Forging press

Abstract

To provide a forging press for a crank shaft that can prevent a work-piece from being conveyed to a position for the next forging step / process, in an inclined state.SOLUTION: A forging press 100, which forges a work-piece W that is a crank shaft, is provided with: a lower mold 25; an upper mold 27; a transfer-type conveying device 30 that conveys the work-piece W positioned in each forging step to the next forging step, while holding the work-piece W; a sensor 60 that senses whether the conveying device 30 is holding the work-piece W or is not holding the work-piece; and interfering members 40, arranged between adjacent positions in the forging step in the lower mold 25 and arranged to protrude upward from an upper surface of the lower mold 25, which is configured to allow the work-piece W to pass when the work-piece W being conveyed by the conveying device 30 is in a proper posture and to interfere with the work-piece W when the work-piece W being conveyed by the conveying device 30 is in an improper posture.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a forging press. [Background technology]

[0002] Patent Documents 1 to 3 describe forging presses equipped with a transfer-type conveying device. The conveying device is configured to grip a workpiece positioned at each forging process and convey it to the position of the next forging process. A sensor is configured to detect whether the conveying device is gripping or not gripping a workpiece.

[0003] Furthermore, Patent Documents 4 and 5 describe a conveying device for a crankshaft, which is different from a forging press. These conveying devices describe members for positioning the crankshaft and for conveying and guiding it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-104610 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-25267 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-102997 [Patent Document 4] Japanese Patent Application Publication No. 6-166413 [Patent Document 5] Japanese Patent Application Publication No. 11429 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0005] In a forging press, a sensor detects whether the conveying device is gripping a workpiece or not. Therefore, if the conveying device is gripping a workpiece during transportation, the sensor is determined to be normal.

[0006] However, in a crankshaft forging press, because crankshafts are irregularly shaped, the posture of the workpiece placed on the lower die may become tilted after a certain forging process has been performed and just before transportation.

[0007] Even if the workpiece is tilted, depending on the degree of tilt, the transfer-type conveying device may be able to grasp the workpiece, and there is a risk that the tilted workpiece may be conveyed to the position for the next forging process. If the tilted workpiece is forged in the next forging process, it will be impossible to form a crankshaft with the desired shape. Therefore, it is necessary to prevent the workpiece from being conveyed to the position for the next forging process in a tilted state.

[0008] The present invention has been made in view of the above background, and aims to provide a crankshaft forging press that can prevent the workpiece from being transported to the position for the next forging process in an inclined state. [Means for solving the problem]

[0009] One aspect of the present invention is a crankshaft forging press, comprising: a lower die having a plurality of lower die forming recesses corresponding to a plurality of forging processes for forming the crankshaft; an upper die arranged opposite the lower die and having a plurality of upper die forming recesses corresponding to the plurality of forging steps; a transfer type conveying device that grasps a workpiece positioned at each of the forging processes and conveys it to the position of the next forging process; a sensor that detects whether the conveying device is gripping the workpiece or not; The forging press is equipped with an interference member that is positioned between adjacent forging process positions in the lower mold, that is positioned to protrude upward from the upper surface of the lower mold, that is configured to allow the work to pass when the work is in the correct position while being transported by the transport device, and that is configured to interfere with the work when the work is in an incorrect position while being transported by the transport device. [Effects of the Invention]

[0010] According to this aspect, the forging press includes an interference member. The interference member is disposed between adjacent forging process positions in the lower die and protrudes upward from the upper surface of the lower die. The interference member is configured to allow the workpiece to pass when the workpiece is in a correct posture during transport by the transport device. On the other hand, the interference member is configured to interfere with the workpiece when the workpiece is in an incorrect posture during transport by the transport device.

[0011] In this way, if the workpiece is in an incorrect position during transport by the transport device, the workpiece will interfere with the interference member. As a result, the position of the workpiece will change and the gripping state of the transport device will be released. The release of the gripping state by the transport device during transport can be detected by a sensor. By detecting with a sensor that the transport device is no longer gripping the workpiece during transport, appropriate action can be taken on the forging press. For example, the operation of the forging press can be stopped. Therefore, if the workpiece is in an incorrect position, the workpiece can be prevented from being transported to the position for the next forging process.

[0012] On the other hand, if the workpiece is in the correct posture, it is transported to the position for the next forging process without interfering with the interference member. Therefore, if the workpiece is in the correct posture, the forging process can be carried out sequentially without any effect from the interference member.

[0013] As a result of the above, it is possible to provide a crankshaft forging press that can prevent the workpiece from being transported to the position for the next forging process in an inclined state. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram showing the configuration of a crankshaft. [Figure 2] FIG. 1 is a front view showing the overall configuration of a forging press. [Figure 3] 3 is an enlarged vertical cross-sectional view showing members constituting a forging area in the forging press shown in FIG. 2. [Figure 4] IV-IV cross-sectional view in FIG. 3. [Figure 5] 5 is an enlarged cross-sectional view of FIG. 4, showing the fingers of the transfer device in a non-gripping position and the sensor in an ON state. [Figure 6] 5 is an enlarged cross-sectional view of FIG. 4, showing the fingers of the transfer device in the gripping position and the sensor in the OFF state. [Figure 7] FIG. 4 is a diagram showing the operation path of the transfer device. [Figure 8] 6 is a flowchart showing a process of determining whether a workpiece is in a gripped state or not gripped state by the control device. [Figure 9] 9 is an enlarged cross-sectional view taken along line IX-IX in FIG. 3, mainly showing an interference member. [Figure 10] FIG. 10 is a diagram showing a state in which a workpiece comes into contact with an interference member and the interference member is deformed. [Figure 11] 10 is a flowchart showing a transport process in the control device. [Figure 12] 10 is a flowchart showing a transport process in the control device. [Figure 13] 4 is a cross-sectional view taken along line IV-IV in FIG. 3, showing a state in which the workpiece is being transported in a normal posture during transport. [Figure 14] 4 is a cross-sectional view taken along line IV-IV in FIG. 3, showing a state in which a workpiece is being transported in an incorrect orientation during transport. DETAILED DESCRIPTION OF THE INVENTION

[0015] The crankshaft forging press comprises a lower die having a plurality of lower die forming recesses corresponding to a plurality of forging processes for forming the crankshaft; an upper die arranged opposite the lower die and having a plurality of upper die forming recesses corresponding to the plurality of forging processes; a transfer-type conveying device that grasps the workpiece located at each forging process and transports it to the position of the next forging process; a sensor that detects whether the conveying device is grasping or not grasping the workpiece; and an interference member that is arranged between the positions of adjacent forging processes on the lower die and protrudes upward from the upper surface of the lower die, and is configured to allow the workpiece to pass when the workpiece is in the correct position during transport by the conveying device, and is configured to interfere with the workpiece when the workpiece is in an incorrect position during transport by the conveying device.

[0016] The interference member may be configured to be positioned in a gap between adjacent counterweights of the crankshaft when the workpiece is in a normal position, thereby allowing the workpiece to pass, and to interfere with the counterweight when the workpiece is in an incorrect position. With this configuration, the interference member targets the counterweight of the workpiece, thereby ensuring the passage and interference of the workpiece.

[0017] It is also preferable that a plurality of the interference members be disposed between the positions of the adjacent forging processes, thereby ensuring that the interference members and the workpiece can interfere with each other even when the workpiece is in an incorrect position.

[0018] The lower mold may have a plurality of mounting holes for mounting the plurality of interference members, the mounting holes may be formed to different mounting depths, and the plurality of interference members may be formed to the same shape and arranged to protrude from the upper surface of the lower mold by different amounts. By making the plurality of interference members the same shape, the number of types of parts can be reduced.

[0019] The interference member may preferably include a mounting shaft portion having a non-circular cross section perpendicular to the axis, a cylindrical tip portion disposed at the tip end of the mounting shaft portion and configured to interfere with the workpiece when the workpiece is in an incorrect position during transport by the transport device, and a male thread portion disposed at the base end of the mounting shaft portion. This allows the interference member to be easily attached to the lower die by using the mounting shaft portion. Furthermore, by making the tip portion, which is the portion that interferes with the workpiece, a separate portion from the mounting shaft portion, the necessary configurations for the tip portion and the mounting shaft portion can be realized.

[0020] The tip portion is preferably formed thinner than the mounting shaft portion and configured to be bendable due to interference with the workpiece. By making the tip portion bendable, breakage of the tip portion can be prevented. Furthermore, by visually confirming that the tip portion has been bent, the worker can easily identify the interfering member that is interfering with the workpiece. As a result, countermeasures can be taken.

[0021] Furthermore, the interference member is made of the same material as the lower mold, which allows the interference member to have the desired strength and toughness.

[0022] The upper die may have an escape hole configured to allow the interference member to be inserted when the upper die is mated with the lower die, thereby preventing the interference member from affecting the forging of the workpiece by the lower die and the upper die.

[0023] The forging press may further include a control device that executes abnormality processing when the sensor detects that the conveying device has changed from gripping the workpiece to not gripping it due to interference between the workpiece and the interference member when the workpiece is in an incorrect position during conveyance by the conveying device. This prevents the forging press from continuing to operate continuously. As a result, the occurrence of breakdowns in the forging press can be suppressed, and the production of defective workpieces can be avoided.

[0024] (Embodiment) 1. Shape of workpiece W The workpiece W of the forging press 100 of this embodiment will be described with reference to Fig. 1. The workpiece W is a crankshaft. As shown in Fig. 1, the crankshaft that is the workpiece W is for a V6 engine, for example. However, the workpiece W of the forging press 100 of this embodiment is not limited to a crankshaft for a V6 engine, and various crankshafts can be used.

[0025] The crankshaft, which is the workpiece W, includes a plurality of journals 11a to 11d, a plurality of pins 12a to 12f, and a plurality of counterweights 13a to 13i. If the number of cylinders differs, the numbers of journals, pins, and counterweights also differ.

[0026] 2. Overall configuration of the forging press 100 The overall configuration of the forging press 100 will be described with reference to Fig. 2. The forging press 100 forms a crankshaft, which is a workpiece W, by hot forging in a plurality of steps.

[0027] 2, the forging press 100 includes a bed 21, a pair of left and right columnar columns 22 supported by the bed 21, and a crown 23 that fixes the upper portion of the column 22. The forging press 100 further includes a bolster 24 fixed to the upper surface of the bed 21, a lower die 25 detachably provided on the upper surface of the bolster 24, a slide 26 supported by the column 22 so as to be able to rise and fall, and an upper die 27 detachably provided on the lower surface of the slide 26. The lower die 25 and the upper die 27 are configured to sequentially perform a plurality of forging steps for forming a crankshaft, which is the workpiece W.

[0028] The forging press 100 also includes a carry-in station 28 and an unloading station 29. The carry-in station 28 is located on the upper surface of the bolster 24, on the carry-in side of the lower die 25 (right side in FIG. 2). The workpiece W that has been carried into the forging press 100 is placed in the carry-in station 28, which is used as a preparation position for transporting the workpiece W to the initial forging process. The unloading station 29 is located on the upper surface of the bolster 24, on the carry-out side of the lower die 25 (left side in FIG. 2). The workpiece W that has been processed in the final forging process is placed in the unloading station 29.

[0029] Furthermore, the forging press 100 is equipped with a transfer-type conveying device 30 that grips the workpiece W positioned at each forging step in the lower die 25 and the upper die 27 and conveys it to the position for the next forging step. The forging press 100 is also equipped with a control device 31 that controls the lifting and lowering of the slide 26 and the operation of the conveying device 30.

[0030] 3. Configuration of the lower die 25, upper die 27 and interference member 40 The configurations of the lower die 25, upper die 27, and interference member 40 will be described with reference to FIGS. 3 and 4. As described above, the lower die 25 is disposed on the upper surface of the bolster 24. The lower die 25 has multiple lower die forming recesses 25a corresponding to multiple forging processes. The lower die 25 is formed so that the portions forming each forging process can be separated. In other words, the lower die 25 is detachable for each portion forming each forging process. In FIGS. 3 and 4, the forging press 100 has first to fourth forging processes, and the lower die 25 has lower die components corresponding to each of the first to fourth forging processes. However, one lower die 25 may have portions corresponding to multiple forging processes. Note that in FIGS. 3 and 4, the first, second, third, and fourth forging processes are shown, starting from the loading station 28.

[0031] Furthermore, lower die 25 has mounting holes 25b that open to the upper surface between adjacent positions for the forging process (positions of lower die forming recesses 25a). Mounting holes 25b are holes for mounting interference member 40. Mounting holes 25b are formed in positions for mounting interference member 40.

[0032] 3 and 4, the mounting holes 25b are formed between the positions of the first and second forging processes, between the positions of the second and third forging processes, and between the positions of the third and fourth forging processes. However, this arrangement is not limited to this, and for example, the mounting holes 25b may be formed only between the positions of the third and fourth forging processes. Furthermore, for example, multiple mounting holes 25b, for example, two mounting holes, may be formed between the positions of adjacent forging processes. Of course, the mounting holes 25b may be formed in one location or three locations between the positions of adjacent forging processes.

[0033] The lower die 25 also includes knockout pins (not shown) for pushing the workpiece W upward at each forging step position.

[0034] The lower die 25 is made of, for example, hot forging die steel. Examples of hot forging die steel include alloy tool steel and high-speed tool steel. Examples of alloy tool steel include SKD4, SKD5, SKD6, SKD61, SKD622, SKD7, SKD8, SKT4, and precipitation hardened steel. Examples of high-speed tool steel include SKH51 and SKH55.

[0035] The interference member 40 is attached to the attachment hole 25b of the lower die 25. Therefore, the interference member 40 is disposed between the positions of adjacent forging processes (the positions of the lower die forming recesses 25a) in the lower die 25. Furthermore, the interference member 40 is disposed so as to protrude upward from the upper surface of the lower die 25. The interference member 40 is configured to allow the workpiece W to pass when the workpiece W is in a correct posture during transport by the transport device 30. Furthermore, the interference member 40 is configured to interfere with the workpiece W when the workpiece W is in an incorrect posture during transport by the transport device 30.

[0036] 3 and 4, the interference member 40 is disposed between the positions of the first and second forging processes, between the positions of the second and third forging processes, and between the positions of the third and fourth forging processes. However, this arrangement is not limited to this, and, for example, the interference member 40 may be disposed only between the positions of the third and fourth forging processes. Also, for example, a plurality of interference members 40, for example, two interference members 40, may be disposed between the positions of adjacent forging processes. Of course, only one interference member 40, or three or more interference members 40 may be disposed between the positions of adjacent forging processes.

[0037] The interference member 40 is formed from the same material as the lower die 25. For example, alloy tool steel, high-speed tool steel, or the like can be used for the interference member 40. The interference member 40 can change the posture of the workpiece W by interfering with the workpiece W, and has enough toughness to prevent breakage due to interference with the workpiece W.

[0038] The upper die 27 is disposed on the underside of the slide 26. The upper die 27 is disposed opposite the lower die 25 in the vertical direction. The upper die 27 has a plurality of upper die forming recesses 27a corresponding to a plurality of forging processes. Like the lower die 25, the upper die 27 is also formed so that the portions forming each forging process can be separated. In other words, the upper die 27 is detachable for each portion forming a forging process. Note that in FIG. 3, the lower die forming recesses 25a and the upper die forming recesses 27a are illustrated schematically, and actually have shapes for forming a crankshaft.

[0039] Furthermore, the upper mold 27 has escape holes 27b configured so that the interference members 40 can be inserted when the upper mold 27 is mated with the lower mold 25. The escape holes 27b are holes that open to the bottom surface of the upper mold 27. The escape holes 27b are formed in the same number as the interference members 40, at positions corresponding to the interference members 40. The depth of the escape holes 27b is deeper than the protrusion amount of the interference members 40, and the inner diameter of the escape holes 27b is larger than the outer diameter of the interference members 40. Therefore, when the upper mold 27 and the lower mold 25 are mated, the interference members 40 do not have any effect.

[0040] 4. Overall configuration of the conveying device 30 The overall configuration of the transfer type conveying device 30 will be described with reference to Figures 3 and 4. The conveying device 30 includes a first feed bar 51, a second feed bar 52, a first finger 53, a second finger 54, and a drive device 55.

[0041] The first feed bar 51 and the second feed bar 52 are arranged to extend in the conveying direction of the workpiece W, and are arranged to sandwich the lower mold 25 in a direction perpendicular to the conveying direction. The first feed bar 51 and the second feed bar 52 are configured to be movable in the conveying direction (X), the gripping / non-gripping direction (Y), and the lifting direction (Z). "Gripping / non-gripping" means gripping or non-gripping.

[0042] The first feed bar 51 is provided with a plurality of first fingers 53, which are arranged in the conveying direction. In FIGS. 3 and 4, five first fingers 53 are provided. Each of the first fingers 53 is formed in a shape that allows it to press one end of the workpiece W present at the corresponding forging process position. Therefore, each of the first fingers 53 is formed in a shape that corresponds to the shape of the workpiece W in the corresponding forging process.

[0043] The second feed bar 52 is provided with a plurality of second fingers 54, which are arranged in the conveying direction. In FIGS. 3 and 4, five second fingers 54 are provided. Each of the second fingers 54 is formed in a shape that allows it to press one end of the workpiece W present at the corresponding forging process position. Therefore, each of the second fingers 54 is formed in a shape that corresponds to the shape of the workpiece W in the corresponding forging process.

[0044] That is, the first finger 53 and the second finger 54 hold the workpiece W by sandwiching it from both sides. With the workpiece W held by the first finger 53 and the second finger 54, the first feed bar 51 and the second feed bar 52 can be moved to transport the workpiece W to a position for the next transport process.

[0045] Drive devices 55 are provided on both ends of first feed bar 51 and second feed bar 52. Drive devices 55 are configured to synchronously move first feed bar 51 and second feed bar 52 in the conveying direction (X), the gripping / non-gripping direction (Y), and the lifting direction (Z).

[0046] 5. Configuration of the first finger 53 and sensor 60 of the transport device 30 The configurations of the first fingers 53 and the sensor 60 of the conveying device 30 will be described with reference to Figures 5 and 6. As described above, the multiple first fingers 53 are arranged on the first feed bar 51. Each first finger 53 includes a first finger body 53a, a bracket 53b, and a detection member 53c.

[0047] The first finger body 53a is configured to be slidable relative to the first feed bar 51 in a gripping / non-gripping direction (Y) perpendicular to the conveying direction. The first finger body 53a is provided with a pressing member (e.g., an elastic member) not shown. Therefore, as a reference state, the first finger body 53a is positioned on the lower mold 25 side (advance position: upper position in FIG. 5) as shown in FIG. 5. On the other hand, as shown in FIG. 6, when the first finger body 53a is gripping the workpiece W, the first finger body 53a receives a reaction force from the workpiece W and is positioned at a position away from the lower mold 25 (retracted position: lower position in FIG. 6) against the pressing force of the pressing member.

[0048] The bracket 53b is fixed to the rear end of the first finger body 53a (the lower end in FIGS. 5 and 6). The bracket 53b is provided, for example, so as to hang down from the rear end of the first finger body 53a. The detected member 53c is fixed near the lower end of the bracket 53b. The detected member 53c is disposed in a position facing the first feed bar 51. Therefore, the bracket 53b and the detected member 53c move integrally with the first finger body 53a.

[0049] The forging press 100 further includes a plurality of sensors 60. The plurality of sensors 60 are arranged at positions on the first feed bar 51 corresponding to the plurality of first fingers 53, respectively. Specifically, the sensors 60 are arranged to face the detection target members 53c. For example, a proximity sensor may be used as the sensor 60. The sensor 60 outputs a signal corresponding to the distance from the detection target member 53c constituting the first finger 53. For example, when the distance between the sensor 60 and the detection target member 53c is closer than a predetermined value, the sensor 60 outputs an ON signal. On the other hand, when the distance between the sensor 60 and the detection target member 53c is farther than the predetermined value, the sensor 60 outputs an OFF signal.

[0050] In other words, the sensor 60 is configured to detect whether the first finger 53 of the transport device 30 is gripping or not gripping the workpiece W. In the example of the ON signal or OFF signal described above, as shown in Fig. 6, when the first finger 53 is gripping the workpiece W, the sensor 60 outputs an OFF signal. On the other hand, as shown in Fig. 5, when the first finger 53 is not gripping the workpiece W, the sensor 60 outputs an ON signal.

[0051] Here, the second finger 54 may be configured to slide relative to the second feed bar 52, similar to the first finger 53, or may be fixed relative to the second feed bar 52. The sensor 60 is disposed only on the first feed bar 51. However, the sensor 60 may also be disposed on the second feed bar 52 to detect the position of the second finger 54 and determine whether it is gripping or not gripping the workpiece W.

[0052] 6. Operation of the conveying device 30 The operation of the conveying device 30 will be described with reference to Fig. 7. Fig. 7 shows the movement paths of the first feed bar 51 and the second feed bar 52 that make up the conveying device 30. The first feed bar 51 and the second feed bar 52 operate in synchronization.

[0053] The first feed bar 51 and the second feed bar 52 operate in the following order: "gripping (approaching each other) → rising → moving forward in the conveying direction → lowering → non-gripping (moving away from each other) → returning in the opposite direction to the conveying direction," and repeat this operation. This operation is a so-called three-dimensional transfer conveying operation. By this operation, a workpiece W present at a predetermined forging process position is conveyed to the position of the next forging process. At this time, multiple workpieces W can be conveyed simultaneously. Note that the conveying device 30 can also be configured to perform two-dimensional transfer conveying operation. The two-dimensional transfer conveying operation is an operation in the following order: "gripping (approaching each other) → moving forward in the conveying direction → non-gripping (moving away from each other) → returning in the opposite direction to the conveying direction."

[0054] 7. Processing for determining whether the workpiece W is being gripped or not in the control device 31 The process of determining whether the sensor 60 is holding or not will be described with reference to Fig. 8. As shown in Fig. 8, the control device 31 acquires output information from the sensor 60 (S1). It is determined whether the acquired output information from the sensor 60 is ON or not (S2).

[0055] If the output information of the sensor 60 is ON (S2: Yes), it is determined that the corresponding first finger 53 and second finger 54 are not gripping the workpiece W (non-gripping state) (S3). On the other hand, if the output information of the sensor 60 is OFF (S2: No), it is determined that the corresponding first finger 53 and second finger 54 are gripping the workpiece W (gripping state) (S4).

[0056] 8. Detailed configuration of interference member 40 and mounting hole 25b The detailed configuration of the interference member 40 will be described with reference to Figures 9 and 10. As shown in Figure 9, the interference member 40 will be described as consisting of a first interference member 40a and a second interference member 40b.

[0057] 9, the first interference member 40a is configured to be positioned in the gap between adjacent counterweights 13c, 13d of the crankshaft, which is the workpiece W, when the workpiece W is in the normal posture during transport by the transport device 30, thereby allowing the workpiece W to pass. The first interference member 40a is configured to be positioned in the gap between adjacent counterweights 13h, 13i of the crankshaft, which is the workpiece W, when the workpiece W is in the normal posture, thereby allowing the workpiece W to pass.

[0058] On the other hand, as shown in Fig. 10, when the workpiece W during transport is in an incorrect position, for example, tilted relative to the correct position, the first interference member 40a is configured to interfere with the counterweight 13c or 13d, and the second interference member 40b is configured to interfere with the counterweight 13h or 13i.

[0059] The first interference member 40a and the second interference member 40b are formed to have the same shape. The first interference member 40a and the second interference member 40b each include a main body 41, a mounting shaft 42, a tip portion 43, and a male thread portion 44. The main body 41, the mounting shaft 42, the tip portion 43, and the male thread portion 44 are arranged coaxially.

[0060] The main body 41 is formed in a cylindrical shape, and at least a portion of it is inserted into the mounting hole 25b. The mounting shaft 42 is disposed at the tip side of the main body 41 and is formed to have the same outer diameter as the main body 41 or a smaller diameter than the main body 41. In this embodiment, the mounting shaft 42 is formed to have a smaller diameter than the main body 41. Furthermore, the mounting shaft 42 has a non-circular cross section perpendicular to its axis. Specifically, the mounting shaft 42 has a width across flats so that the tool is locked in the rotational direction.

[0061] The tip portion 43 is formed in a cylindrical shape. The tip portion 43 is located on the tip side of the mounting shaft portion 42. In particular, the tip portion 43 is located at the very tip of the first interference member 40a and the second interference member 40b. Therefore, as shown in FIG. 10 , if the workpiece W is in an incorrect position during transport, the tip portion 43 will interfere with the counterweights 13c, 13d, 13h, and 13i. The tip portion 43 is also formed thinner than the mounting shaft portion 42. Therefore, the tip portion 43 is configured to bend due to interference with the counterweights 13c, 13d, 13h, and 13i. Here, when the tip portion 43 receives an impact force from the workpiece W, the main body portion 41 and the mounting shaft portion 42 are configured not to bend. In other words, only the tip portion 43 bends due to interference with the workpiece W, and the main body portion 41 and the mounting shaft portion 42 do not bend.

[0062] The male thread portion 44 is disposed at the base end of the main body portion 41. In other words, the male thread portion 44 is disposed on the base end side of the mounting shaft portion 42.

[0063] The first interference member 40a is attached to a first mounting hole 61 of the mounting holes 25b of the lower mold 25, and the second interference member 40b is attached to a second mounting hole 62 of the mounting holes 25b of the lower mold 25.

[0064] The first mounting hole 61 includes a first circular hole 61a and a first female thread portion 61b. The first circular hole 61a has a cylindrical inner circumferential surface and a bottom surface. The main body portion 41 of the first interference member 40a is inserted into the first circular hole 61a, and the bottom surface of the main body portion 41 abuts against the bottom surface of the first circular hole 61a. The depth of the first circular hole 61a is shorter than the axial length of the main body portion 41 of the first interference member 40a. Therefore, the mounting shaft portion 42 and the tip portion 43 of the first interference member 40a protrude from the upper surface of the lower mold 25 over their entire lengths. In other words, the depth of the first circular hole 61a corresponds to the mounting depth of the first mounting hole 61.

[0065] The first female thread portion 61b is formed on the bottom surface of the first circular hole 61a. The male thread portion 44 of the first interference member 40a is screwed into the first female thread portion 61b.

[0066] The second mounting hole 62 includes a second circular hole 62a and a second female thread portion 62b. The second circular hole 62a has a cylindrical inner circumferential surface and a bottom surface. The main body portion 41 of the second interference member 40b is inserted into the second circular hole 62a, and the bottom surface of the main body portion 41 abuts against the bottom surface of the second circular hole 62a. The depth of the second circular hole 62a is shorter than the axial length of the main body portion 41 of the second interference member 40b. Therefore, the mounting shaft portion 42 and the tip portion 43 of the second interference member 40b protrude from the upper surface of the lower mold 25 over their entire lengths. In other words, the depth of the second circular hole 62a corresponds to the mounting depth of the second mounting hole 62.

[0067] In this embodiment, the first circular hole 61a and the second circular hole 62a are formed to have different depths. The depth of the first circular hole 61a is deeper than the depth of the second circular hole 62a. Therefore, the amount by which the first interference member 40a protrudes from the upper surface of the lower mold 25 is shorter than the amount by which the second interference member 40b protrudes.

[0068] The second female thread portion 62b is formed on the bottom surface of the second circular hole 62a. The male thread portion 44 of the second interference member 40b is screwed into the second female thread portion 62b. In this embodiment, the first female thread portion 61b and the second female thread portion 62b are the same.

[0069] 9. Transfer process by the control device 31 The transfer process by the control device 31 will be described mainly with reference to Figures 11 to 14. The control device 31 determines whether the first feed bar 51 and the second feed bar 52 in the transfer device 30 are located at the transfer start position, i.e., the initial position for gripping the workpiece W (S11). The transfer start position is the position where the gripping operation in Figure 7 ends. If the first feed bar 51 and the second feed bar 52 are not located at the transfer start position (S11: No), the process is repeated until they are located at the transfer start position.

[0070] When the first feed bar 51 and the second feed bar 52 are located at the transfer start position (S11: Yes), the control device 31 acquires information about the workpiece W in the target forging process based on pre-stored process information (S12). The process information includes information about whether or not the workpiece W was forged at each timing in each forging process. Therefore, the control device 31 knows whether, in a certain forging process, it is currently the timing to forge the workpiece W or the timing not to forge the workpiece W.

[0071] Next, the control device 31 determines whether or not there is a workpiece W to be forged in each forging process based on the acquired information about the workpiece W (S13). If there is a workpiece W to be forged (S13: Yes), the control device 31 acquires information about the sensor 60 of the transport device 30 that corresponds to the forging process (S14). In other words, the control device 31 acquires whether the target sensor 60 is ON or OFF.

[0072] 8, when the sensor 60 is ON, it indicates that the workpiece W is not being gripped. On the other hand, when the sensor 60 is OFF, it indicates that the workpiece W is being gripped.

[0073] If there is a workpiece W to be forged at the transfer start position and the information from the target sensor 60 is OFF (S15: No), the control device 31 starts the transfer operation of the workpiece W by the transfer device 30 (S16). That is, the transfer device 30 starts the series of operations of "up → forward → down" in FIG. 7.

[0074] Next, the control device 31 acquires information of the sensor 60 corresponding to the forging process of the transport device 30 during transport of the workpiece W (S17). That is, the control device 31 acquires whether the target sensor 60 is ON or OFF.

[0075] If the information from the target sensor 60 is OFF during the transport of the workpiece W (S18: No), the control device 31 determines whether the first feed bar 51 and the second feed bar 52 have reached the transport end position (S19). The transport end position is the position where the lowering operation in FIG. 7 ends, i.e., the position immediately before the non-gripping operation.

[0076] If the first feed bar 51 and the second feed bar 52 have not reached the transport end position (S19: No), transport is still in progress, so the process returns to S17 and repeats. In other words, it continues to determine whether the target sensor 60 remains OFF until transport is completed.

[0077] If the first feed bar 51 and the second feed bar 52 have reached the transfer end position (S19: Yes), a return operation process is performed (S20). The return operation process is a series of operations of "non-gripping (retracting) → return → gripping" in FIG. 7. Therefore, the return operation process returns the first feed bar 51 and the second feed bar 52 to the transfer start position again. Then, the process is repeated again from S1.

[0078] The control device 31 lowers and then raises the slide 26 during the return operation process of the transport device 30. In other words, the control device 31 forges the workpiece W using the lower die 25 and the upper die 27 during the return operation process of the transport device 30.

[0079] The above-described series of operations (S1 → S20) is the normal operation when transporting the workpiece W in the target forging process. Here, FIG. 13 shows a state in which the workpiece W is transported in a normal posture during transport. When the workpiece W is in a normal posture during transport, there is no interference between the interference member 40 and the workpiece W. Therefore, regardless of the presence of the interference member 40, the forging process of the workpiece W is performed continuously as described above.

[0080] Here, the case where S15 in Fig. 11 is Yes will be described. If there is a workpiece W to be forged at the transfer start position and the information from the target sensor 60 is ON (S15: Yes), the control device 31 executes abnormality processing (S21). For example, if the posture of the workpiece W that has been lifted up by the knockout pin after forging is tilted, the information from the target sensor 60 may be ON at the transfer start position even if there is a workpiece W to be forged. In other words, because the workpiece W is in an incorrect posture, the fingers 53, 54 cannot press the workpiece W, and the inappropriate phenomenon described above occurs.

[0081] The abnormality processing here is, for example, processing to stop the transport device 30 and the operation of the slide 26. In addition to this, the abnormality processing may also include processing to display an indication of an abnormality, generation of an alarm sound indicating an abnormality, notification of an abnormality, etc.

[0082] The case where the answer is Yes in S18 of Fig. 11 will be described. If the information from the target sensor 60 is ON while the workpiece W is being transported (S18: Yes), the control device 31 executes abnormality processing (S22). For example, even if the workpiece W is in an incorrect position, such as tilted, the workpiece W may be able to be grasped by the fingers 53, 54. In such a case, in S15, the information from the sensor 60 turns ON, and the transport operation is started.

[0083] However, as shown in Figure 14, if the workpiece W is tilted or has an incorrect posture during transport, the workpiece W will interfere with the interference member 40. Therefore, the posture of the workpiece W during transport will change further. As a result, the pressing state by the fingers 53, 54 can no longer be maintained, and the grip of the workpiece W by the fingers 53, 54 will be released. As a result, the information from the sensor 60 changes from OFF to ON.

[0084] In this way, if the workpiece W is in an incorrect position during transport, the workpiece W interferes with the interference member 40, causing the information from the sensor 60 to change from OFF to ON. In such a case, an abnormality process is executed. The abnormality process is, for example, a process of stopping the transport device 30 and stopping the operation of the slide 26. In addition to this, the abnormality process may also include a display process indicating an abnormality, generation of an alarm sound indicating an abnormality, notification of an abnormality, etc.

[0085] Next, the case where the answer is No in S13 of Fig. 11 will be described with reference to Fig. 12. If there is no workpiece W to be forged at the transfer start position of the target forging process (S13: No), the control device 31 acquires information about the sensor 60 of the transfer device 30 that corresponds to the target forging process (S31). That is, the control device 31 acquires whether the target sensor 60 is ON or OFF.

[0086] 8, when the sensor 60 is ON, it indicates that the workpiece W is not being gripped. On the other hand, when the sensor 60 is OFF, it indicates that the workpiece W is being gripped.

[0087] If there is no workpiece W to be forged at the transfer start position and the information from the target sensor 60 is ON (S32: Yes), the control device 31 starts the transfer operation of the workpiece W by the transfer device 30 (S33). That is, the transfer device 30 starts the series of operations of "up → forward → down" in Fig. 7. However, since there is no workpiece W to be transferred in this forging process, it is an empty transfer.

[0088] Next, during empty transport, the control device 31 acquires information from the sensor 60 corresponding to the forging process of the transport device 30 (S34). That is, the control device 31 acquires whether the target sensor 60 is ON or OFF.

[0089] If the information from the target sensor 60 is ON during empty transport (S35: Yes), the control device 31 determines whether the first feed bar 51 and the second feed bar 52 have reached the transport end position (S36). The transport end position is the position where the lowering operation in FIG. 7 ends, i.e., the position immediately before the non-gripping operation.

[0090] If the first feed bar 51 and the second feed bar 52 have not yet reached the transport end position (S36: No), transport is still in progress, so the process returns to S34 and repeats. In other words, it continues to determine whether the target sensor 60 remains ON until transport is completed.

[0091] If the first feed bar 51 and the second feed bar 52 have reached the transfer end position (S36: Yes), a return operation process is performed (S37). The return operation process is a series of operations of "non-gripping (retracting) → return → gripping" in FIG. 7. Therefore, the return operation process returns the first feed bar 51 and the second feed bar 52 to the transfer start position again. Then, the process is repeated again from S1 in FIG. 11.

[0092] The above-described series of operations (S31 to S37) is the normal operation during empty transport in the target forging process.

[0093] Here, the case where the answer is No in S32 of Fig. 12 will be described. When there is no workpiece W to be forged at the transfer start position and the information from the target sensor 60 is OFF (S32: No), the control device 31 executes abnormality processing (S38). Although the finger 53 should not move normally at the transfer start position, it may be that the finger 53 has moved for some reason, or that the sensor 60 has failed.

[0094] Here, the case where the answer is No in S35 of Fig. 12 will be described. If there is no workpiece W to be forged at the transfer start position and the information from the target sensor 60 is OFF (S35: No), the control device 31 executes abnormality processing (S39). During empty transfer, although the fingers 53 normally would not move, it is possible that the fingers 53 have moved for some reason, or that the sensor 60 has malfunctioned.

[0095] 10.Effects The forging press 100 of this embodiment, which uses a crankshaft as the workpiece W, comprises a lower die 25 having a plurality of lower die forming recesses 25a corresponding to a plurality of forging processes for forming the crankshaft, an upper die 27 arranged opposite the lower die 25 and having a plurality of upper die forming recesses 27a corresponding to a plurality of forging processes, a transfer-type conveying device 30 that grasps the workpiece W located at each forging process and transports it to the position of the next forging process, a sensor 60 that detects whether the conveying device 30 is grasping or not grasping the workpiece W, and an interference member 40 that is arranged between the positions of adjacent forging processes on the lower die 25, protrudes upward from the upper surface of the lower die 25, and is configured to allow the workpiece W to pass when the workpiece W is in the correct posture during transport by the conveying device 30, and is configured to interfere with the workpiece W when the workpiece W is in the wrong posture during transport by the conveying device 30.

[0096] If the workpiece W is in an incorrect position during transport by the transport device 30, the workpiece W will interfere with the interference member 40. As a result, the position of the workpiece W will change, and the workpiece W will be released from its grip by the transport device 30. The sensor 60 can detect that the workpiece W has been released from its grip during transport. By detecting with the sensor 60 that the transport device 30 is no longer gripping the workpiece W during transport, appropriate action can be taken on the forging press 100. For example, the operation of the forging press 100 can be stopped. Therefore, if the workpiece W is in an incorrect position, the workpiece W can be prevented from being transported to the position for the next forging process.

[0097] On the other hand, when the workpiece W is in the correct posture, the workpiece W is transported to the position for the next forging process without interfering with the interference member 40. Therefore, when the workpiece W is in the correct posture, the interference member 40 has no effect, and the forging process can be carried out sequentially. Therefore, it is possible to prevent the workpiece W from being transported to the position for the next forging process in an inclined state.

[0098] Furthermore, the interference member 40 is configured to be positioned in the gap between the adjacent counterweights 13a to 13i of the crankshaft when the workpiece W is in the correct posture, thereby allowing the workpiece W to pass. The interference member 40 is configured to interfere with the counterweights 13a to 13i when the workpiece W is in the incorrect posture. With this configuration, the interference member 40 targets the counterweights 13a to 13i of the workpiece W, thereby ensuring the passage and interference of the workpiece W.

[0099] Furthermore, a plurality of interference members 40 are arranged between the positions of adjacent forging processes, thereby ensuring that the interference members 40 and the workpiece W can interfere with each other even when the workpiece W is in an incorrect position.

[0100] The lower mold 25 also has a plurality of mounting holes 61, 62 for mounting a plurality of interference members 40. The plurality of mounting holes 61, 62 are formed to different mounting depths. The plurality of interference members 40a, 40b are formed to the same shape and are arranged to have different amounts of protrusion from the upper surface of the lower mold 25. By making the plurality of interference members 40a, 40b the same shape, the number of different part types can be reduced.

[0101] The interference member 40 also includes a mounting shaft 42 having a non-circular cross section perpendicular to the axis, a cylindrical tip portion 43 disposed on the tip side of the mounting shaft 42 and configured to interfere with the workpiece W when the workpiece W is in an incorrect position during transport by the transport device 30, and a male thread portion 44 disposed on the base end side of the mounting shaft 42. This allows the interference member 40 to be easily attached to the lower die by using the mounting shaft 42. Furthermore, by making the tip portion 43, which is the portion that interferes with the workpiece W, a separate portion from the mounting shaft 42, the configuration required for the tip portion 43 and the configuration required for the mounting shaft 42 can be realized.

[0102] The tip portion 43 is formed thinner than the mounting shaft portion 42 and is configured to be bendable due to interference with the workpiece W. Making the tip portion 43 bendable can prevent the tip portion 43 from breaking. Furthermore, by visually confirming that the tip portion 43 has been bent, the worker can easily identify the interfering member 40 that has interfered with the workpiece W. As a result, measures can be taken.

[0103] Furthermore, the interference member 40 is formed from the same material as the lower mold 25. This allows the interference member 40 to be a member having desired strength and toughness.

[0104] In addition, the upper die 27 may have an escape hole 27b configured to allow the interference member 40 to be inserted when the upper die 27 is mated with the lower die 25. This prevents the interference member 40 from having an effect when the workpiece W is forged by the lower die 25 and the upper die 27.

[0105] The forging press 100 further includes a control device 31 that executes abnormality processing when the sensor 60 detects that the conveying device 30 has changed from a state in which it is gripping the workpiece W to a state in which it is not gripping the workpiece W due to interference between the workpiece W and the interference member 40 when the workpiece W is in an incorrect position during conveyance by the conveying device 30. This makes it possible to avoid the forging press 100 from continuing to operate continuously. As a result, it is possible to suppress the occurrence of breakdowns in the forging press 100 and further to avoid the production of defective workpieces W. [Explanation of symbols]

[0106] 100 Forging Press 25 Lower mold 25a Lower mold forming recess 25b, 61, 62 Mounting holes 27 Upper mold 27a Upper mold forming recess 27b Relief hole 30 Conveyor device 31 Control device 40, 40a, 40b Interference members 41 Main body 42 Mounting shaft 43 Tip 44 Male thread 53,54 Finger 60 sensors 61a First circular hole 61b First female thread 62a Second circular hole 62b Second female thread double work 11a~11d Journal 12a~12f pin 13a~13i Counterweight X conveying direction Y gripping / non-grasping direction Z Up / Down Direction

Claims

1. 1. A crankshaft forging press, comprising: a lower die having a plurality of lower die forming recesses corresponding to a plurality of forging processes for forming the crankshaft; an upper die arranged opposite the lower die and having a plurality of upper die forming recesses corresponding to the plurality of forging steps; a transfer type conveying device that grasps a workpiece positioned at each of the forging processes and conveys it to the position of the next forging process; a sensor that detects whether the conveying device is gripping the workpiece or not; a forging press comprising: an interference member that is arranged between adjacent forging process positions in the lower die, that is arranged to protrude upward from the upper surface of the lower die, that is configured to allow the work to pass when the work is in the correct position while being transported by the transport device, and that is configured to interfere with the work when the work is in an incorrect position while being transported by the transport device.

2. 2. The forging press according to claim 1, wherein the interference member is configured to be positioned in a gap between adjacent counterweights of the crankshaft when the workpiece is in a correct posture, thereby allowing the workpiece to pass, and to interfere with the counterweights when the workpiece is in an incorrect posture.

3. The forging press according to claim 1 or 2, wherein a plurality of the interference members are arranged between adjacent positions of the forging process.

4. the lower mold has a plurality of mounting holes for mounting a plurality of the interference members, The plurality of mounting holes are formed to have different mounting depths, The forging press according to claim 3 , wherein the plurality of interference members are formed in the same shape and are arranged so that the amounts of protrusion from the upper surface of the lower die are different.

5. The interference member is a mounting shaft portion having a non-circular cross section perpendicular to the axis; a tip portion formed in a cylindrical shape, arranged on a tip side of the mounting shaft portion, and configured to interfere with the workpiece when the workpiece is in an incorrect posture during transport by the transport device; The forging press according to claim 1 or 2, further comprising: a male thread portion disposed on a base end side of the mounting shaft portion.

6. The forging press according to claim 5 , wherein the tip portion is thinner than the mounting shaft portion and is configured to be bendable by interference with the workpiece.

7. 3. The forging press according to claim 1, wherein the interference member is made of the same material as the lower die.

8. 3. The forging press according to claim 1, wherein the upper die has an escape hole configured so that the interference member can be inserted when the upper die is mated with the lower die.

9. The forging press of claim 1 or 2 further comprises a control device that executes abnormality processing when the sensor detects that the conveying device has changed from a state in which it is gripping the work to a state in which it is not gripping the work due to interference between the work and the interference member when the work is in an incorrect position during transport by the conveying device.

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