JP2012020312A - Press device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press technique by which occurrence of wrinkles can be prevented, in a press device for forming pressed articles having a width varying part connecting a narrow width part and a wide width part.SOLUTION: A hydraulic cylinder 34 is provided to the width varying part 33 of a movable die 32. The piston rod 39 of the hydraulic cylinder 34 is flush with the forming face of the movable die 32 at the retreat limit and most projected from the movable die 32 at the advance limit in an ordinary-use stroke region. A servo hydraulic unit 42 is connected to such the hydraulic cylinder 34 via hydraulic hoses 41, 41. The width varying part of a blank material can be pressed against a fixed die with the piston rod of the hydraulic cylinder in the early stage of drawing. Thus, there is no fear of bending of the center of the width varying part and occurrence of the wrinkles.

Description

  The present invention relates to a press apparatus that squeezes a blank material to make a breath product.

  A press apparatus for obtaining a pressed product by narrowing a blank material placed on a fixed mold with a movable mold that proceeds toward the fixed mold is widely used in practice (for example, Patent Document 1 (FIGS. 1 to 1). See 3).).

Patent document 1 is demonstrated based on the following figure.
FIG. 9 is a diagram for explaining the basic configuration of a conventional press apparatus. As shown in FIG. 9A, a lower gas cylinder 102 is placed on a lower mold plate 101, and the punch 103 can be moved up and down by the lower gas cylinder 102. It is supported by. Further, a lower spacer 105 is placed on a cushion pin 104 that extends through the lower die plate 101, and the blank holder 106 is supported by the lower die spacer 105.

  An upper mold spacer 112 is suspended from the upper mold plate 111, and the die 113 is supported by the upper mold spacer 112. A pad 114 is suspended from the center of the die 113 so as to be vertically movable. The upper gas cylinder 115 is lowered from the upper mold plate 111 at a position above the pad 114.

  In (a), the blank material 116 is placed on the punch 103. Next, the upper mold plate 111 is lowered. Then, the edge of the blank material 116 is sandwiched and restrained between the die 113 and the blank holder 106. When the upper plate 111 is further lowered, the punch 103 enters the die 113 and the blank material 116 is drawn as shown in FIG. At this time, the pad 114 only touches the blank material 116 lightly, and the pad 114 does not push the blank material 116 downward.

  From the state of (b), the upper gas cylinder 115 is extended and the lower gas cylinder 102 is contracted. Then, as shown to (c), the blank material 116 becomes a slightly rounded shape, and a press product is obtained.

  By the way, press products obtained by drawing the blank material 116 have various required finished shapes. For example, there is a press product in which a part is wide and the remaining part is narrow. At this time, it was found that the following problems occur in the width changing portion connecting the narrow width portion and the wide width portion.

  As shown in FIG. 10A, the width of the narrow portion 118 of the blank material 116 is W1. On the other hand, as shown in (b), the width of the width changing portion 119 of the blank material 116 is W2 larger than W1. Since the width changing portion 119 is wide, the center is bent upward, and as a result, a gap 121 is generated between the width changing portion 119 and the punch 103.

  When the aperture stops from the state (b), the width changing portion 119 is flattened as shown in (c). However, the curved length W3 of the width changing portion 119 shown in (b) is larger than the linear length W2. When the bending length W3 is (c), it is shortened to a small W2. As a result, the wrinkle 122 approaches somewhere in the width changing portion 119 in (c) so as to absorb the difference of (W3-W2).

  In addition to the reason described above, since the width of the width changing portion 119 changes in the front and back direction of FIG. 10, the influence of the diaphragm is more likely to occur than other portions. Therefore, the wrinkles 122 are noticeably generated in the width changing portion 119.

  When wrinkles 122 are generated in this way, the quality of the pressed product is deteriorated, so that measures against wrinkles are required.

JP 2003-290833 A

  An object of the present invention is to provide a press technique capable of preventing wrinkles from being generated in a press apparatus for forming a press product having a width change portion that connects a narrow width portion and a wide width portion.

The invention according to claim 1 has a narrow part and a wide part wider than the narrow part by squeezing the blank material placed on the fixed mold with a movable mold that proceeds toward the fixed mold. In a press device for forming a press product,
A hydraulic cylinder that presses against the fixed mold a width changing portion connecting the narrow width portion and the wide width portion is provided in the movable mold;
The hydraulic cylinder is provided with a piston rod that is flush with the movable mold at the retreat limit in the normal stroke region of the hydraulic cylinder and protrudes from the movable mold at the most forward limit.
A servo hydraulic unit comprising a controller for controlling the amount of projection of the piston rod from the movable mold and controlling the axial force of the piston rod corresponding to the crank angle of the crankshaft is connected to the hydraulic cylinder. It is characterized by.

In the invention according to claim 2, the control of the protrusion amount performed by the control unit is set to the maximum value at the top dead center, the maximum value is maintained until the piston rod hits the blank material, and the piston rod hits the blank material. Until the bottom dead center is reached, it is gradually reduced, set to zero at the bottom dead center, and maintained from zero to the top dead center.
The control of the axial force performed by the control unit is set to zero at the top dead center, set to the maximum value when the piston rod hits the blank material, this maximum value is maintained within a predetermined range of the crank angle, and thereafter It is characterized by being gradually reduced until the bottom dead center is passed, set to zero at the crank angle past the bottom dead center, and maintained at zero until the top dead center.

  In the invention which concerns on Claim 1, the wide part of a blank material can be pressed against a fixed metal mold | die with the piston rod of a hydraulic cylinder in the initial stage of an aperture_diaphragm | restriction. As a result, there is no worry that the center of the width changing portion is curved, and wrinkles do not approach.

  Therefore, according to the present invention, there is provided a press technique capable of preventing wrinkles from being generated in a press apparatus for forming a press product having a width change portion connecting the narrow width portion and the wide width portion.

  In the invention according to claim 1, the “ordinary stroke” means a stroke that is actually used in the range of the entire stroke of the hydraulic cylinder. It is common practice to employ a commercially available hydraulic cylinder with a stroke larger than the normal stroke. Therefore, not the full stroke of the hydraulic cylinder but the regular stroke is set as the control range.

In the invention according to claim 2, the axial force of the piston rod is set to a maximum value when the piston rod hits the blank material, and this maximum value is maintained within a predetermined range of the crank angle, and then passes the bottom dead center. It is gradually reduced until.
If the pushing force of the piston rod is kept strong even near the bottom dead center, that is, at the final stage of the throttle, the fluidity of the blank material is hindered and the blank material may be broken. Therefore, in the present invention, the pressure on the piston rod is weakened at the final stage of the throttle. By this treatment, the fluidity of the blank material is ensured and the drawing is performed smoothly.

It is a perspective view of the press goods which concern on this invention. It is a front view of the mechanical press which operates the press apparatus which concerns on this invention. It is a top view of the press apparatus which concerns on this invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is a block diagram of a hydraulic cylinder and a servo hydraulic unit. It is an effect | action figure of a press apparatus. It is a figure which shows the correlation of the crank angle implemented by the control part of this invention, protrusion amount, and axial force. It is a figure explaining the basic composition of the conventional press apparatus. It is a figure explaining the problem of the conventional press apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the press product 10 includes an edge portion 11, a narrow width portion 12 raised from the edge portion 11, and a wide width portion 13 wider than the narrow width portion 12.
In particular, the wrinkle tends to approach the width changing portion 14 that connects the narrow width portion 12 and the wide width portion 13. Therefore, it is important to prevent wrinkles from coming into the width changing portion 14. The structure of the press apparatus for that purpose will be described below.

  As shown in FIG. 2, the mechanical press machine 20 includes, for example, a bed 21, columns 22 and 22 raised from both ends of the bed 21, and a top bridge horizontally passed to the upper ends of the columns 22 and 22. 23, a crankshaft 24 horizontally extending above the columns 22, 22 at a position below the top bridge 23, connecting rods (connecting rods) 25, 25 extending downward from the crankshaft 24, The slider 26 is suspended by connecting rods 25, 25, an upper mold spacer 27 attached to the lower surface of the slider 26, and a lower mold spacer 28 attached to the upper surface of the bed 21. A press device 30 is attached between the upper mold spacer 27 and the lower mold spacer 28.

When the crankshaft 24 is rotated via the main gear 29, the slider 26 suspended by the connecting rods 25, 25 moves up and down.
When the crank angle of the crankshaft 24 is 0 °, the slider 26 is at the highest position. The highest position is called top dead center. When the crank angle is 180 °, the slider 26 is in the lowest position. The lowest position is called the bottom dead center. Return to top dead center at 360 ° crank angle.
That is, when the crankshaft 24 is rotated in one direction, a top dead center and a bottom dead center appear once each time during one rotation (360 °).

  As shown in FIG. 3, the press device 30 includes a fixed mold 31, a movable mold 32 that covers the fixed mold 31, and a hydraulic cylinder 34 that is embedded in a width changing portion 33 of the movable mold 32. Become. The narrow cylinder 35 and the wide section 36 of the movable mold 32 are not provided with a hydraulic cylinder.

As shown in FIG. 4, the hydraulic cylinder is not provided in the narrow portion 35 of the movable mold 32.
Cushion pins 37, 37 are extended upward through the fixed mold 31, and blank holders 38, 38 are supported by the cushion pins 37, 37.

As shown in FIG. 5, a hydraulic cylinder 34 is provided in the width changing portion 33 of the movable mold 32. The piston rod 39 of the hydraulic cylinder 34 is flush with the molding surface of the movable mold 32 at the retreat limit in the normal stroke region, and protrudes most from the movable mold 32 at the advance limit (FIG. 6, imaginary line 39). .
A servo hydraulic unit 42 is connected to such a hydraulic cylinder 34 via hydraulic hoses 41, 41.

Details of the hydraulic cylinder 34 and the servo hydraulic unit 42 will be described with reference to the following drawings.
As shown in FIG. 6, the hydraulic cylinder 34 includes a cylinder case 44, a piston 45 movably accommodated in the cylinder case 44, and a piston rod 39 extending from the piston 45 to the outside of the cylinder case 44.

  The servo hydraulic unit 42 includes a servo hydraulic pump 47 and a servo motor 48 that drives the servo hydraulic pump 47 as main elements, and is a special unit that can arbitrarily control the discharge hydraulic pressure and the discharge oil amount independently of each other. is there.

The oil pressure in the oil passage (in this example, the internal pressure of the cylinder case 44) is detected by a pressure gauge 49, and pressure information is sent to the control unit 50. Further, a stroke meter 51 provided in the hydraulic cylinder 34 detects the stroke of the piston 45, that is, the piston rod 39, and sends the stroke information to the control unit 50.
The control unit 50 controls the servo hydraulic unit 42 so that the protrusion amount L of the piston rod 39 and the axial force F by the piston rod 39 become desired values.

The operation of the press device 30 described above will be described with reference to FIG.
In Fig.7 (a), the movable metal mold | die 32 exists in a top dead center, and the piston rod 39 protrudes the largest. Since the hydraulic cylinder 34 is not working, the axial force of the piston rod 39 is set to zero.
In this state, the blank material 53 is placed on the blank holder 38.

  Next, the crankshaft (reference numeral 24 in FIG. 2) is rotated, and the movable mold 32 is lowered as shown in FIG. The blank holder 38 is lowered, the blank material 53 hits the fixed mold 31, and the blank material 53 is sandwiched between the fixed mold 31 and the piston rod 39. At this time, the axial force of the piston rod 39 is set to the maximum in the setting region.

  Subsequently, the crankshaft (reference numeral 24 in FIG. 2) is rotated, and the movable mold 32 is lowered as shown in FIG. The edge of the blank 53 is restrained by the blank holder 38, and the first half of the drawing process is performed.

  By the way, after (c), when the blank material 53 is strongly restrained by the fixed mold 31 with the piston rod 39, fluidization of the blank material 53 in the horizontal direction is hindered. If the blank 53 is pulled by the blank holder 38 in a state of poor flow, the blank 53 may be broken.

Therefore, from (c) to (d), the axial force of the piston rod 39 is gradually weakened. In addition, the piston rod 39 is retracted in response to the lowering of the movable mold 32.
As a result, as shown in (d), the movable die 32 reaches the bottom dead center, the tip of the piston rod 39 is flush with the movable die 32, and the drawing of the blank 53 is finished. At the bottom dead center, the axial force of the piston rod 39 may be slight.

Next, the operation of returning the movable mold 32 from the bottom dead center to the top dead center will be described.
As shown in (e), the movable mold 32 is slightly raised. At this time, the piston rod 39 is kept at the retreat limit position. Then, the axial force of the piston rod 39 is set to zero. As shown in (f), the movable mold 32 is continuously raised. The piston rod 39 is kept in the retreat limit position, and the axial force of the piston rod 39 remains zero.

As shown in (g), when the restraint of the blank holder 38 is released, the piston rod 39 is temporarily advanced to project the press product 10 downward. Thus, the press product 10 is separated from the movable mold 32. When the protrusion is finished, the piston rod 39 is returned to the rear end limit position, and the axial force of the piston rod 39 is returned to zero.
When the crankshaft (reference numeral 24 in FIG. 2) is subsequently rotated, the movable mold 32 reaches the top dead center as shown in (h).

The protrusion amount and axial force of the piston rod 39 described above are controlled by the control unit (FIG. 6, reference numeral 50). This control is performed corresponding to the crank angle of the crankshaft (FIG. 2, reference numeral 24). A specific example will be described.
As shown in FIG. 8A, the protrusion amount is controlled in accordance with the crank angle (°). Further, as shown in (b), the axial force is controlled corresponding to the crank angle (°).
7A to 7H appear between the crank angles 0 to 360 °, and these are shown in FIG.

In the following description, the crank angle in FIG. 8 is expressed as shown in FIG. 7 → (a).
That is, the control of the protrusion amount performed by the control unit is set to the maximum value at the top dead center (FIG. 7 → (a)), and the maximum value is maintained until the piston rod hits the blank material (FIG. 7 → (b)). Maintained until the piston rod hits the blank (FIG. 7 → (b)) until reaching the bottom dead center (FIG. 7 → (d)), the bottom dead center (FIG. 7 → ( d)) is set to zero, and is performed so that zero is maintained from the bottom dead center (FIG. 7 → (d)) to the top dead center (FIG. 7 → (h)).

The control of the axial force performed by the control unit is set to zero at the top dead center (FIG. 7 → (a)), and the maximum value when the piston rod hits the blank (FIG. 7 → (b)). This maximum value is maintained within a predetermined range of the crank angle (FIG. 7 → (b) to (c)) and then gradually decreased until the bottom dead center (FIG. 7 → (d)) is passed. The crank angle past the dead point (FIG. 7 → (d)) is set to zero, and zero is maintained until the top dead center (FIG. 7 → (h)).
As indicated by the broken line Q, it is also recommended to increase the axial force at a time across the bottom dead center (FIG. 7 → (h)). This is because the product accuracy can be improved by increasing the axial force at the bottom dead center.

  Note that the control method of the servo hydraulic unit is not limited to that shown in FIG. 8, and may be appropriately changed according to the shape and material of the press product. For example, as to the protrusion amount, as shown by a broken line P in FIG. 8A before reaching the crank angle of 360 °, the protrusion amount may be gradually increased after protruding the press product.

  In the embodiment, the blank material is directly pressed by the piston rod. However, an attachment fitting may be attached to the tip of the piston rod, and the blank material may be pressed by the attachment fitting.

  In the embodiment, the hydraulic cylinder is not provided in the narrow portion, but a hydraulic cylinder may be provided in the narrow portion and the narrow portion may be pressed by a piston rod of the hydraulic cylinder.

  The present invention is suitable for a press apparatus for forming a press product having a width changing portion connecting the narrow width portion and the wide width portion.

  DESCRIPTION OF SYMBOLS 10 ... Press product, 12 ... Narrow width part of breath product, 13 ... Wide width part of breath product, 14 ... Width change part of breath product, 20 ... Mechanical press machine, 24 ... Crankshaft, 30 ... Press device, 31 ... Fixed mold, 32 ... movable mold, 33 ... variable width of movable mold, 34 ... hydraulic cylinder, 39 ... piston rod, 42 ... servo hydraulic unit, 50 ... control unit, 53 ... blank material, F ... piston rod Axial force, L ... Projection amount of piston rod. The

Claims (2)

In a press apparatus for forming a press product having a narrow width portion and a wide width portion wider than the narrow width portion by squeezing the blank material placed on the fixed die with a movable die that proceeds toward the fixed die. ,
A hydraulic cylinder that presses against the fixed mold a width changing portion connecting the narrow width portion and the wide width portion is provided in the movable mold;
The hydraulic cylinder is provided with a piston rod that is flush with the movable mold at the retreat limit in the normal stroke region of the hydraulic cylinder and protrudes from the movable mold at the most forward limit.
A servo hydraulic unit comprising a controller for controlling the amount of projection of the piston rod from the movable mold and controlling the axial force of the piston rod corresponding to the crank angle of the crankshaft is connected to the hydraulic cylinder. The press apparatus characterized by the above-mentioned. The control of the protrusion amount performed by the control unit is set to the maximum value at the top dead center, the maximum value is maintained until the piston rod hits the blank material, and the piston rod hits the blank material Until the bottom dead center is reached, it is gradually decreased, set to zero at the bottom dead center, and maintained to zero from the bottom dead center to the top dead center,
The control of the axial force performed by the control unit is set to zero at the top dead center, set to the maximum value when the piston rod hits the blank material, and this maximum value maintains a predetermined range of the crank angle. And thereafter, gradually reduced until the bottom dead center is passed, set to zero at the crank angle past the bottom dead center, and maintained to zero until the top dead center. The press apparatus according to 1.

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