Electromagnetic switch for starter

Patent metadata

Field	Value
Publication number	US-10147575-B2
Application number	US-201514948802-A
Country	US
Kind code	B2
Filing date	Nov 23, 2015
Priority date	Nov 28, 2014
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

An electromagnetic switch for a starter includes a coil that includes a first lead wire connected to a power supply side and a second lead wire connected to a ground side, the coil being supplied with an energization current through the first and second lead wires to form an electromagnet while a starter relay is on. The electromagnetic switch further includes a surge suppression device that absorbs part of energy emitted from the coil when the starter relay is turned from on to off so that a remaining part of the energy is applied to the starter relay to cause an arc current to flow between contacts of the starter relay.

First claim

What is claimed is:

1. An electromagnetic switch for a starter, comprising:
a coil that includes a first lead wire connected to a power supply side and a second lead wire connected to a ground side, the coil being supplied with an energization current through the first and second lead wires to form an electromagnet while a starter relay is on, the starter relay being different from the electromagnetic switch; and
a surge suppression device that absorbs part of energy emitted from the coil when the starter relay is turned from on to off so that a remaining part of the energy is applied to the starter relay to cause an arc current to flow between contacts of the starter relay, wherein
the surge suppression device includes a diode and a Zener diode which are coupled such that (i) anodes of the diode and the Zener diode are connected to each other, a cathode of the diode is connected to the power supply side of the coil and a cathode of the Zener diode is connected to the ground side of the coil, or such that (ii) the cathodes of the diode and the Zener diode are connected to each other, the anode of the Zener diode is connected to the power supply side of the coil and the anode of the diode is connected to the ground side of the coil, and
the Zener diode has a predetermined Zener voltage selected to determine an amount of the arc current to flow between the contacts of the starter relay.

2. The electromagnetic switch according to claim 1 , wherein the surge suppression device includes a resistor connected in series with the diode and the Zener diode.

3. The electromagnetic switch according to claim 1 , wherein the diode is a second Zener diode.

4. The electromagnetic switch according to claim 3 , wherein the surge suppression device includes a resistor connected in series with the Zener diode and the second Zener diode.

5. The electromagnetic switch according to claim 1 , wherein the predetermined Zener voltage has a value selected so that an amount of the arc current to flow between the contacts of the starter relay cleans contact surfaces of the contacts of the starter relay without promoting wear of the contacts.

Assignees

• Denso Corp

Inventors

• Suzuki Yoshiaki

Classifications

• H01H47/02 Primary

  for modifying the operation of the relay · CPC title

• H01H47/22 Primary

  for supplying energising current for relay coil · CPC title

• H01H50/021

  structurally combining a relay and an electronic component, e.g. varistor, RC circuit (auxiliary switch inserting resistor during closure H01H50/543) · CPC title

• F02N2011/0874

  characterised by said switch being an electronic switch · CPC title

• H01H50/443

  Connections to coils · CPC title