JP3070477B2 - Magnetic switch for starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet switch used for a starter for starting an engine.

[0002]

2. Description of the Related Art Conventionally, when a starter is used in a cold region or the like, frost adheres to the surface of a fixed contact incorporated in a magnet switch due to rapid cooling after the engine is stopped from a high temperature and high humidity state during engine operation. Contact surfaces can freeze. That is, since the large-diameter cable from the battery is connected to the power terminal of the magnet switch, after the engine is stopped, the cable starts to cool first, and then the power terminal of the magnet switch to which the cable is connected cools, The fixed contact formed integrally with the power terminal cools. At this time, if the humidity in the air inside the magnet switch is high, there is a possibility that moisture in the air first forms dew on the contact surface, then becomes frost, and finally freezes.

Under these conditions, if the magnet switch is reduced in size and the attraction force is reduced, the impact force at the time of collision between the movable contact and the fixed contact of the switch is reduced, and the surface of the fixed contact freezes. In such a case, the ice cannot be broken, resulting in poor conduction, which may increase the probability of malfunction. Therefore, as a method of preventing an operation failure due to icing of the contacts, Japanese Utility Model Application Laid-Open No. 54-88563 discloses a method in which a number of grooves are formed on at least one surface of a movable contact or a fixed contact, and the contact surface is damaged when the contact collides. There has been proposed a magnet switch in which a layer of ice is broken to facilitate conduction. Alternatively, in Japanese Utility Model Laid-Open No. 50-9635 and Japanese Utility Model Laid-Open No. 51-34242, a heating wire is arranged around a contact in a magnet switch, and ice on the contact surface is melted by heating the heating wire. A method is disclosed.

[0004]

However, in the method in which a groove is formed on the contact surface to facilitate conduction, the impact force at the time of contact collision decreases when the magnet switch is reduced in size and the attraction force is reduced. Therefore, there is a problem that a sufficient effect cannot be exhibited. In addition, since the method using the heating wire is a method of melting ice using radiant heat from the heating wire, it takes time to melt the ice. Therefore, not only cannot the user's request that the engine be started quickly by turning the key switch, but also a component for controlling the energization of the heating wire is required,
There is a problem that the cost is increased.

The present invention has been made on the basis of the above circumstances, and an object of the present invention is to provide a starter magnet switch in which a motor is started in two stages to smoothly engage a pinion and a ring gear. Another object of the present invention is to prevent an operation failure due to icing of a contact provided in a motor circuit.

[0006]

The present invention has the following features to attain the object mentioned above. In claim 1,
A heating element is interposed between the main fixed contact and the sub fixed contact. Therefore, even if the starter is cooled by use in a cold region and the main fixed contact is cooled, the heat conductivity of the heating element is small, so the sub-fixed contact is difficult to cool down, and the contact surface of the sub-fixed contact freezes. Can be prevented. On the other hand, in the case of the main fixed contact connected to the power supply terminal, the contact surface may freeze when the power supply terminal cools, but the ice on the contact surface can be melted using the heat of the heating element that is conductive and generates heat. . That is, when the starter motor is energized via the heating element, the heat generated by the heating element is transmitted to the main fixed contact, and the contact surface of the main fixed contact is also heated by the radiant heat from the heating element, so that the main fixed contact is heated. Ice frozen on the contact surface of the contact is quickly melted, thereby preventing conduction failure due to freezing.

According to the second aspect, after the battery is energized to the starter motor through the heating element which is an electric resistor, the heating element is short-circuited and the battery is energized to the starter motor. Thus, the starter motor can be started in two stages: when the current supplied from the battery via the heating element is limited, and when the heating element is short-circuited and energized.

According to the third and fourth aspects, the starter motor can be started in two stages with the movement of the plunger. Specifically, with the movement of the plunger, first, the sub movable contact is brought into contact with the sub fixed contact, thereby energizing the starter motor from the battery via the heating element,
Further, the main movable contact is brought into contact with the main fixed contact with the movement of the plunger, so that the heating element can be short-circuited and the battery can be energized to the starter motor.

According to the fifth aspect of the present invention, the sub movable contact is mechanically and electrically connected to the main movable contact by an elastic conductive holding member. The contact pressure at the time of contact with the fixed contact can be applied. That is, since the holding member that connects the sub movable contact and the main movable contact can be used as a contact pressure spring, a dedicated contact pressure spring is not required, and the number of components can be reduced.

According to the present invention, a curved portion or a bent portion is formed between one end of the holding member connected to the main movable contact and the other end of the holding member connected to the sub movable contact. That is, the total length of the holding member is longer than the linear length connecting the main movable contact and the sub movable contact. By forming a curved portion or a bent portion on the holding member to increase the overall length of the holding member, the stress when the holding member is bent can be reduced. In addition, it can be said that the sub movable contact can be arranged near the main movable contact by forming the holding member not in a linear shape but by forming a curved portion or a bent portion to secure a predetermined length. That is, even if the holding member has a long overall length, the magnet switch can be downsized by forming the whole compact.

According to a seventh aspect of the present invention, a contact holding member for holding the sub-fixed contact is provided between the heating element and the sub-fixed contact, and the contact holding member is made of a bimetal. It can be suppressed by deformation.

According to the present invention, the contact holding member for holding the sub-fixed contact is connected to the main fixed contact via a pair of heating elements. For this reason, since the heat transmitted from the main fixed contact to the contact holding member through the heating element is dispersed, even if the main fixed contact cools, it becomes difficult for the cold heat to be transmitted to the contact holding member, and icing of the sub fixed contact can be prevented. . Also, when the starter motor is energized through the heating element, the heat generated by the pair of heating elements is efficiently transmitted to the main fixed contact. Is quickly melted, and poor conduction due to icing can be prevented.

According to the ninth aspect, the contact holding member made of a bimetal is deformed due to overheating of the heating element, so that the short-circuit contact of the heating element provided on the contact holding member comes into contact with the main fixed contact to generate heat. The body can be shorted. As a result, no current flows through the heating element, so that unnecessary heating of the heating element is suppressed.

According to the tenth aspect, the contact holding member made of bimetal is deformed due to overheating of the heating element, so that the sub-fixed contact provided on the contact holding member is separated from the sub-movable contact to the heating element. Can be shut off.
As a result, no current flows through the heating element, so that unnecessary heating of the heating element is suppressed.

In the eleventh aspect, the number of parts can be reduced by integrally forming the heating element short-circuiting contact and the auxiliary fixed contact.

According to the twelfth aspect, the heating element is constituted by a positive temperature coefficient thermistor, so that unnecessary heating of the heating element can be suppressed. That is, when a current flows through the heating element for a necessary time or more and the temperature of the heating element rises to a predetermined temperature, the resistance value of the heating element, which is a positive temperature coefficient thermistor, increases to suppress the current value, thereby preventing overheating of the heating element. Can be suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a magnet switch for a starter according to the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a sectional view of a starter 1, and FIG. 2 is a motor circuit diagram. The starter 1 of the present embodiment includes a starter motor 2 that generates a rotational force when energized, an output shaft 3 that rotates by receiving a rotational force of the starter motor 2, a pinion 4 that fits around the outer periphery of the output shaft 3, A torque transmitting means (described later) for transmitting the torque of the starting motor 2 to the output shaft 3, a rotation regulating member 5 for regulating the rotation of the pinion 4 at the time of starting, and arranged behind the starting motor 2 (right side in FIG. 1). And a contact device (described later) for opening and closing the motor switch (see FIG. 2).

(Explanation of the starting motor 2)
It comprises a yoke 7, a fixed magnetic pole 8, an armature 9, a brush 10, and the like. The yoke 7 is formed by, for example, press working (deep drawing), and is formed on the rear end side (the right end side in FIG. 1).
It has a cylindrical shape that is open only, and is sandwiched between the housing 12 and the end cover 13 together with the holder 11 arranged on the rear end side of the yoke 7. The front end of the yoke 7
It is bent radially inward and is provided as a partition plate 7a that partitions the starting motor 2 and the rotational force transmitting means. The fixed magnetic pole 8 is made of, for example, a plurality of permanent magnets, and is fixed to the inner peripheral surface of the yoke 7 to form a magnetic field. The fixed magnetic pole 8 may use a field coil that generates a magnetic force when energized, instead of a permanent magnet.

The armature 9 includes a shaft 14 serving as a rotating shaft, an armature core 15 provided on an outer periphery of the shaft 14, and an armature coil 1 wound around the armature core 15.
6, the front end of the shaft 14 fits into a recess formed at the rear end of the output shaft 3 via a bearing 17, and the rear end is rotatably supported by the holder 11 via a bearing 18. Have been. An armature coil 16 bent along the end face of the armature core 15 is provided on the rear end face of the armature 9.
This forms a commutator 16a.

The brush 10 includes at least one pair of a positive brush 10a and a negative brush 10b, each of which is held by a holder 11 and is pressed against a commutator 16a by a spring (not shown) from the rear end in the axial direction. . The lead wire 19 of the positive electrode brush 10a has a movable contact 20 for full-voltage operation described later while having an appropriate slack.
(Hereinafter, referred to as a main movable contact 20),
The lead wire 21 of the negative electrode brush 10b is electrically connected to the holder 11 (made of metal) and is grounded.

(Explanation of Output Shaft 3) The output shaft 3 is arranged coaxially with the shaft 14 of the armature 9, and its front end is rotatably supported by the housing 12 via a bearing 22, and its rear end is provided. It is rotatably supported by a center case 24 housed inside the housing 12 via a bearing 23. The rear end of the output shaft 3 protrudes outward in the radial direction and is integrally provided as a planet carrier 25 of a planetary gear reduction mechanism (described later). In addition, pinion 4
Helical spline 3a is provided on the outer circumference of the output shaft 3 where
Are formed.

(Explanation of Pinion 4) The pinion 4 has a pinion helical spline (not shown) formed on the inner peripheral surface thereof and is fitted with a helical spline 3a formed on the outer periphery of the output shaft 3. By advancing along the helical spline 3a on the shaft 3, it can mesh with a ring gear (not shown) of the engine. The pinion 4 is provided with a spring 26 arranged on the front end side of the pinion 4.
Urges the output shaft 3 rearward. At the rear end of the pinion 4, a rotation regulating plate 27 having an outer diameter larger than that of the pinion 4 is integrally provided. The outer circumferential surface of the rotation restricting plate 27 has an engaging groove 2 extending in the axial direction.
A large number (more than the number of external teeth of the pinion 4) are formed at regular intervals in the plate circumferential direction.

(Description of Torque Transmission Means) The rotation force transmission means is composed of a planetary gear reduction mechanism (reduction means of the present invention) and a one-way clutch. 24. The planetary gear reduction mechanism is a reduction gear that reduces the rotation speed of the armature 9 to increase the output torque of the starting motor 2, and includes a sun gear 28 formed on the outer periphery of the tip of the shaft 14, and three planets meshing with the sun gear 28. Gear 29, each planetary gear 2
An internal gear 30 that meshes with the gear 9 and the planet carrier 25 described above.

The sun gear 28 rotates integrally with the shaft 14 so that the rotation of the shaft 14 is controlled by three planetary gears 2.
9 Each of the three planetary gears 29 is rotatably supported by a pin 31 fixed to the planet carrier 25 via a bearing 32, and revolves around the outer periphery of the sun gear 28 while meshing with the sun gear 28 and the internal gear 30. Then, the revolving force is transmitted to the planet carrier 25, and the rotational force is transmitted to the output shaft 3. The internal gear 30 is provided in a cylindrical shape, and its outer peripheral surface is slidably in contact with the inner peripheral surface of the cylindrical wall of the center case 24 and is rotatably incorporated.

The one-way clutch supports the internal gear 30 of the planetary gear reduction mechanism so as to be rotatable only in one direction (the direction in which the rotation is performed by receiving the rotation of the engine), and includes a clutch outer 33, a clutch inner 34, and a roller. 35, a spring (not shown), and the like. The clutch outer 33 is provided integrally with the internal gear 30 on the front end side of the internal gear 30. A plurality of wedge-shaped cam chambers (not shown) are formed on the inner peripheral surface of the clutch outer 33 in the circumferential direction.

The clutch inner 34 is connected to the center case 24.
And has a cylindrical shape extending in the axial direction at a predetermined interval between the clutch outer 33 and the inner periphery of the clutch outer 33. The roller 35 is housed in the cam chamber, locks the clutch outer 33 and the clutch inner 34 when transmitting the torque of the starting motor 2 to the output shaft 3, and regulates the rotation of the clutch outer 33. The spring is housed in the cam chamber together with the roller 35,
5 is pressed toward the narrow side of the cam chamber.

(Explanation of the rotation regulating member 5) The rotation regulating member 5
Is a spring member provided by winding a rod-shaped metal material about 3/2 times, and both ends are bent at substantially right angles in the same direction at radially opposed positions. The bent one end 5
a is a regulating rod that regulates the rotation of the pinion 4 by engaging with an engaging groove 27a formed on the outer peripheral surface of the rotation regulating plate 27 at the initial stage of operation of the starter 1, and has a wire 5a at the other end 5b. One end of the cord-like member 36 is engaged, and the operation of the magnet switch 6 is transmitted through the cord-like member 36.

The rotation restricting member 5 includes a center case 24
It is held movably in the vertical direction (vertical direction in FIG. 1) in a state where the movement in the axial direction (horizontal direction in FIG. 1) is restricted. The rotation restricting member 5 is constantly urged upward by a return spring (not shown), and the operation of the magnet switch 6 is controlled by the other end 5 through the string-like member 36.
b, the entire rotation restricting member 5 moves downward against the spring force of the return spring, and when the magnet switch 6 is turned off, is urged upward by the spring force of the return spring to move to the initial position. (The position shown in FIG. 1).

(Explanation of Magnet Switch 6) The magnet switch 6 is held in a pedestal 37 press-fitted into the holder 11 and is arranged in the end cover 13, and operates in a direction of movement (up and down in FIG. 1) with respect to the shaft 14 of the armature 9. Direction) is substantially perpendicular. The magnet switch 6 includes a switch cover 38, a coil 3
9, a fixed iron core 40, a plunger 41, a return spring 42, a rod 43 and the like. The switch cover 38 is made of a magnetic material (for example, iron) and is press-molded in a cup shape, and an insertion hole through which the plunger 41 is slidably inserted is formed in the center of the cover bottom surface (the lower surface in FIG. 1). .

As shown in FIG. 2, the coil 39 is connected to a vehicle-mounted battery 45 via a starter switch 44 of the vehicle. When the starter switch 44 is turned on and energized, the coil 39 generates a magnetic force. The fixed iron core 40 is arranged on the upper end side of the coil 39 and is caulked and fixed to the opening of the switch cover 38. The plunger 41 is made of a magnetic material (for example, iron) and has a cylindrical shape. The plunger 41 is disposed inside the hollow of the coil 39 so as to face the fixed core 40, and is attracted to the magnetized fixed core 40 when the coil 39 is energized. You. The other end of the above-mentioned string member 36 is connected to the bottom of the plunger 41.
The operation of the plunger 41 is transmitted to the rotation regulating member 5 by being guided by the rollers 46 held by the center case 24 and the rollers 46 held by the center case 24.

The return spring 42 is interposed between the plunger 41 and the fixed iron core 40 on the inner periphery of the coil 39, and moves the plunger 41 below the fixed iron core 40 (see FIG. 1).
Below). That is, when the power supply to the coil 39 is stopped, the plunger 41 that has been sucked toward the fixed iron core 40 against the urging force of the return spring 42 is returned to the initial position (the position shown in FIG. 1). The rod 43 is made of an insulator (for example, a resin) and made of a plunger 4.
1 is fixed to the upper end side, passes through the hollow interior of the coil 39, slidably penetrates a through hole formed in the center of the fixed iron core 40, and protrudes upward. Of course, if the main movable contact 20 is insulated, the rod 43 may be a conductor.

(Description of Contact Device for Motor Circuit) As shown in FIG. 2, the contact device is composed of a power supply terminal 49 connected to a battery 45 by a cable 48, and a fixing device for full-voltage operation fixed to the power supply terminal 49. A contact 50 (hereinafter referred to as a main fixed contact 50), a main movable contact 20 for full-voltage operation movable corresponding to the main fixed contact 50, and a resistor 51 electrically connected to a power supply terminal 49 (the present invention) And a low-voltage starting fixed contact 52 (hereinafter referred to as a sub-fixed contact 5) that is electrically connected to the power supply terminal 49 via the resistor 51.
2) and a movable contact 53 for low voltage activation (hereinafter, referred to as a sub movable contact 53) that moves in correspondence with the sub fixed contact 52, and the main movable contact 20 and the sub movable contact 53 are magnet switches 6 It is configured to be movable by the operation of.

As shown in FIG. 1, the power supply terminal 49 is attached to the end cover 13 so as to penetrate the end cover 13 so that the tip end is exposed outside the end cover 13 and is fixed to the end cover 13 by tightening a washer 54. . The main fixed contact 50 is provided integrally with the head 49 a of the power supply terminal 49 inside the end cover 13. Main movable contact 20
Is attached to the tip of the rod 43 of the magnet switch 6 so as to face the main fixed contact 50.

The resistor 51 is formed by forming a metal material such as iron chromium, nickel chromium or the like into a coil shape.
As shown in FIG. 3 (A view in FIG. 1), the power supply terminal 49 is provided on both sides of the head 49a,
The other end is connected to a plate-shaped contact holding member 55 (conductor). The auxiliary fixed contact 52 is fixed to the center of the lower surface of the contact holding member 55 by welding or the like. The sub movable contact 53 is connected to the main movable contact 20 via the holding member 56, and is arranged to face the sub fixed contact 52. As shown in FIG. 1, the holding member 56 is formed by bending an elongated metal plate to have elasticity. One end is mechanically and electrically connected to the main movable contact 20, and the other end is the sub movable contact 53. And are connected mechanically and electrically.

In this contact device, the distance between the auxiliary movable contact 53 and the auxiliary fixed contact 52 is set smaller than the distance between the main movable contact 20 and the main fixed contact 50, and the magnet switch 6 operates. When the rod 43 moves upward along with the plunger 41 as shown in FIG.
Before contact with the main fixed contact 50, the sub movable contact 53 contacts the sub fixed contact 52, the battery voltage is applied to the starting motor 2 via the resistor 51, and then the main movable contact 20
Abuts on the main fixed contact 50 to short-circuit the resistor 51, so that the entire voltage is applied to the starting motor 2.

Next, the operation of this embodiment will be described. When the starter switch 44 is turned on and the magnet switch 6 is operated, the string member 36 is moved with the movement of the plunger 41.
Is pulled to the magnet switch 6 side,
The rotation restricting member 5 moves downward along the center case 24. As a result, the regulating rod (hereinafter referred to as 5a) of the rotation regulating member 5 engages with the engagement groove 27a of the rotation regulating plate 27 to regulate the rotation of the pinion 4.

On the other hand, when the plunger 41 is attracted to the fixed iron core 40 and the rod 43 rises, first, the sub movable contact 5
3 contacts the auxiliary fixed contact 52 and conducts. This allows
The current from the battery 45 is supplied from the power supply terminal 49 to the resistor 51.
→ sub fixed contact 52 → sub movable contact 53 → holding member 56 → main movable contact 20 → lead wire 19 of positive brush 10a → positive brush 10a → armature 9 → negative brush 10b → lead wire 21 of negative brush 10b → holder 11 And the starting motor 2 is started with the current supplied thereto being limited by the resistor 51. The rotation of the starting motor 2 (the armature 9) is reduced by the planetary gear reduction mechanism and transmitted to the output shaft 3, whereby the output shaft 3 rotates at a low speed. This output shaft 3
The rotation of the pinion 4 also tries to rotate, but since the rotation of the pinion 4 is restricted by the restriction rod 5a, the rotational force of the output shaft 3 acts as a thrust for pushing the pinion 4 in the axial direction. As a result, the pinion 4 can advance with respect to the output shaft 3 along the helical spline 3a and mesh with the ring gear.

Thereafter, when the pinion 4 completely meshes with the ring gear, the tip of the regulating rod 5a is rotated by the rotation regulating plate 27.
Of the pinion 4 is released by dropping from the engagement groove 27a to the rear end side of the rotation restricting plate 27. The plunger 41 is further sucked by the tip of the regulating rod 5a falling to the rear end side of the rotation regulating plate 27, so that the main movable contact 20 comes into contact with the main fixed contact 50 and becomes conductive. Thus, the current from the battery 45 is
Short-circuit the resistor 51 from the power supply terminal 49 → Main fixed contact 5
0 → main movable contact 20 → lead wire 19 of positive brush 10a
→ positive brush 10a → armature 9 → negative brush 10
b → the lead wire 21 of the negative electrode brush 10 b → the holder 11. As a result, when the rated voltage is applied to the starting motor 2 and the armature 9 rotates, the rotational force is transmitted to the ring gear meshing with the pinion 4 and the engine can be started. When the tip of the regulating rod 5a falls to the rear end side of the rotation regulating plate 27, the sub movable contact 53 remains in contact with the sub fixed contact 52, and
Although movement of the plunger 41 is restricted, the movement of the plunger 41 is not prevented by bending of the elastic holding member 56.

When the pinion 4 advances and meshes with the ring gear, the urging force of the spring 26 for urging the pinion 4 increases. When the pinion 4 is rotated by the ring gear after the engine is started, the rotational force of the engine acts in a direction to retract the pinion 4 by the action of the helical spline 3a. With these forces,
Although the pinion 4 tends to retreat with respect to the output shaft 3, the retraction of the pinion 4 is prevented by the tip of the regulating rod 5 a that has fallen to the rear end side of the rotation regulating plate 27 supporting the rear end face of the rotation regulating plate 27. Is done.

Thereafter, when the starter switch 44 is turned off and the power supply to the coil 39 is stopped, the magnetic force of the coil 39 disappears, so that the plunger 41 that has been attracted to the fixed iron core 40 until then is attached to the return spring 42. The power returns to the initial position (the position shown in FIG. 1).
By the return of the plunger 41, the main movable contact 20 and the main fixed contact 50, and the sub movable contact 53 and the sub fixed contact 52
Are separated from each other to cut off the conduction, whereby the rotation of the armature 9 is stopped. On the other hand, with the return of the plunger 41, the force pulling the rotation restricting member 5 via the string-shaped member 36 disappears, so that the rotation restricting member 5 returns to the initial position by the spring force of the return spring. As a result, the regulating rod 5a, which has prevented the pinion 4 from retreating, comes off the rotation restricting plate 27, so that the pinion 4 receiving the urging force of the spring 26 and the retreating force from the ring gear returns to the initial position (the state shown in FIG. 1). Return.

(Effect of Embodiment) Starter 1 of this embodiment
By connecting one end of the resistor 51 to the head 49a of the power supply terminal 49 protruding into the end cover 13 and connecting the other end to the contact holding member 55 holding the sub-fixed contact 52, Even if the starter 1 is cooled by use in a cold region or the like and the power supply terminal 49 is cooled, since the thermal conductivity of the resistor 51 is as small as several tenths of copper, the auxiliary fixed contact 52 is hardly cooled, Freezing of the fixed contact 52 can be prevented.
As a result, there is no hindrance to starting the starting motor 2. The other end of the resistor 51 is directly connected to the sub-fixed contact 52.
, The contact holding member 55 can be eliminated.

On the other hand, the main fixed contact 50 integral with the head 49a of the power supply terminal 49 may have a contact surface that freezes when the power supply terminal 49 cools down. Of ice can be thawed. That is,
When the starting motor 2 is energized through the resistor 51 and started, the resistor 51 generates heat, and the heat is efficiently transmitted to the main fixed contact 50 by conduction, and the contact surface is also heated by radiant heat. As a result, the ice on the contact surface is quickly melted, and conduction failure due to icing can be prevented. According to the test of the inventor, the time required for melting the ice on the contact surface frozen at −30 ° C. and required for conduction is as follows:
It was 0.5 to 0.6 seconds. As described above, according to the starter 1 of the present embodiment, not only the operation failure due to the icing of the contact surface can be prevented, but also there is almost no delay in starting the engine after the starter switch 44 is turned on, and the user feels uncomfortable. Therefore, the operability is significantly improved as compared with the conventional starter.

Further, since the auxiliary movable contact 53 is mechanically and electrically connected to the main movable contact 20 by the elastic holding member 56, the auxiliary movable contact 53 is moved to the auxiliary movable contact 53 by utilizing the elasticity of the holding member 56. A contact pressure at the time of contact with the fixed contact 52 can be applied. That is, the holding member 56 is
Therefore, a dedicated contact pressure spring and a holding member for the contact pressure spring are not required, and the number of parts can be reduced.

Further, the holding member 56 is connected to the main movable contact 20.
A curved portion 56a is formed between one end connected to the second movable contact 53 and the other end connected to the sub movable contact 53. That is, the entire length of the holding member 56 is set to be significantly longer than the linear length connecting the main movable contact 20 and the sub movable contact 53. By increasing the total length of the holding member 56 in this manner, the stress applied to the holding member 56 when the holding member 56 is bent with the movement of the rod 43 can be reduced. The holding member 56
Is not a linear shape but a curved shape, it can be said that the sub movable contact 53 can be arranged in the vicinity of the main movable contact 20. That is, even if the length of the holding member 56 is long, the starter 1 can be downsized by providing the curved portion 56a and forming the whole compact.

Further, the sub movable contact 53 is
After that, the contact position with respect to the sub-fixed contact 52 changes with the movement of the plunger 41. That is, since the contact surface of the sub movable contact 53 is shifted with respect to the contact surface of the sub fixed contact 52 during the period from the initial contact state to the main movable contact 20 contacting the main fixed contact 50, the sub movable contact A so-called wiping action occurs between the auxiliary fixed contact 52 and the auxiliary fixed contact 52,
The effect of excellent conductivity after contact can be expected. Thereby, the reliability of the starter 1 can be improved.

(Second Embodiment) FIG. 4 is a front view (corresponding to a view A in FIG. 1) around a contact. In this embodiment, a nonmetallic resistor such as a carbon-based or graphite-based resistor, for example, a silicon carbide ceramic-based resistor, is used as the resistor 51. Resistor 51
By using these resistors, there is no danger of corrosion or the like, the durability is high, and the reliability is improved as compared with the resistor 51 using the metal-based resistor of the first embodiment.

(Third Embodiment) FIG. 5 is a sectional view showing a mounted state of a resistor, and FIG. 6 is a view as viewed from B in FIG. Resistor 51
The contact holding member 55 and the contact holding member 55 are each provided with a round hole at the center, and are fitted on the outer periphery of a cylindrical portion 13a integrally formed inside the end cover 13 together with the contact holding member 55 as shown in FIG. The head 4 of the power supply terminal 49
9 a and the inner surface of the end cover 13.

When the starter switch 44 is turned on and the magnet switch 6 is actuated and the sub movable contact 53 comes into contact with the sub fixed contact 52, the current from the battery 45 is supplied to the power supply terminal 49 → the head 49a of the power supply terminal 49 → The current flows from the resistor 51 → the contact holding member 55 → the sub fixed contact 52 → the sub movable contact 53. In this way, the resistor 51 and the contact holding member 55 are formed in a plate shape (rectangular shape) and the cylindrical portion 13 of the end cover 13 is formed.
By adopting the structure fitted to a, the size around the terminals can be reduced as compared with the case of the first embodiment (see FIG. 6).

(Fourth Embodiment) FIG. 7 is a front view (corresponding to the view A in FIG. 1) around a contact. In the present embodiment, the contact holding member 55 described in the first embodiment is made of bimetal, and as shown in FIG.
A contact 57 for resistance short-circuiting is provided on the side opposite to. The auxiliary fixed contact 52 and the resistance short-circuiting contact 57 may be provided separately. However, by integrally forming both, the number of parts can be reduced.

Since the contact holding member 55 is made of bimetal, when a current flows through the resistor 51 for a required time or more, the contact holding member 55 made of bimetal is moved upward (the power supply terminal 49) as shown in FIG. The contact 57 for resistance short-circuit contacts the lower surface of the head of the power supply terminal 49. As a result, the resistance short-circuiting contact 57 is electrically connected to the power supply terminal 49, so that the current flowing from the battery 45 to the power supply terminal 49 is changed from the resistance short-circuiting contact 57 to the contact holding member 55.
→ The sub fixed contact 52 → the sub movable contact 53 flows to the
1 can be short-circuited. As a result, the main current flows, and the pinion restricting force reliably engages the pinion 4. As a result, even if a current flows through the resistor 51 for a necessary time or longer, the resistor 51 does not generate heat more than necessary, so that durability can be improved.

In this embodiment, in order to suppress the overheating of the resistor 51, the contact holding member 55 is made of a bimetal, and the contact holding member 55 only needs to be provided with the contact 57 for resistance short-circuit. It does not complicate the structure and does not increase the size of the device. Note that the contact holding member 55 made of bimetal is bent, and the contact 5 for resistance short-circuit is used.
When the sub-contact 7 contacts the lower surface of the head of the power supply terminal 49, the sub-movable contact 53 does not separate from the sub-fixed contact 52 so that the holding member 5
The size and the amount of deformation are set so that the resistance short-circuiting contact 57 can abut on the lower surface of the head of the power supply terminal 49 within the range in which the contact 6 is bent by applying the contact pressure to the sub movable contact 53.

(Fifth Embodiment) FIG. 8 is a sectional view around a contact point.
9 and 10 are a view in C and a partial cross-sectional view of only the contact portion of FIG.
For easy understanding, the main movable contact 20 and the sub movable contact 53 are shown by imaginary lines in the view C, and the resistor 51, the rod 43, the lead wire 19 and the like are omitted in the partial sectional view. In the present embodiment, the contact holding member 55 described in the fourth embodiment is made of bimetal,
5 shows another method for preventing overheating of the slab.

As shown in FIG. 8, when the sub movable contact 53 moves to the sub fixed contact 52 side by the operation of the magnet switch 6 on the inner wall of the end cover 13, the sub movable contact 53
A restricting wall 13b is provided so that the movement of the control wall is restricted by a predetermined amount. The operation of this embodiment will be described with reference to FIGS. FIG. 9A shows the state of the contact portion when the magnet switch 6 is at rest, and has a positional relationship as shown in the figure. Here, the starter switch 44 is turned on.
The magnet switch 6 is actuated and the plunger 41
When the rod 43 rises with the movement of the sub-contact, the sub-movable contact 53 first comes into contact with the sub-fixed contact 52 and becomes conductive (FIG. 9).
(B)). As a result, the starting motor 2 is connected to the resistor 51
As a result, the energizing current is limited to start up.

Next, when the pinion moves forward so as to mesh with the ring gear, the rod 43 further rises, and the main movable contact 20 deflects the holding member 56 to contact the main fixed contact 50 to conduct (FIG. 10 (a)). )reference). As a result, the starting motor 2 is released from the current limitation by the resistor 51 and rotates with the rated voltage applied. At this time, if icing or the like exists on the surface of the main fixed contact 50 and conduction with the main movable contact 20 is impossible, a current of more than necessary time flows through the resistor 51, but the contact holding member made of bimetal 55 is a resistor 51
And the contact holding member 55 itself is bent upward by heat generation. Then, the sub movable contact 53 also attempts to move upward following the movement, but the end 56 b of the holding member 56 is moved to the end cover 1.
3 cannot contact the regulating wall 13b, and cannot move any further. The sub-fixed contact 52 is separated from the sub-movable contact 53, and the current to the resistor 51 is cut off (FIG. 10B).
reference). As a result, even if a current flows through the resistor 51 for a necessary time or more, the durability of the resistor 51 can be improved because the resistor 51 is not excessively heated.

(Sixth Embodiment) FIG. 11 is a resistance characteristic diagram of a positive temperature coefficient thermistor. In this embodiment, the resistor 51 is constituted by a positive temperature coefficient thermistor (PTC), and can be applied to the resistor 51 of the first to third embodiments. Thereby, the resistor 51
When the current flows for more than the required time and the temperature of the resistor 51 rises to a predetermined temperature, the resistance value of the PTC increases as shown in FIG. 11, and the current value can be suppressed. As a result, unnecessary heat generation of the resistor 51 can be suppressed as in the case of the fourth embodiment. However, in this embodiment, the fourth
Compared with the embodiment, since the resistance short-circuit contact 57 is unnecessary, the number of components can be reduced and the structure can be simplified.

(Modification) In the first embodiment, the holding member 56
Is a curved shape, but the shape is not particularly limited to the curved shape. For example, the shape may be bent in a substantially U-shape, or a shape wound in a coil shape may be used. In short, a length that can reduce the stress when the holding member 56 is bent is secured,
Any shape can be used as long as the sub movable contact 53 can be arranged near the main movable contact 20.

[Brief description of the drawings]

FIG. 1 is a sectional view of a starter.

FIG. 2 is a motor circuit diagram of a starting motor.

FIG. 3 is a view as viewed from A in FIG. 1;

FIG. 4 is a front view around a contact (second embodiment).

FIG. 5 is a sectional view showing a mounted state of a resistor (third embodiment).
Example).

FIG. 6 is a view as viewed from B in FIG. 5 (third embodiment).

7A is a front view around a contact when the bimetal is not deformed, and FIG. 7B is a front view around the contact when the bimetal is deformed (fourth embodiment).

FIG. 8 is a sectional view around a contact (fifth embodiment).

9A and 9B are a C view and a partial cross-sectional view of only a contact portion in FIG. 8;

FIG. 10 is a C-view and a partial cross-sectional view of only the contact portion in FIG. 8;

FIG. 11 is a resistance characteristic diagram of the positive temperature coefficient thermistor (fifth characteristic);
Example).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Starter 2 Starter motor (starter motor) 6 Magnet switch 20 Main movable contact 41 Plunger 45 Battery 49 Power supply terminal 50 Main fixed contact 51 Resistor (heating element / electric resistor) 52 Secondary fixed contact 53 Secondary movable contact 55 Contact holding member 56 Holding member 56a Curved portion 57 Resistance short-circuit contact (heating element short-circuit contact)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-68143 (JP, A) JP-A-8-144905 (JP, A) Fully open 1975-9635 (JP, U) Really open 1951 32342 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02N 11/08

Claims (12)

(57) [Claims] 1. A starter magnet switch for supplying a current from a battery to a starter motor, comprising: a main fixed contact connected to the battery; And a sub-fixed contact electrically connected to the main fixed contact via the heat-generating body, and is electrically connected to the main fixed contact and the sub-fixed contact to energize the starter motor. A magnetic switch for a starter, characterized by controlling the following. 2. The starter magnet switch according to claim 1, wherein said heating element is an electric resistor for limiting a current supplied to said starter motor, and said power is supplied to said starter motor from said battery. A magnet switch for a starter, wherein the operation is performed directly from the battery by short-circuiting the heating element after being restricted via a body. 3. The starter magnet switch according to claim 2, further comprising: a main movable contact in contact with said main fixed contact; and a sub-movable contact in contact with said sub-fixed contact. And a plunger for moving the sub movable contact to the sub fixed contact by moving the plunger, thereby energizing the starter motor from the battery via the heating element. A starter magnet switch, wherein the main movable contact is brought into contact with the main fixed contact, thereby short-circuiting the heating element and energizing the starter motor from the battery. 4. The starter magnet switch according to claim 3, wherein said auxiliary movable contact and said main movable contact are electrically connected, and said auxiliary movable contact or said main movable contact is electrically connected to said starter motor. A magnetic switch for a starter, characterized in that it is electrically connected. 5. The starter magnet switch according to claim 4, wherein the auxiliary movable contact is mechanically and electrically connected to the main movable contact by an elastic conductive holding member. Features starter magnet switch. 6. The starter magnet switch according to claim 5, wherein the holding member has a curved portion or a curved portion between one end connected to the main movable contact and the other end connected to the sub movable contact. A magnet switch for a starter, wherein a bent portion is formed. 7. The starter magnet switch according to claim 1, wherein a contact holding member for holding the sub-fixed contact is provided between the heating element and the sub-fixed contact. A magnet switch for a starter, wherein the contact holding member is made of a bimetal. 8. The starter magnet switch according to claim 7, wherein said heating element is a pair of heating elements having one end connected to said main fixed contact, and said heating element is connected to the other end of said pair of heating elements. A magnet switch for a starter, wherein a contact holding member is fixed. 9. The starter magnet switch according to claim 7, wherein the contact holding member made of a bimetal deforms itself during operation, thereby short-circuiting the heating element and causing the main fixed contact. A magnet switch for a starter, characterized by having a heating element short-circuiting contact that abuts on the magnet. 10. The starter magnet switch according to claim 7, wherein the contact holding member made of a bimetal deforms itself during operation to open the sub-fixed contact from the sub-movable contact. A magnet switch for a starter characterized by being separated. 11. The starter magnet switch according to claim 9, wherein the heating element short-circuiting contact and the auxiliary fixed contact are formed integrally. 12. The magnet switch for a starter according to claim 1, wherein said heating element comprises a positive temperature coefficient thermistor.