Crimping device, cell production equipment, and composite cell production equipment

Abstract

Provided is a device 20 that crimps either a nut or a bolt to a metal panel. The crimping device 20 comprises: an upper stroke displacement meter 37 that measures the stroke when crimping; a pressure gauge 38 that measures a pressing force when crimping; and a control unit 43 that determines whether the crimping result is acceptable on the basis of stroke information from the stroke displacement meter 37 and pressure information from the pressure gauge 38. The control unit 43 has a first acceptance criterion for the nut and a second acceptance criterion for the bolt.

Description

Caulking equipment, cell production equipment, and composite cell production equipment

[0001] The present invention relates to a crimping device for crimping nuts or bolts onto metal panels, and to a cell production facility including the crimping device.

[0002] It is known to fasten nuts and bolts to metal panels by spot welding. However, the heat of welding can cause the nuts and bolts to deform. It is also known to fasten nuts and bolts to metal panels with adhesive. However, this method reduces productivity because it takes a certain amount of time for the adhesive to solidify and exert its bonding strength.

[0003] Crimping is known as an alternative technology. Because crimping is performed at room temperature, thermal deformation does not occur. Furthermore, because no adhesive is used, productivity can be improved. Traditionally, crimping work has been performed manually by workers, but in recent years, the number of locations where nuts and bolts are attached to a single metal panel has been increasing. This increase in work loads has led to demands for improved productivity, and automation of crimping is therefore required.

[0004] A pierce nut driving device has been known as an automatic crimping device (see, for example, Patent Document 1 (FIG. 1)).

[0005] The technology of Patent Document 1 has the advantage that a pierce nut supplied via a hose is driven into a metal panel by a punch, and this driving automatically performs crimping.

[0006] However, the technology of Patent Document 1 only allows one type of nut to be processed with one pierce nut driving device. If there are multiple types of nuts with different sizes, multiple devices must be prepared.

[0007] [Metal Panel] Fig. 1(a) shows an example of a metal panel 10 used in a vehicle. The metal panel 10 is an aluminum alloy panel to which iron nuts and bolts are fastened. Note that the metal panel 10 may be a steel panel or a magnesium alloy panel, and the type of metal is not important.

[0008] As shown in Figure 1(a), two positioning holes 11 are drilled in a metal panel 10, and two nuts 13, two bolts 14, and two special nuts 15 are crimped to the metal panel 10. The special nuts 15 have a more complicated crimping configuration than the nuts 13.

[0009] Figure 1(b) is a cross-sectional view taken along line b-b in Figure 1(a). Figure 1(c) is an enlarged view of part c in Figure 1(b), Figure 1(d) is an enlarged view of part d in Figure 1(b), and Figure 1(e) is an enlarged view of part e in Figure 1(b). As shown in Figure 1(c), a nut 13 is crimped to the metal panel 10, as shown in Figure 1(d), a bolt 14 is crimped to the metal panel 10, and as shown in Figure 1(e), a special nut 15 is crimped to the metal panel 10.

[0010] Demand for such metal panels 10 has been increasing in recent years as automobile bodies have shifted from conventional steel panels to hybrid automobile bodies that combine steel and aluminum alloy panels in order to reduce the weight of automobile bodies. If a crimping device is prepared for each type of nut and bolt, the procurement cost of the crimping device increases. However, this increase in cost is undesirable.

[0011] As cost reductions are required, there is a demand for technology that can reduce the procurement costs of crimping equipment even if the number of types of nuts and bolts increases.

[0012] Japanese Patent Application Publication No. 6-320354

[0013] An object of the present invention is to provide a technology that can automatically crimp multiple types and numbers of nuts and bolts to a metal panel using a single crimping device.

[0014] The invention of claim 1 is a crimping device for crimping either a nut or a bolt to a metal panel, the crimping device comprising: a stroke displacement meter that measures the stroke when crimping; a pressure gauge that measures the applied pressure when crimping; and a control unit that determines whether the crimping result is acceptable based on stroke information from the stroke displacement meter and pressure information from the pressure gauge, and the control unit has at least one of a first pass / fail judgment criterion for the nut and a second pass / fail judgment criterion for the bolt.

[0015] The invention according to claim 2 is the crimping device according to claim 1, further comprising a variable hydraulic controller that changes the hydraulic pressure so that the pressure measured by the pressure gauge becomes a preset pressure.

[0016] The invention of claim 3 is a crimping device as described in claim 1, which has a post that rises from the base of a press machine, a lower holder that is removably attached to the post and holds a lower crimping die, a pressure shaft that is lowered from the frame of the press machine, and an upper holder that is removably attached to the pressure shaft and holds an upper crimping die.

[0017] The invention of claim 4 is a crimping device according to claim 3, which is provided with a positioning pin that passes through the lower crimping die and moves up and down, and a parts feeder that guides one of the nut and bolt to the positioning pin and places it on the positioning pin.

[0018] The invention of claim 5 is a crimping device according to claim 4, which is equipped with a lower stroke displacement meter that measures the lifting stroke of the positioning pin, and the control unit determines whether one of the nut and bolt is placed on the positioning pin in the correct posture based on stroke information from the lower stroke displacement meter.

[0019] The invention of claim 6 is a crimping device according to claim 5, wherein the first pass criterion and the second pass criterion are determined based on stroke information from the lower stroke displacement meter when the positioning pin is placed against the upper crimping die.

[0020] The invention of claim 7 is a crimping device according to claim 3, which is equipped with a camera that identifies the shape of one of the nuts and bolts placed between the lower crimping die and the upper crimping die, and the control unit determines whether the posture of one of the nuts and bolts is correct based on image information from the camera.

[0021] The invention according to claim 8 is the crimping device according to claim 6, wherein the positioning pin has a flat surface at a tip end.

[0022] The invention of claim 9 is a cell production facility including a plurality of crimping devices according to claim 1, the cell production facility comprising an entrance for carrying in the metal panel, a multi-axis robot for transporting the metal panel, a first crimping device having a first lower crimping die and a first lower holder attached to it that correspond to the nut, a second crimping device having a second lower crimping die and a second lower holder attached to it that correspond to the bolt, and an exit for carrying out the metal panel to which the nut and the bolt have been crimped, the entrance, the first crimping device, the second crimping device and the exit being arranged within the rotation range of the multi-axis robot and on the same circumference.

[0023] The invention of claim 10 is the cell production equipment of claim 9, wherein the metal panels include a first metal panel and a second metal panel having different shapes, a first gripping tool for gripping the first metal panel and a second gripping tool for gripping the second metal panel are placed in the cell production equipment, and the cell production equipment is equipped with an automatic tool changer that selects and attaches the first gripping tool and the second gripping tool to the multi-axis robot.

[0024] The invention of claim 11 is a cell production equipment according to claim 10, wherein the first metal panel consists of a left metal panel and a right metal panel having different shapes, the first gripping device has a left gripping portion that grips the left metal panel and a right gripping portion that grips the right metal panel, and the left gripping portion and the right gripping portion each have a positioning pin.

[0025] A twelfth aspect of the present invention is the cell production facility according to the ninth aspect, wherein the outlet is provided adjacent to the inlet.

[0026] An invention according to claim 13 is the cell production facility of claim 9, wherein the cell production facility is surrounded by a safety fence, and the cell production facility comprises a first parts feeder that guides the nuts to the first crimping device, the first parts feeder including a first parts supply unit that is arranged outside the safety fence and supplies the nuts one by one, and a first pipe that guides the nuts supplied by the first parts supply unit to the first crimping device by air transport, and a second parts feeder that guides the bolts to the second crimping device, the second parts feeder including a second parts supply unit that is arranged outside the safety fence and supplies the bolts one by one, and a second pipe that guides the bolts supplied by the second parts supply unit to the second crimping device by air transport.

[0027] The invention according to claim 14 is a composite cell production facility including a plurality of the cell production facilities according to claim 9, wherein the composite cell production facility comprises a first cell production facility and a second cell production facility, and the first cell production facility and the second cell production facility are connected by a common transport path.

[0028] In the invention of claim 1, a stroke displacement meter and a pressure gauge are added to a general-purpose press machine, and the control unit judges the quality of the crimping based on the stroke and pressure during crimping. Because the control unit has a first pass / fail judgment criterion for nuts and a second pass / fail judgment criterion for bolts, visual judgment by an operator is no longer necessary, and crimping can be performed automatically. Furthermore, a single crimping device can crimp many types of nuts and bolts to metal plates.

[0029] As a result, a technology is provided that allows multiple types and numbers of nuts and bolts to be automatically crimped to a metal panel using a single crimping device. That is, the present invention provides a technology that allows a single crimping device to automatically transport nuts and bolts, set them on a metal panel, and crimp them.

[0030] In the invention according to claim 2, the set pressure can be easily changed by the variable hydraulic controller. That is, the pressure is constant in inexpensive general-purpose presses. Even in cases where the pressure of the press cannot be changed, the set pressure can be changed by the variable hydraulic controller. As a result, the equipment cost can be reduced.

[0031] In the invention according to claim 3, the lower crimping die can be attached and detached to the post together with the lower holder, and the upper crimping die can be attached and detached to the pressure shaft together with the lower holder, depending on the type of nut and bolt. As a result, only minor modifications to a general-purpose press are required, which reduces equipment costs.

[0032] In the invention according to claim 4, a parts feeder places nuts or bolts on the positioning pins. If a parts feeder were attached to the top crimping die (or bottom crimping die), the structure of the top crimping die (or bottom crimping die) would become complicated. In this regard, in the present invention, a parts feeder is not attached to the top crimping die (or bottom crimping die), so the structure of the top crimping die (or bottom crimping die) is simplified. As a result, automation and the use of general-purpose presses are further promoted.

[0033] In the invention according to claim 5, the control unit determines whether the posture of the nut or bolt is correct based on the stroke information of the lower stroke displacement meter. Although it is possible to monitor the posture of the nut or bolt with a camera, by monitoring the posture of the nut or bolt with the lower stroke displacement meter according to the present invention, it is possible to reduce or eliminate the need for judgment by the camera.

[0034] In the invention according to claim 6, a height reference is determined by applying a positioning pin to the top crimping die. At this time, if the top crimping die or the bottom crimping die is set incorrectly or has been mistakenly replaced with another die, the error can be detected by applying the positioning pin.

[0035] In the invention according to claim 7, the control unit determines whether the posture of the nut or bolt is correct based on the image information from the camera. In claim 5, the determination of whether the posture of the nut or bolt is correct is based on the stroke information from the lower stroke displacement meter, but this may not be possible depending on the shape of the nut or bolt. Even in this case, a camera can determine whether the posture of the nut or bolt is correct, allowing stable crimping work to be maintained.

[0036] In the invention according to claim 8, the tip of the positioning pin has a flat surface, so that the positioning pin and the upper crimping die can be prevented from being damaged even if they are repeatedly brought into contact with the upper crimping die.

[0037] In the invention according to claim 9, a cell production facility including multiple crimping devices is provided, and the exit, first crimping device, second crimping device, and entrance are arranged on the same circumference within the rotation range of the multi-axis robot, thereby providing a more compact cell production facility. In addition, the transport distance of metal panels is minimized, improving productivity.

[0038] In the invention according to claim 10, the multi-axis robot is equipped with an automatic tool changer, and a first gripping tool for gripping the first metal panel and a second gripping tool for gripping the second metal panel can be selectively attached to the multi-axis robot, allowing crimping to be performed on a plurality of types of metal panels.

[0039] In the invention according to claim 11, the first gripping tool includes a left gripping portion for gripping the left metal panel and a right gripping portion for gripping the right metal panel, and the left gripping portion and the right gripping portion each include a positioning pin. By rotating the robot hand, it is possible to efficiently apply crimping to symmetrical body panels such as those of an automobile, thereby improving productivity.

[0040] In the invention according to claim 12, the exit for carrying out the metal panels is provided next to the entrance for carrying the metal panels in. Because the entrance and exit are adjacent to each other, one robot (or one worker) can handle both the supply and removal of the metal panels.

[0041] In the invention according to claim 13, the cell production equipment is surrounded by a safety fence, and the first and second parts supply units are located outside the safety fence. Nuts can be replenished to the first parts supply unit, and bolts can be replenished to the second parts supply unit outside the safety fence. Because the work is done outside the safety fence, nuts and bolts can be replenished easily and at any time.

[0042] In the invention according to claim 14, the composite cellular production facility comprises a first cellular production facility and a second cellular production facility, and the first cellular production facility and the second cellular production facility are connected by a common conveying path. The composite cellular production facility makes it possible to double the types and number of nuts and bolts.

[0043] (a) is a plan view of a metal panel, (b) is a cross-sectional view taken along line b-b in (a), (c) is an enlarged view of part c in (b), (d) is an enlarged view of part d in (b), and (e) is an enlarged view of part e in (b).

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[0083] [0 (a) is a diagram explaining the operation of the second lower crimping die, the second upper crimping die, and the second positioning pin, (b) is a diagram explaining a comparative example, (c) is a diagram explaining the correlation between pressure force and stroke, and (d) is a diagram explaining a comparative example. (a) and (b) are diagrams explaining the configuration and operation of the third lower crimping die, the third upper crimping die, and the third positioning pin. (a) is a diagram explaining the operation of the third lower crimping die, the third upper crimping die, and the third positioning pin, (b) is a diagram explaining a comparative example, and (c) is a diagram explaining the correlation between pressure force and stroke. Graphs explaining first to third pass criteria. A plan view of a cell production facility according to the present invention. (a) is a plan view of the first to third grippers, (b) is a cross-sectional view taken along line b-b in (a), (c) is a view seen from the arrow c-c in (a), and (d) is a view seen from the arrow d-d in (a). 1A is a plan view of the first to third parts feeders, FIG. 1B is a cross-sectional view taken along line bb in FIG. 1A, and FIG. 1C is a diagram illustrating the operation of the multi-cell production facility according to the present invention.

[0044] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0045] [Crimping Apparatus] As shown in FIG. 2, the crimping apparatus 20 is constructed by mounting a general-purpose press machine 21 with accessories 31 for the present invention.

[0046] The press 21 is a hydraulic press machine with a constant pressurizing force, to which a variable hydraulic controller 22 has been added. The hydraulic press machine has a hydraulic cylinder 24 on top of a C-shaped frame 23. The piston rod of this hydraulic cylinder 24 serves as a pressurizing shaft 25.

[0047] The equipment 31 comprises the variable hydraulic controller 22, a post 32 rising from the base 26 of the press 21, a lower holder 34 removably attached to the post 32 and holding a bottom crimping die 33, an upper holder 36 removably attached to the pressure shaft 25 and holding an top crimping die 35, an upper stroke displacement meter 37 as a stroke displacement meter that measures the lifting stroke of the upper holder 36, a pressure force meter 38 that measures the upward pressure applied to the top crimping die 35, a positioning pin 39 that passes through the bottom crimping die 33 and is lifted and lowered, a pin lifting cylinder 41 that lifts and lowers the positioning pin 39, a lower stroke displacement meter 42 that measures the lifting stroke of the positioning pin 39, and a control unit 43 that performs various controls.

[0048] The lower holder 34 is removably connected to the post 32 with a screw. The upper holder 36 is removably connected to the pressure shaft 25 with a pin. The pressure gauge 38 is preferably a load cell that electrically measures strain and converts this strain into force.

[0049] In the following description, when there are multiple types of bottom crimping dies 33, they will be referred to as the first bottom crimping die 33A with the letter A attached, the second bottom crimping die 33B with the letter B attached, and the third bottom crimping die 33C with the letter C attached. The same applies to the lower holder 34, the upper crimping die 35, the upper holder 36, and the positioning pin 39.

[0050] That is, a first bottom crimping die 33A, a second bottom crimping die 33B, and a third bottom crimping die 33C are interchangeably attached to one post 32 via first to third bottom holders 34A to 34C.

[0051] Similarly, a first upper crimping die 35A, a second upper crimping die 35B, and a third upper crimping die 35C are interchangeably attached to one pressure shaft 25 via first to third upper holders 36A to 36C.

[0052] The first positioning pin 39A, the second positioning pin 39B, and the third positioning pin 39C are replaceable. Since they are replaceable, there is no problem in continuing to use them without replacement.

[0053] Next, the caulking of the nut 13 explained in FIG. 1(c) will be explained in detail with reference to FIGS.

[0054] As shown in Fig. 3(a), the first lower crimping die 33A, the first upper crimping die 35A, and the first positioning pin 39A are replaced. In this case, at least immediately after the replacement, the first positioning pin 39A is raised and brought into contact with the first upper crimping die 35A. By bringing them into contact, the following two effects are obtained.

[0055] First, if the first upper crimping die 35A is displaced after replacement or is replaced with an incorrect die, the height position of the first positioning pin 39A will differ from the expected height position. When this difference occurs, the control unit (FIG. 2, reference numeral 43) issues an alarm indicating that the first upper crimping die 35A is incorrect. This allows for automatic detection of a missetting. Second, the contact position can be used as a reference for the lifting stroke of the first upper crimping die 35A and the first positioning pin 39A.

[0056] After the first positioning pin 39A makes contact, it is possible to lower the first positioning pin 39A to a predetermined height. Then, as shown in FIG. 3(b), the metal panel 10 is placed on the first bottom crimping die 33A by a first gripper 60A attached to a robot hand (FIG. 10, reference numeral 55a). Next, the nut 13 is moved as indicated by arrow (1) by a magnetic head 75A and placed on the first positioning pin 39A. The magnetic head 75A may be either a permanent magnet or an electromagnet. If the magnetic head 75A is an electromagnet, it is demagnetized when the nut 13 reaches the first positioning pin 39A.

[0057] The tip of the first positioning pin 39A is preferably formed as a flat surface 39a. If the tip has a flat surface 39a, the first upper crimping die 35A will not be damaged even if the pin is repeatedly brought into contact with the first upper crimping die 35A. The same applies to the second positioning pin 39B and the third positioning pin 39C.

[0058] 3(b), the nut 13 is composed of a head portion 13a and a neck portion 13b that has a smaller diameter than the head portion 13a and extends downward from the head portion 13a. An internal thread 13c is cut in the head portion 13a. A V-shaped portion 13d is provided at the boundary between the head portion 13a and the neck portion 13b.

[0059] [Camera] The nut 13 can be photographed with a camera 45. The control unit (FIG. 2, reference numeral 43) stores image information indicating the correct posture and compares it with the photographed image information. For example, if the neck portion 13b is on top and the head portion 13a is on the bottom, the control unit determines that the posture of the nut 13 is incorrect. The camera 45 is particularly useful for special nuts 15, in which the upper and lower small diameter portions 15b and the thin-walled cylindrical portion 15c are symmetrical in shape and size around the large diameter portion 15a.

[0060] 3B, when the first upper crimping die 35A is lowered, the protrusion 35a of the first upper crimping die 35A fits into the female thread 13c. Thereafter, the nut 13 and the first positioning pin 39A are lowered by the first upper crimping die 35A.

[0061] As shown in Figure 4(a), a portion of the metal panel 10 (the periphery of the hole) bites into the V-shaped portion 13d. When this biting is sufficient, the nut 13 is crimped to the metal panel 10. In other words, the crimping result is acceptable. The downward stroke of the first upper crimping die 35A at this time is L1, and the pressure is P1. This pressure P1 also serves as a preset pressure.

[0062] 4(b), even though the applied pressure is the set pressure P1, the nut 13 only penetrates partway into the neck portion 13b of the metal panel 10 due to misalignment with the hole or an inclined posture. In this case, the crimping result is rejected. The downward stroke of the upper crimping die 35 at this time is designated as LL1.

[0063] [First pass criterion] As shown in Figure 4(c), imagine a graph with the pressure force P on the horizontal axis and the stroke L on the vertical axis. In Figure 4(a), the crimping results are recorded while changing the pressure force. The correlation between the pressure force P and the stroke L is determined from those whose crimping results pass. Based on this correlation, a first pass area C1 is determined. The coordinates (P1, L1) are within the first pass area C1, and the coordinates (P1, LL1) are outside the first pass area C1. This first pass area C1 is called the first pass criterion for the nut.

[0064] The control unit determines whether the stroke and pressure are within the first pass area C1 as passing, and whether they are outside the first pass area C1 as failing. The control unit then stores, records, and displays the results of determining whether the nut is passing or failing based on the first pass criteria, and suspends production if the nut fails. This suspension allows for maintenance and other operations to be performed.

[0065] Next, the caulking of the bolt 14 explained in FIG. 1(d) will be explained in detail with reference to FIGS. 5 and 6. FIG.

[0066] 5(a), when the second bottom crimping die 33B, the second top crimping die 35B, and, if necessary, the second positioning pin 39B are replaced, the first positioning pin 39A or the second positioning pin 39B is raised and brought into contact with the second top crimping die 35B at least immediately after the replacement. By bringing them into contact, it is possible to confirm that the second top crimping die 35B is the correct type, and the position at which they are brought into contact can be used as a reference for the lifting and lowering strokes of the second top crimping die 35B and the second positioning pin 39B.

[0067] After the contact, the second positioning pin 39B can be lowered to a predetermined height. Then, as shown in Fig. 5(b), the metal panel 10 is placed on the second bottom crimping die 33B by the first gripping tool 60A.

[0068] Next, the second magnetic head 75B and the second cylinder unit 76B press the bolt 14 against the bottom of the second top crimping die 35B. At least the bottom of the second top crimping die 35B is magnetized, and attracts the bolt 14.

[0069] [Bolt] The bolt 14 comprises a head portion 14a, a neck portion 14b that is smaller in diameter than the head portion 14a and extends downward from the head portion 14a, and a male thread portion 14c that extends downward from the neck portion 14b. A V-shaped portion 14d is provided at the boundary between the head portion 14a and the neck portion 14b.

[0070] [Camera] The bolt 14 is imaged by the camera 45. The control unit (FIG. 2, reference numeral 43) stores image information of the correct posture, and by comparing the image information with the captured image, it determines that the posture of the bolt 14 is incorrect if, for example, the neck portion 14b is above and the head portion 14a is below.

[0071] [Bolt Crimping] As shown in Figure 6(a), a portion of the metal panel 10 (the periphery of the hole) bites into the V-shaped portion 14d. When this bite is sufficient, the bolt 14 is crimped into the metal panel 10. In other words, the crimping result is acceptable. At this time, the downward stroke of the second upper crimping die 35B is L2, and the pressure is P2. This pressure P2 also serves as a preset pressure.

[0072] 6(b), even though the applied pressure is the set pressure P2, the bolt 14 only penetrates partway into the neck portion 14b of the metal panel 10 due to misalignment with the hole or an inclined posture. In this case, the crimping result is rejected. The downward stroke of the upper crimping die 35 at this time is designated as LL2.

[0073] [Second Pass Criterion] A second pass area C2 for the second pass criterion is set using the same procedure as for the first pass criterion, as shown in Fig. 6(c). When caulking the bolt 14, the control unit determines that the bolt is passed if the stroke and pressure are within the second pass area C2, and determines that the bolt is failed if they are outside the second pass area C2. The determination result is the same as for the first pass criterion.

[0074] [Poor Bolt Posture] Poor posture of the bolt 14 can be detected not only by the camera 45 shown in Fig. 5(b) but also by the position of the second positioning pin 39B. That is, as shown in Fig. 6(d), when the head portion 14a of the bolt 14 is facing downward, the second upper crimping die 35B or the second positioning pin 39B does not descend to a predetermined height (see reference numeral 39B in Fig. 6(a)). As a result, poor posture of the bolt 14 can be detected. In the case of the bolt 14, the camera can be omitted.

[0075] Next, the caulking of the special nut 15 explained in FIG. 1(e) will be explained in detail with reference to FIGS.

[0076] 7(a), when the third bottom crimping die 33C, the third top crimping die 35C, and, if necessary, the third positioning pin 39C are replaced, the third positioning pin 39C is raised and brought into contact with the third top crimping die 35C at least immediately after the replacement. By bringing the third top crimping die 35C into contact, it is possible to confirm that the third top crimping die 35C is the correct type and in the correct position, and the contact position can be used as a reference for the lifting and lowering strokes of the third top crimping die 35C and the third positioning pin 39C.

[0077] After the pin 39C makes contact, it can be lowered to a predetermined height. Then, as shown in Figure 7(b), the special nut 15 is placed on the pin 39C. Then, the metal panel 10 is placed on the special nut 15.

[0078] [Special Nut] The special nut 15 comprises a large diameter portion 15a, a small diameter portion 15b extending in one direction from the large diameter portion 15a (in this example, extending downward), and a thin-walled cylindrical portion 15c extending in the other direction from the large diameter portion 15a. A female thread portion 15d is provided in the small diameter portion 15b. A V-shaped portion 15e is provided at the boundary between the large diameter portion 15a and the thin-walled cylindrical portion 15c.

[0079] 7(b), with the metal panel 10 placed on the special nut 15, the third upper crimping die 35C is lowered. The cone portion 35b of the third upper crimping die 35C fits into the thin-walled tubular portion 15c. When the third upper crimping die 35C is lowered, the large diameter portion 15a is placed on the third lower crimping die 33C. Once placed, the cone portion 35b begins to expand the thin-walled tubular portion 15c.

[0080] As a result, as shown in Figure 8(a), the thin-walled tubular portion 15c covers the metal panel 10. In this state, the crimping result is acceptable. The downward stroke of the third upper crimping die 35C at this time is L3, and the pressure force is P3. This pressure force P3 also serves as a preset pressure force.

[0081] 8B, even though the pressure is set to P3, the plastic deformation of the thin-walled cylindrical portion 15c of the special nut 15 is not complete. In this case, the crimping result is rejected. The downward stroke of the upper crimping die 35 at this time is designated as LL3.

[0082] [Third Pass Criterion] Using the same procedure as for the first pass criterion, a third pass area C3 for the third pass criterion is set as shown in Figure 8(c). When caulking the special nut 15, the control unit determines that the stroke and pressure are pass if they are within the third pass area C3, and determines that the stroke and pressure are fail if they are outside the third pass area C3. The determination result is the same as for the first pass criterion.

[0083] [Pass / Fail Determination for Crimping Nuts or Bolts] An example of a map (graph) for pass / fail determination is shown in Fig. 9. This map (graph) shows a first pass area C1 for the first pass criterion, a second pass area C2 for the second pass criterion, and a third pass area C3 for the third pass criterion.

[0084] The control unit 43 shown in FIG. 2 stores a map (graph), and when tightening a nut (FIG. 3(b), reference numeral 13), selects the first pass area C1, and judges the pressure obtained by the pressure meter 38 and the stroke obtained by the upper stroke displacement meter 37 as "pass" if they are within the first pass area C1, and as "fail" if they are outside.

[0085] Similarly, the control unit 43 makes the following judgment: When tightening a bolt (FIG. 5B, reference numeral 14), the second pass area C2 is selected, and if the pressure measured by the pressure gauge 38 and the stroke measured by the upper stroke displacement gauge 37 are within the second pass area C2, it is judged as "pass," and if they are outside, it is judged as "fail."

[0086] When a special nut (Figure 7(b), symbol 15) is being crimped, the third pass area C3 is selected, and if the pressure measured by the pressure gauge 38 and the stroke measured by the upper stroke displacement gauge 37 are within the third pass area C3, it is judged as "pass," and if they are outside, it is judged as "fail."

[0087] The crimping device 20 described above can be summarized as follows: The crimping device 20 is a device for crimping either the nut 13 or the bolt 14 to the metal panel 10, and as shown in Fig. 2, the crimping device 20 includes an upper stroke displacement meter 37 that measures the stroke during crimping, a pressure force meter 38 that measures the applied pressure during crimping, and a control unit 43 that determines whether the crimping result is acceptable based on the stroke information from the stroke displacement meter 37 and the pressure force information from the pressure force meter 38, and the control unit 43 has at least one of a first pass criterion for nuts (first pass area C1) and a second pass criterion for bolts (second pass area C2), as shown in Fig. 9.

[0088] 4A, the nut 13 can be crimped using the first lower crimping die 33A and the first upper crimping die 35A. In FIG. 2, the first lower crimping die 33A and the first upper crimping die 35A are replaced with the second lower crimping die 33B and the second upper crimping die 35B.

[0089] 6(a), the bolt 14 can be crimped by the second lower crimping die 33B and the second upper crimping die 35B. In other words, the present invention has the advantage of providing a technology that allows a nut and a bolt to be crimped using a single crimping device 20.

[0090] 2, the crimping device 20 is preferably provided with a variable hydraulic controller 22 that changes the hydraulic pressure so that the pressure measured by the pressure gauge 38 becomes a preset pressure (for example, P1 shown in FIG. 4(c)). The variable hydraulic controller 22 has the advantage of making it easy to set the set pressure.

[0091] 2, the crimping device 20 preferably includes a post 32 extending from the base 26 of the press 21, a lower holder 34 removably attached to the post 32 and holding a bottom crimping die 33, a pressure shaft 25 lowered from the frame 23 of the press 21, and an upper holder 36 removably attached to the pressure shaft 25 and holding an top crimping die 35. Depending on the type of nut and bolt, the bottom crimping die 33 can be attached and detached to the post 32 together with the lower holder 34, and the top crimping die 35 can be attached and detached to the pressure shaft 25 together with the lower holder 36. This provides the advantage of facilitating the use of a general-purpose press 21.

[0092] Preferably, the crimping device 20 includes a positioning pin 39 that passes through the lower crimping die 33 and moves up and down, and a parts feeder that guides one of the nut 13 and the bolt to the positioning pin 39 and places it on the positioning pin 39, as shown in FIG. 3(b). The parts feeder is composed of a first magnetic head 75A, a first cylinder unit 76A, etc. This simplifies the structure of the upper crimping die 35A (or the lower crimping die 33A). As a result, there is an advantage in that the use of a general-purpose press 21 is further promoted.

[0093] 2, the crimping device 20 preferably includes a lower stroke displacement meter 42 that measures the lifting stroke of the positioning pin 39. The control unit 43 determines whether the nut or bolt is placed in the correct posture on the positioning pin 39 based on stroke information from the lower stroke displacement meter 42. The lower stroke displacement meter can be used to determine whether the posture of the nut or bolt is correct.

[0094] Preferably, as shown in Fig. 3(a), a positioning pin (first positioning pin 39A) is placed on the top crimping die (first top crimping die 35A). Stroke information is obtained using a lower stroke displacement meter (Fig. 2, reference numeral 42). Based on this stroke information, the first pass / fail criteria and the second pass / fail criteria are determined, as shown in Fig. 9. When the top crimping die has been mistakenly replaced with another die, the positioning pin is placed on the die, which has the advantage of detecting the error because the detected height differs from the predetermined value.

[0095] Preferably, as shown in Fig. 3(b), the shape of the nut or bolt between the lower crimping die (first lower crimping die 33A) and the upper crimping die (first upper crimping die 35A) is identified by a camera 45. This has the advantage of being able to maintain stable crimping work, as it is possible to determine whether the posture of the nut or bolt is correct.

[0096] Preferably, as shown in Fig. 3(a), the tip of the positioning pin (first positioning pin 39A) is formed into a flat surface 39a, which has the advantage that damage to the positioning pin and the upper crimping die can be prevented even when the pin is repeatedly brought into contact with the upper crimping die.

[0097] In the above description, the nuts 13, bolts 14, and special nuts 15 can be crimped with one crimping device 20 shown in Fig. 2. However, it is also possible to increase productivity by using a plurality of crimping devices 20. A specific example of this is described below.

[0098] [Difference between cell production and line production] Line production facilities, which have many presses and multi-axis robots arranged alongside long conveyors, are suited to high-volume, small-item production, but are expensive to set up and difficult to modify. In contrast, cell production facilities, which have presses and multi-axis robots arranged in cells (small rooms), are suited to low-volume, high-item production, have low equipment costs, and are easy to modify.

[0099] [Cell Production Facility] Fig. 10 is a plan view of the cell production facility. As shown in Fig. 10, the cell production facility 50 includes a cell 53 surrounded by a wall 51 and a safety fence 52, an entrance 54 for carrying in metal panels, a multi-axis robot 55 for transporting the metal panels, a first crimping device 20A having a first bottom crimping die and a first bottom holder for nuts, a second crimping device 20B having a second bottom crimping die and a second bottom holder for bolts, a third crimping device 20C having a third bottom crimping die and a third bottom holder for special nuts, and an exit 56 for carrying out the metal panels with nuts, bolts, and special nuts crimped thereto. The entrance 54, the first crimping device 20A, the second crimping device 20B, the third crimping device 20C, and the exit 56 are arranged within the rotation range of the multi-axis robot 55 and on the same circumference 57.

[0100] Since the entrance, first crimping device, second crimping device, and exit are arranged on the same circumference, a more compact cell production facility is provided, and in addition, the metal panels are transported over the shortest distance, which has the advantage of improving productivity.

[0101] Furthermore, the cell production equipment 50 is equipped with a cell-side control unit 58 that comprehensively controls the first control unit 43A, the second control unit 43B, the third control unit 43C, and the multi-axis robot 55. This cell-side control unit 58 receives, memorizes, records, and displays the results of the crimping judgments from the first control unit 43A, the second control unit 43B, and the third control unit 43C, and suspends production if the result is unsuccessful. This suspension allows for maintenance and other operations to be performed. Furthermore, the cell production equipment 50 is equipped with multiple grippers (e.g., a first gripper 60A, a second gripper 60B, and a third gripper 60C) that grip the metal panel.

[0102] [Gripping Tool] As shown in FIG. 11( a), a vehicle is composed of a left metal panel 10L (L is a suffix indicating left) and a right metal panel 10R (R is a suffix indicating right), such as a left door and a right door. Therefore, the first gripping tool 60A includes a left gripping portion 61L corresponding to the left metal panel 10L, a right gripping portion 61R corresponding to the right metal panel 10R, a common frame 62 connecting the left and right gripping portions 61L and 61R, and a jig-side ATC (ATC: automatic tool changer) 63 provided in the middle of the common frame 62. The jig-side ATC 63 and the robot-side ATC 64 constitute an automatic tool changer 65. Furthermore, the left gripping portion 61L has a positioning pin 66 inserted into the positioning hole 11 of the left metal panel 10L, a clamp claw 67, and a rotary actuator 68. The right gripping portion 61R is similar.

[0103] As shown in FIG. 11( b ), the left metal panel 10L placed on the left gripping portion 61L and positioned by the positioning pin 66 is held down by a clamp claw 67 that is rotated by a rotary actuator 68 .

[0104] Fig. 11(c) is a view taken along the line c-c in Fig. 11(a), and Fig. 11(d) is a view taken along the line dd in Fig. 11(a). As shown in Fig. 11(c), the jig-side ATC 63 has a fitting recess 63a and two pins 63b on the left and right.

[0105] 11(d), the robot-side ATC 64 has a mating protrusion 64a and two claws 64b on the left and right. The jig-side ATC 63 can be connected to the robot-side ATC 64 by fitting the mating protrusion 64a into the mating recess 63a and hooking the claws 64b onto the pin 63b. The jig-side ATC 63 can be separated from the robot-side ATC 64 by removing the claws 64b from the pin 63b.

[0106] 11(a), when a first metal panel 10A is composed of a left metal panel 10L and a right metal panel 10R, there are generally second metal panels 10B and third metal panels 10C that differ in shape, size, etc. from the first metal panel 10A. When the first metal panel 10A is gripped with a first gripping tool 60A, a second gripping tool 60B for gripping the second metal panel 10B and a third gripping tool 60C for gripping the third metal panel 10C are also prepared.

[0107] 10 , a first gripping tool 60A, a second gripping tool 60B, and a third gripping tool 60C are arranged in a cell 53. Any of the first gripping tool 60A, the second gripping tool 60B, and the third gripping tool 60C can be attached to a robot hand 55a of a multi-axis robot 55.

[0108] 10, a first parts feeder 70A is attached to the first crimping device 20A, a second parts feeder 70B is attached to the second crimping device 20B, and a third parts feeder 70C is attached to the third crimping device 20C. The structures of the first to third parts feeders 70A to 70C will be described with reference to FIG.

[0109] 12(a), the first parts feeder 70A includes a first parts supply unit 71A that aligns nuts by vibrating them, a first shutter 72A that separates the leading part from the following parts, a first pipe 73A that transports the leading part by air, a first temporary placement unit 74A at the end of the first pipe 73A that temporarily places parts, a first magnetic head 75A that magnetically attracts the temporarily placed part (nut 13), and a first cylinder unit 76A that moves the first magnetic head 75A. The air flow for air transportation can be generated by a first vacuum pump 77A.

[0110] Fig. 12(b) is a cross-sectional view taken along line b-b in Fig. 12(a), and Fig. 12(c) is an operation diagram. The nut 13 attracted by the first magnetic head 75A in Fig. 12(b) is moved to the first positioning pin 39A as shown in Fig. 12(c).

[0111] The second parts feeder 70B for supplying bolts and the third parts feeder 70C for supplying special nuts have the same structure as the first parts feeder 70A, and therefore detailed description thereof will be omitted.

[0112] [Composite Cell Production Facility] The cell production facility 50 described in Fig. 10 can be combined by arranging a plurality of units. As shown in Fig. 13, a composite cell production facility 80 comprises at least a first cell production facility 50A and a second cell production facility 50B.

[0113] The first cell production equipment 50A is provided with a first entrance 54A, first to third crimping devices 20A to 20C, a first articulated robot 55A, and a first exit 56A. The second cell production equipment 50B is provided with a second entrance 54B, fourth to sixth crimping devices 20D to 20F, a second articulated robot 55B, and a second exit 56B. Metal panels are transported from the first exit 56A to the second entrance 54B via a transport path 81.

[0114] That is, the first cell production equipment 50A and the second cell production equipment 50B are connected by a common transport path 81. Similarly, a third cell production equipment may be connected to the second cell production equipment 50B via a common transport path, and further, a fourth cell production equipment may be connected to the third cell production equipment.

[0115] Although the present invention is suitable for metal panels that make up a car body, it can also be applied to metal panels other than car bodies. For example, spot welding is difficult between aluminum and steel plates. In this case, using the crimping device of the present invention can significantly improve production speed. With the future trend toward lighter car bodies, the present invention can contribute to increasing the proportion of lightweight aluminum used.

[0116] Furthermore, in the present invention, when replacing the upper and lower caulking dies, the positioning pins may be used as they are without being replaced.

[0117] In addition, in the present invention, it is sufficient that at least one pass / fail criterion is stored in the control unit. This is because there may be cases where only one type of nut or bolt is fastened. However, in the case where two types of nuts or bolts are fastened, the control unit stores a first pass / fail criterion and a second pass / fail criterion. Furthermore, in the case where three types of nuts or bolts are fastened, a third pass / fail criterion is also stored.

[0118] In addition, in the case of cell production using multiple crimping machines, the cell-side control unit may integrate the control units of each crimping machine. In other words, when there is only one crimping machine of the present invention, its control unit stores, records, displays, and performs maintenance and interrupts production in the event of a failure. In the case of multiple machines, such as in cell production, the cell-side control unit may include the control units of each crimping machine.

[0119] The present invention is suitable for use in metal panels that constitute a vehicle body.

[0120] 10...metal panel, 10A...first metal panel, 10B...second metal panel, 10L...left metal panel, 10R...right metal panel, 13...nut, 14...bolt, 15...special nut, 20...crimping device, 20A...first crimping device, 20B...second crimping device, 21...press machine (general-purpose press machine), 22...variable hydraulic control machine, 23...press machine frame, 25...pressurizing shaft, 26...press machine base, 32...post, 33...bottom crimp Die, 33A...first bottom crimping die, 33B...second bottom crimping die, 34...lower holder, 34A...first lower holder, 34B...second lower holder, 35...upper crimping die, 35A...first upper crimping die, 35B...second upper crimping die, 36...upper holder, 36A...first upper holder, 36B...second upper holder, 37...stroke displacement meter (upper stroke displacement meter), 38...pressure meter, 39...positioning pin, 39a...flat surface, 39A...first positioning pin, 39B...second positioning pin, 42...lower stroke displacement meter, 43...control unit, 43A...first control unit, 43B...second control unit, 45...camera, 50...cell production equipment, 50A...first cell production equipment, 50B...second cell production equipment, 52...safety fence, 54, 54A, 54B...entrance, 55...multi-axis robot, 55a...robot hand, 56, 56A, 56B...exit, 57...circumference, 60A...gripping tool (first gripping tool), 60B...second gripping tool, 61A ...first gripping portion, 61B...second gripping portion, 65...automatic tool changer, 66...positioning pin, 70A-70B...first and second parts feeders, 71A-71B...first and second parts supply portions, 73A-73B...first and second pipes, 75A-75B...first and second magnetic heads, 76A-76B...first and second cylinder units, 80...complex production equipment, 81...conveying path, L, L1-L3...stroke, P...pressure force, P1, P2...set pressure force.

Claims

1. A crimping device for crimping one of a nut and a bolt to a metal panel, This crimping device comprises a stroke displacement meter for measuring the stroke during crimping, a pressure meter for measuring the pressure applied during crimping, and a control unit that determines whether the crimping result is acceptable or not based on the stroke information from the stroke displacement meter and the pressure information from the pressure meter. The control unit has at least one of a first pass criterion for the nut and a second pass criterion for the bolt, and is a crimping device that determines whether the orientation of either the bolt or the nut is correct.

2. A crimping device according to claim 1, This crimping device is equipped with a lower stroke displacement meter for measuring the vertical stroke of the positioning pin, The control unit determines, based on stroke information from the lower stroke displacement meter, that one of the nut and bolt is placed on the positioning pin in the correct position.

3. A crimping device according to claim 2, The first and second acceptance criteria are determined based on stroke information from the lower stroke displacement meter when the positioning pin is applied to the upper crimping die of the crimping device.

4. A crimping device according to claim 1, This crimping device is equipped with a camera that identifies the shape of one of the nuts and bolts, which is placed between the lower crimping die and the upper crimping die. The control unit is a crimping device that determines whether the orientation of one of the nuts and bolts is correct based on the image information from the camera.

5. A crimping device according to claim 3, The positioning pin is a crimping device having a flat surface at its tip.

6. A cell production facility comprising a plurality of crimping devices for crimping either a nut or a bolt onto a metal panel, The crimping device comprises a stroke displacement meter for measuring the stroke during crimping, a pressure meter for measuring the pressure applied during crimping, and a control unit for determining whether the crimping result is acceptable based on the stroke information from the stroke displacement meter and the pressure information from the pressure meter. The control unit has at least one of the first pass criteria for the nut and the second pass criteria for the bolt. The cell production equipment comprises an entrance for loading the metal panels, a multi-axis robot for transporting the metal panels, a first crimping device equipped with a first lower crimping die and a first lower holder corresponding to the nuts, a second crimping device equipped with a second lower crimping die and a second lower holder corresponding to the bolts, and an exit for discharging the metal panels on which the nuts and bolts have been crimped. A cell production facility in which the inlet, the first crimping device, the second crimping device, and the outlet are arranged within the rotational range of the multi-axis robot and on the same circumference.

7. A cell production system according to claim 6, The metal panel includes a first metal panel and a second metal panel, which have different shapes from each other. The cell production equipment is provided with a first gripping device for gripping the first metal panel and a second gripping device for gripping the second metal panel. The cell production equipment is equipped with an automatic tool changer that selects and attaches the first gripping tool and the second gripping tool to the multi-axis robot.

8. A cell production facility according to claim 7, The first metal panel consists of a left metal panel and a right metal panel with different shapes. The first gripping device comprises a left gripping portion for gripping the left metal panel and a right gripping portion for gripping the right metal panel, and the left gripping portion and the right gripping portion are each equipped with positioning pins.

9. A cell production system according to claim 6, The aforementioned outlet is a cell production facility located next to the aforementioned inlet.

10. A cell production system according to claim 6, This cell production facility is surrounded by a safety fence. The cell production equipment includes a first parts feeder that guides the nuts to the first crimping device, and this first parts feeder includes a first parts supply unit located outside the safety fence that supplies the nuts one by one, and a first pipe that guides the nuts supplied by the first parts supply unit to the first crimping device by pneumatic transport. A cell production system comprising a second parts feeder that guides the bolts to the second crimping device, the second parts feeder being located outside the safety fence and supplying the bolts one by one, and a second pipe that guides the bolts supplied by the second parts supply unit to the second crimping device by pneumatic transport.

11. A composite cell production facility comprising a plurality of cell production facilities according to claim 6, This combined cell production facility consists of a first cell production facility and a second cell production facility. A composite cell production system in which the first cell production equipment and the second cell production equipment are connected by a common transport route.