JP2003518229A - Pressure-actuated piston and cylinder unit used for dies - Google Patents

Abstract

(57) [Summary] A pressure-actuated piston and cylinder unit that is used as a die block. The unit has an installation site and an inspection site on the back of the unit. Further, there is provided a pressure operated piston and cylinder unit having a simplified structure for use with a die block.

Description

Detailed Description of the Invention

[0001]

[Field of the Invention]

The present invention relates to a pressure-actuated piston and cylinder unit for use with a die block. Such a unit can be used as a die punching unit for making a hole or making a recess in the side wall of a pipe when hydraulically forming (hydroforming) the pipe.

[0002]

[Prior art]

It is difficult to place the punching unit in association with the die and perform the drilling. In particular, for example, pipe walls, molded containers, protruding profiled parts, inaccessible,
In other words, it is difficult to punch a complex shaped item surrounded by a die that has an inaccessible area. The holes in such items can often be cut through, but today punching is preferred. This is because the cylinders available on the market help with the simple assembly of the punching unit and generally allow punching at low cost. In such an environment, for example, as described in US Pat. No. 3,487,668 to Fuchs, Jr. and 4,989,482 to Mason. In addition, the die can be used in connection with the pressurized fluid in contact with the backside of the material. In these water pressure forming methods, the die punching tool needs to be housed in the forming die block. The back surface of the workpiece is supported by the pressurized fluid as the punch advances and engages the front surface of the material. The indentation is achieved, i.e. the slug is stripped, under the mechanical force exerted on the material by the leading edge of the punch and the force exerted by the pressurized fluid on the back side of the workpiece.

US Pat. No. 2,173,358 to Ernst discloses
A work piece ejector press having a reciprocating piston is disclosed. Ernst mentions a rather complicated penstock system. The piston outlet is located on the back of the unit and the corresponding hydraulic piston inlet conduit runs around the front of the unit to the sides of the unit. The piston inlet is installed at the tip of the die punching unit, and the corresponding piston withdrawal conduit goes round and reaches the side of the unit. The unit is fixed on the front of the unit by bolts.

US Pat. No. 3,027,877 to Lansky discloses a hydraulic motor for use in a die. The Lansky unit provides a cushioning means. This gives the piston a smooth stop at the end of its stroke and assists the piston on its return stroke. Lanski refers to the piston outlet and piston inlet on the back of the unit and the throttle valve extending at right angles to the unit. The unit is fixed to the front and back of the unit by bolts.

US Pat. No. 3,185,295 to Hastings
No. 042 and Mandelko, No. 3,188,9
No. 23 refers to an air cylinder with a reciprocating piston. Both refer to a piston outlet located on the back of the cylinder and a piston inlet located on the front of the cylinder. Hastings describes bolts on both the front and back of the cylinder, but Mandelco does not mention a device for securing the Cinder to other devices.

[0006] None of the prior art mentions a pressure-actuated piston and cylinder unit configured to facilitate and assist in housing the unit in a forming die block. Known designs, such as the patents mentioned above, have a large number of parts which make them difficult to assemble, yet these parts are prone to breakage and difficult to install, repair and replace. Furthermore, the known designs are not well matched to the often limited area of the forming die block and the associated machine.

[0007]

[Outline of the present invention]

The present invention provides a pressure actuated piston and cylinder unit for use in a die block. The piston and cylinder unit has a main body having a rear surface and a front surface communicating with the die block, a piston that reciprocates in a hole in the main body, a piston withdrawal chamber in fluid communication with the piston withdrawal port, and a piston withdrawal. A piston retraction chamber in flow communication with the mouth, and a bolt means container reaching the back of the unit that houses bolt means for securing the unit to the die block. The piston mouth is installed on the back of the unit.

The present invention also provides a cylinder unit with an integral cylinder housing. The invention further provides a piston and cylinder unit with a rod made of hardened steel.

In one embodiment, the present invention further provides a bleeder thread passage reaching the rear of the unit in flow communication with the piston retraction chamber. In the preferred embodiment, the bleed passage communicates directly with the piston retraction chamber. In another preferred embodiment, the bleed passage communicates directly with the piston withdrawal chamber.

In a preferred embodiment, the piston and cylinder unit comprises a plurality of bolt means vessels. In a further preferred embodiment, the bolt means container is recessed on the back side. In a further preferred embodiment, the die block is a hydraulically formed die block.

[0011]

【Example】

Examples will be described below to facilitate understanding of the present invention. The description is given as an example and does not limit the invention.

The piston and cylinder unit of the present invention can be used as a die punch to punch holes and make indentations in the side wall of a workpiece such as a tube. Meanwhile, the workpiece is shaped into the die, for example in hydraulic forming. The piston and cylinder unit is incorporated into the wall of the die and typically operates while two such dies are closed together by a press to contain the workpiece. As will be further envisioned, the piston and cylinder unit of the present invention may be used as an ejector or the like to separate and / or eject parts from a die. In this case the unit normally operates when the die is open. The piston and cylinder unit can also be used for any other purpose that requires a die cylinder. The present invention is particularly useful when a large number of cylinders are needed in a limited space.

Due to wear and tear of moving parts such as punching tools, maintenance or replacement of the unit or its parts is required periodically. In the well-known configuration shown in FIG. 1, the input and output conduits 10 project from the sides of the piston and cylinder unit 12 at right angles to the axis "Z" and the piston reciprocates within the unit along the axis "Z". Exercise and reach the die. In this configuration, a wide opening or clearance must be provided to the die 20 around the unit to attach and operate the unit, and the hydraulic input / output conduit 1
There must also be room for a 0 to stick out of the unit. In addition, unit 2
A clearance is also required to reach the bolt 14 that is fixed to 0.

FIG. 4 is a cross-sectional view of a piston and cylinder unit 12 according to the present invention. Figure 2
Referring to 3 and 4, the piston and cylinder unit of the present invention is
It has a cylindrical body 26 with opposite flat sides 26a. The body 26 is preferably constructed from a piece of steel.

The body 26 includes a rod, the rod comprising three continuous portions, namely a rod tip 4
0, a rod center portion 41 and a rod base portion 34. The rod center part 41 and the rod base part 34 are cylindrical. The rod tip portion 40 has a cylindrical shape having flat surfaces 40a facing each other (shown in FIG. 3). The rod tip 40 supports dies, punches, and other tools on its tool surface 52 to apply force to the workpiece.

The rod is preferably composed of a piece of hardened steel. As shown, the tool surface 52 is preferably a large mounting end.

The piston and cylinder unit is fixed to the die block 70. Typically, the die block includes an upper die adapted to advance with respect to a lower die to form a workpiece mounted within the die. The work piece is preferably a tube formed by partial hydraulic forming. The upper and / or lower dies are countersunk to accommodate the piston and cylinder unit 12 of the present invention. Referring to FIG. 3, a plug 38 having a circular cross section is provided on the front surface 42 so as to surround the outer diameter of the rod central portion 41, and seals the hole 48 with respect to the die block.

The piston and cylinder unit 12 is assembled to receive a punching tool which is advanced by rod tip 40 along a centerline “Z”,
Penetrate or abut the work piece. Accordingly, the forming operation of the upper die and the lower die is completed. The piston and cylinder unit 12 is pulled into the counterbore of the die aligned with the centerline Z and the punching tool pierces or dents the work piece or ejects the work piece or any other required work. To execute.

The piston / cylinder unit 12 is hydraulically actuated and a valve manifold may be fitted to connect the piston outlet 23 and piston inlet 22 of the cylinder unit 12 by suitable lines. A connector for rapidly connecting / disconnecting the manifold is provided so that the piston outlet 23 and the piston inlet 22 can be connected to an external water pressure source. Such a quick connect coupler system allows the connection of hydraulic and pneumatic lines.
These are available on the market and are well known in the art (eg Cejin Industrial Corporation of Niles, IL and Cleveland, OH).
By Parker Hannifin).

Details of unit 12 will be apparent with reference to FIG. The housing cylinder 26 has a back surface 24 and a front surface 42. The housing cylinder 26 surrounds the rod center 41, the rod base 34 and the hydraulic actuation element.

The rod base portion 34 is fixed to the sealing ring 50, and the sealing ring 50 is attached to the rod base portion 3.
It is arranged around the four. The sealing ring 50 is secured to the piston 58 in a fixed relationship. The rod base 34 can be further secured to the piston 58 by a rod and piston key 62. By doing so, the rod is fixed to the piston 58. In other embodiments, the rod base 34 and piston 58 may be secured to each other by welding, a female screw fit, or other suitable means known in the art. Furthermore, FIG.
The piston 58 is interference fit with respect to the rod center 41, as seen in FIG.
In another embodiment, piston 58, rod center 41 and rod base 34 are
It can be one continuous part.

Thus, as the piston 58 moves, the piston 58 carries the rod base 34 and its corresponding rod portion 41 and rod tip 40 along the axis “Z”. A piston seal 56 is provided between the outer periphery of the piston 58 and the inner hole 48 by an O-ring that slides in the inner hole 48. Although piston seal 56 is shown and described herein as being provided by O-rings, any suitable sealing scheme known in the art can be used for piston seal 56.

The piston withdrawal chamber 45 is a space between the piston 58 and the piston withdrawal opening 23. The piston retraction chamber 44 is the space between the tip fitting 46 and the piston 58 and is in fluid communication with the piston retraction conduit 25. The piston seal 56 and seal ring 50 combine to make the piston withdrawal chamber 45 and piston withdrawal chamber 44 fluid tight against the pressure generated therein. This allows the piston 58 to move with the rod along the axis "Z" while maintaining a fluid tight seal against the piston withdrawal chamber 45 and piston withdrawal chamber 44.

The tip fitting portion 46 is fixed in the hole 48 near the front surface 42 of the housing cylinder 26. The tip fitting portion 46 is fixed to the cylinder 26 by the tip fitting key 60, and the fitting key 60 can be welded to the cylinder 26 and the tip fitting portion 46. Further, the tip fitting portion 46 can be fixed to the cylinder 26 by any means known in the art, for example, by threading the tip fitting portion 46 into the cylinder 26 inner hole 48.

The tip rod seal 66 of the tip fitting 46 comprises an O-ring or other suitable seal known in the art. The tip rod seal 66, which has a circular cross section, has an axis Z
Sealing is carried out while sliding between the inner hole of the tip fitting portion 46 and the outer diameter of the rod center portion 41 along. The tip fitting portion 46 is fixed to the inner hole 48, and therefore the retracting chamber 4
4 is sealed by a coupling interference fit between the inner bore 48 of the cylinder and the tip fitting portion 46, a tip fitting key 60, and an O-ring or other means known in the art. By doing so, the tip fitting portion 46 is provided with the rod center portion 41 and the cylinder 26.
Acting as an interface seal between them, creating a seal against the surface of the piston retraction chamber 44.

The extraction chamber bleed passage 27 is provided from a bleed screw 30 inserted through the rear surface 24 to a piston extraction chamber 45 in a hole that accommodates the rod and the piston 58 through a hole that penetrates the cylinder. The bleed passage 27 is used to establish a somewhat bleeded (purged) flow through the system, eliminating the need for system bleed to remove air bubbles, or to release excess system pressure. Similarly, the drawing bleed passage 2
8 is also provided as a right-angled hole through the unit 12 and connects the lead-in conduit 25 to the bleed screw 30 to establish the bleed flow through the lead-in system. After the drawing-in extraction passage 28 is bored, it is sealed at the opposite end of the extraction screw 30 by the extraction seal 36.

The pressure required to discharge the liquid or gas through the extraction passage 28, that is, the actual discharge of the liquid or gas through the extraction system can be controlled by adjusting the extraction screw 30. In the preferred embodiment described, the pressure of the bleed air is controlled by the bleed screw 30, but other controlled pressure release means such as pressure valves well known in the art can be used.

FIG. 2 shows a rear perspective view of the pressure actuated piston and cylinder unit body 12 of the present invention. The piston inlet 22, the piston outlet 23, the bleed screw 30, and the bolt container 32 are all arranged on the rear surface 24 of the cylinder 26. Therefore, all elements that need to be reached for repair and replacement of the unit are located on the back side 24.
Therefore, no clearance is required between the unit and the die for repair, assembly and disassembly. Since the piston outlet 23, piston inlet 22, bleed screw 30, and bolt container 32 are all located on the rear surface 24 of the unit 12, the conduit is parallel to the axis "Z" of the inlet. Referring to FIG. 4, the rearward facing arrangement of the piston inlet 22 is possible by partially arranging the inlet passage 25 in the cylinder body 26 parallel to the axis "Z" of the inlet. The passage 25 is bored in the cylinder 26 along the axis Z.

To facilitate assembly and disassembly and to reach out to the push-out tool for repair, a bolt container 32 is provided on the unit and the head of the bolt is placed on the back of the unit for access. To make it easy. The whole unit fits snugly in the narrow recess of the die. In the preferred embodiment described, the unit is bolted to the die, but other fastening means known in the art can be used. Further, in order to facilitate the access, the bolt container 32 is recessed to form the bolt recess 33. Thus, the bolt head (not shown) does not interfere with operation on the back surface 24 when in place.

In practical use, the piston 58 reciprocates in the cylinder 26 while moving forward and backward to move toward and away from the workpiece. The first and second opposing regions define a piston withdrawal chamber 45 and a piston withdrawal chamber 44 in the cylinder bore. A pump device (not shown) supplies liquid or gas in a conversion method by the method described below. The conversion feed can be actuated electrohydrodynamically in response to a control signal from an external control device, i.e. a sensor responsive to the position or displacement of the piston 58.

The first pressure is activated when a strong force is required, for example when piercing the workpiece during the punching operation. The first pressure is applied to the piston drawing chamber 4 via the piston drawing port 23.
5 is supplied. The strong pressure on piston 58 and the lock fit between piston 58 and rod base 34 force the rod out of cylinder 26. The electrohydraulic controller can switch the pressure to the piston retraction chamber, but the supply pressure also allows continuous maintenance of the piston retraction chamber. In each case, after the punching stroke, the control device reduces the pressure on the piston withdrawal chamber 45. The pressure difference between piston withdrawal chamber 45 and piston withdrawal chamber 44 then imparts a net return force to the piston, causing the return stroke between the piston and rod. After the work piece has been pierced, depressed or recessed, the pumping system is switched and the pressure is restored, as required for the given work at hand.

Unlike the known prior art, the present unit allows the die to fit into a hollowed-out cylindrical pocket and is constructed and constructed from a unitary body. This allows the entire unit to fit snugly into a narrow recess in the die. Furthermore, the unitary design simplifies the structure of the unit. Another significant benefit of having an integral body is that the entire unit can be made smaller and simpler than the corresponding prior art unit. One reason is that the integral structure enhances the structural integrity of the cylinder 26 as compared to the prior art.

Another feature of the present invention is the arrangement of the extraction passage and the extraction screw. In the prior art,
Generally, the bleed passage and bleed screw are accessible from the side of the cylinder (see Lanski U.S. patent). This sometimes requires the bleed passage to extend through the die, which of course requires precise drilling of the actual die.

In contrast, in the present invention shown in FIG. 4, the extraction passage 28 has a direct intake passage 25.
Communicate with. The bleed passage 28 is perpendicular to the axis "Z" while the bleed screw 30
Are arranged parallel to the axis "Z", and the head of the extraction screw 30 projects from the rear surface 24 of the cylinder 26. This allows the bleed screw 30 to be easily accessed and the screw 30 to be accessed even when the unit is placed in a tight area of the die structure. This arrangement also allows the bleed screw assembly to create bleed passage and bleed screw openings without the precise boring of the die required in the prior art.

Accordingly, the present invention provides a piston-cylinder unit including a cylinder mounting bolt arranged only on the rear surface of the cylinder and an extraction screw arranged on the rear surface of the cylinder. This design allows the unit to be placed in a tight area of the die structure that would not be accommodated by prior art piston and cylinder units. Having a cylinder that can be placed in a cramped area allows for die / unit assembly / disassembly and allows for more precise placement of the punching unit. This enhances the number of holes punched in the workpiece and the flexibility beyond that location.
Similarly, the present invention allows the unit to be mounted on a die so that holes can be punched closer to the parting line of the workpiece than is possible with the prior art. The closer proximity of the cylinder units further allows the unit of the present invention to be used in a series of sequentially energized cylinders.

The compact size of the piston and cylinder unit also reduces the die machining required for mounting the unit, thus enhancing the strength of the machined die and for mounting cylinder and cylinder units. Reduce the total cost.

Furthermore, by fixing the unit to the die block only on the back side of the unit with bolts and the piston mouth arranged only on the back side of the unit, a circular shape smaller than the plugs available in the prior art It can be a cross-section plug 38. This reduces the processing effort required to establish a tight fit between the die and the unit, facilitates maintenance, removal and replacement, and places the unit closer to the rest of the die,
Further, it can be arranged particularly in an area where the die and surrounding structures are difficult to reach. Accordingly, the present invention provides an apparatus for rapidly changing the tooling set of multiple dies in a double-acting press, and more reliably mounts the unit to the dies as compared to the prior art. Further, by assembling the area of the circular cross-section plug 38 of FIG. 3 into a circle, the total area of the area required to be sealed between the die and the unit is smaller than other shapes, and thus easily improved. A fit is obtained.

Further, (a) an integral structure, (b) a bleed screw on the rear surface of the piston and cylinder unit, and (c) a cylinder main body that supports a punching tool and is commercially available in comparison with a unit available in the market By having a hardened steel piston that also serves as a factor contributing to the advantage of being able to shorten the length of 26, the piston and cylinder unit body can be simplified, which facilitates handling and maintenance. become.

Other benefits of the present invention can be demonstrated by contrasting the inventive unit with the prior art of FIG. As shown in FIG. 1, the support 16 of the punching tool is inserted between the piston 18 and the punching piece 15. The punch support 16 is a hardened steel part,
Supporting the piston 18 by bearing the shock transmitted through the punch piece 15 during the drilling operation. The punch support 16 needs to deal with the fact that the punch is prone to making holes in the work piece made of soft metal.

Because the design of the present invention assembles a compact and concise unit, the rod tip 40 can be constructed from hardened, corrosion resistant steel to support the punch directly as it penetrates the workpiece. Thus, a second, special punch tool support die part is no longer required, and the use of a special die part between the rod and the punch tool is exempt by making it a hardened steel piston. .

It will be apparent to those skilled in the art that there are various changes and modifications that can be made to the present invention. These changes and modifications are included in what is referred to in this disclosure, and the invention is intended to be limited only by the scope of the appended claims.

[Brief description of drawings]

[Figure 1]   FIG. 3 is a cross-sectional view of a pressure actuated piston and cylinder unit according to the prior art.

[Fig. 2]   It is a rear perspective view of a unit of a piston and a cylinder of the present invention.

[Figure 3]   3 is a front perspective view of the piston and cylinder unit of FIG. 2. FIG.

[Figure 4]   FIG. 3 is a cross-sectional view of the piston and cylinder unit of FIG. 2.

[Explanation of symbols]

  12 Unit of piston and cylinder   22 Piston inlet   23 Piston outlet   24 back   25 Piston lead-in conduit   26 Housing cylinder   27 Extraction chamber extraction passage   28 Intake bleed passage   30 Bleed screw   32 volt container   33 Bolt recess   34 Rod base   36 Bleed seal   38 Round cross section plug   40 Rod tip   41 Rod center   42 front   44 Piston retract chamber   45 Piston withdrawal chamber   46 Tip fitting part   48 inner hole   50 seal ring   52 Tool surface   56 piston seal   58 piston   60 Tip fitting key   62 Key of rod and piston   66 Tip rod seal   70 die blocks

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE, TR), OA (BF , BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, G M, KE, LS, MW, MZ, SD, SL, SZ, TZ , UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, B Z, CA, CH, CN, CR, CU, CZ, DE, DK , DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, J P, KE, KG, KP, KR, KZ, LC, LK, LR , LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, R O, RU, SD, SE, SG, SI, SK, SL, TJ , TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW F-term (reference) 3H081 AA03 BB01 CC21 DD19 DD28                       DD33 HH04                 4E048 KA09

Claims (12)

[Claims] 1. A body of a pressure-operated piston and cylinder used for a die block, the body having a back surface and having a front surface communicating with the die block, and a reciprocating motion in a hole in the body. A piston, a piston withdrawal chamber in fluid communication with the piston withdrawal opening, a piston withdrawal chamber in fluid communication with the piston withdrawal opening, a rod secured to the piston, and bolt means for securing the unit to the die block. A bolt-actuated container reaching the rear surface of the unit, the unit comprising a pressure-actuated piston and a cylinder, the mouth of the piston being disposed on the back surface of the unit. And unit. 2. The piston and cylinder unit according to claim 1, wherein the main body is integrated. 3. The piston and cylinder unit according to claim 1, wherein the rod is hardened steel. 4. The piston and cylinder unit according to claim 1, wherein the front surface is circular. 5. The unit of piston and cylinder according to claim 1, further comprising an extraction passage in fluid communication with the piston intake chamber, the extraction passage reaching a rear surface of the unit. 6. The piston and cylinder unit of claim 1, further comprising a plurality of said bolt means containers. 7. The piston-cylinder unit according to claim 1, wherein the bolt means container is made by denting the back surface. 8. The piston-cylinder unit according to claim 1, wherein the piston retraction port communicates with the piston retraction chamber via a retraction conduit, the retraction conduit being parallel to the rod. A unit of a piston and a cylinder, which is characterized by extending in the unit of. 9. The piston / cylinder unit according to claim 1, wherein the die block is a hydraulically formed die block. 10. A unit of a piston and a cylinder according to claim 5, wherein:
The piston / cylinder unit, wherein the bleed passage is in direct communication with the piston drawing chamber. 11. A unit of a piston and a cylinder according to claim 5, wherein:
The piston and cylinder unit, wherein the bleed passage is in direct communication with the piston retraction chamber. 12. A piston-cylinder unit according to claim 1, wherein:
A unit of a piston and a cylinder, wherein the unit is cylindrical.