JP2019171517A - Processing line of crank shaft - Google Patents

Abstract

To provide a processing line of a crank shaft which achieves further consolidation of processes to improve productivity and reduce facility costs and production costs.SOLUTION: A processing line 1 of a crank shaft W according to the invention includes machine work processes S11 to S16 in which predetermined machine work is performed to the crank shaft W. The machine work processes S11 to S16 include a centering process S12 in which centering processing is performed to the crank shaft W. The centering process S12 has a lathe 40 for performing the centering processing.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a crankshaft processing line, and more particularly to a technique for integrating a plurality of machining processes.

  For example, in manufacturing a crankshaft for an automobile engine, first, axial end surfaces of a crankshaft material formed by forging or the like (hereinafter simply referred to as a crankshaft) are first cut. Then, by performing centering processing, the overall length of the crankshaft is determined and the center of rotation is set. Next, the outer peripheral surface of the journal part is cut and the outer peripheral surface of the pin part is cut. Further, processing such as oil drilling and screw tapping is performed (for example, see Patent Document 1). Further, if necessary, machining such as recentering may be performed after the heat treatment. These series of machining are sequentially performed by dedicated equipment (machining center, lathe, mirror processing machine, etc.) provided for each machining process.

  By the way, in this type of processing line, it is desired to construct a processing line that is more resistant to production fluctuations than ever. In addition, it is desired to construct the processing line at a low cost. However, in the case of the conventional processing line, as described above, dedicated equipment is required for each process, so play time is inevitably generated due to the processing time difference in each process, and productivity is not necessarily achieved. It was not good. In addition, since the number of facilities is required for the number of processes, the installation space becomes huge and the degree of freedom of layout change is reduced.

  Here, for example, in Patent Document 2, as a processing apparatus for complex processing of a crankshaft, both ends including a support means for fixing and supporting the crankshaft horizontally and cutters for processing both axial end faces of the crankshaft are provided. There has been proposed a machining apparatus including a surface machining unit and a center reference hole machining unit having a center drill for machining center reference holes on both end faces.

JP-A-6-31542 JP 2001-225233 A

  However, in the processing apparatus described in Patent Document 2, various processes are performed with the crankshaft fixed by a dedicated jig, and therefore, for example, the cutting of the outer peripheral surface of the journal part or the cutting of the outer peripheral surface of the pin part. There is a problem that machining performed while rotating the shaft in the centered state cannot be performed by the same processing apparatus.

  In view of the above circumstances, the present invention aims to provide a crankshaft processing line capable of improving productivity by consolidating further processes and reducing facility costs and thus production costs. The technical problem to be solved.

  The solution to the above problem is achieved by the crankshaft processing line according to the present invention. That is, this machining line is a crankshaft machining line provided with a plurality of machining processes for performing predetermined machining on the crankshaft, and the plurality of machining processes includes a centering process for performing centering on the crankshaft. Including, the centering process is characterized by having a lathe for centering.

  As described above, the centering process is conventionally performed by using a machining apparatus of a type that performs machining with the crankshaft fixed, such as a machining center, whereas in the present invention, the centering process is a lathe for performing the centering process. It was made to have. According to the above configuration, at least a part of the machining process that has been performed by the conventional lathe among the machining processes after the centering process can be performed by the machining apparatus having the lathe for the centering process. Therefore, not only the centering process but also one or two or more machining processes that are conventionally performed using a lathe can be performed using a single lathe. Thereby, since each machining process can be consolidated more than before, productivity can be improved, and the facility cost and thus the production cost can be greatly reduced.

  In the crankshaft machining line according to the present invention, the crankshaft is held and machined using a lathe drive device in the centering process and at least a part of the machining process after the centering process. Also good.

  In this way, by using the lathe drive device, it is possible to hold the crankshaft and perform machining, so that each machining process is carried out without newly installing a dedicated holding device or machining device on the lathe. can do. Accordingly, it is possible to smoothly and sequentially perform a plurality of machining steps on a single lathe without the trouble of attaching or removing a dedicated device.

  Further, in the crankshaft processing line according to the present invention, the lathe has a tool table on which a tool can be mounted, and the tool table serves as a driving device that applies a driving force to the tool mounted on the tool table. It has an electric motor, and the centering process has a clamping device that is mounted on the tool stand and can clamp the crankshaft. The clamping device is generated by a hydraulic pump that generates hydraulic pressure by the driving force of the electric motor and a hydraulic pump. And a hydraulic actuator that operates by hydraulic pressure, and the crankshaft can be clamped by the operation of the hydraulic actuator.

  In this way, when the lathe has a tool table on which a tool can be mounted and the tool table has an electric motor as a driving device that applies a driving force to the tool, hydraulic pressure is generated using the electric motor. In addition, by providing a clamping device that can clamp the crankshaft by operating the hydraulic actuator with the generated hydraulic pressure, for example, a greater clamping force can be achieved than when the clamping part is directly operated by the driving force of the electric motor. be able to. Therefore, it is possible to hold the crankshaft firmly and perform various processes with high accuracy. In addition, since the hydraulic actuator can be operated by using the driving force of the electric motor as a power source, it is not necessary to extend and connect an electric wire or a hydraulic hose from the periphery of the lathe. Thereby, interference with the movable part of a lathe can be avoided and a plurality of machining operations can be performed more smoothly on a single lathe.

  As described above, according to the crankshaft processing line according to the present invention, productivity can be improved by further integrating processes. Moreover, since each machining process can be performed on one lathe, the equipment cost and thus the production cost can be reduced.

It is the flow which showed the procedure of the processing method of the crankshaft which concerns on one Embodiment of this invention. It is the top view which showed notionally one structural example of the processing line for enforcing the processing method of the crankshaft shown in FIG. It is a top view of the processing apparatus used in the machining process shown in FIG. It is a side view of the processing apparatus shown in FIG. It is A arrow directional view in the unclamped state of the clamp apparatus shown in FIG. It is A arrow view in the clamped state of the crank apparatus shown in FIG. FIG. 5 is a hydraulic circuit diagram of the clamp device shown in FIG. 4. It is a side view for demonstrating one Example of the crankshaft full length determination process and centering process using the processing apparatus shown in FIG. It is a side view for demonstrating one Example of the journal part cutting process of the crankshaft using the processing apparatus shown in FIG. It is a principal part side view of the cutting unit for pin part cutting. It is a B arrow view of the cutting unit shown in FIG. It is a side view for demonstrating one Example of the pin part cutting process of the crankshaft using the cutting unit shown in FIG. It is a side view of the support apparatus of a crankshaft. It is C arrow line view of the support apparatus shown in FIG. It is a side view for demonstrating one Example of the screw tapping process of a crankshaft using the processing apparatus provided with the support apparatus shown in FIG. It is a hydraulic-circuit figure of the clamp apparatus which concerns on other embodiment of this invention.

  Hereinafter, the content of the processing line of the crankshaft concerning one embodiment of the present invention is explained based on a drawing.

  FIG. 1 is a flow showing a procedure of a crankshaft processing method according to the present embodiment. This machining method includes, for example, a machining step S1 in which a crankshaft formed by forging or the like is subjected to predetermined machining to process the crankshaft into a predetermined shape, and a predetermined heat treatment is performed on the crankshaft that has undergone the machining step S1. And a finishing step S3 for finishing the crankshaft after the heat treatment step S2 into a predetermined product shape.

  Of these, the machining step S1 includes a full length determining step S11 in which both axial end faces of the crankshaft are cut to set the overall axial length of the crankshaft, and a centering process is performed on the crankshaft to center the axial end faces. Centering step S12 for providing a hole, journal portion cutting step S13 for cutting the journal portion of the crankshaft, pin portion cutting step S14 for cutting the pin portion of the crankshaft, and oil hole processing for the crankshaft An oil hole machining step S15, and a screw tapping step S16 that performs screw tapping on both axial end surfaces of the crankshaft. The finishing process S3 includes an end face grinding process S31 for grinding both end faces of the crankshaft, a pin part grinding process S32 for grinding the pin part of the crankshaft, and a journal part grinding process S33 for grinding the journal part of the crankshaft. With. Of course, depending on the type and specification of the crankshaft, it may further include machining steps other than those described above.

  FIG. 2 is a plan view showing the entire configuration of a crankshaft processing line 1 for processing the crankshaft in the procedure shown in FIG. As shown in this figure, the crankshaft machining line 1 according to the present embodiment includes a machining process S1, a heat treatment process S2, and a finishing process S3 arranged in series. Step S1 implements all the machining steps shown in FIG. 1 (full length determination step S11, centering step S12, journal portion cutting step S13, pin portion cutting step S14, oil hole machining step S15, screw tapping step S16). A machining apparatus 10 is provided. Further, the heat treatment step S2 includes a heat treatment apparatus 20 for applying a predetermined heat treatment to the crankshaft, and the finishing step S3 is a first grinding process for grinding the both end faces of the crankshaft in the end face grinding step S31. A device 30a, a second grinding device 30b for grinding the pin portion of the crankshaft in the pin portion grinding step S32, and a third for grinding the journal portion of the crankshaft in the journal portion grinding step S33. And a grinding apparatus 30c. Hereinafter, details of the machining apparatus 10 will be described.

 As shown in FIG. 3, the machining apparatus 10 mainly includes a lathe 40 and a clamp device 50. Among these, the lathe 40 includes a bed 41, a main shaft 42 attached to the bed 41, a tailstock 43 that moves relative to the main shaft 42, and a first tool table 44 and a second tool table 45. The first tool base 44 and the second tool base 45 are configured to be movable in three dimensions with respect to the bed 41 (in FIG. 3, it can be moved in all directions of XYZ). In the present embodiment, tools such as a milling tool 46 and a drill 47 are mounted on the tool mounting portion 44a of the first tool base 44, and the clamping device 50 according to the present invention is mounted on the tool mounting portion 45a of the second tool base 45. ing.

  As shown in FIGS. 4 to 6, the clamp device 50 includes a hydraulic pump 51, a hydraulic actuator 52 that operates with the hydraulic pressure generated by the hydraulic pump 51, and a crankshaft W (in FIG. 5, It mainly has a pair of clamp parts 53, 53 for clamping (shown by a two-dot chain line). In the present embodiment, two pairs of clamp portions 53, 53, 54, 54 are attached to the hydraulic actuator 52 in order to clamp the crankshaft W as a long workpiece at two positions spaced apart in the axial direction (FIG. 4). See).

  Here, the hydraulic pump 51 is mounted on the outer periphery of the tool mounting portion 45 a of the second tool base 45. The tool mounting portion 45a incorporates an electric motor 45b as a driving device (shown by a broken line in FIG. 4), and the hydraulic pump 51 can generate hydraulic pressure by the driving force of the electric motor 45b. The output shaft 45b1 of the electric motor 45b and the input shaft (not shown) of the hydraulic pump 51 are configured to be connectable. In the present embodiment, when the tool attachment portion 45a rotates, the clamp device 50 attached to the tool attachment portion 45a also rotates integrally. The input shaft of the hydraulic pump 51 is connected to the output shaft 45b1 of the electric motor 45b by matching the phase of the electric motor 45b built in the tool base 45 with the phase of the hydraulic pump 51. . The same applies to the connection mode between the hydraulic pump 63 of the cutting unit 60 and the electric motor 45b, which will be described later, and the connection mode between the hydraulic pump 73 of the support device 70 and the electric motor 45b.

  In the present embodiment, as shown in FIG. 5, the hydraulic actuator 52 includes a hydraulic cylinder 55, a link portion 56 that changes the movement direction of the hydraulic cylinder 55 to the clamping direction of the pair of clamp portions 53, 53, and the hydraulic pump 51. Hydraulic supply passages 57a and 57b for supplying the hydraulic pressure generated in the above to the hydraulic cylinder 55. In the present embodiment, the hydraulic cylinder 55 is a so-called reciprocating hydraulic cylinder, and the first port 51a of the hydraulic pump 51 and the first oil chamber 55a of the hydraulic cylinder 55 are connected by a first hydraulic supply path 57a. It is connected. The second port 51b of the hydraulic pump 51 and the second oil chamber 55b of the hydraulic cylinder 55 are connected by a second hydraulic supply path 57b. The first oil chamber 55a and the second oil chamber 55b are partitioned by a linear motion portion 55c. Accordingly, the hydraulic pressure is supplied to one of the first oil chamber 55a and the second oil chamber 55b of the hydraulic cylinder 55 according to the rotational drive direction of the hydraulic pump 51, and the linear motion portion 55c of the hydraulic cylinder 55 is set to a predetermined value. It is designed to move straight in the direction.

  Specifically, when the hydraulic pump 51 rotates in the first direction R1 (see FIG. 7) according to the rotational drive direction of the electric motor 45b (see FIG. 4), the first port 51a first A predetermined hydraulic pressure is supplied to the first oil chamber 55a of the hydraulic cylinder 55 via the hydraulic pressure supply path 57a. As a result, the linear motion portion 55c of the hydraulic cylinder 55 is pushed into the hydraulic pump 51 side, so that the pair of clamp portions 53, 53 move in a direction approaching each other via the link portion 56 (state shown in FIG. 6). Further, when the hydraulic pump 51 rotates in the second direction R2 (see FIG. 7) according to the rotational drive direction of the electric motor 45b, a predetermined value is transmitted from the second port 51b via the second hydraulic pressure supply path 57b. Hydraulic pressure is supplied to the second oil chamber 55 b of the hydraulic cylinder 55. As a result, the linearly moving portion 55c of the hydraulic cylinder 55 is pushed into the crankshaft W side, so that the pair of clamp portions 53 and 53 move away from each other via the link portion 56 (state shown in FIG. 5). 5 and 6 show one hydraulic cylinder 55 and one link portion 56, but actually, the hydraulic cylinder 55 and the link are respectively connected to the two pairs of clamp portions 53 and 53 (54 and 54). A portion 56 is provided.

  In addition to the lathe 40 and the clamp device 50, the machining device 10 according to the present embodiment includes a cutting unit 60 (see FIG. 10) for cutting the outer peripheral surface of the crankshaft W, and the crankshaft W. And a support device 70 (see FIG. 13) for rotatably supporting.

  Among these, the cutting unit 60 is used in a state of being mounted on the second tool base 45 of the lathe 40 as shown in FIGS. 10 and 11, for cutting the outer peripheral surface of the crankshaft W, for example. A cutting cutter 61 and a rotating device 62 that rotates the cutting cutter 61 are provided. In this embodiment, the cutting cutter is an outer cutter. The rotating device 62 includes a hydraulic pump 63 connected to the electric motor 45b of the second tool base 45, and a hydraulic motor 64 that operates with the hydraulic pressure generated by the hydraulic pump 63 by driving the electric motor 45b.

  Here, the output shaft 45b1 of the electric motor 45b and the input shaft (not shown) of the hydraulic pump 63 are connected to each other so that the hydraulic pump 63 can generate hydraulic pressure by the driving force of the electric motor 45b. . The primary side of the hydraulic motor 64 and the hydraulic pump 63 are connected via a hydraulic supply path 65a, and the secondary side of the hydraulic motor 64 is connected to a hydraulic discharge path 65b. As a result, the hydraulic pressure generated by the hydraulic pump 63 is supplied from the primary side to the hydraulic motor 64 via the hydraulic pressure supply path 65 a and discharged from the secondary side of the hydraulic motor 64. With such movement of the hydraulic pressure, the rotating shaft 64a of the hydraulic motor 64 rotates in a predetermined direction, and the cutting cutter 61 connected to the rotating shaft 64a via the connecting member 66 rotates in a predetermined direction. It has become.

  The support device 70 is a device for rotatably supporting the centered crankshaft W, and is attached to the tool mounting portion 45a of the second tool base 45 as shown in FIG. As shown in FIG. 14, the support device 70 is hydraulically operated with a plurality of claw portions 71, 71, 71 that can come into contact with the outer peripheral surface of the crankshaft W, and each claw portion 71, 71, 71 is connected to each other. The hydraulic cylinders 72, 72, 72 as hydraulic actuators of the same number as the claw portions that are driven to move forward and backward with respect to the outer peripheral surface of the crankshaft W, and the hydraulic pressure supply for supplying hydraulic pressure to the hydraulic cylinders 72, 72, 72 And a hydraulic pump 73 as a part. In this embodiment, three claw portions 71, 71, 71, hydraulic cylinders 72, 72, 72, and one hydraulic pump 73 are provided in the support device 70.

  The hydraulic pump 73 has a hydraulic supply path 74 that branches and is connected to the three hydraulic cylinders 72, 72, 72, respectively. Specifically, as shown in FIG. 14, the hydraulic supply path 74 connects the first port 73 a of the hydraulic pump 73 and the first oil chambers 72 a, 72 a, 72 a of the hydraulic cylinders 72, 72, 72 to each other. The first hydraulic pressure supply path 74b that connects the first hydraulic pressure supply path 74a to be connected, the second port 73b of the hydraulic pump 73, and the second oil chambers 72b, 72b, 72b of the hydraulic cylinders 72, 72, 72 to each other. And have. The first oil chamber 72a and the second oil chamber 72b are partitioned by a linear motion portion 72c. Thereby, according to the rotational drive direction of the hydraulic pump 73, the hydraulic pressure is supplied to one of the first oil chamber 72a and the second oil chamber 72b of each hydraulic cylinder 72, and the linear motion portion 72c of the hydraulic cylinder 72 is predetermined. It is designed to move straight in the direction of.

  Further, the first oil chambers 72a, 72a, 72a of the three hydraulic cylinders 72, 72, 72 described above can circulate a hydraulic transmission medium (usually oil) through the first hydraulic pressure supply path 74a. It is said. Further, the second oil chambers 72b, 72b, 72b of the three hydraulic cylinders 72, 72, 72 are capable of circulating a hydraulic transmission medium with each other via the second hydraulic pressure supply path 74b. Therefore, the hydraulic pressure acting on the linear motion portion 72c from the first oil chamber 72a side and the second oil chamber 72b side of each hydraulic cylinder 72 is equalized in all the hydraulic cylinders 72, 72, 72. Is equalized automatically.

  The hydraulic pump 73 is configured to be able to transmit power to the electric motor 45 b built in the second tool base 45. Specifically, similarly to the hydraulic pump 51 of the clamp device 50, the output shaft 45b1 of the electric motor 45b and the output shaft (illustrated) of the hydraulic pump 73 so that the hydraulic pump 73 can generate hydraulic pressure by the driving force of the electric motor 45b. Are omitted).

  The machining step S1 of the crankshaft W using the machining apparatus 10 having the above configuration is performed as follows, for example.

(S11) Total length determination step (S12) Centering step In the above step, the clamping device 50 mounted on the second tool base 45 of the lathe 40 is used to hold both ends Wc, Cut Wc. Further, centering processing (processing for opening a center hole (not shown)) is performed on both end faces Wc and Wc. Specifically, first, as shown in FIG. 8, the tool mounting portion 45a of the second tool base 45 is rotated so that the two pairs of clamp portions 53, 53 (54, 54) are both upward (in FIG. 8, The clamping device 50 is arranged at a position that is oriented in the (Z direction). Then, the crankshaft W in a state of being supported by being suspended by a gantry loader or the like (not shown) is moved onto the clamp device 50 or the second tool base 45 is moved to a position below the crankshaft W. Lower. As a result, the journal portion Wa of the crankshaft W is introduced between the pair of clamp portions 53, 53 (54, 54) (state shown in FIG. 5).

  Then, with the crankshaft W being introduced between each pair of clamp parts 53, 53 (54, 54), the electric motor 45b of the second tool base 45 is driven and connected to the output shaft 45b1 of the electric motor 45b. The hydraulic pump 51 of the clamp device 50 located in is operated. Thereby, the hydraulic pressure is generated, and the generated hydraulic pressure is supplied to the first oil chamber 55a of the hydraulic cylinder 55 via the first port 51a and further the first hydraulic pressure supply path 57a. Thereby, the linear motion part 55c of the hydraulic cylinder 55 is pushed into the hydraulic pump 51 side, and the pair of clamp parts 53, 53 (54, 54) cooperate with each other by the link part 56 and the pair of clamp parts 53, 53 (54, 54). 53 (54, 54) move toward each other. As a result, as shown in FIG. 6, the journal portion Wa of the crankshaft W is clamped at two positions by the pair of clamp portions 53, 53 (54, 54) and fixed at a predetermined position.

  Thus, in a state where the crankshaft W is fixed at a position deviated from the main shaft 42 of the lathe 40, the tool mounting portion 44a of the first tool base 44 is rotated, for example, so that the tool mounting portion 44a is mounted. The milling 46 is connected to the output shaft 44b1 of the electric motor 44b built in the first tool base 44. Then, the milling 46 is rotated by the drive of the electric motor 44b, and is brought into contact with both axial end surfaces Wc, Wc of the crankshaft W. Thereby, the cutting process with respect to the both end surfaces Wc of the crankshaft W is started. As a result, the overall axial length of the crankshaft W is set to a predetermined size (full length determination step S11). At this time, with the crankshaft W completely fixed, only the milling tool 46 (first tool base 44) may be moved to sequentially cut both end faces Wc, Wc. The second tool base 45 may be moved together with the base 44 to sequentially cut both end faces Wc and Wc. In any case, the tailstock 43 is preferably retracted with respect to the main shaft 42 for the purpose of avoiding interference with the crankshaft W and the tool bases 44 and 45 during the cutting process. The same applies to the centering step S12 described later.

  Further, by rotating the tool mounting portion 44a, the drill 47 mounted on the tool mounting portion 44a of the first tool base 44 is connected to the output shaft 44b1 of the electric motor 44b in the same manner as the milling tool 46, and by driving the electric motor 44b. The drill 47 is pushed into both end faces Wc, Wc of the crankshaft W while rotating the drill 47. Thereby, centering processing is performed on both end faces Wc, Wc of the crankshaft W, and center holes (not shown) are formed in the end faces Wc, Wc (centering step S12).

(S13) Journal part cutting step In this step, the second tool base 45 is moved from the state shown in FIG. 8, and the crankshaft W held by the clamp device 50 is moved between the main shaft 42 and the tailstock 43. To be transferred to. Specifically, the clamping device 50 is moved together with the second tool base 45 to introduce one end portion of the crankshaft W in the axial direction into the main shaft 42, and the one end portion of the crankshaft W is held by the chuck portion 42 a of the main shaft 42. . Then, the tailstock 43 is brought close to the main shaft 42, and the crankshaft W is supported in the centered state by the main shaft 42 and the tailstock 43 using the center holes formed in the both end faces Wc and Wc. In this way, after confirming that the crankshaft W is rotatably supported by the main shaft 42 and the tailstock 43, the hydraulic pump 51 is rotated in the second direction R2 by the rotational drive of the electric motor 45b (FIG. 7). The clamp state by each pair of clamp parts 53 and 53 (54, 54) is cancelled | released (state shown in FIG. 5). After releasing the clamped state, the second tool base 45 is moved to detach the clamp device 50 from the crankshaft W.

  Then, the cutting tool 48 mounted on the tool mounting portion 44a of the first tool base 44 is connected to the journal portion of the crankshaft W in the state in which the crankshaft W is rotated by the rotational drive of the main shaft 42, like the milling cutter 46 and the drill 47. It abuts on Wa (see FIG. 9). Thereby, the outer peripheral surface of each journal part Wa of the crankshaft W is cut into a predetermined outer diameter (journal part cutting step S13).

(S14) Pin part cutting step In this step, the first tool base 44 is retracted from the state shown in FIG. 9, that is, from the state in which the crankshaft W is rotatably supported by the main shaft 42 and the tailstock 43, The cutting unit 60 mounted on the tool mounting portion 45a of the second tool base 45 is connected to the output shaft 45b1 of the electric motor 45b built in the second tool base 45 by rotation of the tool mounting portion 45b. Then, the crankshaft W is rotated by the rotational drive of the main shaft 42, the hydraulic pressure is generated by the hydraulic pump 63 by the drive of the electric motor 45b, and the hydraulic motor 64 is rotationally driven by the generated hydraulic pressure. Accordingly, the outer peripheral surface of the cutting cutter 61 is brought into contact with the outer peripheral surface of the pin portion Wb of the crankshaft W while rotating the cutting cutter 61 of the cutting unit 60 connected to the rotating shaft 64a of the hydraulic motor 64 (see FIG. 12). Further, the cutting cutter 61 (second tool base 45) is moved according to the rotation of the crankshaft W. With the above operation, the outer peripheral surface of the pin portion Wb is cut over the entire circumference and the entire length in the axial direction (pin portion cutting step S14).

(S15) Oil hole drilling step In this step, an oil hole drill (not shown) mounted on the tool mounting portion 44a of the first tool base 44 is changed from the state shown in FIG. 12 to the output shaft of the electric motor 44b. 44b1 is connected. Then, the oil drilling drill is pushed into a predetermined portion of the crankshaft W while rotating the oil drilling drill by driving the electric motor 44b. Thereby, a predetermined oil hole is formed in a predetermined part of the crankshaft W (oil hole machining step S15).

(S16) Screw tapping process In this process, the support device in a state in which the crankshaft W that is rotatably supported by the main shaft 42 and the tailstock 43 is mounted on the tool mounting portion 45a of the second tool base 45. 70 is rotatably supported. Specifically, the hydraulic pump 73 of the support device 70 is connected to the output shaft 45b1 of the electric motor 45b of the second tool base 45 by rotating the tool mounting portion 45a. Then, the second tool rest 45 is moved to introduce a predetermined portion of the crankshaft W (for example, the journal portion Wa most distant from the main shaft 42) between the three claw portions 71, 71, 71 of the support device 70 ( (See FIGS. 14 and 15).

  Thereafter, the electric motor 45b of the second tool base 45 is rotationally driven to generate a predetermined hydraulic pressure by the hydraulic pump 73, and the generated hydraulic pressure is supplied to the first port 73a and further to the first hydraulic pressure supply path 74a. To the first oil chambers 72a, 72a, 72a of the three hydraulic cylinders 72, 72, 72. As a result, the linear motion parts 72c, 72c, 72c of the three hydraulic cylinders 72, 72, 72 are pushed toward the crankshaft W side and connected to the linear motion parts 72c, 72c, 72c. , 71, 71 are pressed against the outer peripheral surface of the crankshaft W. Further, at this time, since the hydraulic pressure of an equal size acts on each of the linear motion parts 72c, 72c, 72c, the crankshaft W is pressed with an equal force from three directions, so that the main shaft 42 and the tailstock 43 The crankshaft W is rotatably supported by the support device 70 while maintaining the centered state.

  Thereafter, the tailstock 43 is moved backward to cancel the support state of the crankshaft W by the tailstock 43. As a result, the crankshaft W is rotatably supported by the main shaft 42 and the support device 70 while maintaining the previous centering state (see FIG. 15).

  From this state, the screw tap 49 attached to the tool mounting portion 44a of the first tool base 44 is connected to the output shaft 44b1 of the electric motor 44b of the first tool base 44, and the electric motor 44b rotates. While rotating the screw tap 49 by driving, the screw tap 49 is introduced into the screw hole formed in advance on the axial end face Wc far from the main shaft 42 of the crankshaft W (see FIG. 15). Thereby, a screw hole is formed in the axial direction end surface Wc (screw tapping process S16).

  As described above, after performing a plurality of machining steps S1 (S11 to S16) on the crankshaft W, one or more crankshafts W are transferred to the heat treatment step S2 by a transfer means (not shown). And after performing predetermined heat processing (for example, hardening process) with the heat processing apparatus 20, the one or several crankshaft W is similarly conveyed to finishing process S3 by the conveyance means which is not shown in figure. Then, the crankshaft W is finished to a predetermined product shape by applying a finishing process such as grinding to a predetermined portion of the crankshaft W by the grinding devices 30a to 30c. Thereafter, the crankshaft W as a product is obtained by performing cleaning, inspection, and the like as necessary.

  As described above, in the processing line 1 of the crankshaft W according to the present invention, the apparatus for carrying out the centering step S12 is constituted by the lathe 40, so that the lathe 40 is used as one or more machines after the centering step S12. It can be shared in the processing step (for example, the journal part cutting step S13). In other words, the same single lathe 40 can constitute an apparatus for performing one or more machining steps after the centering step S12. As a result, not only the centering step S12 and the total length determining step S11, but also all the machining steps such as the journal portion cutting step S13 in which the rotation of the crankshaft W is required, a single machining apparatus 10 (see FIG. 3 and the like). ), The machining steps S11 to S13... Can be consolidated more than before, and the productivity can be improved and the equipment cost and thus the production cost can be greatly reduced. Become.

  In the present embodiment, the cutting of the outer peripheral surface of the pin portion Wb, which has been conventionally performed using a dedicated processing device (such as a mirror processing machine), is performed by the machining device 10 including the lathe 40 and the cutting unit 60. It was possible. Specifically, a cutting unit 60 including a cutting cutter 61 for cutting the outer peripheral surface of the pin portion Wb of the crankshaft W and a rotating device 62 for rotating the cutting cutter 61 is used as a second of the lathe 40. The cutting cutter 61 was made rotatable by using the driving force generated by the electric motor 45b of the second tool table 45 mounted on the tool table 45. By configuring the cutting unit 60 in this way, it is possible to perform cutting on the outer peripheral surface of the pin portion Wb while the crankshaft W is supported by the main shaft 42 of the lathe 40. Thereby, all the machining processes S13 to S16 after the centering process including the pin part cutting process S14 can be performed by one lathe 40 (machining apparatus 10). Therefore, a plurality of machining processes can be further integrated, productivity can be further improved, and facility costs and thus production costs can be further greatly reduced.

  Further, in the present embodiment, the driving device for the lathe 40 (electric motor 44b built in each tool table 44, 45) is used in the total length determining step S11, the centering step S12, and all the machining steps S13 to S16 after the centering step S12. 45b), the crankshaft W is held and machined, so that the machining steps S11 to S16 are performed without newly attaching a dedicated holding device or machining device to the lathe 40. be able to. Thereby, it is possible to smoothly and sequentially carry out the machining steps S11 to S16 on one lathe 40 without the trouble of attaching or removing a dedicated device.

  Further, as described above, since all the machining steps S11 to S16 can be performed by the single machining apparatus 10, the recentering step after the heat treatment step S2 that has been necessary in some cases can be omitted. . That is, the crankshaft W is distorted by a certain amount of heat treatment such as quenching. Therefore, in the conventional processing line, it is indispensable to redo the centering processing after the heat treatment (the recentering step is provided after the heat treatment step S2). However, as in the processing line 1 according to the present embodiment, By performing the machining steps S11 to S16 before the heat treatment step S2, it is possible to omit the recentering step, thereby further reducing the production cost.

  In the present embodiment, the hydraulic pump 51 of the clamp device 50 is operated by the drive device of the lathe 40 (the electric motor 45b of the second tool base 45), and the hydraulic actuator 52 (hydraulic cylinder 55) is generated by the hydraulic pressure generated by the operation. The crankshaft W is configured to be clamped by actuating. As a result, while using the electric motor 45b as a drive source, a large clamping force can be exhibited as compared with a case where the pair of clamp portions 53 (54) are directly operated by the electric motor 45b. Therefore, it is possible to hold the crankshaft W firmly and perform various types of processing (end surface cutting processing, centering processing) with high accuracy. Further, since the hydraulic actuator 52 can be operated by using the electric motor 45b as a power source, it is not necessary to extend and connect an electric wire or a hydraulic hose from the periphery of the lathe 40. This avoids interference with the movable part of the lathe 40 (the tailstock 43, the first and second tool bases 44, 45, etc.), and makes a plurality of machining operations smoothly and smoothly on one lathe 40. It becomes possible to carry out.

  In the present embodiment, the three claw portions 71, 71, 71 driven by the hydraulic cylinders 72, 72, 72 support the outer peripheral surface of the crankshaft W, and the three hydraulic cylinders 72, 72, 72 are hydraulically operated. End face of the crankshaft W using a support device 70 provided with a hydraulic supply path 74 (74a, 74b) branched and connected to the three hydraulic cylinders 72, 72, 72 respectively. A predetermined process (screw tapping process) was performed on Wc (see FIGS. 13 to 15). As described above, the support device 70 that can supply hydraulic pressure to the hydraulic cylinders 72, 72, 72 through the hydraulic supply paths 74 (74 a, 74 b) branched and connected to the three hydraulic cylinders 72, 72, 72, respectively. By using this, the hydraulic pressure of an equal size is supplied to each hydraulic cylinder 72, 72, 72. Accordingly, the operation of each hydraulic cylinder 72, 72, 72 can automatically support the outer peripheral surface of the crankshaft W from each of the corresponding claw portions 71, 71, 71 with a uniform force from three directions. As a result, it is possible to support the outer peripheral surface of the crankshaft W while maintaining the position (centering position) of the crankshaft W that has already been centered. Therefore, it is possible to perform highly accurate end face machining on the crankshaft W supported in the centering state by the main shaft 42 of the lathe 40 while further reducing the cost by integrating the machining steps S11 to S16. It becomes possible.

  Although one embodiment of the present invention has been described above, the processing line for the crankshaft according to the present invention can adopt a configuration other than that described above without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the hydraulic actuator 52 that operates the pair of clamp portions 53 of the clamp device 50 includes the hydraulic cylinder 55, the link portion 56, and the hydraulic pressure supply passages 57a and 57b. The case where a closed hydraulic circuit is formed between the hydraulic supply passages 57a and 57b and the hydraulic pump 51 is illustrated (see FIG. 7). Of course, the hydraulic circuit of the clamping device 50 is not limited to the above configuration. . For example, as shown in FIG. 16, a switching valve 58 is disposed between the hydraulic pump 51 and the hydraulic cylinder 55, the second port 51 b of the hydraulic pump 51 is connected to the oil storage tank 59, and a switching operation of the switching valve 58 is performed. The connection destination of the first port 51a of the hydraulic pump 51, that is, the supply destination of the hydraulic pressure, may be configured to be switchable between the first oil chamber 55a and the second oil chamber 55b of the hydraulic cylinder 55. In this case, the hydraulic circuit according to this configuration forms a so-called open hydraulic circuit. According to this configuration, the flow rate of the hydraulic transmission medium (oil) can be increased, and the temperature increase of the upper transmission medium can be suppressed. Therefore, it is possible to construct a hydraulic circuit having excellent durability, and thus a clamping device 50 having excellent durability.

  In addition, when taking the structure shown in FIG. 16, the switching valve 58 may be an electromagnetic type, but may be a mechanical type, for example. If it is a mechanical type, wiring for power supply becomes unnecessary, so that interference with the movable part of the lathe 40 can be avoided and a series of machining can be carried out more smoothly. Further, when the clamping device 50 is mounted on the second tool base 45 of the lathe 40 as in the above-described embodiment, for example, a switching operation jig is mounted on the tool mounting portion 44a of the first tool base 44, The switching operation unit may be operated by moving the tool base 44 and engaging the switching operation jig with the switching operation unit of a mechanical switching valve 58 having a lever shape, for example. In this way, since the switching operation of the switching valve 58 can be automatically performed, it is possible to efficiently perform the clamping operation while saving mechanical labor while being mechanical.

  Of course, the hydraulic actuator 52 and the hydraulic pump 51 are not essential. For example, if there is no problem with the clamp output and the interference with the surroundings, each pair of clamp parts 53 and 53 (54, 54) is directly operated with electric power as a drive source, in other words, with the drive force generated by the electric motor 45b. It doesn't matter if you let them. Further, the form of the clamp mechanism is arbitrary as long as it can be clamped, and it is of course possible to take forms other than the form shown (each of the pair of clamp parts 53, 53, 54, 54).

  Moreover, in the said embodiment, although the structure which operates the clamp apparatus 50 by making the electric motor 45b built in the 2nd tool stand 45 into a drive device was illustrated, of course, drive devices other than this are used as a drive source of the clamp apparatus 50. It doesn't matter. In this case, the clamping device 50 may be used by being attached to a movable part of the lathe 40 other than the tool table (first tool table 44, second tool table 45).

  Of course, the clamp device 50 may be fixed to the bed 41 of the lathe 40 and the crankshaft W may be held if it does not adversely affect the series of machining using the lathe 40. At this time, as long as the above-described series of machining using the lathe 40 is not adversely affected, the clamping device 50 may be operated by obtaining a driving force from the outside of the lathe 40. In that case, there is no problem even if only one tool stand is used.

  Further, according to the processing line 1 of the crankshaft W according to the present invention, the installation space can be greatly reduced as compared with the prior art, so the degree of freedom of the means for transporting the crankshaft W between each process is increased. Can do. Moreover, if it is the processing line 1 which concerns on this invention, the arrangement | positioning aspect of each process S1, S2, S3 is also comparatively free (because it does not necessarily arrange | position in series one step at a time), and conveyance means also by this Can increase the degree of freedom.

DESCRIPTION OF SYMBOLS 1 Crankshaft processing line 10 Machine processing apparatus 20 Heat processing apparatus 30a, 30b, 30c Grinding apparatus 40 Lathe 41 Bed 42 Spindle 42a Chuck part 43 Tailstock 44, 45 Tool base 44a, 45a Tool mounting part 44b, 45b Electric motor 46 Milling 47 Drill 48 Cutting tool 49 Screw tap 50 Clamping device 51 Hydraulic pump 52 Hydraulic actuators 53, 54 A pair of clamp portions 55 Hydraulic cylinder 55a First oil chamber 55b Second oil chamber 55c Direct acting portion 56 Link portions 57a, 57b Hydraulic supply path 58 Switching valve 59 Oil storage tank 60 Cutting unit 61 Cutting cutter 62 Rotating device 63 Hydraulic pump 64 Hydraulic motor 64a Rotating shaft 66 Connecting member 70 Support device 71 Claw portion 72 Hydraulic cylinder 72a First oil chamber 72b Second oil chamber 72c linear motion part 73 Pressure pumps 74, 74a, 74b Hydraulic supply path S1 Machining process S2 Heat treatment process S3 Finishing process S11 Total length determining process S12 Centering process S13 Journal part cutting process S14 Pin part cutting process S15 Oil hole machining process S16 Tap machining process W Crankshaft Wa Journal part Wb Pin part Wc Axial end face

Claims (3)

A crankshaft processing line having a plurality of machining steps for performing predetermined machining on the crankshaft,
The plurality of machining steps include a centering step of performing a centering process on the crankshaft,
The centering step is a crankshaft processing line having a lathe for performing the centering process.   2. The crankshaft machining according to claim 1, wherein the crankshaft is held and machined by using the lathe drive device in the centering process and at least a part of the machining process after the centering process. line. The lathe has a tool table on which a tool can be mounted, and the tool table has an electric motor as the driving device that applies a driving force to the tool mounted on the tool table,
The centering step includes a clamp device that is attached to the tool rest and can clamp the crankshaft.
The clamp device includes a hydraulic pump that generates hydraulic pressure by the driving force of the electric motor, and a hydraulic actuator that operates by hydraulic pressure generated by the hydraulic pump, and the crankshaft can be clamped by the operation of the hydraulic actuator. The crankshaft processing line according to claim 2.

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