Accumulator

• US 4,799,048 A
• Filed: 06/10/1987
• Issued: 01/17/1989
• Est. Priority Date: 09/28/1984
• Status: Expired due to Fees

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Jidosha Kabushiki Kaisha
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation), Jidosha Kabushiki Kaisha
• Inventors: Goshima, Takahiro, Otsuki, Hiromi, Hattori, Yoshiyuki, Nomura, Yoshihisa, Nakanishi, Nobuyasu, Kinbara, Hiroji
• Primary Examiner(s): Marcus, Stephen
• Application Number:
  US07/060,959
• Time in Patent Office: 587 Days
• Field of Search: 92/101, 138/31, 200/82 E, 200/84 C, 340/52 B, 340/52 C, 340/626, 340/686, 303/115
• US Class Current: 340/626
• CPC Class Codes: B60T 8/4068 the additional fluid circuit comprising means for attenuating pressure pulsations
• CPC Class Codes: F15B 1/04 Accumulators
• CPC Class Codes: F15B 1/24 with rigid separating means, e.g. pistons
• CPC Class Codes: F15B 2201/21 using springs
• CPC Class Codes: F15B 2201/312 Sealings therefor, e.g. piston rings
• CPC Class Codes: F15B 2201/411 having valve means
• CPC Class Codes: F15B 2201/515 Position detection for separating means

Abstract

An accumulator has a piston axially slidably disposed in a cylinder mounted in a casing, the cylinder and the piston jointly defining a reservoir communicating with an inlet/outlet port in the casing. A piston rod axially movably disposed in the casing has an end slidably fitted in the cylindrical hole of the piston. The piston rod is normally urged by a spring to force the piston into the reservoir. The accumulator also includes a switch mechanism for detecting the position of the piston in the cylinder. The switch mechanism may comprise a reed switch, a light-sensitive switch, a pressure-sensitive switch, or a pushbutton switch.

Claims

1. An accumulator comprising:

a casing having an inlet/outlet port;

a cylinder disposed in said casing;

a piston slidably disposed in said cylinder, said cylinder and one end of said piston jointly defining a reservoir of variable volume communicating with said inlet/outlet port and said piston having a coaxial recess extending from the other end of said piston to a bottom therein;

a piston ring held on an outer surface of said piston and lying in substantially the same plane as the inner surface of said bottom;

a piston rod axially movably disposed in said casing and having an end slidably fitted in said recess; and

a spring engaged with said piston rod for normally urging said piston rod toward said bottom to keep said end of said piston rod and said piston ring positioned in substantially the same position at all times with respect to a longitudinal axis of said piston to force said piston to reduce the volume of said reservoir.

2. An accumulator according to claim 1, wherein the surface of said bottom is concave and said end of the piston rod has convex end surface urged against said concave bottom surface.

3. An accumulator according to claim 2, wherein aid concave bottom surface has a radius of curvature larger than the radius of curvature of said convex end surface of the end of the piston rod.

4. An accumulator according to claim 1, wherein the spring is a coil disposed around the piston rod and further including a cylindrical wear-resistant lining layer made of a material of high rigidity fitted in said casing and held against the inner surface of said casing and disposed around said spring.

5. An accumulator comprising;

a casing having an inlet/outlet port;

a cylinder disposed in said casing;

a piston axially slidably disposed in said cylinder, said cylinder and one end of said piston jointly defining a reservoir of variable volume communicating with said inlet/outlet port and said piston having a coaxial recess extending from the other end of said piston to a bottom therein;

a piston ring held on an outer surface of said piston, said piston ring and the inner surface of said bottom being located in substantially the same plane;

a piston rod axially movably disposed in said casing and having an end slidably fitted in said coaxial recess;

a spring engaged with said piston rod for normally urging said piston rod to keep said end of the piston rod and said piston ring positioned in substantially the same position at all times with respect to the longitudinal axis of said piston to force said piston into said reservoir; and

means for electrically detecting the position of said piston in said cylinder.

6. An accumulator according to claim 5, including a plug connected to said casing remotely from said piston and supporting said spring, said detecting means comprising a reed switch mounted on said plug and a ring-shaped permanent magnet mounted n said piston rod and movable therewith to a position in which said switch is located within said magnet for actuating said switch when said piston reaches a prescribed position in said cylinder.

7. An accumulator according to claim 5, including a plug connected to said casing remotely from said piston and supporting said spring, said detecting means comprising a light-sensitive switch mounted on said plug and a rod mounted on said piston rod for actuating said light-sensitive switch.

8. An accumulator according to claim 7, wherein said light-sensitive switch comprises a light-emitting element and a lightdetector spaced therefrom, said rod mounted on said piston rod serving as a light-shielding rod movable into a position between said light-emitting element and said lightdetector.

9. An accumulator according to claim 8, including a bolt axially threaded into said piston rod, said means further including a second light-sensitive switch mounted on said plug and actuatable by said bolt.

10. An accumulator according to claim 9, wherein said second light-sensitive switch comprises a light-emitting element and a lightdetector spaced therefrom along a line off said light-shielding rod.

11. An accumulator according to claim 5, including a plug connected to said casing remotely from said piston and supporting said spring, said detecting means comprising a pressure-sensitive switch mounted on said plug and a rod mounted on said piston rod for actuating said pressure-sensitive switch.

12. An accumulator according to claim 5, including a plug connected to said casing remotely from said piston and supporting said spring, said detecting means comprising a pushbutton switch mounted on said plug and a rod mounted on said piston rod for actuating said pushbutton switch.