JP2012143791A - Material pressing device and material pressing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of wrinkles of a press-molded product in a press forming machine with a simple structure.SOLUTION: The press forming machine 101 includes a lower die and an upper die 102. A material W arranged upward of the lower die is pressed from upward with the upper die 102 to form the press-molded product. The upper die 102 has an upper face forming face for pressing the upper face of the material W. A material pressing device 201 is provided on the press forming machine 101. The material pressing device 201 includes a pin 203 and a driving part 250. The pin 203 is arranged on the upper die 102 and extended vertically. The driving part 250 vertically moves the pin 203 in accordance with a distance between the upper die 102 and the lower die. A lower end 203a of the pin 203 vertically moves with the driving part 250 so that it is positioned between a position lower than the upper face forming face of the upper die 102 and a position flush with the upper forming face or higher than the upper face forming face of the upper die 102.

Description

  The present invention includes a material pressing device used in a press molding machine that includes a lower die and an upper die, and presses a material (work) disposed above the lower die from above with an upper die to form a press-formed product, and The present invention relates to a material pressing method performed in a press molding machine.

  Press molded products such as panels, luggage compartment door outer panels, and back door outers, which are part of automobiles, are formed by press molding a plate-shaped material (work) with a press molding machine. The press-molded product has a mountain shape extending in the vehicle vertical direction with the ridge line as a vertex. In such press molding, it is important not to cause wrinkles in the press-molded product.

  In a press molding machine, generally, a press-molded product in which generation of wrinkles is suppressed is formed by the following procedure. (1) First, align the edge part of the material with the material receiving part of the pendulum gauge provided in the press molding machine, and press the part that becomes the ridgeline in the press-formed product at the center part of the material. Align with the top of the wrinkle holding surface formed on the machine. (2) Next, a portion of the material that is aligned with the top of the wrinkle holding surface is clamped with a clamper so that the plate-shaped material does not shift or rise during the press molding. (3) Thereafter, the upper die provided in the press molding machine is slid down to perform drawing of the plate material.

  One of the factors that cause wrinkles in the press-formed product may be that the upper mold or the like provided in the press-forming machine shakes in the horizontal direction before and after the deformation of the material, causing a positional shift of the press-formed product. In this regard, in Patent Document 1 and Patent Document 2, a plunger or lifter guide post that is constantly urged upward by a spring or the like is provided in the lower mold of the press molding machine, and a preceding pin that protrudes downward and can be moved up and down is press molded. An invention is disclosed that is provided in the upper die of the machine, and the leading pin is brought into contact with the plunger in the middle of lowering the upper die to prevent horizontal displacement between the upper die and the lower die.

Japanese Utility Model Publication No. 6-083126 JP 2008-246571 A

  In the process of forming a press-formed product by the method shown in (1) to (3) above, the state immediately before the blank hold (the upper die of the press molding machine is positioned 20 mm to 30 mm above the blank hold state) It is known that the material is distorted between the blank hold state and the blank hold state, and this strain is crushed and wrinkled between the blank hold state and the bottom dead center state. As a cause of this, it is considered that there is a large difference in the moving distance between the edge portion and the center portion of the material until the material is blank-held after the plate-shaped material is put into the press molding machine. Another factor is that the contact area of the lower mold against the lower surface of the material from the blank hold state to the bottom dead center state is smaller than the contact area of the upper mold with respect to the upper surface of the material. May run away.

  The inventor applies the technology described in Patent Document 1 and Patent Document 2 to the press molding machine in order to prevent wrinkles generated as described above, and provides a leading pin on the upper mold provided in the press molding machine, We thought about pressing down the location where the material was distorted at the tip of the leading pin. However, if the technique described in Patent Document 1 or Patent Document 2 is used as it is, the tip of the preceding pin directly contacts the upper surface of the material, and the press-formed product is deformed into an unintended shape. . Here, as a hypothetical example, the inventor lightly pressed a portion where wrinkles occur in the material with a preceding pin, and brought the leading pin into contact with the material in the bottom dead center state, and the leading pin in a state immediately before the blank hold. I thought to evacuate from the material.

  FIG. 13 is an explanatory view showing a press forming method in a virtual example. The details of this hypothetical example will be described based on FIG. 13. First, an upper die 903 having a leading pin 902 protruding downward is formed on the upper surface of a plate-like material 901 held by a material receiving portion (not shown). Face each other ((1) in FIG. 13), and move the upper mold 903 downward. When the upper die 903 is positioned 20 mm above the blank hold state ((2) in FIG. 13), the leading pin 902 starts to retract upward. The leading pin 902 is moved by a driving source 904 such as an air cylinder. Thereafter, when the blank hold state is entered ((3) in FIG. 13), the retreating of the preceding pin 902 is completed ((4) in FIG. 13). Drawing is started with the preceding pin 902 retracted ((5) in FIG. 13), and the press forming of the material 901 is completed when the bottom dead center state ((6) in FIG. 13) is reached. The drive source 904 starts to extend the material 901 downward when the upper die 903 moves up after press molding ((7) in FIG. 13) and reaches the top dead center state ((8) in FIG. 13). Complete 902 protrusion. The press-molded material 901 is removed from the lower mold 905 and conveyed to the next process.

  However, in such a virtual example, the modification of the equipment for providing the drive source 904 becomes significant. For example, when an air cylinder is adopted as the driving source 904, there are problems such as the arrangement of air piping, adjustment of the driving speed of the leading pin 902 with respect to the stroke speed of the press machine, and the relationship with the air cylinder used in other equipment. Arise. If the driving speed of the preceding pin 902 is not adjusted precisely with respect to the stroke speed of the press machine, the intersection of the material 901 with the axis of the preceding pin 902 cannot be formed well, and the material 901 must be re-striated. It will not be.

  The present invention has been made in view of the above points, and an object of the present invention is to prevent wrinkling of a press-formed product in a press-forming machine with a simple structure.

  A material pressing device according to the present invention includes a lower die and an upper die, and a material pressing device used in a press molding machine that presses a material disposed above the lower die from above with the upper die to form a press-formed product. The pin is arranged on the upper mold and extends in the vertical direction, and the pin is moved up and down according to the distance between the upper mold and the lower mold, and the lower end of the pin is formed on the upper mold. And a drive unit that moves up and down so as to be positioned between a position below the upper surface forming surface for pressing the upper surface of the material and a position flush with or above the upper surface forming surface.

  The material pressing method of the present invention includes a lower mold and an upper mold, and a material pressing method performed by a press molding machine that presses a material disposed above the lower mold from above with the upper mold to form a press-formed product. The upper die is positioned in a position below the upper surface forming surface that is formed on the upper die and presses the upper surface of the material. And moving the pin upward in accordance with the distance between the upper mold and the lower mold while the upper mold is being lowered, and the lower end of the pin is flush with the upper surface forming surface or And a second stage positioned between the upper position and the upper position.

  According to the present invention, the pin pushes the upper surface of the material downward to fit the material to the lower mold. Then, the pin is retracted from the upper surface forming surface of the upper mold while the upper mold is descending, and the portion of the material that is fitted to the lower mold is securely pressed into the upper mold. Accordingly, it is possible to prevent wrinkling of the press-formed product in the press molding machine with a simple structure.

It is the sectional view on the AA line of FIG. 2 which shows the internal structure of a press molding machine. It is the top view of the press molding machine which abbreviate | omitted the upper mold | type. It is a schematic diagram which shows a raw material pressing device. It is the bottom view which looked at the pin from the lower part. It is a front view of the internal structure of the material pressing device in a state where the upper die is lowered and the hydraulic cylinder starts to operate. FIG. 6 is a front view of the internal structure of the material pressing device in a state where the passive cam is moved following FIG. 5. FIG. 7 is a front view of the internal structure of the material pressing device in a state where the passive portion has been fully raised following FIG. 6. FIG. 8 is a front view of the internal structure of the material pressing device in a state where the hydraulic cylinder is further operated following FIG. 7. FIG. 9 is a front view of the internal structure of the material pressing device in a state where the upper mold starts to rise, following FIG. 8. FIG. 10 is a front view of the internal structure of the material pressing device in a state where the upper mold is further raised following FIG. 9. FIG. 11 is a front view of the internal structure of the material pressing device in a state where the upper die is further raised and the engagement between the guide cam and the passive cam starts to be released, following FIG. 10. FIG. 12 is a front view of the internal structure of the material pressing device that has reached the state where the engagement between the guide cam and the passive cam is released, following FIG. 11. It is explanatory drawing which shows the press molding method in a virtual example.

  One embodiment will be described with reference to FIGS.

  FIG. 1 is a cross-sectional view taken along line AA in FIG. 2 showing the internal structure of the press molding machine 101. FIG. 2 is a plan view of the press molding machine 101 with the upper mold 102 omitted. The press molding machine 101 is a device that press-molds a plate-shaped material W (work) to form a press-molded product such as a panel, a luggage compartment door outer panel, a back door outer, or the like that forms part of an automobile. The press molding machine 101 according to the present embodiment has a ridge line, forms an inclined surface that descends downward as the distance from the ridge line, and forms a press-formed product that has a mountain shape extending in the vertical direction with the ridge line as a vertex. Is particularly useful to do.

  The press molding machine 101 includes an upper mold 102, a slide 103, a lower mold 104, a bolster 105, a cushion ring 106, and a cushion pin 107. The slide 103 is provided above the press molding machine 101. An upper mold 102 is attached to the lower surface of the slide 103. The slide 103 moves the upper mold 102 in the vertical direction. The lower surface of the upper mold 102 functions as an upper surface forming surface 102a that forms the upper surface of a press-formed product formed from the material W. The bolster 105 is provided below the press molding machine 101. A lower mold 104 is attached to the upper surface of the bolster 105. The lower mold 104 faces the upper mold 102. The upper surface of the lower mold 104 functions as a lower surface forming surface 104a that forms the lower surface of a press-formed product formed from the material W. The cushion ring 106 is disposed so as to surround the lower mold 104 in the horizontal direction. The upper mold 102 moved downward by the slide 103 contacts the upper surface of the cushion ring 106. The cushion pin 107 is attached to the bolster 105 via an elastic body (not shown) such as a spring, and extends upward from the bolster 105. The cushion pin 107 supports the cushion ring 106. The cushion pin 107 is pushed downward by the upper mold 102 and moves downward to try to push back the cushion ring 106 upward.

  The material W is disposed inside the press molding machine 101 in a state where the upper mold 102 and the lower mold 104 are opened. At this time, the edge portion of the material W is aligned with the gauge 108 and the pendulum gauge 109 provided on the upper surface of the cushion ring 106. Further, the central portion of the material W (the central portion in the left-right direction in FIG. 2) is aligned with the ridge line-shaped wrinkle pressing surface vertex 106b. The wrinkle pressing surface apex 106b is formed on the upper surface of the cushion ring 106 in a region (wrinkle pressing surface 106a) inside the gauge 108, pendulum gauge 109, and top clamper 110 (described later). Further, a portion of the edge portion of the material W that is aligned with the wrinkle pressing surface vertex 106b is clamped by a top clamper 110 provided on the upper surface of the cushion ring 106 so that the material W does not shift or rise during the press molding. Is done. A ridgeline portion 104b is provided on the upper surface (lower surface forming surface 104a) of the lower mold 104. The ridge line portion 104b extends so as to continue to the ridge line-shaped wrinkle pressing surface vertex 106b. Subsequently, the upper mold 102 is moved down by moving the slide 103 and the material W is sandwiched between the upper mold 102 and the lower mold 104, whereby the material W is drawn. At the time of drawing, the material W is pushed by the upper mold 102 and is bent from a portion of the material W that is aligned with the wrinkle pressing surface vertex 106b. The wrinkle pressing surface 106a of the cushion ring 106 is parallel to the lower surface (upper surface forming surface 102a) of the upper die 102. When the upper die 102 continues to descend, the lower surface (upper surface forming surface 102a) of the upper die 102 and the cushion The wrinkle pressing surface 106a of the ring 106 is in close contact (blank hold state). Thereafter, when the upper mold 102 pushes the cushion ring 106 to the bottom dead center (bottom dead center state), the press molding is completed. Then, the upper mold | type 102 and the lower mold | type 104 are opened, and the raw material W used as the press molded product is taken out.

  In the material W, a portion sandwiched between the upper surface (lower surface forming surface 104a) of the lower die 104 and the lower surface (upper surface forming surface 102a) of the upper die 102 is compressed and pressed in the vertical direction. Similarly, in the material W, the portion sandwiched between the upper surface (lower surface forming surface 104a) of the lower mold 104 and the wrinkle pressing surface 106a of the cushion ring 106 is also compressed and pressed in the vertical direction. The wrinkle pressing surface vertex 106b of the cushion ring 106 and the ridge line portion 104b of the lower mold 104 form a ridge line in a press-molded product formed by press-molding the material W.

  The press molding machine 101 includes a material pressing device 201. The material pressing device 201 is attached to the upper mold 102. The material pressing device 201 includes a main body 202, a pin 203, a hydraulic cylinder 204, and a hose 205. The main body 202 is provided with a power transmission unit 251. The power transmission unit 251 includes a linear actuator 207, an actuating unit 208, a passive unit 214, a spring 222, a stopper 218, and the like (all of which will be described later with reference to FIG. 3). The pin 203 is moved up and down according to the distance from the mold 104.

  The main body 202 is embedded in the upper mold 102. The pin 203 extends downward from the main body 202 and can be displaced up and down. The lower end 203 a of the pin 203 is positioned below the lower surface (upper surface forming surface 102 a) of the upper mold 102 and the upper mold 102. It moves between the lower surface (upper surface forming surface 102a) and the same position. The pin 203 is moved up and down by the main body 202, the hydraulic cylinder 204, and the hose 205 in accordance with the distance between the upper mold 102 and the lower mold 104, as will be described later with reference to FIGS. Here, the drive unit 250 (see FIG. 3) is configured.

  As another embodiment, the pin 203 is moved from the lower surface (upper surface forming surface 102a) of the upper mold 102 until it is sunk upward, and the lower end 203a of the pin 203 is moved to the lower surface (upper surface forming surface 102a) of the upper mold 102. You may make it come upwards.

  The hydraulic cylinder 204 has a base portion 204a and a piston portion 204b. The base portion 204 a is attached to the upper mold 102 and moves up and down together with the upper mold 102. The piston portion 204b extends downward from the base portion 204a. When the upper mold 102 moves up and down, the tip of the piston portion 204b comes into contact with the peripheral area 106c outside the wrinkle pressing surface 106a on the upper surface of the cushion ring 106 and is displaced in the vertical direction. Here, the hydraulic cylinder 204 serves as a detection unit that detects the distance between the upper mold 102 and the lower mold 104.

  The hose 205 connects the main body 202 and the base 204 a of the hydraulic cylinder 204. The hose 205 transmits the oil pressure of oil (not shown) in the base portion 204a changed by the displacement of the piston portion 204b to the linear actuator 207 (see FIG. 3).

  FIG. 3 is a front view showing the internal structure of the material pressing device 201. For explanation, the hydraulic cylinder 204 and the hose 205 are schematically shown in FIG. Based on FIG. 3, the main body 202 and the pins 203 constituting the material pressing device 201 will be described.

  The main body 202 has a case 206. A linear actuator 207 is attached to the side surface of the case 206. The linear actuator 207 has an action part 207a that is movable in the vertical direction, and moves the action part 207a up and down in accordance with the hydraulic pressure fluctuation of the hydraulic cylinder 204 transmitted through the hose 205.

  An operation unit 208 and a passive unit 214 are disposed in the case 206. The operating unit 208 includes a plate 209, an elastic body 210, a guide cam 211, and a weight 212. The plate 209 is slidable in the vertical direction along the inner wall surface of the case 206. The plate 209 is connected to the operating portion 208 of the linear actuator 207 and is displaced up and down in accordance with the hydraulic pressure fluctuation of the hydraulic cylinder 204. The elastic body 210 is sandwiched between the plate 209 and the guide cam 211 and pushes the guide cam 211 toward the passive cam 217 (described later) in the horizontal direction. An example of the elastic body 210 is urethane rubber. The guide cam 211 moves up and down together with the plate 209. A first inclined portion 213 that is inclined in a direction away from the plate 209 as it goes downward is formed on a side surface of the guide cam 211. A first engagement that engages with a second engagement portion 219a (described later) and a third engagement portion 219c (described later) formed on the passive cam 217 below the first inclined portion 213 on the side surface of the guide cam 211. A portion 213a is formed. The weight 212 is attached to the guide cam 211. The weight 212 increases the weight of the operating unit 208 and lowers the operating unit 208 when the hydraulic pressure from the hydraulic cylinder 204 is not acting on the linear actuator 207. If the plate 209 and the guide cam 211 have sufficient weight, it is not necessary to attach the weight 212 to the operating unit 208.

  The passive part 214 is a part moved by the operating part 208. The passive portion 214 includes a plate 215, an elastic body 216, a passive cam 217, and a stopper 218. The plate 215 is disposed on the inner surface of the case 206 at a location facing the plate 209 of the operating unit 208. The plate 215 is slidable in the vertical direction along this inner surface. The elastic body 216 is sandwiched between the plate 215 and the passive cam 217 and pushes the passive cam 217 toward the guide cam 211 in the horizontal direction. An example of the elastic body 216 is urethane rubber. The passive cam 217 is sandwiched vertically between a cam support portion 203b (described later) of the pin 203 and a fourth engagement portion 218b (described later) of the stopper 218, and is slidable in the horizontal direction in FIG. A second inclined portion 219 that is in sliding contact with the first inclined portion 213 of the guide cam 211 is formed on the side surface of the passive cam 217. A second engagement portion 219a is formed above the second inclined portion 219 on the side surface of the passive cam 217. Further, on the side surface of the passive cam 217, a third inclined portion 219 b that is positioned rightward and upward in FIG. 3 than the second inclined portion 219 and extends in parallel with the second inclined portion 219 is also formed. A third engaging portion 219c is formed above the third inclined portion 219b on the side surface of the passive cam 217. The second engagement portion 219a and the third engagement portion 219c engage with a first engagement portion 213a formed on the passive cam 217 and a fourth engagement portion 218b (described later) formed on the stopper 218. In particular, when the passive cam 217 is sandwiched vertically between a cam support portion 203b (described later) of the pin 203 and a fourth engaging portion 218b (described later) of the stopper 218, the third engaging portion 219c of the passive cam 217 is provided. Is in contact with the fourth engagement portion 218b of the stopper 218.

  The stopper 218 is suspended from a top plate 206 a that forms a part of the ceiling of the case 206. The stopper 218 engages with a fourth inclined portion 218a that is in sliding contact with the third inclined portion 219b of the passive cam 217, and a third engaging portion 219c that is positioned below the fourth inclined portion 218a and formed on the passive cam 217. And a fourth engaging portion 218b. The stopper 218 restricts the movement of the passive portion 214 as will be described later with reference to FIGS.

  The pin 203 has a bar shape extending in the vertical direction. The pin 203 passes through the bottom portion 206b of the case 206, and is further inserted into a through hole 220 formed in the upper mold 102 so as to penetrate vertically. A bush 221 is provided on the inner peripheral surface of the through hole 220. The outer peripheral surface of the pin 203 is slidably in contact with the bush 221. A cam support portion 203 b is provided at the upper end of the pin 203. The upper surface of the cam support portion 203b supports the lower surface 217a of the passive cam 217, and is slidably in contact with the lower surface 217a.

  A spring 222 as a biasing portion is disposed between the bottom portion 206b of the case 206 and the cam support portion 203b of the pin 203. The spring 222 pushes up the cam support portion 203b of the pin 203 and pushes the passive cam 217 upward. When the passive portion 214 is pushed down as will be described later, the passive portion 214 pushes the pin 203 downward, and the spring 222 contracts. Thus, the pin 203 is interlocked with the vertical displacement of the passive portion 214.

  A release driver 223 is also arranged in the case 206. The release driver 223 releases the engagement between the guide cam 211 and the passive cam 217 as will be described later with reference to FIGS. 11 and 12. The release driver 223 has an inclined portion 223a. As will be described later, the guide cam 211 comes into sliding contact with the inclined portion 223a and is pushed by the inclined portion 223a. As a result, the engagement between the guide cam 211 and the passive cam 217 is released.

  FIG. 4 is a bottom view of the pin 203 as viewed from below. Please refer to FIG. 1, FIG. 3 and FIG. The pin 203 is provided on a convex portion 102 b that is formed to protrude from the upper surface forming surface 102 a of the upper mold 102. The convex portion 102 b is formed in a shape that meshes with the concave portion 104 c formed on the upper surface of the lower mold 104. The pin 203 is displaced up and down, and presses the portion of the material W that should enter the convex portion 102b from the top evenly during press molding to fit the lower surface of the material W to the inner peripheral surface of the concave portion 104c. Therefore, a plurality of pins 203 are arranged so as to match the shape of the recess 104c.

  A method for press-forming the material W in the press-forming machine 101 configured as described above will be described. FIG. 5 is a front view of the internal structure of the material pressing device 201 in a state where the upper die 102 is lowered and the hydraulic cylinder 204 starts to operate. FIG. 5 shows a state where the upper mold 102 is positioned 20 mm above the blank hold state as an example before the blank hold. In the press molding machine 101, the pin 203 projects downward from the upper surface forming surface 102a of the upper mold 102 from the top dead center state to the state shown in FIG.

  When the slide 103 (see FIG. 1) is actuated and the upper die 102 is lowered, the lower end 203a of the pin 203 comes into contact with the material W arranged above the lower die 104 (see FIG. 1), and the recess of the lower die 104 The material W is pressed into 104c (see FIG. 1). Thereafter, when the piston part 204b of the hydraulic cylinder 204 starts to contact the peripheral region 106c of the cushion ring 106 as the upper mold 102 is lowered, the action part 207a of the linear actuator 207 moves upward and the operating part 208 rises. Accordingly, the first inclined portion 213 of the guide cam 211 is in sliding contact with the second inclined portion 219 of the passive cam 217, and the passive cam 217 is slid rightward in FIG. 5 to compress the elastic body 216. Accordingly, the guide cam 211 is pushed by the passive cam 217 and moves to the left in FIG. Further, the elastic body 210 is compressed.

  FIG. 6 is a front view of the internal structure of the material pressing device 201 in a state where the passive cam 217 is moved following FIG. FIG. 6 shows a state in which the upper mold 102 is positioned 15 mm above the blank hold state as an example in a state closer to the blank hold than FIG. 5. When the passive cam 217 moves in the right direction in FIG. 6, the engagement between the third engagement portion 219c of the passive cam 217 and the fourth engagement portion 218b of the stopper 218 is released. Until the engagement is released, the protruding length of the pin 203 from the upper surface forming surface 102a of the upper mold 102 remains unchanged.

  FIG. 7 is a front view of the internal structure of the material pressing device 201 in a state where the passive unit 214 has been fully raised following FIG. FIG. 7 shows a state in which the upper mold 102 is positioned 10 mm above the blank hold state as an example in a state closer to the blank hold than FIG. 6. When the engagement between the third engagement portion 219 c of the passive cam 217 and the fourth engagement portion 218 b of the stopper 218 is disengaged, the passive portion 214 rises due to the pushing force of the spring 222. Further, the push-up force of the spring 222 raises the pin 203 at a high speed, and the protruding length of the pin 203 from the upper surface forming surface 102a of the upper mold 102 becomes shorter. When the third engaging portion 219c of the passive cam 217 comes into contact with the top plate 206a, the lower end 203a of the pin 203 and the upper surface forming surface 102a of the upper mold 102 are flush with each other. At this time, the elastic body 216 presses the passive cam 217 in the left direction in FIG. 7, and causes the third inclined portion 219b of the passive cam 217 and the fourth inclined portion 218a of the stopper 218 to contact each other with a pressing force. Thereby, the passive part 214 is caught by the stopper 218 and does not fall.

  As another embodiment, when the second engagement portion 219a of the passive cam 217 contacts the fourth engagement portion 218b of the stopper 218, the lower end 203a of the pin 203 and the upper surface forming surface 102a of the upper mold 102 May be flush with each other.

  FIG. 8 is a front view of the internal structure of the material pressing device 201 in a state where the hydraulic cylinder 204 is further operated following FIG. FIG. 7 shows a state in which the upper mold 102 is positioned at a height position that is closer to the blank hold than FIG. 6 and is just before the blank hold state. When the upper die 102 is further lowered, the operating portion 208 is further raised by the hydraulic pressure in the hydraulic cylinder 204, and the guide cam 211 comes into contact with the passive cam 217 again. At this time, the first inclined portion 213 of the guide cam 211 and the second inclined portion 219 of the passive cam 217 come into contact with each other, and the passive cam 217 moves rightward in FIG. Thereafter, when the operating portion 208 is further raised, the first engaging portion 213a of the guide cam 211 is positioned above the second engaging portion 219a of the passive cam 217 (see FIG. 9). Here, the lower end 203a of the pin 203 and the upper surface forming surface 102a of the upper die 102 remain flush with each other, and the upper die 102 continues to move down until the press molding machine 101 reaches the bottom dead center state. The aperture is completed.

  FIG. 9 is a front view of the internal structure of the material pressing device 201 in a state where the upper mold 102 starts to rise following FIG. When the drawing of the material W is completed and the slide 103 is actuated and the upper mold 102 starts to rise, the actuating portion 208 starts to fall due to its own weight. When the actuating portion 208 is lowered, the first engaging portion 213a of the guide cam 211 is caught by the second engaging portion 219a of the passive cam 217, the guide cam 211 pushes down the passive cam 217, and the entire passive portion 214 moves downward. start. At this time, the oil in the linear actuator 207 (not shown) is returned to the piston portion 204b by the fall of the operating portion 208 due to its own weight and the separation between the upper die 102 and the lower die 104, and the piston of the hydraulic cylinder 204 Part 204b begins to extend.

  FIG. 10 is a front view of the internal structure of the material pressing device 201 in a state where the upper mold 102 is further raised following FIG. As the entire passive portion 214 moves downward, the pin 203 begins to protrude from the upper surface forming surface 102 a of the upper mold 102. When the passive cam 217 is pushed down, the third inclined portion 219b of the passive cam 217 slides on the fourth inclined portion 218a of the stopper 218, and the passive cam 217 is pressed by the stopper 218 to compress the elastic body 216 as shown in FIG. Move to the right. As a result, the catch between the passive cam 217 and the stopper 218 is released.

  FIG. 11 is a front view of the internal structure of the material pressing device 201 in a state where the upper mold 102 is further raised and the engagement between the guide cam 211 and the passive cam 217 starts to be released following FIG. When the operation unit 208 is further lowered, the guide cam 211 comes into sliding contact with the inclined portion 223a of the release driver 223. The inclined portion 223a is inclined so as to approach the operating portion 208 as it goes downward. When the guide cam 211 is lowered, the guide cam 211 is pushed by the inclined portion 223a and moves to the left in FIG. Thereby, the engagement between the first engagement portion 213a of the guide cam 211 and the second engagement portion 219a of the passive cam 217 is gradually released.

  When the passive cam 217 is pushed down, the third engagement portion 219c of the passive cam 217 reaches the same height position as the fourth engagement portion 218b of the stopper 218, and the engagement between the passive cam 217 and the stopper 218 is released. 217 can be moved leftward in FIG. 11 without being restricted by the stopper 218. Thereby, the passive cam 217 moves leftward in FIG. 11 by the restoring force of the elastic body 216.

  FIG. 12 is a front view of the internal structure of the material pressing device 201 that has reached the state where the engagement between the guide cam 211 and the passive cam 217 is released, following FIG. 11. After the passive cam 217 is pushed down by the guide cam 211, when the engagement with the guide cam 211 is released by the release driver 223 (see FIG. 11), the passive cam 217 is pushed up again by the spring 222. Accordingly, the passive portion 214 is sandwiched between the cam support portion 203b of the pin 203 and the fourth engagement portion 218b of the stopper 218 in the vertical direction. As a result, the passive unit 214 does not move up and down. Further, the protruding length of the pin 203 from the upper surface forming surface 102a of the upper mold 102 is the same as that shown in FIG. Here, the release driver 223 is disposed at such a height position that the engagement between the stopper 218 and the passive cam 217 is released and at the same time the engagement between the guide cam 211 and the passive cam 217 is released. For this reason, the pin 203 does not return upward after protruding downward from the upper surface forming surface 102a of the upper mold 102 more than necessary.

  When the engagement between the guide cam 211 and the passive cam 217 is released by the release driver 223, the operation unit 208 can be further lowered. In this state, the upper mold 102 continues to rise, and the press molding machine 101 reaches the top dead center state. In the top dead center state, the material W (see FIG. 11) turned into a press-molded product is taken out, and a new plate-like material W is disposed above the lower die 104 (see FIG. 1).

  After reaching the top dead center state, in the press molding machine 101, the upper mold 102 is moved downward by the slide 103 (see FIG. 1) to reach the state shown in FIG. In this way, the vertical movement of the upper mold 102 is repeated. As a result, the movement of each part from the state shown in FIG. 5 to the state shown in FIG. 12 is repeated inside the material pressing device 201, and the pin 203 is repeatedly displaced up and down to direct the material W toward the recess 104c (see FIG. 1). Hold it down.

  As described with reference to FIGS. 5 to 12, the passive portion 214 is moved by the pressing portion by the stopper 218 and the elastic body 216 included in the passive portion 214 while being moved by the operating portion 208. Specifically, the stopper 218 allows the horizontal movement while restricting the upward movement of the passive part 214 moved by the raising of the operating part 208. Thereafter, the passive portion 214 pushed up by the spring 222 after being moved in the horizontal direction is held by the stopper 218 and the elastic body 216. The stopper 218 and the elastic body 216 allow the passive portion 214 held in this way to be moved downward by the lowering of the operating portion 208. Here, a restricting portion 252 (see FIG. 3) that restricts the movement of the passive portion 214 is configured.

  As described above, according to the press molding machine 101 of the present embodiment, the pin 203 presses the upper surface of the material W downward, and fits the material W into the recess 104 c of the lower mold 104. Then, the pin 203 is retracted from the upper surface forming surface 102 a of the upper mold 102 while the upper mold 102 is descending, and the portion of the material W that is fitted to the recess 104 c is securely pressed into the upper mold 102. Accordingly, it is possible to prevent wrinkling of the press molded product in the press molding machine 101 with a simple structure.

  In the press molding machine 101 of the present embodiment, the distance between the upper mold 102 and the lower mold 104 is detected by the hydraulic cylinder 204, and the power transmission unit 251 provided in the main body 202 uses an air cylinder or the like. Without a simple structure. For this reason, the adoption with respect to the conventional installation is easy. In particular, it is not necessary to adjust the driving speed, which should be considered when an air cylinder is used.

  Further, in the present embodiment, the passive portion 214 performs a specific movement by the restriction portion 252, and the pin 203 is pushed up by the spring 222 and moves upward at a high speed. Thereby, the pin 203 does not come into contact with the material W immediately before the blank hold, and the generation of wrinkles of the material W due to the contact of the pin 203 is suppressed.

  Furthermore, in the present embodiment, the weight of the operating unit 208 is increased by the weight 212, and the operating unit 208 is quickly lowered. For this reason, it is not necessary to consider the reciprocating speed of the pin 203 when increasing the moving speed of the upper mold 102, and the manufacturing efficiency of the press-formed product in the press-forming machine 101 can be increased.

DESCRIPTION OF SYMBOLS 101 Press molding machine 102 Upper mold | type 102a Upper surface formation surface 104 Lower mold | type 201 Material pressing device 202 Main-body part 203 Pin 204 Hydraulic cylinder (detection part)
208 Actuator 214 Passive Part 222 Spring (Biasing Part)
250 Drive unit 251 Power transmission unit 252 Restriction unit W Material

Claims (6)

A material pressing device used in a press molding machine that includes a lower mold and an upper mold and presses a material disposed above the lower mold from above with the upper mold to form a press-molded product,
A pin arranged in the upper mold and extending in the vertical direction;
The pin is moved up and down according to the distance between the upper mold and the lower mold, and the lower end of the pin is positioned below the upper surface forming surface that is formed on the upper mold and presses the upper surface of the material, and the upper surface A drive unit that moves up and down so as to be positioned between the forming surface and a position flush with or above the surface;
A material pressing device comprising: The drive unit is
A main body that is disposed inside the upper mold and projects the pin downward;
A detection unit for detecting a distance between the upper mold and the lower mold;
A power transmission unit that is provided in the main body unit and moves the pin up and down according to the distance detected by the detection unit;
The material pressing device according to claim 1, comprising: The power transmission unit is
An operating part that is displaced up and down according to the distance detected by the detecting part;
A passive part moved by the actuating part;
An urging portion that pushes up the passive portion;
Restricting the upward movement of the passive part moved by the raising of the actuating part to allow horizontal movement, holding the passive part pushed up by the biasing part after being moved in the horizontal direction, A restricting portion that allows downward movement of the passive portion held by the lowering of the operating portion;
Including
The pin is interlocked with the vertical displacement of the passive part,
The material pressing device according to claim 2. The dead weight of the operating part contributes to the lowering of the operating part,
The material pressing device according to claim 3. A material pressing method performed by a press molding machine that includes a lower mold and an upper mold and presses a material disposed above the lower mold from above with the upper mold to form a press-molded product,
A lower end of a pin arranged in the upper mold and extending in the vertical direction is lowered in a state where the lower mold is positioned at a position lower than an upper surface forming surface formed on the upper mold and pressing the upper surface of the material. One step,
During the lowering of the upper mold, the pin is moved upward in accordance with the distance between the upper mold and the lower mold, and the lower end of the pin is positioned so as to be flush with or above the upper surface forming surface. A second stage positioned in between,
A material pressing method comprising: In the second stage, the pin is pushed up by the urging portion and moves upward at a high speed.
The material pressing method according to claim 5.

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