view, which is fixed to the lower end surface of the dust collecting case 36 with a screw 38.
(See FIG. 4). The hollow shaft 36a of the dust collection case 36 allows the main shaft 14 and the drill 25 to move up and down, and the other end of the flexible hose 41 (see FIGS. 3 and 5) connected to the side surface of the dust collection case 36 in communication therewith. A pump (not shown) as a dust collector that compulsorily sucks and removes the cutting chips is connected and connected to the.

On the lower surface side of the mounting base body 32, a mounting groove portion 40 for detachably fitting the holder body 31 made of metal and having a substantially rectangular shape in plan view is formed so as to be opened downward. The mounting groove 40 is formed in the long side direction of the mounting base body 32 (the arrangement direction of the air cylinders 34, 34).
Is formed long along the line (see FIG. 5).

On the other hand, on the upper surface side of the mounting base body 32,
A shaft hole 39 through which the drill 25 can pass in the vertical direction is provided so as to communicate with the hollow portion 36a of the dust collection case 36 and the mounting groove portion 40 on the lower surface side of the mounting base body 32 (see FIGS. 3 and 6). ).

Further, as shown in FIGS. 5 to 9, on the front surface side of the mounting base body 32, there is formed an elongated hole 47 as an air intake portion that opens outward, and a mounting groove portion on the lower surface side of the mounting base body 32. It is provided so as to communicate with 40.

Further, a pair of vertically long mounting holes 44, 44 are formed in the mounting groove portion 40, and although not shown in detail, steel balls and a pressing spring are provided in the upper and lower middle portions of these mounting holes 44. A ball joint consisting of and is provided.

In this case, the pair of mounting shafts 45, 45 (see FIG. 3) protruding from the upper surface of the holder body 31 are inserted into the corresponding mounting holes 44, whereby the mounting base body 32 is mounted.
The mounting position and the posture of the holder body 31 with respect to can be accurately set, and the steel ball is pressed against the small diameter portion in the middle of the longitudinal direction of each mounting shaft 45, so that the holder body 31 moves to the lower surface side of the mounting base body 32. It is designed so as not to be accidentally dropped from the mounting groove 40.

The length of the holder body 31 in the long side direction is
It is formed to be longer than the length of the mounting base body 32 in the long side direction, and is set so that both ends of the holder body 31 fitted in the mounting groove portion 40 project from both end edges of the mounting base body 32 by an appropriate size. (See Figure 5).

In the substantially central portion of the holder body 31 in the long side direction,
A mounting groove 46 for detachably fitting a bush body 30, which will be described later, is formed so as to open downward. The mounting groove 46 extends in a direction intersecting the mounting groove portion 40 (orthogonal direction in the first embodiment), and the holder body 31.
Is open in the short side direction.

Further, a cylindrical portion 31a formed integrally with the upper surface of the holder body 31 is constructed so that the outer periphery of the upper portion of the bush body 30 to be described later fits. The cylindrical portion 31a
An annular groove 31b that opens downward is formed on the lower surface of the holder (see FIGS. 6 and 8). When the holder body 31 is fitted into the mounting groove portion 40, a communication hole formed in the outer peripheral portion of the cylindrical portion 31a. The annular groove 31b is configured to communicate with the elongated hole 47 on the front side of the mounting base body 32 via 31c.

The work holding bush according to the present invention comprises the above-mentioned holder body 31, polyethylene, nylon resin,
Bush body made of synthetic resin such as epoxy resin (pressing cylinder)
It is composed of 30 and.

The bush body 30 has an inner cylindrical portion 30a having a through hole 30d through which the tip side of the drill 25 can pass vertically.
And a tubular outer tubular portion 30b surrounding a lower portion of the outer peripheral surface of the inner tubular portion 30a.
It has a structure in which the bridge portions 30c (four in the first embodiment) that are appropriately spaced along the annular gap between the 30b are integrally connected. In other words, the bush body 30 is formed in a double cylinder shape. The outer shape of the outer tubular portion 30b is formed in a non-circular shape by cutting out portions of the outer periphery of the substantially circular shape in plan view which face each other in a substantially parallel shape (FIGS.
reference).

As shown in FIGS. 5 and 7, the inner and outer tubular portions 30
The annular gap between a and 30b is a plurality of vertically long bridge portions 30c (four in the first embodiment), and the same number of spaces as the bridge portions 30c (hereinafter, vertical holes 30e).
It is divided into). Therefore, each of the vertical holes 30e penetrates in the vertical direction. Then, when the bush body 30 is fitted into the mounting groove 46 of the holder body 31, each vertical hole 30e is configured to communicate with the annular groove 31b on the lower surface side of the cylindrical portion 31a (FIGS. 6 and 9).
reference).

Further, the lower surface of each bridge portion 30c is set so as to be flush with the circumferential edges of the lower surfaces of the inner and outer tubular portions 30a and 30b, and the lower surfaces of the inner and outer tubular portions 30a and 30b and the respective bridge portions. The lower surface of 30c presses the surface (upper surface) of the work W1.

Around the through hole 30d on the lower surface of the inner tubular portion 30a of the bush body 30, communication grooves 30f (four in the first embodiment) for communicating the through hole 30d with each vertical hole 30e are viewed from the bottom. Is radially formed, in other words, is formed radially when viewed from the axial direction of the main shaft 14 (up-down direction, see the alternate long and short dash line in FIG. 6).

As shown in FIG. 6, the O-ring 50 is provided at the upper portion of the outer peripheral surface of the inner cylindrical portion 30a of the bush body 30.
It is in close contact with the inner peripheral surface of the cylindrical portion 31a of the holder body 31 via the.
Is designed so as not to be accidentally dropped from the holder body 31. The presence of the O-ring 50 prevents the air inside the pressure body 35 from leaking to the lower surface side of the mounting base body 32 (the side facing the work W1).

The lower surface of the bush body 30 attached to the holder body 31 projects slightly downward from the lower surface of the holder body 31, and when the drill 25 is used for drilling, the bush body 3
Only the lower surface of 0 contacts the surface of the work W1, and the metal holder body 31 does not damage the work W1.

At both ends of the dust collecting case 36 in the longitudinal direction, a height position regulating rail (not shown) of the holder base 29 is provided.
Rotating roller-shaped abutting portions 52, 52 which are slidably contacted with are attached (see FIGS. 3 and 4).

In the above configuration, the drilling by the machine tool 1 is executed as follows, for example. First,
The spindle block 6 and the pressure body 35 are connected to the bush body 3
The lower surface of 0 is lowered until it comes close to the position directly above the surface of the work W1 (see FIG. 9).

Here, a pump (not shown) as a dust collector is operated to forcibly suck the air in the hollow portion 36a of the dust collection case 36, so that the lower surface of the bush body 30 and the work W1. External air flows in from the gap between the front surface of the mounting base body 32 and the long hole 4 on the front side of the mounting base body 32.
7, air from the outside also passes through the communication hole 31c of the holder body 31 and the annular groove 31b and each vertical hole 30e of the bush body 30.
To the through hole 30d of the inner cylinder portion 30a (arrow A direction, see FIG. 9).

By the pressure of this air, the chips remaining in the vicinity of the processing portion of the work W1 are blown up in the direction of the arrow A, and the shaft hole 39 of the mounting base 32 and the hollow portion in the dust collection case 36. It is sucked and removed by a pump through 36a and the flexible hose 41, and is removed from the vicinity of the processing site of the work W1 and the like.

Next, the spindle block 6 and the pressure body 35 are further lowered to remove the chips from the work W.
The surface of No. 1 is pressed down by the lower surface of the bush body 30 (Fig. 6).
reference). Then, the tip of the rotating drill 25 is the inner cylinder portion 3
After passing through the through hole 30d of 0a and coming into contact with the work W1, a processing hole is formed at the processing location.

A pump (not shown) as a dust collector is
The air in the hollow portion 36a of the dust collection case 36 is forcibly sucked in during the drilling process. At this stage, the air that has flowed in from the long hole 47 on the front side of the mounting base body 32 flows from each vertical hole 30e of the bush body 30 toward the through hole 30d through the communication hole 31c of the holder body 31 and the annular groove 31b. However, a flow of air is formed in the direction of arrow B (see FIG. 6).

Due to the pressure of the air, chips around the drill 25 (chips generated during drilling) are blown up in the direction of arrow B, and the shaft hole 39 of the mounting base 32 and the hollow inside the dust collection case 36 are blown. Portion 36a and flexible hose 4
It is removed by suction from the periphery of the drill 25 by the pump via 1 through the pump.

From the above, according to the work pressing device of the first embodiment, not only the chips generated during the drilling process can be removed by suction, but the lower surface of the bush 30 can be attached to the work W1.
Before being pressed against the surface of the workpiece W1, since the chips remaining in the vicinity of the processed portion of the work W1 can be removed by suction in advance, the chips may be sandwiched between the lower surface of the bush body 30 and the surface of the work W1. Absent. Therefore, it is possible to surely avoid the problem caused by the residual cutting chips on the work W1, that is, the problem that the work W1 is damaged by the cutting chips and the hole position accuracy of the work W1 is deteriorated.

Further, in the first embodiment, since the communication grooves 30f are radially arranged on the lower surface of the inner cylindrical portion 30a in a bottom view, air can be blown evenly around the drill 25, so that at the time of drilling. The suction removal effect of chips can be further improved.

In the second embodiment shown in FIG. 10, the air supply port 4 communicating with the elongated hole 47 is provided on the front surface of the mounting base body 32.
An air supply source (not shown) such as a blower is communicatively connected to the air supply port 48 via a flexible hose 49. The air supply port 48 corresponds to the outward opening end of the air intake portion described in the claims. Since other configurations are the same as those in the first embodiment, the same reference numerals as those in the first embodiment are attached and detailed description thereof is omitted.

In the configuration of the second embodiment, the bush body 30
Before pressing the bottom surface of the workpiece W1 against the surface of the workpiece W1, when suction and removal of the chips remaining near the processing location of the workpiece W1 in advance are performed, an air supply source (not shown) and a pump as a dust collector If both (not shown) are activated,
The air forcibly supplied from the air supply source (not shown) is attached to the mounting base body 3 via the flexible hose 49.
2 from the front long hole 47 to the communication hole 31c of the holder body 31
And each vertical hole 30c of the bush body 30 through the annular groove 31b.
(See the arrow C direction shown in FIG. 10).
One of the pumps forcibly sucks the air in the hollow portion 36a of the dust collection case 36, and as a result, the inner tubular portion 30
The flow of air toward the through hole 30d of a becomes strong. In other words, the pressure of this air can be increased. As a result, the chips remaining in the vicinity of the processed portion of the work W1 are efficiently sucked and removed by the pump, and the work W1 is removed.
It can be reliably removed from the vicinity of the processing location.

Similarly, during the drilling process, an air supply source (not shown) and a pump (not shown) as a dust collector.
By operating both of them, the flow of air toward the through hole 30d of the inner cylindrical portion 30a can be strengthened.
The chips around 5 (chips generated during drilling) can be removed efficiently from the periphery of the drill 25 by efficiently sucking and removing them with a pump.

From the above, according to the work pressing device of the second embodiment, it is possible to further improve the suction and removal effect of chips before and during drilling.

11 to 13 show a third embodiment showing another example of the mounting pattern of the pressure body and the work holding bush (pressing cylinder). As shown in FIG. 11, a spindle device 61, which is vertically movable above a table 69 for mounting the work W2, includes a spindle 62 rotatable by a spindle motor (not shown). A drill 63 as a drilling tool is attached to the lower end of the.

A pressure body 64 (pressure foot) having a hollow portion 64a is arranged below the main spindle device 61 so as to be able to move up and down via rods 65, 65 of actuators provided on both left and right sides of the main spindle device 61. Has been done.

The main shaft 62 and the drill 63 can be moved up and down in the hollow portion 64a of the pressure body 64, and chips are forced to the other end of the flexible hose 66 connected to the side surface of the pressure body 64. A pump (not shown) as a dust collecting device for electrically sucking and removing is connected and connected.

A cylindrical portion 64b connected to the lower surface of the pressure body 64 is provided with a shaft hole 64c for allowing the drill 63 to pass in the vertical direction, and a lower surface of the cylindrical portion 64b has a bush to be described later. A mounting hole 64d for detachably fitting the 67 is formed so as to open downward.

The cylindrical portion 64b has a shaft hole 64c.
An annular groove 64e surrounding the outer peripheral side is formed so as to open downward. Therefore, the annular groove 64e
Communicates with a mounting hole 64d on the lower surface side of the cylindrical portion 64b. An intake hole 64f serving as an intake portion that opens outward is formed in an upper portion of the outer peripheral surface of the cylindrical portion 64b so as to communicate with the annular groove 64e in the cylindrical portion 64b (FIG. 13). reference).

The work holding bush 67 detachably fitted in the mounting hole 64d of the cylindrical portion 64b is made of synthetic resin such as polyethylene, nylon resin, epoxy resin, or the like.
Through hole 67 through which the tip side of the drill 63 can pass vertically
The inner tubular portion 67a with d and the tubular outer tubular portion 67b surrounding the outer circumference of the inner tubular portion 67a are provided in the inner and outer tubular portions 67.
It has a structure in which the bridge portions 67c (four in the third embodiment) that are appropriately spaced along the annular gap between a and 67b are integrally connected. That is, the bush 67 is formed in a double cylinder shape.

As shown in FIG. 12, the inner and outer cylindrical portions 67a, 6a
The annular gap between 7b is a plurality of vertically long and short bridge portions 67c (four in the third embodiment).
It is partitioned into the same number of spaces as the number of 7c (hereinafter referred to as vertical holes 67e). Therefore, each of these vertical holes 67
e penetrates up and down. Bush 67 to cylindrical portion 6
When fitted in the mounting holes 64d of 4b, the respective vertical holes 67e
Are configured to respectively communicate with the annular groove 64e in the cylindrical portion 64b (see FIG. 11).

Further, the lower surface of each bridge portion 67c is set so as to be flush with the circumferential edges of the lower surfaces of the inner and outer tubular portions 67a and 67b, and the lower surfaces of the inner and outer tubular portions 67a and 67b and the respective bridge portions. The lower surface of 67c presses the surface (upper surface) of the work W2. A communication groove 67 for communicating the through hole 67d with each vertical hole 67e is provided around the through hole 67d on the lower surface of the inner tubular portion 67a of the bush 67.
f (four in the third embodiment) are formed radially in a bottom view.

As shown in FIG. 11, the outer peripheral surface of the outer cylindrical portion 67 b of the bush 67 is provided with a cylindrical portion 64 via an O-ring 68.
The bush 67 is closely attached to the inner peripheral surface of the mounting hole 64d of b, and the elasticity of the O-ring 68 prevents the bush 67 from being accidentally dropped from the mounting hole 64d. The presence of the O-ring 68 prevents the air inside the pressure body 64 from leaking to the lower surface side of the pressure body 64 (the side facing the work W2).

The lower surface of the bush 67 mounted in the mounting hole 64d of the cylindrical portion 64b projects slightly downward from the lower surface of the cylindrical portion 64b, and when drilling with the drill 63, only the lower surface of the bush 67 is the work W2. It is configured so that the workpiece W2 is not damaged by the cylindrical portion of the metal pressure body that comes into contact with the surface of the workpiece W2.

Also in the case of the above configuration, by operating the pump to forcibly suck the air in the hollow portion 64a of the dust collection case 64, the gap between the lower surface of the bush 67 and the surface of the work W2 and From the intake hole 64f of the cylindrical portion 64b of the pressure body 64 to each vertical hole 67 of the bush 67.
e and the communication groove 67f of the inner tubular portion 67a and the like, and then the through hole 67
An air flow in the direction of arrow D (see FIG. 11) toward d can be formed.

Therefore, similar to the first embodiment, not only the chips generated at the time of drilling can be removed by suction, but also before the lower surface of the bush 67 is pressed against the surface of the work W2, the vicinity of the processed portion of the work W2 is previously set. It is possible to reliably remove the chips remaining in the workpieces, and it is possible to reliably avoid problems such as the work W2 being damaged by the chips and the hole position accuracy of the work W2 being deteriorated.

14 and 15 show a fourth embodiment in which the present invention is applied to a fixed work pressing bush (pressing cylinder) 67 '. Here, components having the same configurations and operations as those in the third embodiment are designated by the same reference numerals as those in the third embodiment, and detailed description thereof will be omitted.

A main shaft 62 and a drill 63 can be moved up and down in a hollow portion 64a 'of a pressure body 64' provided on the lower part of the main shaft device 61 so as to be movable up and down. A screw cylinder portion 64b 'continuously provided on the lower surface of the pressure body 64'.
Has a shaft hole 6 for passing the drill 63 in the vertical direction.
4c 'is bored, and two threads are formed on the outer peripheral surface of the screw cylinder portion 64b'.

The work holding bush 67 'in the fourth embodiment is made of synthetic resin such as polyethylene, nylon resin or epoxy resin, and has an inner cylinder with a through hole 67d' through which the tip side of the drill 63 can pass vertically. Part 67a '
And a tubular outer tubular portion 67b 'surrounding the outer periphery of the inner tubular portion 67a' via an annular bridge portion 67c 'vertically blocking the annular gap between the inner and outer tubular portions 67a', 67b '. It has a structure that is integrally connected.

The upper end surface of the inner cylindrical portion 67a 'is flush with the upper surface of the annular bridge portion 67c', and the bush 6
The upper surface side of 7'is a screw-in portion 67e 'opened upward. Two threads are formed on the inner peripheral surface of the threaded portion 67e '. As a result, the bush 6
7'is screwed into the screw cylinder portion 64b 'of the pressure body 64'. The inner peripheral surface of the threaded portion 67e 'of the bush 67' and the threaded cylindrical portion 64 of the pressure body 64 '.
Form a thread on either the outer peripheral surface of b ',
A thread groove may be formed on the other side.

At the lower portion of the outer peripheral surface of the outer cylindrical portion 67b 'of the bush 67', an intake hole 67g 'as an intake portion that opens outward is formed in an annular shape between the inner and outer cylindrical portions 67a', 67b '. An appropriate number of holes (four in the fourth embodiment) are provided so as to communicate with a clearance below the annular bridge portion 67c '(hereinafter referred to as an annular clearance 67f').

Around the through hole 67d 'on the lower surface of the inner cylindrical portion 67a' of the bush 67 ', a communicating groove 67h' (fourth hole) for communicating the through hole 67d 'with the annular gap 67f' is provided.
In the embodiment, four are radially formed in bottom view.

Also in the case of the above configuration, the pump is operated to forcibly suck the air in the hollow portion 64a 'of the dust collecting case 64', so that the lower surface of the bush 67 'and the surface of the work W2 are separated from each other. Gap and the air intake hole 6 of the bush 67 '
It is possible to form an air flow in the direction of arrow E (see FIG. 14) from 7g ′ to the through hole 67d ′ through the annular gap 67f ′, the communication groove 67h ′ of the inner cylindrical portion 67a, and the like.

Therefore, similarly to the first and third embodiments, not only the chips generated at the time of drilling can be removed by suction, but also before the lower surface of the bush 67 'is pressed against the surface of the work W2, The chips remaining in the vicinity of the processing location can be removed by suction, and problems such as the work W2 being damaged by the chips and the hole position accuracy of the work W2 deteriorating can be reliably avoided.

The present invention is not limited to the above-described embodiment, but can be embodied in various aspects. For example, the pressure body (pressure foot) is not limited to be configured to be vertically movable by itself as in each of the above-described embodiments, but may be integrally or separately provided at the lower end of the spindle device (spindle block). It may be configured to vertically move integrally with the spindle device (spindle block).

[0081]

EFFECTS OF THE INVENTION Drilling in a machine tool provided with the work pressing device according to the first aspect of the invention is performed as follows, for example.

First, with the lower surface of the bush close to the position directly above the surface of the work, for example, a dust collector provided in the work holding device is operated to forcibly suck air in the work holding device. Thereby, a flow of air is formed in the bush through the gap between the lower surface of the bush and the surface of the work and the gap between the intake portion and the inner and outer cylindrical portions of the bush toward the through hole of the inner cylindrical portion. can do.

As a result, the chips remaining in the vicinity of the processed portion of the work are lifted up by the pressure of the air and sucked and removed by the dust collector, and the chips are removed from the vicinity of the processed portion of the work. Can be removed.

Next, the surface of the work from which the chips have been removed is pressed down by the lower surface of the bush, and the boring process is performed on the work. In this case as well, by operating the dust collector, the flow of air from the air intake portion toward the through hole via the gap between the inner and outer tubular portions of the bush and the communication grooves of the inner tubular portion, Since it can be formed in the bush, chips around the tool (chips generated during drilling) are raised by the pressure of the air and sucked and removed by the dust collector, Can be removed.

Therefore, according to the work pressing device of the first aspect of the present invention, not only can the chips generated during the drilling process be sucked and removed, but the work can be processed in advance before the lower surface of the bush is pressed against the surface of the work. Since the chips remaining in the vicinity of the location can be removed by suction, the chips are not sandwiched between the lower surface of the bush and the surface of the work. Therefore, there is an effect that it is possible to reliably avoid problems such as the work being damaged by cutting chips and the hole position accuracy of the work being deteriorated.

According to a second aspect of the present invention, the communication groove is radially arranged on the lower surface of the inner cylindrical portion of the bush when viewed from the axial direction of the main shaft, so that the space between the intake portion and the inner and outer cylindrical portions of the bush is increased. Since the air that has flowed into the gap can be blown evenly around the tool,
This has the effect of further improving the suction and removal effect of chips during the drilling process.

According to the third aspect of the present invention, by operating both the air supply source and the dust collector, the flow of air from the intake section to the through hole of the inner cylinder section can be strengthened. That is, since it is possible to increase the pressure of the air, it is possible to reliably lift up the chips remaining in the vicinity of the machining location of the workpiece, etc., or the chips produced during the drilling process. The effect that the suction removal effect of the chips before and during processing can be further improved is achieved.

[Brief description of drawings]

FIG. 1 is a front view of a machine tool according to a first embodiment.

FIG. 2 is a plan view of a machine tool.

FIG. 3 is a partially cutaway front view of the work holding device.

FIG. 4 is an enlarged side view of the IV-IV partly cutaway view of FIG. 3.

FIG. 5 is a perspective view of the work holding device as viewed from below.

6 is an enlarged sectional view taken along line VI-VI of FIG.

FIG. 7 is a bottom view of the bush body.

8 is a vertical cross-sectional view taken along the line VIII-VIII of FIG.

FIG. 9 is a vertical cross-sectional view showing a state in which the lower surface of the bush body is brought close to a position directly above the surface of the work.

FIG. 10 is a vertical sectional view of a work holding device according to a second embodiment.

FIG. 11 is a vertical sectional view of a work holding device according to a third embodiment.

FIG. 12 is a bottom view of the work holding device.

13 is a plan sectional view taken along the line XIII-XIII in FIG.

FIG. 14 is a vertical sectional view of a work holding device according to a fourth embodiment.

FIG. 15 is a bottom view of a bush for pressing a work.

FIG. 16 is a vertical cross-sectional view of a work holding device according to the related art.

FIG. 17 is a bottom view of the bush for pressing the work.

[Explanation of symbols]

1 machine tool 2 bases 5 heads 6 spindle block 14 spindle 22 Tool changer 30 Bush body 30a inner cylinder part 30b Outer cylinder part 30c bridge section 30d through hole 30e Vertical hole 30f communication groove 31 Holder body 31a cylindrical part 31b annular groove 31c communication hole 32 Mounting base body 35 Pressure body 36 Dust collection case 41 Flexible hose 47 Long hole as air intake

Claims (3)

[Claims] 1. A work presser comprising an inner cylinder part having a through hole through which a tool mounted on a main shaft is inserted, and an outer cylinder part located outside the inner cylinder part integrally connected to each other via a bridge part. A work holding device including a bush, wherein a peripheral portion of the inner tubular portion that abuts the work is formed with a communication groove that communicates the gap between the inner and outer tubular portions with the through hole, and the bush is attached to the work holding device. A work holding device, wherein an intake portion that opens outward is formed in an outer cylinder portion of the pressure body or the bush so as to communicate with a gap between the inner and outer cylinder portions. 2. The work pressing device according to claim 1, wherein a plurality of the communication grooves are radially provided when viewed from the axial direction of the main shaft. 3. The work holding device according to claim 1, wherein an air supply source such as a blower is connected to the outward opening end of the air intake portion.