JP2016203243A - Manufacturing device and manufacturing method for vehicle wheel rim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an effective technique that solves problems caused in an annular work-piece for wheel rim put out from a roll die after roll-forming when manufacturing a vehicle wheel rim.SOLUTION: A roll-forming apparatus 100 that is a manufacturing device for a vehicle wheel rim comprises: a first servo motor 120 which is a first drive mechanism driving a top roll die 150 that is a first roll die to rotate; a second A servo motor 130 and a second B servo motor 140 which are a second drive mechanism driving a bottom roll die 160 that is a second roll die to rotate; and a controller 170 which controls the servo motors 130, 140 so that rotation number of the bottom roll die 160 becomes, after roll-forming, a target rotation number that is smaller than rotation number at the time when completing roll-forming.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for manufacturing an automobile wheel rim.

  2. Description of the Related Art Conventionally, there has been known a technique for roll forming using a roll mold in which an annular rim work is arranged on each of the outer periphery side and the inner periphery side of a rim work. An example of this type of technique is disclosed in Patent Document 1 below. According to the technique disclosed in Patent Document 1, each roll mold is rotated while the rim work is sandwiched between a top roll mold disposed on the outer periphery side of the rim work and a bottom roll mold disposed on the inner periphery side of the rim work during roll forming. The spacing between the two roll molds is adjusted.

JP-A-60-261625

  By the way, at the end of the above roll forming, the annular rim work is paid out from the rotating bottom roll mold. Since the rim work rotates integrally with the bottom roll type before paying out, when the bottom roll type rotates at high speed, the rim work rotates at high speed even after paying out due to inertia. Accordingly, when the discharged rim work rotates at a high speed and comes into contact with the floor surface and rotates freely, the rim work outer periphery of the rim work may be damaged. Further, when the rim work that has been paid out contacts the floor surface while rotating at a high speed, the noise generated by the high-speed collision with the wall after the rim work moves while rotating on the floor surface may be a problem.

  The present invention has been made in view of the above-mentioned points, and one of its purposes is to eliminate problems that may occur in an annular rim work that is paid out from a roll mold after roll forming in the manufacture of an automobile wheel rim. It is to provide effective technology.

  In order to achieve the above object, an automobile wheel rim manufacturing apparatus (100) according to the present invention includes a first roll type (150) in which an annular rim work (W) is arranged on the rim work outer peripheral side and an inner rim work inner side. It is a manufacturing apparatus for roll-forming using both the 2nd roll type | mold (160) arrange | positioned. The manufacturing apparatus (100) includes a first drive mechanism (120), a second drive mechanism (130, 140), and a control device (170). The first drive mechanism (120) rotationally drives the first roll mold (150). The second drive mechanism (130, 140) rotationally drives the second roll type (160). The control device (170) controls the second drive mechanism (130, 140) so that the rotation speed of the second roll mold (160) is lower than the rotation speed at the end of roll forming after roll forming. Fulfills the function of Here, the description “the target rotational speed below the rotational speed at the end of roll forming” is based on the gist including various forms in which the target rotational speed is smaller than the rotational speed at the end of roll forming. This description includes not only a mode in which the target rotational speed is larger than 0 (zero) and smaller than the rotational speed at the end of roll forming, but also a mode in which the target rotational speed is 0 (zero).

  According to this manufacturing apparatus, the rotational speed of the annular rim work paid out from the second roll mold after roll forming can be kept low. As a result, the rim work after being paid out rotates at a low speed or hardly rotates, so that the outer periphery of the rim work becomes difficult to be damaged, and the rim work after being paid out collides with a wall or the like at a high speed to generate a large noise. Can be suppressed.

  In the manufacturing apparatus (100), the second drive mechanism (130, 140) includes the motor shaft (131, 140) that rotates integrally with the second roll mold (160) to rotationally drive the second roll mold (160). 141) and a servo motor (130, 140) having an encoder (130a, 140a) for detecting the rotation angle of the motor shaft (131, 141). In this case, the control device (170) causes the rotation speed of the second roll type (160) to be the target rotation speed based on the rotation angle of the motor shaft (131, 141) detected by the encoder (130a, 140a). The servo motors (130, 140) are feedback-controlled.

  According to this manufacturing apparatus, the rotational speed of the annular rim work paid out from the second roll mold after roll forming can be kept low, while the cycle time required for one roll forming of the annular rim work is shortened to produce. Can be improved.

  The manufacturing apparatus (100) preferably further includes a movable device (132, 142). The movable device (132, 142) drives at least one of the two split rolls (161, 162) constituting the second roll mold (160) in a direction along the rotation center of the second roll mold (160). Accordingly, the two split rolls (161, 162) are engaged with each other by the split rolls (161, 162) to form a second roll mold (160), and the two split rolls (161, 162). ) Are separated to form a separated state in which a space (163) for delivering the rim work (W) is formed between the two divided rolls (161, 162).

  According to this manufacturing apparatus, the rim work can be smoothly removed from the second roll type by controlling the movable device so that the two split rolls are switched from the engaged state to the separated state to form a space for discharging the rim work. It becomes possible to pay out.

  In order to achieve the above object, a method for manufacturing a wheel rim for an automobile according to the present invention includes a first roll type (150) in which an annular rim work (W) is arranged on the rim work outer peripheral side and a first roll type (150) arranged on the rim work inner peripheral side. A step of roll forming using both the two-roll mold (160). This manufacturing method includes at least three steps from the first step to the third step. In this manufacturing method, one or a plurality of steps other than these three steps may be further added, or a plurality of steps among these three steps may be integrated. In the first step, the rim work (W) was sandwiched between the first roll mold (150) and the second roll mold (160) while rotating each of the first roll mold (150) and the second roll mold (160). In this state, the rim work (W) is roll-formed by adjusting the distance (d) between these two roll dies (150, 160). In the second step, after the first step, the interval (d) between the two roll dies (150, 160) is widened so that the first roll dies (150) and the second roll dies (160) are separated from each other. In this step, the second roll mold (160) is controlled to have a target rotational speed that is lower than the rotational speed at the end of roll forming. The third step is a step of paying out the rim work (W) from the second roll mold (160) after the second step.

  According to this manufacturing method, the rotational speed of the annular rim work paid out from the second roll mold after roll forming can be kept low. As a result, the rim work after being paid out rotates at a low speed or hardly rotates, so that the outer periphery of the rim work becomes difficult to be damaged, and the rim work after being paid out collides with a wall or the like at a high speed to generate a large noise. Can be suppressed.

  In the above manufacturing method, in order to rotationally drive the second roll mold (160), the rotation angles of the motor shaft (131, 141) and the motor shaft (131, 141) that rotate integrally with the second roll mold (160) are set. Servo motors (130, 140) having encoders (130a, 140a) for detection are preferably used. In this case, in the second step, the servo is performed so that the rotation speed of the second roll mold (160) becomes the target rotation speed based on the rotation angle of the motor shaft (131, 141) detected by the encoder (130a, 140a). The motors (130, 140) are preferably feedback controlled.

  According to this manufacturing method, the rotational speed of the annular rim work paid out from the second roll mold after roll forming can be kept low, while the cycle time required for one roll forming of the annular rim work is shortened for production. Can be improved.

  In the manufacturing method described above, in the third step, at least one of the two divided rolls (161, 162) engaged so as to form the second roll mold (160) is used as the two divided rolls (161, 162). A space (163) for driving out the rim work (W) is formed between the two divided rolls (161, 162) by driving in the direction along the rotation center of the second roll mold (160) so as to be separated from each other. Is preferred.

  According to this manufacturing method, it is possible to smoothly pay out the rim work from the second roll mold by forming a space for paying out the rim work by separating the two divided rolls.

  In the above description, in order to help the understanding of the invention, the reference numerals used in the embodiments are attached to the configuration of the invention corresponding to the embodiment in parentheses, but each constituent element of the invention is the reference numeral. It is not limited to the embodiment defined by.

  As described above, according to the present invention, in the production of an automobile wheel rim, it is possible to keep the rotational speed of the annular rim work paid out from the roll mold after roll forming low.

FIG. 1 is a diagram schematically showing an outline of a roll forming apparatus as an automobile wheel rim manufacturing apparatus. FIG. 2 is a diagram showing a cross-sectional structure of a rim work sandwiched between a top roll type and a bottom roll type. FIG. 3 is a diagram schematically illustrating how the rim work is paid out from the roll forming apparatus in FIG. 1. FIG. 4 is a diagram schematically illustrating a state in which the rim work paid out from the roll forming apparatus in FIG. 1 collides with the wall after moving on the floor surface. FIG. 5 is a diagram showing a time chart regarding the rotational speed R of the bottom roll type.

  Hereinafter, an embodiment of a wheel rim manufacturing apparatus for manufacturing an automobile wheel rim (hereinafter also simply referred to as “wheel rim”) of the present invention will be described in detail with reference to the drawings. In the drawing, the vertical direction (vertical direction) of the wheel rim manufacturing apparatus is indicated by an arrow X, and the horizontal direction (horizontal direction) of the wheel rim manufacturing apparatus is indicated by an arrow Y.

  As shown in FIG. 1, a roll forming apparatus 100 as a wheel rim manufacturing apparatus includes a metal frame member 101 to which a plurality of components are assembled. The frame member 101 includes a base 101a placed on a floor surface (mounting surface) M, an upper support base 101b disposed above the base 101a, and a guide frame that connects the base 101a and the upper support base 101b. 101c. The guide frame 101c is configured to be able to guide the movable support base 102 disposed between the base 101a and the upper support base 101b in the vertical direction Y.

  A third servo motor 110 is fixed to the upper support base 101b. A drive gear 112 fixed to the motor shaft 111 of the third servo motor 110 is engaged with a driven gear 113 fixed to a power transmission shaft 114 extending in parallel with the motor shaft 111. The power transmission shaft 114 is supported by the upper support base 101b through a bearing 115 so as to be rotatable about its axis. A male screw portion 116 made of a helical thread is provided at the lower part of the power transmission shaft 114, while the male hole of the power transmission shaft 114 is inserted into the through hole of the bracket 103 fixed to the upper surface of the movable support base 102. A female screw portion 104 that is screwed with the screw portion 116 is provided. The female screw portion 104 and the male screw portion 116 slide the power transmission shaft 114 in the vertical direction X with respect to the bracket 103 together with a plurality of steel balls (not shown) filled between the female screw portion 104 and the male screw portion 116. A structure to be moved, that is, a so-called “ball screw mechanism” is configured. According to this ball screw mechanism, it is possible to realize an operation in which the power transmission shaft 114 slides smoothly by suppressing the frictional resistance using the rolling motion of the steel ball.

  According to this ball screw mechanism, when the third servo motor 110 rotates the power transmission shaft 114 via the drive gear 112 and the driven gear 113, the movable support base 102 moves in the vertical direction. For example, when the third servo motor 110 is controlled so that the motor shaft 111 rotates in a predetermined direction, the movable support base 102 moves up. On the other hand, when the third servo motor 110 is controlled so that the motor shaft 111 rotates in the direction opposite to the predetermined direction, the movable support base 102 moves downward. That is, the rotational movement of the drive gear 112 by the third servo motor 110 is converted into a linear lifting movement in the vertical direction X of the movable support base 102 via the driven gear 113 and the power transmission shaft 114.

  The third servo motor 110 is configured as a servo mechanism type electric motor equipped with an encoder 110a capable of detecting the rotation angle (motor rotation position) of the motor shaft 111. Accordingly, the third servo motor 110 outputs detection information from the encoder 110a to the control device 170 and is driven and controlled by a control signal output from the control device 170. Specifically, the control device 170 controls control parameters such as the start and stop timings, the rotation direction, and the rotation speed of the third servo motor 110. The control device 170 includes output means for inputting / outputting detection signals and control signals, arithmetic processing means (CPU) for calculating information, storage means (memory) for storing input signals and calculation results, and the like. It is configured as a known control device provided. This control device 170 corresponds to the “control device” of the present invention. The control device 170 includes a gear ratio between the drive gear 112 and the driven gear 113, a pitch distance between the threads 116, a rotation angle of the third servo motor 110, and a vertical position X ascending / descending position of the top roll mold 150 described later. By storing the initial information indicating the correlation in advance, the elevation position of the top roll mold 150 can be uniquely derived from the motor rotation angle of the third servo motor 110. In short, the encoder 110a of the third servo motor 110 serves to indirectly derive the elevation position of the top roll mold 150 and output it to the control device 170.

  On the lower surface of the movable support 102, a support arm 105 that supports a rotary shaft 151 of a top roll type (simply referred to as “top roll”) 150 as a first roll type so as to be rotatable about an axis, and a rotary shaft 151. A first servo motor 120 including a motor shaft 121 connected coaxially is fixed. The motor shaft 121 is configured to rotate integrally with the top roll mold 150, and the top roll mold 150 rotates about the axis together with the motor shaft 121 when the first servo motor 120 operates. The first servo motor 120 is a rotational drive servo motor that rotationally drives the top roll mold 150 and constitutes the “first drive mechanism” of the present invention. Similar to the third servo motor 110, the first servo motor 120 is configured as a servo mechanism type electric motor equipped with an encoder 120a capable of detecting the rotation angle (motor rotation position) of the motor shaft 121. Accordingly, the first servo motor 120 outputs detection information from the encoder 120 a to the control device 170 and is driven and controlled by a control signal output from the control device 170. The top roll mold 150 is a cylindrical metal member used for roll forming the annular rim work W, and is disposed on the rim work outer peripheral side of the rim work W. The rim work W is a cylindrical metal member before the wheel rim is formed, and is typically formed by butting both ends of a plate after a metal plate piece is rounded into a ring.

  On the upper surface of the base 101a, a movable device 132 that supports the second A servo motor 130 slidably in the left-right direction Y along the motor shaft 131, and the second B servo motor 140 slides in the left-right direction Y along the motor shaft 141. The movable device 142 that is supported is provided in a state of being separated from each other in the left-right direction Y. These movable devices 132 and 142 correspond to the “movable device” of the present invention. The movable device 132 outputs information related to the slide position of the second A servomotor 130 in the left-right direction Y to the control device 170 and drives the second A servomotor 130 in the left-right direction Y by a control signal output from the control device 170. . According to this movable device 132, the 2A servo motor 130 is moved between the first position (roll processing position indicated by a solid line) and the second position (retracted position indicated by a two-dot chain line) in FIG. It moves linearly in the direction along the rotation center of the mold 160 (direction in which the motor shaft 131 extends). Similar to the movable device 132, the movable device 142 outputs information regarding the slide position of the second B servo motor 140 in the left-right direction Y to the control device 170, and the second B servo motor 140 is controlled by a control signal output from the control device 170. Is driven in the left-right direction Y. According to this movable device 142, the 2B servo motor 140 is moved between the first position (roll processing position indicated by a solid line) and the second position (retracted position indicated by a two-dot chain line) in FIG. It moves linearly in a direction along the rotation center of the mold 160 (direction in which the motor shaft 141 extends).

  A left divided bottom roll 161 constituting a left region of a bottom roll type (simply referred to as “bottom roll”) 160 which is a second roll type is fixed to the motor shaft 131 of the second A servomotor 130. Similarly, a right divided bottom roll 162 constituting the right region of the bottom roll mold 160 is fixed to the motor shaft 141 of the second B servo motor 140. These left divided bottom roll 161 and right divided bottom roll 162 correspond to “two divided rolls” of the present invention.

  When the second A servo motor 130 is in the second position, the left divided bottom roll 161 is in a separated state in which the engagement with the right divided bottom roll 162 is released, and is supported in a cantilever manner by the motor shaft 131. . When the second B servo motor 140 is in the second position, the right divided bottom roll 162 is in a separated state in which the engagement with the left divided bottom roll 161 is released, and is supported in a cantilever manner by the motor shaft 141. . On the other hand, when the left divided bottom roll 161 and the right divided bottom roll 162 are set close to each other and set to the first positions by the movable devices 132 and 142, the opposing surfaces are abutted and engaged with each other. A bottom roll mold 160 is formed which is in an engaged state and is disposed opposite to the top roll mold 150 in the vertical direction X. In this case, the bottom roll type 160 is a right / left split type (left / right separation type) roll type, and is supported by both the motor shaft 131 and the motor shaft 141 in a supported manner. The motor shafts 131 and 141 are configured to rotate integrally with the bottom roll mold 160, and the bottom roll mold 160 rotates together with the motor shafts 131 and 141 when the second A and second B servo motors 130 and 140 are operated. Rotate. The second A servo motor 130 and the second B servo motor 140 are rotational drive servo motors that rotationally drive the bottom roll type 160, and constitute the “second drive mechanism” of the present invention. The bottom roll mold 160 is a cylindrical metal member used for roll forming of the rim work W, and is disposed on the rim work inner peripheral side of the rim work W.

  The 2A and 2B servomotors 130 and 140 are configured as servomechanism type electric motors similar to the servomotors 110 and 120 described above. That is, the 2A servo motor 130 includes a motor shaft 131 that rotates integrally with the left divided bottom roll 161 in order to rotationally drive the left divided bottom roll 161 that constitutes the bottom roll mold 160, and a rotation angle of the motor shaft 131 (motor And an encoder (position detecting means) 130a for detecting the rotational position). For this reason, the second A servomotor 130 outputs detection information from the encoder 130 a to the control device 170 and is driven and controlled by a control signal output from the control device 170. Similarly, the second B servo motor 140 includes a motor shaft 141 that rotates integrally with the right divided bottom roll 162 in order to rotationally drive the right divided bottom roll 162 that constitutes the bottom roll mold 160, and a rotation angle of the motor shaft 141 ( And an encoder (position detection means) 140a for detecting the motor rotation position). Therefore, the second B servo motor 140 outputs detection information from the encoder 140a to the control device 170 and is driven and controlled by a control signal output from the control device 170. The second A and second B servo motors 130 and 140 here correspond to the “servo motor” of the present invention.

  During roll forming of the rim work W, the second A servo motor 130 and the second B servo motor 140 are controlled such that the left divided bottom roll 161 and the right divided bottom roll 162 rotate in the same direction and at the same speed. In this case, the second A servo motor 130 and the second B servo are adjusted so that both the rotation speed detected by the encoder 130a of the second A servo motor 130 and the rotation speed detected by the encoder 140a of the second B servo motor 140 coincide with each other. The motor 140 is feedback controlled. Thereby, the bottom roll mold 160 formed by the left divided bottom roll 161 and the right divided bottom roll 162 rotates. Further, when roll forming the rim work W, the first servo motor 120 is controlled so that the top roll mold 150 rotates in the opposite direction and at the same speed as the bottom roll mold 160. In this case, for example, the first servomotor 120 performs feedback control so that both the rotational speed detected by the encoder 130a of the second A servomotor 130 and the rotational speed detected by the encoder 120a of the first servomotor 120 coincide. Is done.

  Next, a wheel rim manufacturing method using the roll forming apparatus 100 having the above-described configuration will be described with reference to FIGS. This manufacturing method includes a step of performing flare processing and a step of performing multi-stage (typically three-stage) roll forming (also referred to as “roll processing”). The flare processing is a known processing technique and will not be described in detail, but is a technique in which both end opening edges of a metal cylindrical body are sandwiched between a pair of frusto-conical flaring molds and pressed. By subjecting the annular rim work W obtained by this flare processing to roll forming in a plurality of stages, the wheel rim shape is gradually adjusted to suppress the occurrence of plate sinks and wrinkles.

  In each of the multiple stages of roll forming, as particularly referring to FIG. 2, a top roll mold 150 in which the rim work W is disposed on the outer periphery side of the rim work and a bottom roll mold 160 (left divided bottom) disposed on the inner periphery side of the rim work. Each of the top roll mold 150 and the bottom roll mold 160 is rotated in the opposite direction while being sandwiched between both the roll 161 and the bottom roll mold integrally formed by the right divided bottom roll 162. At this time, as indicated by an arrow in FIG. 2, the third servomotor 110 moves the distance between the two roll dies 150, 160 (“distance” or “ It is driven in the adjustment direction (vertical direction X). The third servo motor 110 is an electric motor for adjusting the distance that drives the top roll mold 150 in the adjustment direction (vertical direction X) of the distance between the roll molds 150 and 160 (roll mold interval) d. The third servo motor 110 is controlled so that the distance d is lowered, so that the interval d is adjusted to be gradually reduced. In this case, the rim work W is rolled such that the rim work outer peripheral surface Wa follows the shape of the mold surface of the top roll mold 150 and the rim work inner peripheral surface Wb follows the shape of the mold surface of the bottom roll mold 160. . As a result, a wheel rim having a desired shape and dimension can be obtained.

  In each roll forming, when increasing the clamping force with the top roll mold 150 and the bottom roll mold 160 sandwiching the rim work outer peripheral surface Wa and the rim work inner peripheral surface Wb, both roll molds 150, 160 are used. The position of the top roll mold 150 is controlled so that the interval d between them gradually decreases. Alternatively, when reducing the clamping force, the position of the top roll mold 150 is controlled so that the distance d between the roll molds 150 and 160 gradually increases.

  At the end of the final roll forming, the annular rim work W is paid out from the bottom roll mold 160 in the rotating state. In this payout, the control device 170 controls the movable device 132 to move the second A servo motor 130 from the first position toward the second position, and the second B servo motor 140 is moved from the first position to the second position. This is done by controlling the movable device 142 to move toward the position. In this case, as shown in FIG. 3, the bottom roll mold 160 has the left divided bottom roll 161 moved in the left direction Y1 and the right divided bottom roll 162 moved in the right direction Y2 to be separated. A space for paying out the rim work W, that is, a payout space 163 is formed between the rolls 161 and 162. When the distance in the left-right direction Y of the payout space 163 exceeds the work width Wc of the rim work W, the rim work W is released from the holding by the both rolls 161 and 162 and is paid out in the downward direction X1 according to gravity.

  By the way, since the rim work W is rotated integrally with the bottom roll mold 160 before being paid out, when the bottom roll mold 160 is rotated at a high speed, the rim work W is rotated at a high speed by inertia even after being paid out. Therefore, as shown in FIG. 4, there is a concern that the outer periphery of the rim work W of the rim work W may be damaged if the rim work W that has been paid out contacts the floor surface M while rotating at a high speed and idles. Further, when the rim work W that has been paid out contacts the floor M while rotating at high speed, noise generated by the rim work W colliding with the wall L at high speed after moving on the floor M becomes a problem. obtain. On the other hand, if the number of rotations of the bottom roll mold 160 is lowered to a desired level by inertial rotation at the end of roll forming, the cycle time required for one roll forming is extended and the productivity of the wheel rim is lowered. The problem can arise.

  Therefore, in the present embodiment, the control device 170 causes the second A, second B servo motors 130, and so on to reduce the rotational speed (rotational speed) of the bottom roll mold 160 after roll forming to a desired level in a short time. By controlling the driving of 140, the rotational speed (rotational speed) of the rim work W paid out from the bottom roll mold 160 is kept low, or the rotation of the rim work W is stopped. A specific example of this control will be described below with reference to FIG.

  In the roll forming described above, the control device 170 controls the second A and the second A so that the rotation speed R (hereinafter also simply referred to as “roll rotation speed”) R of the bottom roll mold 160 is adjusted according to the time chart shown in FIG. The 2B servo motors 130 and 140 are driven and controlled. According to this time chart, the roll rotation speed R is maintained at the first rotation speed Ra for a time Ta (typically 1 to 2 seconds) after the rim work is charged, and then the roll rotation speed R is increased during the time Tb. Adjustment is performed by increasing the rotation speed Ra from the first rotation speed Ra to the second rotation speed Rb. In this increase adjustment, the motor rotation speed (change amount of rotation angle per unit time) of the motor shafts 131 and 141 actually detected by the encoders 130a and 140a and the set target rotation speed (that is, the first rotation speed). The second rotational speed Rb) exceeding Ra is compared, and the second A and second B servomotors 130 and 140 are feedback-controlled so that the actual motor rotational speed matches the target rotational speed. As a result, the roll rotation speed R of the bottom roll mold 160 is controlled to be the second rotation speed Rb. The third servo motor 110 is driven and controlled to adjust the distance d between the two roll dies 150 and 160 in a state where the roll rotational speed R has reached the second rotational speed Rb, so that the time Tc (typically 2 to 3 seconds), a substantial roll forming process is performed. In addition, you may make it adjust roll rotation speed R as needed in this roll forming process. This roll forming process corresponds to the “first step” of the present invention.

  After the roll forming process, a preparatory process is performed before the roll-formed rim work W is dispensed. This preparation process includes a first preparation process and a second preparation process. The first preparation process is a process of driving and controlling the third servo motor 110 so as to widen the distance d between the two roll molds 150 and 160 so that the top roll mold 150 and the bottom roll mold 160 are separated from each other in the vertical direction X. It is. The second preparation process is a process of adjusting the roll rotational speed R to be decreased from the second rotational speed Rb to the first rotational speed Ra during the time Td. In this lowering adjustment (second preparation process), the motor speeds of the motor shafts 131 and 141 actually detected by the encoders 130a and 140a (the amount of change in the rotation angle per unit time) and the control device set in advance are set. The target rotational speed (that is, the first rotational speed Ra lower than the second rotational speed Rb) stored in the storage means (memory) 170 is compared, and the actual motor rotational speed matches this target rotational speed. The second A and second B servo motors 130 and 140 are feedback-controlled. This target rotational speed may be set by calculation of the control device 170. As a result, the roll rotation speed R of the bottom roll mold 160 is controlled to be the first rotation speed Ra. The second preparation process may be executed after the first preparation process, or may be executed in parallel with the first preparation process. This preparation process corresponds to the “second step” of the present invention.

  Thereafter, the bottom roll mold 160 is divided into left and right by the movable devices 132 and 142. In this case, the time Td is the time from the end of the roll forming process until the bottom roll mold 160 starts to be divided into left and right. When the roll rotation speed R is the first rotation speed Ra, the bottom roll mold 160 is divided into left and right portions during a time Te (typically 1 to 2 seconds), and the process of paying out the rim work W is executed. The In this process, the left divided bottom roll 161 and the right divided bottom roll 162, which are two divided rolls, are set at the rotation center of the bottom roll mold 160 (that is, the motor shafts 131 and 141 of the second A and second B servo motors 130 and 140). A relative movement is made in the direction in which the mutual joining is released along the direction. This process corresponds to the “third step” of the present invention.

  When the above three steps are executed, the processing time required for one roll forming of the rim work W, so-called cycle time Tt, is the sum of time Ta, time Tb, time Tc, time Td, and time Te. In the present embodiment, one or a plurality of steps other than these three steps may be further added, or a plurality of steps among these three steps may be integrated.

  In the adjustment of the roll rotation speed R, as an example, the first rotation speed Ra is set to 0 rpm (times / minute), the second rotation speed Rb is set to 450 rpm, and the time Tb and rotation required for the rotation speed increase adjustment are set. Each time Td required for the number reduction adjustment is set to 0.5 seconds. In this case, since the rim work W is paid out in a state where the bottom roll mold 160 rotating at 450 rpm is stopped in 0.5 seconds, the paid out rim work W does not idle on the floor surface M.

  As a modification of this embodiment, the first rotation speed Ra can be set to 150 rpm and the second rotation speed Rb can be set to 600 rpm. In this case, since the rim work W is paid out in a state where the bottom roll mold 160 is lowered from 600 rpm to 150 rpm in 0.5 seconds, the rotational speed of the paid out rim work W can be kept low.

  According to the above-described embodiments and modifications, the rim work W after paying out rotates at a low speed or hardly rotates, so that the rim work outer periphery of the rim work W after paying out is hardly damaged, and the rim work W after paying out is a wall. It is possible to suppress the generation of large noises due to high-speed collisions.

  The first rotational speed Ra is selected from the rotational speeds in the range from 0 (zero) rpm to 150 rpm as necessary, and the second rotational speed Rb is in the range from 450 rpm to 600 rpm as necessary. It can be selected from the number of rotations to which it belongs.

  Further, in this embodiment, since the rotation speed of the bottom roll mold 160 is controlled with high accuracy using feedback control by the 2A and 2B servo motors 130 and 140, the bottom roll mold 160 is quickly accelerated and decelerated. Is possible. On the other hand, in the known motor control using an inverter instead of these 2A and 2B servo motors 130 and 140, it is limited to perform acceleration / deceleration in a short time due to a problem such as a voltage rise inside the inverter due to a regenerative operation. It is known that there is. As a result of the study by the present inventor, when this motor control is used, it takes a time of 1 second or more to increase the rotational speed of the bottom roll mold 160, for example, from 0 rpm to 450 rpm or from 450 rpm to 0 rpm. It turned out to be necessary. On the other hand, in the present embodiment, since the rotation speed of the bottom roll mold 160 can be controlled to a desired rotation speed in a short time, the time Tb related to acceleration and the time Td related to deceleration are 0.5 seconds. Can be set to a short time. As a result, the cycle time Tt can be shortened, and the wheel rim productivity can be increased.

  Note that the time Tb and the time Td can be selected from a time shorter than 1 second (a time belonging to a range from 0.30 seconds to 0.99 seconds) as necessary. As a preferable time Tb and time Td, a time belonging to a range from 0.35 seconds to 0.90 seconds is selected. As a more preferable time Tb and time Td, a time belonging to a range from 0.40 seconds to 0.80 seconds is selected. As the most preferable time Tb and time Td, a time belonging to a range from 0.45 seconds to 0.70 seconds is selected.

  Further, in the present embodiment, since the servo motor equipped with the encoder (position detecting means) for detecting the rotation angle of the motor shaft is used to detect the rotation angle of the top roll mold 150 and the bottom roll mold 160, the position There is no need to provide a detection means separately, and it is possible to construct a system that is structurally simple and inexpensive.

  The present invention is not limited to the above-described exemplary embodiments, and various applications and modifications can be considered without departing from the object of the present invention. For example, each of the following embodiments to which the above embodiment is applied can be implemented.

In the above embodiment, the case where both the top roll mold 150 and the bottom roll mold 160 are rotationally driven by feedback control with a servo motor has been described. However, in the present invention, the top roll mold 150 and the bottom roll mold 160 may be rotationally driven by an electric motor that does not perform feedback control. In this case, when the second preparation process is performed, the roll rotation speed R is adjusted to be decreased from the second rotation speed Rb to the first rotation speed Ra during the time Td without performing feedback control.
In the above embodiment, the case where both the top roll mold 150 and the bottom roll mold 160 are rotationally driven by the servo motor has been described. However, in the present invention, the top roll mold 150 and the bottom roll mold 160 are used as electric motors other than the servo motor. It is also possible to adopt a structure that is driven to rotate.
When an electric motor not incorporating an encoder is employed, the rotation angle of the motor shaft of the electric motor is detected by an encoder independent of the electric motor, and the electric motor is feedback-controlled.

  In the above embodiment, the case where the left and right split type roll roll configured by the left split bottom roll 161 and the right split bottom roll 162 is used as the bottom roll mold 160 is described, but in the present invention, one bottom roll mold is used. A roll type can also be used. In the above embodiment, the case where both of these two split rolls 161 and 162 are configured to be slidable in the left-right direction Y by the movable devices 132 and 142 is described. However, in the present invention, the left and right split rolls 161 are configured. , 162 can be slidably movable in the left-right direction Y. In this case, instead of assigning the second A and second B servo motors 130 and 140 to the left and right split rolls 161 and 162, a structure in which the servo motor is assigned to only one of the left and right split rolls 161 and 162, respectively. Can be adopted. Furthermore, the dividing direction in which the dividing rolls 161 and 162 are divided is not limited to the left-right direction Y, and the dividing directions can be set in various directions as necessary.

  In the above embodiment, the case where only the top and bottom roll molds 150 are adjusted in the roll forming process is described. However, in the present invention, the top roll mold and the bottom roll mold are selected. The structure which adjusts the raising / lowering position of at least one roll type | mold can be employ | adopted.

  DESCRIPTION OF SYMBOLS 100 ... Roll forming apparatus, 110 ... 3rd servo motor, 120 ... 1st servo motor, 130 ... 2A servo motor, 130a, 140a ... Encoder, 131, 141 ... Motor shaft, 132, 142 ... Movable device, 140 ... 1st 2B servo motor, 150 ... top roll type, 160 ... bottom roll, 161 ... left divided bottom roll, 162 ... right divided bottom roll, 163 ... dispensing space, 170 ... control device, W ... rim work

Claims (6)

An apparatus for manufacturing a wheel rim for an automobile for roll forming using both a first roll type in which an annular rim work is arranged on the outer peripheral side of the rim work and a second roll type arranged on the inner peripheral side of the rim work,
A first drive mechanism for rotationally driving the first roll mold;
A second drive mechanism for rotationally driving the second roll mold;
A control device for controlling the second drive mechanism so that the rotation speed of the second roll mold is lower than the rotation speed at the end of the roll molding after the roll forming;
An automobile wheel rim manufacturing apparatus comprising: The vehicle wheel rim manufacturing apparatus according to claim 1,
The second drive mechanism is constituted by a servo motor having a motor shaft that rotates integrally with the second roll mold and an encoder that detects a rotation angle of the motor shaft to rotationally drive the second roll mold.
The control device feedback-controls the servo motor so that the rotation speed of the second roll type becomes the target rotation speed based on a rotation angle of the motor shaft detected by the encoder. manufacturing device. An apparatus for manufacturing a wheel rim for an automobile according to claim 1 or 2,
By driving at least one of the two divided rolls constituting the second roll type in a direction along the rotation center of the second roll type, the two divided rolls are engaged with each other. A movable device that can be set to an engaged state forming the second roll mold and a separated state in which the two divided rolls are separated to form a space for delivering the rim work between the two divided rolls. An apparatus for manufacturing a wheel rim for an automobile. A method for manufacturing a wheel rim for an automobile, comprising a step of roll-forming using both a first roll mold in which an annular rim work is arranged on the outer peripheral side of the rim work and a second roll mold arranged on the inner peripheral side of the rim work,
By adjusting the distance between the two roll molds while the rim work is sandwiched between the first roll mold and the second roll mold while rotating each of the first roll mold and the second roll mold. A first step of roll forming the rim work;
After the first step, the interval between the two roll dies is widened so that the first roll dies and the second roll dies are separated from each other. A second step of controlling the target rotational speed to be lower than the rotational speed of
A third step of paying out the rim work from the second roll mold after the second step;
The manufacturing method of the wheel rim for motor vehicles containing this. A method for producing a wheel rim for an automobile according to claim 4,
In order to rotationally drive the second roll mold, a servo motor having a motor shaft that rotates integrally with the second roll mold and an encoder that detects a rotation angle of the motor shaft is used.
In the second step, a wheel rim for an automobile that feedback-controls the servo motor so that the rotation speed of the second roll type becomes the target rotation speed based on the rotation angle of the motor shaft detected by the encoder. Manufacturing method. A method for producing a wheel rim for an automobile according to claim 4 or 5,
In the third step, at least one of the two divided rolls engaged so as to form the second roll mold is arranged in a direction along the rotation center of the second roll mold so that the two divided rolls are separated from each other. A method for producing a wheel rim for an automobile, wherein a space for driving and delivering the rim work is formed between the two divided rolls.