JP2010225596A - Electromagnetic switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology reducing direct influence given to an electromagnetic coil 27 by heat generated in a resistor 9, without enlarging the outer diameter of an auxiliary switch 10. <P>SOLUTION: The resistor 9 is disposed in a space formed between a magnetic plate 28 and an auxiliary contact in the inside of a contact cover 31, one end side 9a of the resistor 9 is joined to a first terminal bolt 32, and the other end side 9b is joined to a second terminal bolt 33. The resistor 9 is disposed with a gap provided against the inner surface of the contact cover 31 by a prescribed distance, and between one end side 9a joined to the first terminal bolt 32 and the other end side 9b joined to the second terminal bolt 33, two or more bent portions are provided on a plane perpendicular to an axial direction. In this structure, the resistor 9 is not disposed on the periphery side of the magnetic coil 27, but it is disposed in the space formed in the inside of the contact cover 31, and thereby, the outer diameter of the auxiliary switch 10 can be made small. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic switch having a built-in resistor for suppressing a current to be supplied when starting a starter motor, for example.

  2. Description of the Related Art Conventionally, a technique for controlling the operation of a motor used for a starter in two stages is known (see Patent Document 1). In this prior art, a main contact and an auxiliary contact are provided in a motor circuit, and a resistor is connected in series to a circuit formed by closing the auxiliary contact.

  When the motor is started, the auxiliary contact is closed before the main contact, and the motor is rotated at a low speed by applying the current suppressed by the resistor to the motor, and then (after the pinion gear meshes with the ring gear) By closing the main contact, the entire voltage of the battery is applied to the motor, and the motor rotates at a high speed.

  The resistor is housed in a resin-made cage that is disposed on the outer periphery of the electromagnetic coil via an air layer inside the electromagnetic switch.

Japanese Patent No. 3767650

  However, in the prior art disclosed in Patent Document 1, since the resistor housed in the resin cage is disposed on the outer periphery of the electromagnetic coil via the air layer, the thickness of the air layer + resistor + cage The outer diameter of the electromagnetic switch increases by the amount.

  Moreover, since the whole outer periphery of an electromagnetic coil is covered with the resin-made cage | baskets with low heat conductivity, the heat which generate | occur | produces in an electromagnetic coil by electricity supply becomes difficult to escape to an outer peripheral side. As a result, the temperature rise of the electromagnetic coil is increased and the allowable heat resistant time is shortened. As a measure for reducing the temperature rise, it is conceivable to increase the size of the electromagnetic coil. In this case, however, the electromagnetic switch cannot be reduced in size and the weight is increased.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide an electromagnetic switch with a built-in resistor for suppressing a current to be supplied when starting a starter motor. An object of the present invention is to provide a technique capable of reducing the direct influence of heat generated by a resistor on an electromagnetic coil without increasing the size.

(Invention of Claim 1)
The present invention relates to an electromagnetic coil that forms an electromagnet when energized, a magnetic plate that is disposed on one end side in the axial direction of the electromagnetic coil to form a part of a magnetic circuit, and a through hole is formed in the center, A movable iron core that moves in the axial direction through the through-hole of the plate, a contact cover that is arranged on the anti-electromagnetic coil side of the magnetic plate, and is fixed to this contact cover and connected to the high potential side of the motor circuit, A first terminal provided with a first fixed contact inside the contact cover, and fixed to the contact cover, connected to the low potential side of the motor circuit, and second fixed inside the contact cover A second terminal provided with a contact and an axially anti-movable iron core side with respect to the first and second fixed contacts are disposed between the first and second fixed contacts in conjunction with the movement of the movable iron core. Movable contacts that open and close A resistor for suppressing a current flowing in the circuit, and the resistor is disposed in a space formed between the magnetic plate and the first and second fixed contacts inside the contact cover. In addition, one end side of the resistor is electrically and mechanically joined to the first terminal, and the other end side is electrically and mechanically joined to the second terminal.

  In the above configuration, since the resistor is not disposed on the outer periphery of the electromagnetic coil via the air layer, but is disposed in the space formed inside the contact cover, the outer diameter of the electromagnetic switch is increased. There is nothing. In addition, since the resistor is disposed inside the contact cover and is not exposed to the outside, it is possible to prevent moisture and the like from adhering to the resistor and to prevent corrosion, thereby improving durability. Furthermore, even when the resistor is heated red by energization for a long time, a flammable object brought in from the outside does not come into contact with the resistor, thereby improving safety.

  Further, since the resistor is disposed at a position away from the electromagnetic coil, the heat dissipation of the electromagnetic coil is not impaired, and the magnetic plate is disposed between the resistor and the electromagnetic coil. Since the heat generated by the resistor hardly affects the electromagnetic coil, the heat resistance and excitation performance of the electromagnetic coil are not impaired.

  Further, the movable contact is arranged on the side opposite to the movable core in the axial direction from the first and second fixed contacts, that is, the movable contact is between the first fixed contact and the second fixed contact and the magnetic plate. Since it does not exist, the risk of contact between the resistor and the movable contact can be eliminated, and the reliability can be improved.

(Invention of Claim 2)
2. The electromagnetic switch according to claim 1, wherein the first terminal has one end provided with the first fixed contact disposed inside the contact cover, and the other end exposed to the outside of the contact cover. The second terminal is characterized in that one end side on which the second fixed contact is provided is disposed inside the contact cover, and the other end side is exposed to the outside of the contact cover.

  The resistor has one end joined to the first terminal and the other end joined to the second terminal, and the first terminal and the second terminal are provided with the first fixed contact and the second fixed contact. Therefore, the heat generated by the resistor is easily conducted to the first fixed contact and the second fixed contact. As a result, even if the first and second terminals exposed to the outside of the contact cover are exposed to the outside air (cold air) and the temperature of both terminals decreases, contact continuity failure due to condensation, freezing, etc. on the contact surface Can be prevented.

(Invention of Claim 3)
The electromagnetic switch according to claim 1 or 2, wherein the resistor is disposed with a gap of a predetermined distance from the inner peripheral surface of the contact cover.

  Since the gap is formed between the inner peripheral surface of the contact cover and the resistor, the contact cover is not easily damaged by heat generated by the resistor, and the reliability can be improved.

(Invention of Claim 4)
The electromagnetic switch according to any one of claims 1 to 3, wherein the resistor has a shaft between one end side joined to the first terminal and the other end side joined to the second terminal. Two or more bent portions are provided on a plane orthogonal to the direction.

  By providing two or more bent portions in the resistor, the total length of the resistor can be adjusted, and the resistance value of the resistor can be changed without changing the inner diameter of the contact cover.

(Invention of Claim 5)
The electromagnetic switch according to any one of claims 1 to 4, wherein the contact cover is formed of a resin, and when the resistor is energized, the resistor is moved before the contact cover reaches the heat softening temperature. It is set so as to melt.

  When a conduction failure occurs in the contact portion composed of the first and second fixed contacts and the movable contact, it is conceivable that the resistor is energized continuously and becomes red hot. In contrast, in the present invention, when the resistor is heated red, the resistor is blown before the contact cover reaches the heat softening temperature. That is, since the resistor is melted before the inner surface of the contact cover is thermally damaged, the contact cover is not thermally damaged by the red heat of the resistor, and the safety and reliability of the electromagnetic switch are improved.

(Invention of Claim 6)
6. The electromagnetic switch according to claim 1, wherein each of the first terminal and the second terminal has a hole having a predetermined depth at a center portion of both axial end surfaces thereof. In addition, a recess such as a hole or a groove is formed from the outer diameter toward the inner diameter at two locations facing each other in the radial direction via the hole, and one end side of the resistor is formed in the hole formed in the first terminal. And insert the other end of the resistor into the hole formed in the second terminal, and the bottom of the recess formed in the first terminal and the recess formed in the second terminal One end side and the other end side of the resistor are caulked and fixed to the first terminal and the second terminal, respectively, by pressing and deforming the bottom part in the inner diameter direction.

  According to the above configuration, when joining both ends of the resistor to the first terminal and the second terminal, it is not necessary to use whole heating and melting means such as brazing in the furnace. Sometimes the strength of the first terminal and the second terminal is not impaired. Accordingly, for example, when the first terminal or the second terminal is formed with a bolt, when the cable terminal or the like is tightened to the first terminal or the second terminal outside the electromagnetic switch, the bolt is broken against breaking. A margin can be secured.

  Further, when the one end side and the other end side of the resistor are caulked and fixed to the first terminal and the second terminal, respectively, recesses (holes or grooves) are formed in the first terminal and the second terminal. Since the bottom portion of the concave portion is pressed and deformed in the inner diameter direction, the thickness of the portion where the concave portion is formed is reduced and partially deformed, so that the bending deformation of the entire terminal is reduced and the assembling property can be improved.

(Invention of Claim 7)
6. The electromagnetic switch according to claim 1, wherein each of the first terminal and the second terminal has a hole having a predetermined depth at a center portion of both axial end surfaces thereof. Then, the hole is filled with brazing material, one end of the resistor is inserted into the hole formed in the first terminal, and the other end of the resistor is inserted into the hole formed in the second terminal. By inserting and melting the brazing filler metal by means of partial heating means such as energization, one end side of the resistor is electrically and mechanically joined to the first terminal, and the other end side of the resistor is second. It is characterized in that it is electrically and mechanically joined to the terminal.

  According to the above configuration, when joining both ends of the resistor to the first terminal and the second terminal, it is not necessary to use whole heating and melting means such as brazing in the furnace. Sometimes the strength of the first terminal and the second terminal is not impaired. Accordingly, for example, when the first terminal or the second terminal is formed with a bolt, when the cable terminal or the like is tightened to the first terminal or the second terminal outside the electromagnetic switch, the bolt is broken against breaking. A margin can be secured and the reliability of the electromagnetic switch is improved.

  For example, a paste-like brazing material can be used as the brazing material filled in the holes formed in the first terminal and the second terminal.

(Invention of Claim 8)
The electromagnetic switch according to any one of claims 1 to 5, wherein the first terminal and the second terminal are each provided with a convex portion having a predetermined height on the axial end face of each of the first terminal and the second terminal. One end side of the resistor is electrically and mechanically joined to the convex portion formed on the terminal by welding, and the other end side of the resistor is electrically connected to the convex portion formed on the second terminal by welding, and It is mechanically joined.

  According to the above configuration, when joining both ends of the resistor to the first terminal and the second terminal, it is not necessary to use whole heating and melting means such as brazing in the furnace. Sometimes the strength of the first terminal and the second terminal is not impaired. Accordingly, for example, when the first terminal or the second terminal is formed with a bolt, when the cable terminal or the like is tightened to the first terminal or the second terminal outside the electromagnetic switch, the bolt is broken against breaking. A margin can be secured and the reliability of the electromagnetic switch is improved.

(Invention of Claim 9)
The electromagnetic switch according to any one of claims 1 to 8, further comprising a fixed iron core disposed on the inner circumference of the electromagnetic coil and disposed on the other end side in the axial direction from the magnetic plate, When an electromagnet is formed, it is attracted to a fixed iron core.

(Invention of Claim 10)
The electromagnetic switch according to any one of claims 1 to 9, wherein the first terminal and the second terminal are constituted by bolts.

(Example 1) which is sectional drawing of an auxiliary switch. (Example 1) which was the top view which looked at the inside of the contact cover provided in an auxiliary switch from the opening part side. It is a top view of a starter. It is an electric circuit diagram of a starter. It is a time chart which shows the electricity supply control of ECU with respect to a switch coil and an electromagnetic coil. (Example 2) which is sectional drawing of an auxiliary switch. (Example 3) which is sectional drawing of an auxiliary switch. (Example 3) which was the top view which looked at the inside of the contact cover provided in an auxiliary switch from the opening part side.

  The best mode for carrying out the present invention will be described in detail by the following examples.

Example 1
FIG. 1 is a cross-sectional view of an auxiliary switch 10 that is an electromagnetic switch according to the present invention, FIG. 3 is a plan view of a starter 1, and FIG. 4 is an electrical circuit diagram of the starter 1.

  As shown in FIGS. 3 and 4, the starter 1 of the present embodiment includes a housing 2 attached to an engine (not shown), a motor 4 fastened to the housing 2 by fastening a through bolt 3, and the motor 4 opens and closes a pinion gear 6 (see FIG. 4) that transmits the rotational force generated in the engine 4 to the engine ring gear 5 (see FIG. 4), and a main contact (described later) provided in the motor circuit, and a shift lever 7 (see FIG. 4). 4) and a resistor 9 (see FIG. 4) for suppressing the current to be supplied when starting the motor 4. The main switch 8 has a function of pushing the pinion gear 6 in the direction opposite to the motor (right direction in FIG. 4). ) And an auxiliary switch 10 for opening and closing an auxiliary contact (described later) provided in parallel with the resistor 9 in the motor circuit.

  The housing 2 is provided with a flange portion 2a that is fixed to a starter mounting surface (not shown) on the engine side, and a switch mounting portion 2b that fixes the main switch 8.

  As shown in FIG. 4, the motor 4 is provided with a commutator 4b on one end side (the left side in the figure) of the armature 4a. When the main contact is closed by the main switch 8, the motor 4 is disposed on the outer periphery of the commutator 4b. This is a known commutator motor that generates a rotational force in the armature 4a by energizing the armature 4a from the battery 12 through the brush 11.

  The pinion gear 6 is disposed integrally with the clutch 14 on the outer periphery of the output shaft 13 driven by the motor 4, and the rotation of the output shaft 13 is transmitted via the clutch 14.

  As shown in FIG. 4, the main switch 8 is constituted by a solenoid incorporating a switch coil 15 and a plunger 16. The main switch 8 has a function of attracting the plunger 16 by forming an electromagnet by energizing the switch coil 15. The main contact is closed in conjunction with the movement of the. When the energization of the switch coil 15 is stopped and the attractive force disappears, the plunger 16 is pushed back by the reaction force of a spring (not shown) to open the main contact. As shown in FIG. 3, the main switch 8 is fixed by fastening two bolts 17 to a switch mounting portion 2 b provided in the housing 2.

  As shown in FIG. 4, the main contact includes a B fixed contact 18 a connected to the high potential side (battery side) of the motor circuit via the B terminal bolt 18 and a low potential of the motor circuit via the M terminal bolt 19. The fixed contact 18a and 19a are intermittently connected by a movable contact 20 that is configured to move integrally with the plunger 16 and is configured with an M fixed contact 19a connected to the side (motor side).

  Each of the B terminal bolt 18 and the M terminal bolt 19 is fixed to a contact cover 21 (see FIG. 3) of the main switch 8, and the main contact is disposed inside the contact cover 21. Note that the M terminal bolt 19 is electrically connected to the brush 11 on the positive electrode side via a motor lead wire 22 (see FIG. 3). Connection of the B terminal bolt 18 will be described later.

  The switch coil 15 includes two coils (a suction coil 15a and a holding coil 15b).

  The suction coil 15 a has one end connected to an excitation terminal 23 (see FIG. 4) fixed to the contact cover 21 of the main switch 8 and the other end electrically connected to the M terminal bolt 19. Yes. The holding coil 15b has one end connected to the excitation terminal 23 together with one end of the suction coil 15a, and the other end connected to the ground side (for example, the fixed core of the main switch 8).

  As shown in FIG. 4, the excitation terminal 23 is connected to the battery 12 via a starter relay 24. When the starter relay 24 is turned on in response to a signal from the ECU 25 (an electronic control device that controls engine start), the battery The current flowing from 12 is supplied through the starter relay 24.

  Next, the configuration of the auxiliary switch 10 will be described in detail with reference to FIG.

  The auxiliary switch 10 has a cylindrical switch case 26 having a bottom surface, an electromagnetic coil 27 housed in the switch case 26, and one end side in the axial direction of the electromagnetic coil 27 (on the bottom surface side of the switch case 26). A magnetic plate 28 that is disposed to form a part of the magnetic circuit, a fixed iron core 29 that is magnetized by energization of the electromagnetic coil 27, a movable iron core 30 that is arranged to face the fixed iron core 29, and the magnetic plate 28. A resin contact cover 31 disposed on the anti-electromagnetic coil side, two terminal bolts 32 and 33 fixed to the contact cover 31, and auxiliary contacts provided on the two terminal bolts 32 and 33. The movable contact 34 is configured to open and close the auxiliary contact in conjunction with the movement of the movable core 30.

  The switch case 26 forms a magnetic circuit (fixed magnetic path) together with the magnetic plate 28 and the fixed iron core 29, and the outer diameter of the opening (on the bottom side) where the magnetic plate 28 is disposed accommodates the electromagnetic coil 27. The step is formed larger than the outer diameter of the portion, and has a step between the portion accommodating the electromagnetic coil 27 and the opening side.

  The electromagnetic coil 27 is wound around a resin bobbin 35, one end is connected to an external lead terminal 36 (see FIG. 4), and the other end is grounded at a position not shown.

  The external lead terminal 36 is led out of the contact cover 31 through a terminal lead hole 31a (see FIG. 2) formed in the contact cover 31, and is connected to the ECU 25 as shown in FIG.

  The magnetic plate 28 is formed in an annular body having a round hole (through hole of the present invention) opened in the center in the radial direction, molded by a resin member 37 provided integrally with the bobbin 35, and the switch case 26. It is positioned in contact with the step provided in. The electromagnetic coil 27 is mechanically fixed to the magnetic plate 28 via a resin member 37.

  The fixed iron core 29 is disposed on the inner periphery of the electromagnetic coil 27 with one end face in the axial direction in close contact with the bottom surface of the switch case 26.

  The movable iron core 30 moves in the axial direction through the round hole of the magnetic plate 28 and is urged by the return spring 38 in the anti-fixed iron core direction (the right direction in FIG. 1). The return spring 38 is disposed between a stepped portion formed on the outer peripheral portion of the fixed iron core 29 and a stepped portion formed on the outer peripheral portion of the movable core 30.

  The contact cover 31 is provided in a bottomed shape with one end opening in a cylindrical shape, the outer diameter on the opening side is fitted to the inner periphery of the switch case 26, and the end surface on the opening side is the magnetic plate 28. A part or the entire circumference in the circumferential direction is caulked and fixed to the end of the switch case 26.

  The contact cover 31 and the switch case 26 are sealed by a seal member 39 such as an O-ring, for example, to prevent intrusion of water or the like from the outside.

  The two terminal bolts 32 and 33 are a first terminal bolt 32 connected to the positive terminal of the battery 12 by a cable and a B terminal bolt 18 of the main switch 8 by a connecting member 40 (see FIG. 3) made of a metal plate. The second terminal bolt 33 is electrically and mechanically connected to the contact cover 31 by washers 41 and 42 and crimping washers 43 and 44, respectively.

  The auxiliary contact is formed by a first fixed contact 45 provided integrally with the first terminal bolt 32 and a second fixed contact 46 provided integrally with the second terminal bolt 33. Arranged inside the cover 31. The first fixed contact 45 and the second fixed contact 46 may be formed separately from the first terminal bolt 32 and the second terminal bolt 33 and then joined by means such as brazing.

  The movable contact 34 is disposed inside the contact cover 31 on the side opposite to the movable core from the auxiliary contacts (the first fixed contact 45 and the second fixed contact 46), and is connected to the movable core 30 via a resin rod 47. It is connected. The movable contact 34 is pressed against a contact receiving surface 31 b provided at the bottom of the contact cover 31 by urging the movable core 30 toward the anti-fixed core by a return spring 38. Further, the contact cover 31 is formed with an annular concave space around the contact receiving surface 31b. In this concave space, when the movable contact 34 closes the auxiliary contact, that is, the movable contact 34 is the first fixed. A contact pressure spring 48 is provided that applies a pressing force to the movable contact 34 when it contacts the contact 45 and the second fixed contact 46.

  The rod 47 is fixed in a state where one end is embedded in the central portion in the radial direction of the movable iron core 30, and the other end is inserted between the first fixed contact 45 and the second fixed contact 46. The movable contact 34 is in contact with the tip.

  The auxiliary switch 10 is disposed close to the radial direction of the main switch 8 and is fixed to the housing 2 via a bracket 49.

  In the bracket 49, the auxiliary switch 10 is fixed by welding or the like to an end face on one end side provided in a substantially disc shape, and the other end side in which two round holes (not shown) are formed is the switch mounting portion of the housing 2. It is fixed to the housing 2 together with the main switch 8 by two bolts 17 that are sandwiched between 2b and the main switch and are inserted into the round hole.

  Next, the arrangement and mounting structure of the resistor 9 will be described with reference to FIGS.

  The resistor 9 is disposed at a predetermined distance from the magnetic plate 28 and the auxiliary contact in a space formed between the magnetic plate 28 and the auxiliary contact in the contact cover 31. One end side 9 a is electrically and mechanically joined to the first terminal bolt 32, and the other end side 9 b is electrically and mechanically joined to the second terminal bolt 33.

  As shown in FIG. 2, the resistor 9 is disposed with a gap from the inner peripheral surface of the contact cover 31 by a predetermined distance and is joined to the first terminal bolt 32 at one end side 9 a. And two or more bent portions 9c (three in FIG. 2) on the plane orthogonal to the axial direction are provided between the second terminal bolt 33 and the other end 9b.

  Furthermore, when the resistor 9 receives red heat when continuously energized, before the contact cover 31 is thermally damaged, in other words, before the contact cover 31 reaches a thermal softening temperature (for example, 260 ° C.), It is set so that the body 9 is fused.

  Next, the operation of the starter 1 will be described.

  On the time chart shown in FIG. 5, the ECU 25 energizes the switch coil 15 at time t1, and then energizes the electromagnetic coil 27 at time t2. As a result, during t seconds from time t1 to time t2, the current value supplied to the motor 4 is A1, which is suppressed from the current value A2 at all voltages.

  More specifically, first, at time t1, the starter relay 24 is turned on in response to a signal from the ECU 25, whereby the switch coil 15 is energized. As a result, the plunger 16 is sucked and moved leftward as shown in FIG. 4, whereby the pinion gear 6 is pushed out in the counter-motor direction (rightward in the figure) via the shift lever 7.

  Subsequently, when the main contact is closed, a current (current value A1) suppressed from the battery 12 via the resistor 9 is energized to the motor 4, whereby the motor 4 rotates at a low speed.

  After the pinion gear 6 meshes with the ring gear 5 due to the rotation of the motor 4, and when the electromagnetic coil 27 of the auxiliary switch 10 is energized by the ECU 25 at a predetermined timing (time t2), the movable contact 34 is attracted and the auxiliary contact By closing, a short-circuit path for short-circuiting the resistor 9 is formed. As a result, the entire voltage of the battery 12 is applied to the motor 4 and a high current (current value A2) flows through the motor 4, whereby the motor 4 rotates at a high speed, and the rotation of the motor 4 is changed from the pinion gear 6 to the ring gear. 5 is transmitted to crank the engine.

(Effect of Example)
In the starter 1 of this embodiment, since the current suppressed by the resistor 9 is applied to the motor 4 in the initial energization of the motor 4 (between the main contact is closed and the auxiliary contact is closed), the pinion gear 6 and the ring gear The impact at the time of meshing with 5 is alleviated. As a result, wear of the pinion gear 6 and the ring gear 5 is reduced, and durability is improved.

  Further, since the inrush current that flows when the motor 4 starts to rotate can be reduced, the contact life of the main switch 8 and the brush life of the motor 4 can be improved.

  The auxiliary switch 10 incorporating the resistor 9 is not disposed on the outer peripheral side of the electromagnetic coil 27 but is disposed in a space formed inside the contact cover 31. As compared with the prior art described in the above (a structure in which the resistor is housed in a resin cage and arranged on the outer periphery of the electromagnetic coil via an air layer), the outer diameter of the auxiliary switch 10 can be reduced. In particular, the switch case 26 has an outer diameter on the opening side larger than the outer diameter of the portion in which the electromagnetic coil 27 is accommodated, and the resistor 9 is disposed in the inner space of the contact cover 31 fitted to the inner periphery thereof. Therefore, the outer diameter of the portion in which the electromagnetic coil 27 is accommodated can be formed to the minimum necessary size, and the overall shape of the auxiliary switch 10 can be made compact.

  Further, since the resistor 9 is not exposed to the outside by being disposed inside the contact cover 31, it is possible to prevent moisture and the like from adhering to the resistor 9 and to prevent corrosion, thereby improving durability. . Furthermore, even when the resistor 9 is red-heated due to energization for a long time, a flammable object brought in from the outside does not come into contact with the resistor 9, so that safety can be improved.

  Furthermore, since the resistor 9 is disposed at a position away from the electromagnetic coil 27, the heat dissipation of the electromagnetic coil 27 is not impaired, and the magnetic plate 28 is interposed between the resistor 9 and the electromagnetic coil 27. Therefore, the heat generated by the resistor 9 hardly affects the electromagnetic coil 27, so that the heat resistance and excitation performance of the electromagnetic coil 27 are not impaired.

  The movable contact 34 is disposed on the side opposite to the movable core in the axial direction from the auxiliary contact, that is, between the first fixed contact 45 and the second fixed contact 46 that form the auxiliary contact and the magnetic plate 28. Since there is no movable contact 34, the risk of contact between the resistor 9 and the movable contact 34 can be eliminated, and the reliability can be improved.

  In this embodiment, one end side 9 a of the resistor 9 is joined to the first terminal bolt 32, and the other end side 9 b is joined to the second terminal bolt 33, and the first terminal bolt 32 and the second terminal bolt 32 are connected. Since the first fixed contact 45 and the second fixed contact 46 are provided on the terminal bolt 33, the heat generated by the resistor 9 is easily conducted to the first fixed contact 45 and the second fixed contact 46. As a result, even if the first terminal bolt 32 and the second terminal bolt 33 exposed to the outside of the contact cover 31 are exposed to the outside air (cold air) and the temperature of both the terminal bolts 32 and 33 is lowered, the contact surface Contact conduction failure due to condensation, freezing, etc. can be prevented.

  The resistor 9 is disposed at a predetermined distance from the magnetic plate 28 and the auxiliary contact, and is disposed with a gap of a predetermined distance from the inner peripheral surface of the contact cover 31. Therefore, the contact cover 31 is less likely to be thermally damaged by the heat generated by the resistor 9. In addition, when a conduction failure occurs between the first and second fixed contacts 45 and 46 forming the auxiliary contact and the movable contact 34, it is considered that the resistor 9 is energized continuously and becomes red hot. On the other hand, the resistor 9 is set to melt before the resin contact cover 31 reaches the thermal softening temperature. That is, the resistor 9 is melted before the contact cover 31 is thermally damaged. Therefore, the contact cover 31 is not thermally damaged, and the reliability and safety of the auxiliary switch 10 are improved.

  Further, the resistor 9 is formed between the one end side 9a joined to the first terminal bolt 32 and the other end side 9b joined to the second terminal bolt 33 on a plane orthogonal to the axial direction. Since more than 9 bent portions 9c are provided, the resistance value can be set to a desired value by adjusting the total length of the resistor 9 by changing the curvature of the bent portion 9c. Further, by providing the resistor 9 with the bent portion 9c, the resistor 9 can be easily bent when both ends of the resistor 9 are joined to the first terminal bolt 32 and the second terminal bolt 33. The distance L (refer FIG. 2) between the both ends of the body 9 can be adjusted easily.

(Example 2)
FIG. 6 is a cross-sectional view of the auxiliary switch 10.

  In the second embodiment, a means for joining the resistor 9 to the first terminal bolt 32 and the second terminal bolt 33 will be described.

  The first terminal bolt 32 and the second terminal bolt 33 are each provided with a hole 32a having a predetermined depth at the center of the axial end surface where the first fixed contact 45 and the second fixed contact 46 are provided. , 33a are formed, and concave portions 32b, 33b such as holes or grooves are formed from the outer diameter toward the inner diameter side at two locations facing each other in the radial direction through the holes 32a, 33a. The resistor 9 has one end 9a inserted into a hole 32a formed in the first terminal bolt 32, and the other end 9b inserted into a hole 33a formed in the second terminal bolt 33. One end side 9a of the resistor 9 and the bottom of the recess 32b formed in the first terminal bolt 32 and the bottom of the recess 33b formed in the second terminal bolt 33 are respectively deformed by pressing in the inner diameter direction. The other end side 9b is caulked and fixed to the first terminal bolt 32 and the second terminal bolt 33, respectively.

  According to said structure, when joining the both ends of the resistor 9 to the 1st terminal volt | bolt 32 and the 2nd terminal volt | bolt 33, it is not necessary to use whole heating fusion joining means, such as brazing in a furnace. The strength of the first terminal bolt 32 and the second terminal bolt 33 is not impaired at the time of joining. As a result, when the cable terminal or the like is fastened to the first terminal bolt 32 or the second terminal bolt 33 outside the auxiliary switch 10, it is possible to ensure a tightening margin against bolt breakage.

  Further, when the one end side 9 a and the other end side 9 b of the resistor 9 are caulked and fixed to the first terminal bolt 32 and the second terminal bolt 33, respectively, the first terminal bolt 32 and the second terminal bolt 33. In addition, the concave portions 32b and 33b (holes or grooves) are respectively formed and the bottom portions of the concave portions 32b and 33b are pressed and deformed in the inner diameter direction, so that the thickness of the portion where the concave portions 32b and 33b are formed is reduced. Therefore, the bending deformation of the entire bolt is reduced and the assemblability can be improved.

  In addition to the above joining means, for example, joining by brazing is also possible.

  Specifically, the holes formed in the first terminal bolt 32 after filling the holes 32a and 33a formed in the first terminal bolt 32 and the second terminal bolt 33 with a paste-like brazing material. One end side 9 a of the resistor 9 is inserted into the portion 32 a, and the other end side 9 b of the resistor 9 is inserted into the hole 33 a formed in the second terminal bolt 33. Thereafter, the brazing material is heated and melted by partial heating means such as energization, whereby one end side 9 a of the resistor 9 is electrically and mechanically joined to the first terminal bolt 32, and the other of the resistor 9. The end side 9b is joined to the second terminal bolt 33 electrically and mechanically. Also in this joining means, since it is not necessary to use whole heating and melting joining means such as brazing in the furnace, the strength of the first terminal bolt 32 and the second terminal bolt 33 is not impaired at the time of joining. Since the tightening margin can be ensured, the reliability of the auxiliary switch 10 can be improved.

(Example 3)
FIG. 7 is a cross-sectional view of the auxiliary switch 10.

  In Example 3, a method of joining both ends of the resistor 9 to the first terminal bolt 32 and the second terminal bolt 33 by welding will be described.

  As shown in FIG. 7, each of the first terminal bolt 32 and the second terminal bolt 33 has a predetermined center portion on the axial end surface where the first fixed contact 45 and the second fixed contact 46 are provided. Protrusions 32c and 33c having a height are provided. As shown in FIG. 8, the convex portions 32c and 33c are provided in a planar rectangular shape having a short dimension in the horizontal width direction, which is the horizontal direction in the figure, and a long dimension in the vertical width direction, which is the vertical direction in the figure. Are provided in a trapezoidal cross section that gradually decreases toward the tips of the convex portions 32c and 33c.

  In addition, the dimension of the vertical direction of the convex parts 32c and 33c is sufficiently larger than the diameter of the resistor 9 (for example, about 3 times larger). Moreover, the height of the convex parts 32c and 33c is a dimension which can arrange | position the resistor 9 in the substantially the same position as the case of Example 1. FIG. In other words, the magnetic plate 28 and the first and second fixed contacts 45 and 46 have a height that can ensure a substantially equivalent distance from both.

  As shown in FIG. 8, one end side 9a of the resistor 9 is electrically and mechanically joined to the tip end surface of the convex portion 32c provided on the first terminal bolt 32 by projection welding, and the other end side 9b. However, it is electrically and mechanically joined to the front end surface of the convex portion 33c provided on the second terminal bolt 33 by projection welding.

  According to the configuration of the present embodiment, as in the case of the second embodiment, when the both end portions 9a and 9b of the resistor 9 are joined to the first terminal bolt 32 and the second terminal bolt 33, Since it is not necessary to use whole heating and melting joining means such as brazing, the strength of the first terminal bolt 32 and the second terminal bolt 33 is not impaired during joining.

  In addition, since the dimensions of the convex portions 32c and 33c in the vertical width direction are sufficiently larger than the diameter of the resistor 9, both end portions 9a and 9b of the resistor 9 are formed even if a slight displacement occurs during welding. The protrusions 32c and 33c do not come off. For this reason, both ends 9a and 9b of the resistor 9 can be reliably joined to the both convex portions 32c and 33c, and the distance L between both ends 9a and 9b of the resistor 9 can be easily adjusted.

(Modification)
In the first embodiment, an example in which the auxiliary switch 10 that is the electromagnetic switch of the present invention is fixed to the housing 2 of the starter 1 via the bracket 49 is described. However, the auxiliary switch 10 is not necessarily fixed to the starter 1. 10 can be arranged away from the starter 1.

  For example, since the mounting position of the starter 1 is often limited in the engine room, when the auxiliary switch 10 is fixed to the starter 1 as in the first embodiment, the mounting position of the starter 1 including the auxiliary switch 10 is changed. It may be difficult to ensure. In such a case, the mounting position of the starter body can be secured by disposing the auxiliary switch 10 physically apart from the starter body. Moreover, since the auxiliary switch 10 is smaller in size than the starter body, the mounting position of the auxiliary switch 10 can be easily secured.

1 Starter 4 Motor (Starter motor)
9 Resistor 9c Bending part of resistor 10 Auxiliary switch (electromagnetic switch)
27 Electromagnetic coil 28 Magnetic plate 29 Fixed iron core 30 Movable iron core 31 Contact cover 32 First terminal bolt 32a A hole formed in the first terminal bolt 32b A recess formed in the first terminal bolt 32c First terminal Convex part provided in the bolt 33 Second terminal bolt 33a Hole part provided in the second terminal bolt 33b Concave part formed in the second terminal bolt 33c Convex part provided in the second terminal bolt 34 Movable contact 45 First fixed contact 46 Second fixed contact

Claims (10)

An electromagnetic coil that forms an electromagnet when energized;
A magnetic plate that is disposed on one end side in the axial direction of the electromagnetic coil to form a part of the magnetic circuit, and a through hole is formed in the center,
A movable iron core movable in the axial direction through the through hole of the magnetic plate;
A contact cover disposed on the anti-electromagnetic coil side of the magnetic plate;
A first terminal fixed to the contact cover, connected to the high potential side of the motor circuit, and provided with a first fixed contact inside the contact cover;
A second terminal fixed to the contact cover, connected to the low potential side of the motor circuit, and provided with a second fixed contact inside the contact cover;
A movable contact that is arranged on the side opposite to the movable core in the axial direction from the first and second fixed contacts, and that electrically opens and closes between the first and second fixed contacts in conjunction with the movement of the movable core;
A resistor for suppressing a current flowing through the motor circuit,
The resistor is disposed in a space formed between the magnetic plate and the first and second fixed contacts inside the contact cover, and one end side of the resistor serves as the first terminal. An electromagnetic switch characterized in that it is electrically and mechanically joined, and the other end is electrically and mechanically joined to the second terminal. The electromagnetic switch according to claim 1,
The first terminal has one end provided with the first fixed contact disposed inside the contact cover, and the other end exposed outside the contact cover.
One end of the second terminal provided with the second fixed contact is disposed inside the contact cover, and the other end is exposed to the outside of the contact cover. Electromagnetic switch. In the electromagnetic switch according to claim 1 or 2,
The electromagnetic switch according to claim 1, wherein the resistor is disposed with a gap from the inner peripheral surface of the contact cover by a predetermined distance. In the electromagnetic switch according to any one of claims 1 to 3,
The resistor has two or more bent portions on a plane orthogonal to the axial direction between one end side joined to the first terminal and the other end side joined to the second terminal. An electromagnetic switch characterized by being provided. The electromagnetic switch according to any one of claims 1 to 4,
The contact cover is made of resin,
An electromagnetic switch, wherein when the resistor is energized, the resistor is blown before the contact cover reaches a heat softening temperature. The electromagnetic switch according to any one of claims 1 to 5,
Each of the first terminal and the second terminal has a hole portion having a predetermined depth at the center portion of the axial end surfaces of the first terminal and the second terminal, and is opposed to the radial direction through the hole portion. A recess such as a hole or groove is formed from the outer diameter toward the inner diameter at the place,
Inserting one end side of the resistor into the hole formed in the first terminal, inserting the other end side of the resistor into the hole formed in the second terminal, By pressing and deforming the bottom of the recess formed in the terminal and the bottom of the recess formed in the second terminal in the inner diameter direction, one end side and the other end side of the resistor are respectively in the first side. An electromagnetic switch characterized in that it is fixed by crimping to the terminal and the second terminal. The electromagnetic switch according to any one of claims 1 to 5,
Each of the first terminal and the second terminal has a hole portion having a predetermined depth at the center portion of the axial end surfaces of both, and the hole portion is filled with a brazing material,
Insert one end of the resistor into the hole formed in the first terminal and insert the other end of the resistor into the hole formed in the second terminal, The brazing material is heated and melted by a mechanical heating means, whereby one end side of the resistor is electrically and mechanically joined to the first terminal, and the other end side of the resistor is connected to the second terminal. An electromagnetic switch characterized by being electrically and mechanically joined. The electromagnetic switch according to any one of claims 1 to 5,
The first terminal and the second terminal are each provided with a convex portion having a predetermined height on the axial end surfaces thereof,
One end side of the resistor is electrically and mechanically joined to the convex portion formed on the first terminal by welding, and the other end side of the resistor is connected to the convex portion formed on the second terminal. An electromagnetic switch that is electrically and mechanically joined by welding. The electromagnetic switch according to any one of claims 1 to 8,
A fixed iron core disposed on the inner circumference of the electromagnetic coil and disposed on the other end side in the axial direction from the magnetic plate;
The electromagnetic switch, wherein the movable iron core is attracted to the fixed iron core when the electromagnet is formed. The electromagnetic switch according to any one of claims 1 to 9,
The electromagnetic switch, wherein the first terminal and the second terminal are constituted by bolts.

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