An embodiment of the present invention will be described with reference to
The press machine is a punch press that uses a punch 61 and a die 62 to perform a press working on a plate-like workpiece W such as a sheet metal. The press machine comprises a press frame 41, a punch linear motor 1 provided in an upper frame 41b of the press frame 41 to elevate and lower the punch 61, and a die linear motor 1A provided in a lower frame 41c to elevate and lower the die 62.
The press frame 41 comprises the upper frame 41b, the lower frame 41c and a column portion 41a to which the upper frame 41b and the lower frame 41c are coupled, and the press frame 41 is open in a front surface and has a C-shaped side surface. A vertical pair of tool supports 42, 43 and a workpiece feeding mechanism 44 are installed between the upper frame 41b and the lower frame 41c. A press mechanism 45 using the punch linear motor 1 as a driving source is installed in the upper frame 41b. The press frame 41 may be a gate-, ring-, or hollow-rectangle-like frame in which the upper and lower frame portions with an equivalent length are coupled together at a front end and a rear end by the column portion.
The tool supports 42, 43 comprise an upper turret and a lower turret which are concentrically installed and each of which has punches 61 and dies 62 mounted at a plurality of points in a circumferential direction thereof. Rotation of the tool supports 42, 43 allows each of the punches 61 and the dies 62 to be indexed to a predetermined punch position P.
In
The press mechanism 45 supports a ram 49 that elevates and lowers the punch 61 indexed to the punch portion P in the tool support 42 so that the ram 49 can be freely elevated and lowered by a ram guide 50. The ram 49 is drivingly elevated and lowered by an output shaft 12 of the linear motor 1.
As shown in
Each of the unit linear motors 2 comprises a shaft member 3 composed of a permanent magnet having alternately arranged N pole and S pole, and a coil unit 4 through which the shaft member 3 is movable in an axial direction relative to the coil unit 4. The coil unit 4 is composed of a plurality of coils 5 arranged in a cylindrical coil case 7 in the axial direction and surrounding the shaft member 3. The coil unit 4 constitutes a stator, and the shaft member 3 constitutes the output shaft of the motor 2, which constitutes a moving member of the unit linear motor 2. The shaft member 3 is composed of one round bar-like member but may be composed of a plurality of permanent magnets arranged in the axial direction.
The motor case 25 has an inner cylinder 26 and an outer cylinder 27 arranged concentrically with each other, and end plates 28, 29 that couple the opposite ends of the inner cylinder 26 and the outer cylinder 27 together. The unit linear motors 2 are arranged in the annular space between the inner cylinder 26 and the outer cylinder 27 in the circumferential direction. The opposite ends plates 28, 29 have a plurality of shaft member insertion holes 28a, 29a through which the shaft member 3 of each unit linear motor 2 is inserted, and the end plate 28 has a guide shaft insertion hole 28b in its center.
The shaft members 3 of the unit linear motors 2 are coupled together at their opposite ends by coupling members 10, 11, and the plurality of shaft members 3 and the coupling members 10, 11 constitute a moving member 30. The coupling member 11 of the moving member 30 has the output shaft 12 located in the center 0 of the arrangement of the unit linear motors 2.
A guide mechanism 32 is provided between the motor case 25 and the moving member 30 to guide movement of the shaft members 3 of the plurality of unit linear motors 2. The guide mechanism 32 is composed of an inner cylinder 26 of the motor case 25, a bush 15 that is a guide portion fixedly fitted into the inner cylinder 26, and a guide shaft 13, as a guided portion, provided at the center of one end side of the coupling member 10 and fitted into a bush 15 so as to be movable in the axial direction. The bush 15 constitutes a sliding shaft. Instead of the bush 15, a direct-acting roll bearing may be interposed.
The guide mechanism 32 has a rotation inhibiting means 16 for inhibiting rotation of the moving member 30 relative to the motor case 25. The rotation inhibiting means 16 comprises a key groove 17 formed in the guide shaft 13 along the axial direction and a key portion 18 fixed to the inner cylinder 26 of the motor case 25 and slidably engaged with the key 17.
The coupling member 11 on an output side of the die linear motor 1A has an output shaft 12A comprising a hollow shaft and internally constituting a slag discharge hole, the output shaft 12A projecting upward. The remaining part of the configuration of the die linear motor 1A is similar to that of the punch linear motor 1, described with reference to
The punches 61 installed on the upper tool support 42 and the dies 62 installed on the lower tool support 43 in
The shape-forming punch 612 is recessed and has a recessed portion 65 on its bottom surface. The shape forming die 622 is projecting and has a projecting portion 66 at the top. The shape forming die 622 is installed so as to be able to elevate from and lower to the die holder 63, installed on the lower tool support 43. In a lowered condition, the shape forming die 622 is located below a die height DH. The shape forming die 622 is pushed up above the die height DH by the output shaft 12A of the die linear motor 1A.
The shape forming die 622 has an output shaft engaging projection 67 provided on its bottom surface. During elevation, an upper end of the output shaft 12A of the die linear motor 1A is pressed against the bottom surface of the output shaft engaging projection 67. The shape forming die 622 is urged downward by a return spring (not shown in the drawings).
A hollow hole 69A is formed at the installation position of each die 62 of the lower tool support 43, comprising a turret; the output shaft 12A of the die linear motor 1A is advanced through the hollow hole 69A so as to be able to elevate and lower. A bolster 68 that receives the tool support 43 comprises a pair of bolster components, and the area between the bolster components constitutes a hollow space 69B through which the output shaft 12A of the die linear motor 1A is advanced so as to be able to elevate and lower.
In
A description will be given of the operation of the press machine configured as described above.
As shown in
Punch working such as normal hole making is performed by drivingly lowering the punch 61 of the upper tool support 42 by means of the punch linear motor 1 with the die linear motor 1A thus lowered. Slag resulting from hole making falls down from the machine through the slag discharge hole 70, formed in the center of the die linear motor 1A.
For shape forming, the upper tool support 42 and the lower tool support 43 are rotated to index the shape forming die 622 to the punch center P as shown in
Once shape forming is finished, the punch linear motor 1 is elevated, and the die linear motor 1A is lowered. Thus, the shape forming portion Wa formed by the punch working projects upward from the workpiece W and thus does not interfere with feeding of the workpiece W on the table 48 by means of the workpiece feeding mechanism 44.
The press machine configured as described above uses the linear motor 1 as a press driving source. Compared to press machines using rotary motors, this press machine thus does not need any mechanism that converts the rotation into the rectilinear motion of the ram 49, and this also reduces the number of parts required for the press mechanism 45 and simplifies its configuration. Further, compared to press machines using a hydraulic cylinder as a press driving source, this press machine eliminates the need for the hydraulic unit, simplifying the configuration. Furthermore, the linear motor 1 offers excellent positional accuracy, enabling high-quality, accurate machining.
The shape forming die 622 is also drivingly elevated and lowered by the linear motor 1A. Thus, compared to conventional press machines using a horizontal cylinder device and a cam, a link mechanism, or the like for elevating and lowering driving, this press machine has a simple configuration, offers excellent controllability, and enables the accurate control of the elevating and lowering strokes of the shape-forming die 622. Thus, both the punch 61 and the die 62 can be driven to enable various types of machining, and the linear motors 1, 1A are used to drive the punch 61 and the die 62, respectively. This simplifies the configuration and enables accurate machining.
Each of the punch linear motor 1 and the die linear motor 1A is the unit linear motor assembly including the plurality of unit linear motors 2 around the press drive axis center; each of the unit linear motors 2 has the output shaft that is parallel to the press drive axis center. This provides high power. Punch working may require a high thrust. However, the linear motors generally use permanent magnets with a strong magnetic force. Accordingly, it is difficult to manufacture motors each providing a high thrust owing to the manufacturing limit on the size of magnets, limitations on supply voltage, or the like. However, in the present embodiment, each of the linear motors 1, 1A includes the assembly of the plurality of unit linear motors 2, allowing the power of the individual unit linear motors 2 to be collectively utilized, providing high power.
Further, the die linear motor 1A has the slag discharge hole 70 in the area thereof which coincides with the press drive axis center so that slag resulting from the press working can be discharged from the slag discharge hole 70. Slag can thus be smoothly discharged. This prevents the die linear motor 1A from interfering with discharge of slag even though the die linear motor 1A is installed below the hole-making die 611. Since the die linear motor 1A is the assembly of the plurality of unit linear motors 2, the press machine can be easily configured so that the slag discharge hole 70 is formed in the press drive axis center.
Further, the present linear motor mounted press machine operates under the control of the control means 84 in
In the above embodiment, each of the punch linear motor 1 and the die linear motor 1A comprises the assembly of the plurality of unit linear motors 2. However, a unitary linear motor that is a single larger unit linear motor 2 may be used. In this case, the die linear motor 1A preferably has the slag discharge hole 70 penetrating the center of the shaft member 3, for example, as shown in
While the present invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the present invention that fall within the true spirit and scope of the invention.
Number | Date | Country | Kind |
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2006-223779 | Aug 2006 | JP | national |