Method and device for producing bent spring elements

• US 8,333,093 B2
• Filed: 11/17/2006
• Issued: 12/18/2012
• Est. Priority Date: 12/29/2005
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kleckner, Josef, Mazurkiewicz, Julius, Criel, Paul
• Primary Examiner(s): Ross, Dana
• Assistant Examiner(s): BATTULA, PRADEEP CHOUDARY
• Application Number:
  US12/159,052
• Publication Number:
  US 20080302157A1
• Time in Patent Office: 2,223 Days
• Field of Search: 722/03, 721/27, 721/32, 721/60, 721/61, 721/64, 721/66, 721/68, 722/05
• US Class Current: 72/132
• CPC Class Codes: B21D 11/10 Bending specially adapted to produce specific articles, e.g. leaf springs making or bending leaf springs B21D53/886
• CPC Class Codes: B21D 53/886 leaf springs
• CPC Class Codes: B21D 7/08 by passing between rollers or through a curved die
• CPC Class Codes: B23D 25/04 in which a cutting unit moves bodily with the work while cutting B23D25/06 takes precedence
• CPC Class Codes: B23D 25/08 having two coacting shearing blades mounted independently
• CPC Class Codes: B60S 2001/3898 method for manufacturing wiper blades
• CPC Class Codes: Y10T 29/49609 Spring making

Abstract

The invention is based on a method of producing bent spring elements from a spring steel strip (14), wherein a feed unit (16) delivers the spring steel strip (14) from a supply roll (12) to a bending unit (32) having at least three bending rollers (34) and a reverse bending roller (36), of which at least one bending roller (34) and the reverse bending roller (36) can be adjusted transversely to the spring steel strip (14) by bending motors (60, 62), and wherein a cutting-off unit (44) adjoins the bending unit (32), said cutting-off unit (44) cutting off the spring steel strip (14) into individual spring elements by means of cutting-off tools (46, 48; 76, 78). It is proposed that the cutting-off tools (46, 48; 76, 78) be movable in the longitudinal direction of the spring steel strip (14) in a numerically controlled manner and that they be synchronized with the feed movement of the spring steel strip (14) during the cutting-off operation.

Claims

1. A method for producing bent spring elements from a spring steel strip (14), the method comprising providing a device with a feed unit (16) delivering the spring steel strip (14) from a supply roll (12) to a bending unit (32) having at least three bending rollers (34) and a reverse bending roller (36), of which at least one bending roller (34) and the reverse bending roller (36) can be adjusted transversely with respect to the spring steel strip (14) by bending roller movement devices, and with the bending unit (32) being connected to a cutting unit (44) which cuts the spring steel strip (14) into individual spring elements by means of cutting tools (46, 48;

76, 78), characterized in that the cutting tools (46, 48;

76, 78) can be moved in the longitudinal direction of the spring steel strip (14) in a numerically controlled fashion and are synchronized with the feed movement of the spring steel strip (14) during the cutting process, the cutting unit (44) having an upper cutting tool (46) and a lower cutting tool (48), between which the spring steel strip (14) is guided, the cutting tools (46, 48;

76, 78) being adjustable relative to the spring steel strip (14) in the longitudinal direction (52) of the feed movement of said spring steel strip (14), and using an electronic control unit (42) to synchronize the adjusting movement of said cutting tools (46, 48;

76, 78) with the feed movement of the spring steel strip (14) during the cutting process, wherein some guide rollers (50) in the region of the cutting tools (46, 48;

76, 78) can be varied in terms of their position with respect to one another in the longitudinal direction (52) in such a way that their spacings to one another are increased or decreased as a function of the movement of the cutting tools (46, 48;

76, 78) in the longitudinal direction (52).

2. A device (10) for producing bent spring elements from a spring steel strip (14), the device comprising a feed unit (16) delivering the spring steel strip (14) from a supply roll (12) to a bending unit (32) having at least three bending rollers (34) and a reverse bending roller (36), of which at least one bending roller (34) and the reverse bending roller (36) can be adjusted transversely with respect to the spring steel strip (14) by bending roller movement devices, and with the bending unit (32) being connected to a cutting unit (44) which cuts the spring steel strip (14) into individual spring elements by means of cutting tools (46, 48;

76, 78), wherein the cutting tools (46, 48;

76, 78) can be moved in the longitudinal direction of the spring steel strip (14) in a numerically controlled fashion and are synchronized with the feed movement of the spring steel strip (14) during the cutting process, the cutting unit (44) having an upper cutting tool (46) and a lower cutting tool (48), between which the spring steel strip (14) is guided, characterized in that the cutting tools (46, 48;

76, 78) are arranged so as to be adjustable relative to the spring steel strip (14) in the longitudinal direction (52) of the feed movement of said spring steel strip (14), with the adjusting movement of said cutting tools (46, 48;

76, 78) being synchronized with the feed movement of the spring steel strip (14) during the cutting process by means of an electronic control unit (42), wherein a roller guide (74) is provided downstream of the bending unit (32), the rollers of which roller guide (74) can be pneumatically adjusted onto the spring steel strip (14).

3. The device (10) as claimed in claim 2, characterized in that the cutting tools (46, 48;

76, 78) together with the cutting unit (44) are adjustable relative to the spring steel strip (14) in the longitudinal direction (52) of the feed movement of said spring steel strip (14).

4. The device (10) as claimed in claim 2, characterized in that the cutting tools (46, 48;

76, 78) are arranged in a stationary housing (54) of the cutting unit (44), in which said cutting tools (46, 48;

76, 78) are adjustable relative to the housing (54) and relative to the spring steel strip (14) in the longitudinal direction (52) of the feed movement of said spring steel strip (14).

5. The device (10) as claimed in claim 4, characterized in that the cutting tools are an upper punching tool (76) and a lower punching tool (78) which are mounted on an upper tool carriage (80) and on a lower tool carriage (82) respectively, with the tool carriages (80, 82) being guided on carriage guides (84, 86) in the housing (54) in the longitudinal direction (52).

6. The device (10) as claimed in claim 2, characterized in that some guide rollers (50) in the region of the cutting tools (46, 48;

76, 78) can be varied in terms of their position with respect to one another in the longitudinal direction (52) in such a way that their spacings to one another are increased or decreased as a function of the movement of the cutting tools (46, 48;

76, 78) in the longitudinal direction (52).

7. The device (10) as claimed in claim 2, characterized in that the cutting unit (44) is adjoined by an ejection device (88) which is driven and which can be activated by the electronic control unit (42).

8. The device (10) as claimed in claim 2, characterized in that the bending unit (32), the feed unit (16) and at least one NC measuring wheel (56, 58) are combined to form a structural unit (90) which can be adjusted in the longitudinal direction (52).

9. The device (10) as claimed in claim 8, characterized in that the structural unit (90) can be adjusted in a motor-driven fashion by means of a motor-driven spindle drive, with the adjustment process being part of an automatic set-up process.

10. The device (10) as claimed in claim 2, characterized in that a pre-bending unit (20) is provided upstream of the bending unit (32).

11. The device (10) as claimed in claim 2, characterized in that the bending roller movement devices comprise bending motors (60, 62).

12. The device (10) as claimed in claim 11, characterized in that at least one of the bending rollers (34) is mounted on a bending roller support (70) and the reverse bending roller (36) is mounted on a bending roller support (68), with the bending roller supports (68, 70) being adjusted by the bending motors (60, 62) via spindles (64, 66).

13. The device (10) as claimed in claim 12, characterized in that the bending motors (60, 62) are CNC bending motors, with the travel of the bending roller supports (68, 70) being determined, taking into consideration the set-point values of the control unit (42), by a rotating incremental encoder.

14. The device (10) as claimed in claim 13, characterized in that the travel of the bending roller supports (68, 70) is determined by an absolute measured value encoder which is integrated in the form of software.

15. The device (10) as claimed in claim 14, characterized in that the absolute measured value encoder comprises a glass scale with a sensor.

16. The device (10) as claimed in claim 15, characterized in that two NC measuring wheels (56, 58) are provided, of which a first (56) is arranged in the feed direction (72) upstream of the bending unit (32) and a second (58) is arranged downstream of the bending unit (32).

17. The device (10) as claimed in claim 16, characterized in that the second NC measuring wheel (58) is arranged on the housing (54) of the cutting unit (44).

18. The device (10) as claimed in claim 12, characterized in that the bending motors (60, 62) are linear motors.

19. The device (10) as claimed in claim 2, characterized in that the bending unit (32) is adjoined by the cutting unit (44).