MACHINE TOOL

Abstract: This invention relates to a machine tool for conducting several types of machining such as drilling, cutting etc., without sacrificing machining accuracy and requiring more than one fitting of a work to a work head to reduce the fitting time of the work. To this end, the work head (4) in this invention has a spindle (16) and a tool head (5) has a spindle (42). A first index section (6) changes the direction of axis of the spindle (42). A second index section (8) indexes the spindle (16) in a first direction (A). A first check section (9) prevents the rotation of the spindle (16) whenever necessary. A second check section (11) prevents the rotation of the spindle (42) whenever necessary. First and second driving sections (7, 10) rotate the spindles (16, 42), respectively. Driving systems (12, 13) move the work head (4) and the tool head (5) relatively and three-dimensionally.

Description: This invention relates to a machine tool for performing multiple processing operations on a workpiece. Technical Background For example, consider the case where an outer surface of a cylindrical workpiece is turned and then a hole is bored in the workpiece. First, in order to have these operations done on the workpiece, the workpiece is loaded in a chuck of a lathe and then turned by a turning tool bit. Then, it is removed from the lathe and set onto a boring machine to perform boring operation by a drill. As a consequence, too much time is wasted loading and removing the workpiece and it is difficult to maintain high quality processing requirements. Document EP-A-0 249 046 (closest prior art) disloses a turning machine which allows turning operations at different angles without removal of the workpiece from the chuck between the turning operations. The chuck itself is movable to allow machining operations with stationary tools. A machine tool allowing different kinds of machining operations simultaneously at different angles on a stationary workpiece is disclosed in the document EP-A-0 172 299. Disclosure of the Invention This invention relates to a machine tool which can perform a multiple processing operations on the workpiece once the workpiece is loaded onto the machine tool. Referring to Fig. 1, a workhead 4 has a spindle 16. A workpiece is detachably attached to the spindle 16. A toolhead 5 has a spindle 42. A tool bit is detachably attached to the spindle 42. A machine tool body 1 has the workhead 4 and the toolhead 5. A first indexing means 6 is designed to index the axis of the spindle 16 of the workhead 4 with respect to the axis of the spindle 42 of the toolhead 5. A first driving means 7 can rotate continuously the spindle 16 of the workhead 4 in the first direction A. A second indexing means 8 indexes the spindle 16 of the workhead 4 in the first direction A. A first stopping means 9 can stop rotation of the spindle 16 of the workhead 4 if necessary. A second driving means 10 can rotate the spindle 42 of the toolhead 5. A second stopping means 11 can stop rotation of the spindle 42 of the toolhead 5 if necessary. Driving systems 12,13 is provided to the body 1 and make it possible to move the workhead 4 and the toolhead 5 relative to each other in the three dimentional manner. Consider the case where multiple processing operations such as turning and boring operations on the workpiece W are done. In this instance, the work can be carried out without removing the workpiece W from the workhead 4. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing an embodiment of a machine tool according to this invention. Figure 2 shows the internal structure of the workhead. Figures 3 and 4 show sections of the toolhead. Figure 5 shows a control system. Figures 6, 7 and 8 show steps in processing the workpiece. Figures 9, 10, 11, and 12 show a variety of sample operations carried out on the workpieces. BEST MODE FOR CARRING OUT THE INVENTION Referring to Fig. 1, a machine tool according to this invention has a body 1, a workhead 4, a toolhead 5, a first indexing means 6, a first driving means 7, a second indexing means 8, a first stopping means 9, a second driving means 10, a second stopping means 11, and driving systems 12, 13. Body 1 The body 1 of Fig. 1 comprises a bed 2 and a column 3. Workhead 4 Referring to Figs. 1 and 2, a casing 15 of the workhead 4 is provided with the first driving means 7, the second indexing means 8 and the first stopping means 9. A spindle 16 is rotatably supported by a casing 15 through bearings 17 to 19. A workholder 20 is detachably attached to the spindle 16 in the conventional collet-chuck manner. A tapered portion 21 of the workholder 20 is designed to fit a hole 22 of the spindle 16. A rod 24 of a hydraulic system 23 can be moved in the direction of an arrow e. While doing this, the tapered portion 21 of the workholder 20 can be inserted into the hole 22. The tapered portion 21 can be also removed from the hole 22 by moving the rod 24 in the direction of an arrow f. The stopping means 9 is located around the other end of the spindle 16. The first stopping means 9 comprises a hydraulic brake equipment 25 and a rotor 26. The hydraulic brake equipment 25 is placed in the casing 15. The rotor 26 is fixed to the other end of the spindle 16. Rotation of the rotor 26, that is, rotation of the spindle 16, can be stopped if necessary by the hydraulic brake equipment 25. The first driving means 7 has a motor 27, gears 28 and 29. The gear 28 is fixed to the output shaft of the motor 27. The gear 29 is fixed to the spindle 16. The gears 28 and 29 can transmit power through gears which are not shown in Figures. When the motor 27 starts, the spindle 16 rotates continuously. The second indexing means 8 has an indexing motor 30, gears 31, 32, 33, 34, a slide mechanism 35, and a shaft 36. The gear 31 is fixed to the output shaft of the indexing motor 30. The gear 32 is fixed to the shaft 36. The gear 32 engages the gear 31 while the gear 33 engages the gear 34. The spindle 16 can be indexed in the direction A by the indexing motor 30. For example, the spindle 16 can be indexed at 10 degrees or 1 degree. However, the gear 33 can slide only along the shaft 36. A lever 37a of the slide mechanism 35 engages a portion 33a of the gear 33. If a rod 37b of a cylinder 37 contracts, the gear 33 can slide along the shaft 36 so as to leave the gear 33 from the gear 34, and thus the spindle 16 does not receive power from the motor 30. The reason for this disengagement feature, is to protect the motor 30 by keeping it from rotating while the spindle 16 is in rotation. The motor 30 can be, for example, a servo motor. The workholder 20 in Figure 2 contains an air chuck 40. The cylindrical workpiece W is fixed to this chuck 40. Toolhead 5 Referring to Fig. 1, a casing 41 for the toolhead 5 contains a spindle 42, the second stopping means 11 and the second driving means 10. The spindle 42 is similar to the spindle 16 of the workhead 4. A toolholder 43 is detachably attached to the spindle 42 in the normal collet chuck manner. A tool bit 43a for turning operation is fixed to the toolholer 43. The second driving means 10 has a motor and gears and makes the spindle 42 continuously rotate. In addition, the second stopping means 11 has an air cylinder 43 and a member 44 as shown in Figs. 3 and 4. The member 44 is attached to a rod 45 of the air cylinder 43. The rod 45 is extended for enough so the member 44 can be engaged in a concave portion 46. Thus, rotation of the spindle 42 can be stopped. A sensor 47 is used to bring the concave portion 46 in contact with the member 44 as shown in Figure 4. When the sensor 47 senses a detection plate 48 of the spindle 42, the spindle 42 is angulary indexed by stopping the second driving means 10 according to instructions from a CNC (computer numerical control) unit 100. The CNC unit 100 will be explained hereinafter. First indexing means 6 The first indexing means 6 of Fig. 1 is located on the saddle 60 of the driving system 12. The first indexing means 6 has a rotary disc 51, a fixed disc 53 and a motor 52. The workhead 4 is fixed on the rotary disc 51. The rotary disc 51 can be indexed in the B direction by the motor 52. The mechanism for such indexing is a commonly utilized technique. Driving systems 12 and 13 The driving systems 12 and 13 enable the toolholder 5 and the workholder 4 to move relative to each other in the three dimensional manner. The driving system 12 has a saddle 60, a saddle 61, a motor 62, a motor 63, and a guide 64. The saddle 61 can be move in the direction of Z along guides 64, of the bed 2, by using the motor 63. The saddle 60 can also move in the direction of X along the guide 65, of the saddle 61, by using the motor 62. The driving system 13 has a motor 66 and a guide 67. The motor 66 can move the tool holder 5 in the Y direction by the motor 66. Control system The components of the machine tool are controlled by the CNC unit 100 as shown in Figure 5. The components controlled include the motor 27, the motor 30, the first stopping means 9, the hydraulic system 23, and the motor 62, 63, and 52, which are all related to the workhead 4. Furthermore, the second driving means 10, the second stopping means 11, and the motor 66 are also controlled by the CNC unit 100. These components are all associated with the toolhead 5. Utilizing the position signal from sensor 47 as shown in Figure 4, the CNC unit 100 will stop the second driving means 10 if necessary. The function of changer 101 is to replace the chuck 20 of the workhead 4 with another chuck when requested. The changer 101 can, for example, be the workpiece changer described in Japanese Patent Laying-Open No. 62-88536. The changer 102 can also replace the toolholder 43 of the toolhead 5 with another toolholder. The changer 102 can also adapt the changer mentioned above. A magazine 103 contains many workholders while a magazine 104 contains many toolholders. Operation Multiple processing operations are performed on the workpiece W as illustrated in Figures 6, 7 and 8. The workpiece W (such as a cylindrical bar) is fixed in the chuck 40 of the spindle 16 on the workhead 4 as shown in Figure 6. The tool bit 43a is fixed to the toolholder 43 of the toolhead 5. The toolhead 5 is adjusted to the appropriate height, in the Y direction, as shown in Figure 1. The workhead 4 can be moved in the direction of Z1 by revolving the spindle 16 in the direction A1. The outer face of the workpiece W is turned by the tool bit 43a. At the same time, the spindle 42 of toolhead 5 does not rotate but is fixed by the member 44 of the second stopping means 11 as shown in Figure 3. After this operation, the workhead 4 is moved back in the direction Z2. Referring to Figure 7, the height of toolhead 5 is adjusted. Another toolholder 143 is attached, replacing the toolholder 43 as shown in Figure 6. This toolholder 143 has a drill 143a. The drill 143a faces the side face of the workpiece W which is held by the workholder 40. The spindle 16 is stopped from rotating and then the workhead 4 is advanced in the direction Z1. At the same time, the spindle 42 is made to rotate continuously by release the member 44 from the concave portion 46 of the spindle 42 in Figure 3. By doing this, a hole h can be drilled on the workpiece W along the axis of the workpiece W as shown in Figure 8. The workhead 4 is returned in the direction Z2 as shown in Figure 7. The position of the work head 4 is indexed in the direction B1 as shown in Figure 8. Then, a hole h2 is made on the workpiece W by moving the workhead 4 in the direction of Z1 as shown in Figure 9. The axis of the hole h and that of hole h2 will intersect at predetermined angle. Next, other examples of multiple operations on the workpiece are shown in Figures 10 to 12. The workpiece W1 shown in Figure 10 has tow holes. The axis of hole h3 and that of hole h4 intersect at an angle of 90 degrees. In Figure 11, the workpiece W2 consists of a round part P1 and tapered part P2. In Figure 12, the workpiece W3 contains a relatively small circular part P3 with a hole h5 created in the rounded side face. Now, this invention is not limited to the above mentioned embodiments. The toolhead 5 can be moved in the X or Z direction. Under many conditions, this eliminates the need for moving the workhead 4 along the X or Y axis. In Figure 1, the chuck 40 of the workholder 20 is equipped with a workpiece which is round. However, the workholder 20 can also utilize a chuck that can load square materials as well. In addition to turning and boring operations, other processing operations such as tapping and milling operations can be done by selecting the tools. This invention makes multiple operations possible on a workpiece once the workpiece is attached onto the workhead. As a result, the much time for loading up and unloading the workpiece is not required. Also, errors do not occur as the workpiece is not transterred from a chuck to another chuck. INDUSTRIAL FIELD A machine tool of this invention can be used for performing operations such as drilling and turning operations on a workpiece.

Claims: A machine tool comprising: a workpiece supporting means (4) having a workpiece spindle (16) for mounting a workpiece (W); a tool supporting means (5) having a tool spindle (42) for mounting one of a plurality of tools (43a, 143a); a body (1) provided with the workpiece supporting means (4) and the tool supporting means (5); a first driving means (7) for rotating the workpiece spindle (16) when performing a turning operation of the workpiece (W) by the tool (43a); a first indexing means (6) for indexing the workpiece supporting means (4) about a first axis perpendicular to a second axis of the workpiece spindle (16); a second indexing means (8) for indexing the workpiece spindle (16) about the second axis of the workpiece spindle (16); a first stopping means (9) for preventing rotation of the workpiece spindle (16) when performing other machining operations of the workpiece (W) by the tool (143a); a second drive means (10) for rotating the tool spindle (42) when performing the machining operations of the workpiece (W); a drive mechanism (12, 13) for causing relative motion between the workpiece supporting means (4) and the tool supporting means (5) in the three dimensional manner; characterized in a second stopping means (11) for preventing rotation of the tool spindle (42) when performing the turning operation of the workpiece (W) by the tool (43); and in that a sensor (47) monitors the position of the tool spindle (42) and actuates the second stopping means (11) so as to perform the turning operation of the workpiece (W). The machine tool of claim 1, characterized in that the second stopping means (11) has an air cylinder (43) and a lock member (44) attached to a rod (45) of the air cylinder (43), the rod (45) being extended in such a way that the lock member (44) can be engaged in a concave portion (46) so that rotation of the spindle (42) can be stopped. The machine tool of claim 1, characterized in that a sensor (47) is used to bring a concave portion (46) in contact with a lock member (44) when the sensor (47) senses a detection plate (48) of the spindle (42) in such a way that the spindle (42) is angulary indexed by stopping the second driving means (10) according to instructions from a computer numerical control unit (100). The machine tool of claim 1, characterized in that a first stopping means (9) comprises a disc (26) fixed to the workpiece spindle (16) and a brake (25) for stopping rotation of the workpiece spindle (16) by way of the disc (26). The machine tool of claim 1, characterized in that the workpiece spindle (16) is provided with a power chuck for holding the workpiece (W). The machine tool of claim 1, characterized in that the workpiece supporting means (4) is associated with a first magazine containing workpiece holders, and the tool supporting means (5) is associated with a second magazine containing tool holders. The machine tool of claim 1, characterized in that one of the tools is selected from a drill, a tap, a mill or a turning tool which is mounted in the tool spindle (42). The machine tool of claim 1, characterized in that the drive mechanism (12) comprises a first saddle (60) movable in a first direction (X) and a second saddle (61) movable in a second direction (Z), the first saddle (60) being provided with the first indexing means (6). The machine tool of claim 8, characterized in that the tool supporting means (5) is moved in a third direction (Y) perpendicular to both the first and second directions (X, Z). The machine tool of claim 1, characterized in that a workpiece changer (101) is arranged between the workpiece supporting means (4) and a magazine for stocking workpieces and a tool changer (102) is arranged between the tool supporting means (5) and a magazine (104) for stocking tools. The machine tool of claim 10, characterized in that the magazines (103, 104), the workpiece supporting means (4), the tool supporting means (5), and the drive mechanism (12, 13) can be controlled by a computer numerical control (100).

Inventors: KITAMURA KOICHIRO, KITAMURA, KOICHIRO, KITAMURA, KOICHIRO 11-5, EKINAN 3-CHOME
Applicants: KITAMURA MACHINERY CO LTD, KITAMURA MACHINERY CO., LTD.
Application year: 1989
Main classification: B23P23
IPC codes: B23Q1, B23Q39, B23P23