Knock detecting apparatus for internal combustion engines

Claim 2

A knock detecting apparatus for internal combustion engines comprising: vibrating means attached to an engine, including at least one reed member made of a magnetic material and adapted to vibrate in response to vibrations of said engine, and a support member which is greater in thickness than said reed member and adapted to support said reed member, said reed member having a resonance characteristic corresponding to a knocking frequency of said engine; magnetic path forming means disposed adjacent to said reed member to form a magnetic path therewith and define a gap therebetween; magnetic flux generating means including an excitation coil; output adjusting means including impedance means for adjusting the supply of current to said excitation coil; and magnetic flux sensing means disposed adjacent to said magnetic path to sense changes in the magnetic relunctance of said magnetic path caused by changes in the width of said gap due to vibrations of said reed member.

Claim 3

A knock detecting apparatus for internal combustion engines, comprising: vibrator means including at least one reed member and a ring-shaped support member, said reed member being projected from an inner wall of said ring-shaped support member toward the center thereof, both of said reed member and said support member being made as a unitary body of a magnetic material, said reed member having a resonance characteristic corresponding to a knocking frequency of an engine; a bar-shaped magnetic core having one end being located adjacent to but spaced from said reed member to form an air gap therebetween; a cup-shaped housing of a magnetic material for accommodating said vibrator means and said bar-shaped magnetic core so that said support member of said vibrator means is fixed to an inside surface of said cup-shaped housing; magnetic flux generating means for generating magnetic flux through a magnetic path formed by said bar-shaped magnetic core, said air gap, said reed member, said support member and a side wall of said cup-shaped housing, said magnetic flux generating means including an excitation coil for generating controllable magnetic flux; and magnetic flux sensing means disposed adjacent to and coupled with said magnetic path to sense changes in the magnetic reluctance of said magnetic path caused by changes in the width of said gap due to vibrations of said reed member.

Claim 4

A knock detecting apparatus for internal combustion engines, comprising: vibrator means including at least one reed member and a ring-shaped support member, said reed member being projected from an inner wall of said ring-shaped support member toward the center thereof, both of said reed member and said support member being made as a unitary body of a magnetic material, said reed member having a resonance characteristic corresponding to a knocking frequency of an engine; a bar-shaped magnetic core having one end being located adjacent to but spaced from said reed member to form an air gap therebetween; a cup-shaped housing of a magnetic material for accommodating said vibrator means and said bar-shaped magnetic core so that said support member of said vibrator means is fixed to an inside surface of said cup-shaped housing; magnetic flux generating means for generating magnetic flux through a magnetic path formed by said bar-shaped magnetic core, said air gap, said reed member, said support member and a side wall of said cup-shaped housing, said magnetic flux generating means including an excitation coil for generating controllable magnetic flux; and magnetic flux sensing means disposed adjacent to and coupled with said magnetic path to sense changes in the magnetic reluctance of said magnetic path caused by changes in the width of said gap due to vibrations of said reed member.

Claim 5

An apparatus according to claim 2, wherein said reed element is shaped such that said reed member is gradually increased in width in a portion thereof connected to said support member.

Claim 6

An apparatus according to claim 2, wherein said reed member is shaped such that said reed member is gradually increased in thickness in a portion thereof connected to said support member.

Claim 7

An apparatus according to claim 2, wherein said vibrating means is formed through plastic deformation produced by pressing.

Claim 8

An apparatus according to claim 2, wherein said vibrating means is made by bending a magnetic sheet material such that said reed member and said support member are integrally formed.

Claim 9

An apparatus according to claim 2, wherein said vibrating means is subjected to a surface reinforcing treatment.

Claim 10

An apparatus according to claim 2, wherein said magnetic flux sensing means includes a sensing coil, and said knock detecting apparatus further comprises output adjusting means including impedance means connected to said sensing coil.

Claim 11

An apparatus according to claim 2, wherein said magnetic flux generating means includes a magnet.