Spring load adjusting apparatus and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9863541-B2
Application number	US-201213728085-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Dec 27, 2011
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A sleeve has a female thread, which is formed in an inner peripheral surface of the sleeve. An adjust screw adjusts a spring load of a spring, which is placed in an inside of the sleeve. The adjust screw has a male thread, which is formed in an outer peripheral surface of the adjust screw and is threadably engaged with the female thread. The sleeve has at least one protrusion that is formed integrally with the rest of the sleeve and is urged against the adjust screw toward the spring in an axial direction to urge the male thread against the female thread and thereby to provide a predetermined degree of sealing between the male thread and the female thread.

First claim

What is claimed is:

1. A spring load adjusting apparatus comprising:
a female-threaded member that has a female thread, which is formed in an inner peripheral surface of the female-threaded member; and
an adjust screw that adjusts a spring load of a spring, which is placed in an inside of the female-threaded member, wherein:
the adjust screw has a male thread, which is formed in an outer peripheral surface of the adjust screw and is threadably engaged with the female thread;
the female-threaded member has at least one protrusion that is formed integrally with the rest of the female-threaded member and is urged against a head of the adjust screw toward the spring in an axial direction to urge the male thread against the female thread and thereby to provide a predetermined degree of sealing between the male thread and the female thread, and
the at least one protrusion is urged against the head of the adjust screw in the axial direction so that the at least one protrusion limits rotation of the adjust screw in both of a tightening direction and a loosening direction of the adjust screw.

2. The spring load adjusting apparatus according to claim 1 , wherein the at least one protrusion includes a plurality of protrusions.

3. The spring load adjusting apparatus according to claim 2 , wherein an axial end surface of the adjust screw includes:
at least one primary slope that receives an urging force from a corresponding one of the plurality of protrusions to exert a rotational force against the adjust screw in a tightening direction of the adjust screw; and
at least one secondary slope that receives an urging force from a corresponding one of the plurality of protrusions to exert a rotational force against the adjust screw in a loosening direction of the adjust screw, which is opposite from the tightening direction of the adjust screw.

4. The spring load adjusting apparatus according to claim 3 , wherein:
the at least one primary slope includes a plurality of primary slopes;
the at least one secondary slope includes a plurality of secondary slopes;
the plurality of primary slopes and the plurality of secondary slopes are alternately continuously arranged one after another in a circumferential direction along an outer peripheral edge of the axial end surface of the adjust screw;
each of the plurality of primary slopes and the plurality of secondary slopes circumferentially extends for a predetermined angular extent;
the plurality of protrusions includes two protrusions, which are circumferentially arranged one after another at generally equal intervals about a central axis of the adjust screw; and
the predetermined angular extent of each of the plurality of primary slopes and the plurality of secondary slopes is set to satisfy the following equation:
θ=360 degrees/2 N

where θ denotes the predetermined angular extent of each of the plurality of primary slopes and the plurality of secondary slopes, and N is an odd number that is equal to or larger than 3.

5. The spring load adjusting apparatus according to claim 3 , wherein:
the at least one primary slope includes a plurality of primary slopes;
the at least one secondary slope includes a plurality of secondary slopes;
the plurality of primary slopes and the plurality of secondary slopes are alternately continuously arranged one after another in a circumferential direction along an outer peripheral edge of the axial end surface of the adjust screw;
each of the plurality of primary slopes and the plurality of secondary slopes circumferentially extends for a predetermined angular extent;
the plurality of protrusions includes three protrusions, which are circumferentially arranged one after another at generally equal intervals about a central axis of the adjust screw; and
the predetermined angular extent of each of the plurality of primary slopes and the plurality of secondary slopes is set to satisfy the following equation:
θ=360 degrees/(3 N+ 1)

where θ denotes the predetermined angular extent of each of the plurality of primary slopes and the plurality of secondary slopes, and N is an odd number that is equal to or larger than 1.

6. The spring load adjusting apparatus according to claim 2 , wherein:
an axial end surface of the adjust screw includes a plurality of primary slopes and a plurality of secondary slopes;
the plurality of primary slopes and the plurality of secondary slopes are alternately continuously arranged one after another in a circumferential direction along an outer peripheral edge of the axial end surface of the adjust screw to form a plurality of peaks and a plurality of valleys, which are alternately arranged one after another in the circumferential direction;
each of the plurality of protrusions is urged against a corresponding one of the plurality of peaks;
each of the plurality of primary slopes and the plurality of secondary slopes circumferentially extends for a predetermined angular extent; and
a circumferential length of each of the plurality of protrusions is set to be larger than a predetermined circumferential length, which is twice larger than the predetermined angular extent of each of the plurality of primary slopes and the plurality of secondary slopes.

7. The spring load adjusting apparatus according to claim 2 , wherein an axial end surface of the adjust screw includes a plurality of recesses, each of which is recessed in the axial direction and receives a corresponding one of the plurality of protrusions.

8. The spring load adjusting apparatus according to claim 2 , wherein:
an axial end surface of the adjust screw includes a plurality of slopes, each of which is tilted by a predetermined angle relative to an imaginary plane that is perpendicular to a central axis of the adjust screw;
the predetermined angle of each of the plurality of slopes is generally the same as a lead angle of the male thread; and
each of the plurality of protrusions is urged against a corresponding one of the plurality of slopes.

9. The spring load adjusting apparatus according claim 1 , wherein:
the spring is a compression coil spring;
the adjust screw has a spring-holding portion that holds and supports one end portion of the spring;
the spring-holding portion includes a centering projection that axially projects into the spring and guides an inner peripheral portion of the spring such that the spring is centered by the centering projection relative to the adjust screw; and
a tool-engaging hole is formed in an axial end surface of the adjust screw and axially extends into the centering projection.

10. The spring load adjusting apparatus according to claim 1 , wherein:
the spring is a compression coil spring;
the adjust screw has a spring-holding portion that holds and supports one end portion of the spring;
the spring-holding portion includes a centering recess that guides an outer peripheral portion of the spring such that the spring is centered by the centering recess relative to the adjust screw;
an inner diameter of the centering recess is progressively increased from a bottom of the centering recess to an insertion opening of the centering recess, through which the one end portion of the spring is inserted into the centering recess; and
the adjust screw includes an extended tubular portion, by which an axial length of the centering recess is increased.

11. The spring load adjusting apparatus according to claim 1 , wherein:
the spring load adjusting apparatus is provided in a spool valve, which controls a hydraulic pressure of an automatic transmission; and
the female-threaded member is a sleeve of the spool valve.

12. The spring load adjustin

Assignees

• Denso Corp

Inventors

• Hirano Akinori

Classifications

• Y10T29/49908

  Joining by deforming · CPC title

• B21K25/00 Primary

  Uniting components to form integral members, e.g. turbine wheels and shafts, caulks with inserts, with or without shaping of the components (uniting by interference- or press-fitting B23P11/02, B21K19/02) · CPC title

• F16K1/523 Primary

  for limiting the maximum flow rate, using a stop · CPC title

• B21J5/00

  Methods for forging, hammering, or pressing (for working sheet-metal or metal tubes, rods, or profiles B21D; for working wire B21F); Special equipment or accessories therefor · CPC title

• F16K11/07

  with cylindrical slides · CPC title