Piston pump

• US 6,341,950 B1
• Filed: 03/23/1998
• Issued: 01/29/2002
• Est. Priority Date: 03/21/1997
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schuller, Wolfgang, Sinnl, Erwin
• Primary Examiner(s): Solis, Erick R.
• Application Number:
  US09/045,537
• Time in Patent Office: 1,408 Days
• Field of Search: 417/554, 417/470, 417/540, 417/541, 921/17.A, 921/17.R, 921/72
• US Class Current: 417/554
• CPC Class Codes: B60T 8/4031 Pump units characterised by their construction or mounting pump units in combination with valve blocks B60T8/36
• CPC Class Codes: F04B 1/0421 Cylinders
• CPC Class Codes: F04B 11/0025 the spring fluid being in direct contact with the pumped fluid
• CPC Class Codes: F04B 53/126 Ball valves
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: F04B 9/045 the means being eccentrics

Abstract

The invention relates to a piston pump, which is intended for use as a return pump for a slip-controlled hydraulic vehicle brake system. To simplify the manufacture of a piston of the piston pump, the piston includes a thin sleeve.

Claims

1. A piston pump for a vehicle brake system, comprising a pump housing with a cylinder bore, a piston in said housing that can be driven to reciprocate is axially displaceably received, the piston (18) has at least one sleeve (20;

68, 70) as a deforming part, which forms a circumferential wall of the piston (18), in which a check valve (32) is integrated into the piston (18).

2. The piston pump in accordance with claim 1, in which the sleeve (20;

68, 70) has substantially a constant wall thickness.

3. The piston pump in accordance with claim 1, in which the piston (18) is thin-walled.

4. The piston pump in accordance with claim 1, in which the check valve (32) has a valve seat part (44), which is joined nondisplaceably to the sleeve (20;

68, 70).

5. The piston pump in accordance with claim 1, in which the piston has two sleeves (68, 70), which are joined together in aligned fashion.

6. The piston pump in accordance with claim 1, in which the piston (18) has an interior (56), which communicates with brake fluid to be pumped.

7. The piston pump in accordance with claim 6, in which an elastic damper body (58) is received in the interior (56).

8. The piston pump in accordance with claim 5, in which each of said sleeves have axial portions of equal diameters.

9. A piston pump for a vehicle brake system, comprising a pump housing with a cylinder bore, a piston in said housing that can be driven to reciporate is axially displaceably received, the piston (18) has at least one sleeve (20;

68, 70) as a deforming part, which forms a circumferential wall of the piston (18), in which the piston has two sleeves (68, 70), which are joined together in aligned fashion.

10. The piston pump in accordance with claim 9, in which the piston (18) is thin walled.

11. The piston pump in accordance with claim 9, in which a check valve (32) is integrated into the piston (18), and the check valve (32) has a valve seat part (44), which is joined nondisplaceably to the sleeve (20;

68, 70).

12. The piston pump accordance with claim 9, in which the piston (18) has an interior (56), which communicates with brake fluid to be pumped.

13. The piston pump in accordance with claim 9, in which an elastic damper body (58) is received in the interior (56).

14. The piston pump in accordance with claim 9, in which each of said sleeves have axial portions of equal diameters.

15. A piston pump for a vehicle brake system, comprising a pump housing with a cylinder bore, a piston in said housing that can be driven to reciprocate is axially displaceably received, the piston (18) has at least one sleeve (20;

68, 70) as a deforming part, which forms a circumferential wall of the piston (18), in which sleeve (20;

68, 70) has substantially a constant wall thickness, and on its side which is driven the sleeve (20;

68, 70) is closed by a stopper (24) which is joined firmly to the sleeve (20;

68, 70).

16. The piston pump in accordance with claim 15, in which at least a portion of the stopper (24) extends from the sleeve (20;

68, 70), and which portion includes a crowned surface.

17. The piston pump in accordance with claim 16, in which the crowned surface is hardened.

18. The piston pump in accordance with claim 17, in which the check valve (32) has a valve seat part (44), which is joined nondisplaceably to the sleeve (20;

68, 70).

19. The piston pump in accordance with claim 15, in which the piston (18) has an interior (56), which communicates with brake fluid to be pumped.

20. The piston pump in accordance with claim 15, in which an elastic damper body (58) is received in the interior (56).