JPH09177644A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure suction force sufficient enough to suck up a planger for the period of time when electricity is conducted between a motor side stationary contact and a battery side stationary contact after electricity between an auxiliary contact and the battery side stationary contact has been conducted by a movable contact. SOLUTION: A movable contact 24 mounted onto a planger rod 36 can cause electricity to be conducted between a battery side stationary contact 19 and a motor side stationary contact 21 while an auxiliary contact 22 producing electrical continuity by letting the auxiliary contact 22 provided for the end part of a starting resistance 23 produce electrical continuity, and also letting a planger 17 be furthermore sucked in thereafter. The resistance value of the starting resistance 23 is so set that the applied voltage of the other end part connected with a starting switch 12 for a suction coil 13 is higher than the applied voltage of one end part connected between the starting resistance 23 and a starting motor 2 for the period of time when electricity has been conducted between the motor side stationary contact 21 and the battery side stationary contact 19 since electricity was conducted between the auxiliary contact 22 and the battery side stationary contact 19 by a movable contact 24.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Laid-Open No. 7-174062
There is a magnet switch for a starter disclosed in Japanese Patent Publication. In addition to the fixed contact and the movable contact that energize the starting motor from the battery, this magnet switch is equipped with a pair of auxiliary contacts that can be displaced in the moving direction of the movable contact, and the fixed contact after the movable contact conducts the auxiliary contact. A starting resistor that limits the current flowing to the starting motor through the auxiliary contact until it becomes conductive. As a result, the starter motor rotates at a low speed because the movable contact conducts the auxiliary contact and a current flows through the starting resistance, and then the movable contact conducts the fixed contact to short-circuit the starting resistance and generate a large current. It can rotate at high speed by flowing.

[0003]

On the other hand, in an automobile engine, wiring (B) between the battery and the starter motor is used.
Since the positional relationship between the battery and the starter is usually relatively close to each other, the terminal circuit (hereinafter referred to as a terminal circuit) is short such as a battery, a power supply side terminal (B terminal) of the magnet switch, a movable contact, a motor side terminal of the magnet switch, and a motor. Since it is connected over a distance and the starter motor obtains a high output in a short time to drive the engine, a high input is also required, so a thick electric wire is used for the wiring, and the wiring resistance is very low. Compared with this, the wire for the suction coil of the magnet switch (referred to as a 50-terminal circuit) has a key switch as a starting switch arranged at the driver's hand, so
Wiring of a very long distance from the coil terminal of the key switch to the magnet switch is required, and a safety fuse and a connection terminal are also provided on the way, and the wiring has a large wiring resistance compared to the B terminal circuit. Resulting in.

In the operation of the magnet switch under such conditions, when the key switch is turned on, the attraction coil and the holding coil are excited, the plunger is attracted, and the movable contact moves to the auxiliary contact and the fixed contact side. . When the movable contact conducts the auxiliary contact, the suction coil is short-circuited via the starting resistor, and the magnetic force of the suction coil (that is, the plunger suction force) is reduced. At this time, the wiring resistance from the battery of the 50 terminal circuit to the coil terminal is the battery of the B terminal circuit
If it is larger than the wiring resistance up to the B terminal plus the starting resistance, the voltage applied to both ends of the suction coil will be lower than that of the coil terminal short-circuited through the auxiliary contact, and A little current flows in the opposite direction. In this direction, a magnetic field is generated in the direction opposite to the magnetic field excited by the energization of the holding coil, and the attractive force of the coil is reduced.

Therefore, for example, when the performance of the battery is deteriorated, the voltage applied to the coil (suction coil and holding coil) is low, or the sliding loss of the plunger is large, so that the plunger is sucked. If the speed of is not sufficient, the suction force after the movable contact conducts through the auxiliary contact is extremely reduced and the plunger is returned by the return spring. However, when the movable contact separates from the auxiliary contact, the magnetic force of the attraction coil is generated again and the plunger is attracted, so that the movable contact again conducts the auxiliary contact. Then, by repeating this operation, the plunger cannot move any more and stays there, and cannot move the entire stroke.

As a result, the pinion cannot move to the position where it meshes with the ring gear, and the engine cannot be started. Alternatively, even if the pinion is pushed out to a position where it comes into contact with the end face of the ring gear, a sufficient force for pressing the pinion is not ensured, resulting in poor meshing between the pinion and the ring gear. Further, the movable contact repeatedly comes into contact with and separates from the auxiliary contact, which causes a problem that abrasion of the auxiliary contact is accelerated. The present invention has been made based on the above circumstances, and its purpose is to
(EN) A starter capable of attracting a plunger until a movable contact conducts an auxiliary contact and a fixed contact conducts.

[0007]

According to the invention of claim 1, the resistance value of the starting resistor is set to the other end side of the suction coil from the time when the movable contact conducts the auxiliary contact to the fixed contact conducts. The applied voltage is set to be higher than the voltage applied to one end side. Therefore, even if the movable contact conducts the auxiliary contact and the suction coil is short-circuited, the voltage applied to both ends of the suction coil should be connected to the battery via the start switch when the start resistor and the start motor are connected. Therefore, the magnetic field excited by the current flowing through the suction coil is not in the opposite direction to the magnetic field excited by the holding coil. As a result, it is possible to reduce the drop in plunger attraction force (coil magnetic force), which is reduced when the attraction coil is short-circuited.Therefore, because the applied voltage to the coil is low, the sliding loss of the plunger is large, etc. It is possible to prevent the plunger from being returned even if the speed at which the plunger is sucked is not sufficient. That is, it becomes possible to secure the suction force required to suck the plunger until the movable contact conducts the auxiliary contact and the fixed contact conducts.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a starter of the present invention will be described with reference to the drawings. FIG. 1 is an electric circuit diagram of the starter. The starter 1 of the present embodiment includes a starting motor 2 that generates a rotational force, a pinion 4 that is fitted to an armature shaft 3 of the starting motor 2, a one-way clutch 5 that transmits the rotational force of the starting motor 2 to the pinion 4, and a pinion. The magnet switch 8 (see FIG. 2) and the like generate a force to push the engine 4 toward the ring gear 6 of the engine and control the switch operation in the electric circuit from the battery 7 to the starter motor 2.

The starting motor 2 is provided with an armature 9 in which an armature shaft 3 is rotatably supported by a housing (not shown), and a field coil 10 arranged on the outer periphery of the armature 9. 1 and the armature 9 are in sliding contact with a commutator (not shown) provided at the end of the armature 9
1 are connected in series. The pinion 4 can be meshed with the ring gear 6 of the engine by being pushed forward on the armature shaft 3 together with the one-way clutch 5. The one-way clutch 5 is fitted on the outer circumference of the armature shaft 3 via a helical spline, and can transmit the rotational force of the armature 9 to the pinion 4 only when the engine is started.

As shown in FIG. 2, the magnet switch 8 includes coils 13 and 14 (described below) which are energized by turning on a start switch 12 (see FIG. 1).
3, a yoke 15 forming a magnetic path, an iron core 16, a plunger 17 attracted by a synthetic magnetic force generated by the coils 13, 14, a battery side fixed contact 19 integrally formed with a battery side terminal bolt 18, a motor side Terminal bolt 20
Motor side fixed contact 21 and auxiliary contact 2 formed integrally with
It is composed of a start-up resistor 23 which also serves as 2, a movable contact 24 which electrically connects the auxiliary contact 22 and the fixed contacts 19 and 21 with the movement of the plunger 17.

The coil is composed of a suction coil 13 that generates a magnetic force necessary to attract the plunger 17, and a holding coil 14 that generates a magnetic force required to hold the attracted plunger 17, and the outer circumference of the bobbin 25. It is wound in two layers. One end of the suction coil 13 is electrically connected to the motor-side fixed contact 21 (between the starting resistor 23 and the starting motor 2), and the other end of the suction coil 13 is started through the electric wiring 26 together with one end of the holding coil 14. Switch 12
It is connected to the. The other end of the holding coil 14 is grounded through the main body of the starter 1. The suction coil 13 and the holding coil 14 are wound in the same direction as the start switch 1
It is wound in such a direction that a magnetic field is generated in the same direction when a current flows from the 2 side.

The plunger 17 is disposed so as to be slidably movable on the inner circumference of the sleeve 27 inserted into the inner peripheral surface of the bobbin 25, and is elastically actuated by a return spring 28 interposed between the plunger 17 and the iron core 16. It is biased to one side (left side in FIG. 2). Further, the plunger 17 has a lever 29
The joint 30 connected to the one-way clutch 5 via (see FIG. 1) is assembled by receiving the elastic force of the drive spring 31. Therefore, when the plunger 17 is sucked and moved, the lever 2 connected to the joint 30
The one-way clutch 5 is pushed forward via 9 to allow the pinion 4 to move to the ring gear 6 side. Even if the pinion 4 pushed forward together with the one-way clutch 5 contacts the ring gear 6 and the movement of the joint 30 is restricted, the plunger 17 can move while bending the drive spring 31.

One end of the joint 30 having the flange 30a formed therein enters the recess of the plunger 17 and is pressed against the bottom surface of the recess of the plunger 17 by the resilience of the drive spring 31. Spring receiving member 3 which is caulked and fixed to the end of the
It projects through the inner circumference of the boot 2 to the outside of the boot 33. The boot 33 is made of a flexible material such as rubber and can expand and contract as the plunger 17 moves. The drive spring 31 has one end locked to the flange portion 30 a of the joint 30 and the other end locked to the spring receiving member 32.

The battery-side terminal bolt 18 and the motor-side terminal bolt 20 are attached to a mold cover 34, and a battery-side fixed contact 19 and a motor-side fixed contact 21 are provided inside the mold cover 34.
The battery-side terminal bolt 18 protruding outside the mold cover 34 is connected to the positive electrode of the battery 7 through the battery cable 35 (see FIG. 1), and the motor-side terminal bolt 20 protruding outside the mold cover 34 also starts. It is connected to the field coil 10 of the motor 2.

The starting resistor 23 is formed in a spiral coil shape, one end of which is fitted to the outer periphery of the motor side terminal bolt 20 to be electrically connected to the motor side fixed contact 21 and the other end of which is connected. The auxiliary contact 22 is provided by being bent and bent outward. However, the start-up resistor 23 is provided between the movable contact 24 and the auxiliary contact 22 and the battery-side fixed contact 19 until the motor-side fixed contact 21 and the battery-side fixed contact 19 are brought into conduction. The resistance value is set such that the voltage applied to the other end connected to the start switch 12 is higher than the voltage applied to the one end connected to the motor side fixed contact 21.
The auxiliary contact 22 is provided next to the motor-side fixed contact 21 (see FIG. 3) and is located in front of the motor-side fixed contact 21 (on the movable contact 24 side).

The movable contact 24 has a pair of insulators 37, 3 at the end of a rod 36 which is integral with the plunger 17.
8, the contact spring 3 interposed between the plunger 17 and the insulator 37.
The elastic force of 9 causes the rod 36 to be urged toward the tip side (right side in FIG. 2). However, the insulator 37 is provided so that the movable contact 24 can freely tilt with respect to the rod 36.
A wedge-shaped gap 40 is provided on the fitting surface between the rod 36 and the rod 36. Further, as shown in FIG. 4, the movable contact 24 has contact surfaces 24a and 2a that contact the fixed contacts 19 and 21, respectively.
In addition to 4b, an auxiliary contact surface 24c that contacts the auxiliary contact 22 is provided. Since the auxiliary contact 22 is located in front of the motor side fixed contact 21, the movable contact 24
The gap between the auxiliary contact surface 24c of the movable contact 24 and the auxiliary contact 22 is set to be smaller than the gap between the contact surfaces 24a and 24b and the fixed contacts 19 and 21.

Next, the operation of the starter 1 will be described. When the start switch 12 is turned on and the coils 7 and 14 of the magnet switch 8 are energized from the battery 7, the combined magnetic force of the coils 13 and 14 causes the plunger 17 to compress the return spring 28 and draw it toward the iron core 16 side. To be done. As a result, the movable contact 24 attached to the plunger rod 36 moves, and the auxiliary contact surface 24c of the movable contact 24 contacts the auxiliary contact 22 and the auxiliary contact 22.
Is conducted. At this time, by setting the set load of the start-up resistor 23 to a certain degree larger than the set load of the contact spring 39 that presses the insulator 37, the movable contact 24 is attached to the fitting surface of the insulator 37 and the rod 36. Only the provided gap 40 can cause the inclination with respect to the rod 36.

As a result, the auxiliary contact surface 2 of the movable contact 24 is
4c remains in contact with the auxiliary contact 22 and one contact surface 24
The a contacts the fixed contact 19 on the battery side to conduct the fixed contact 19 on the battery side (see FIG. 5). At this time, since the attraction coil 13 and the holding coil 14 are short-circuited and the current flowing is reduced, the combined magnetic force of the coils 13 and 14 is reduced, but the other end portion of the attraction coil 13 connected to the start switch 12 is reduced. Since the applied voltage is set to be higher than the applied voltage at the one end connected between the starting resistor 23 and the starting motor 2, the performance of the battery 7 is reduced or the plunger 17 is Even if the sliding speed of the plunger 17 is large and the suction speed of the plunger 17 is reduced, it is possible to secure a suction force sufficient to suck the plunger 17 until the movable contact 24 conducts both the fixed contacts 19 and 21.

Simultaneously with the suction of the plunger 17, the one-way clutch 5 is pushed forward along the helical spline on the armature shaft 3 (to the left in FIG. 1) via the lever 29 connected to the joint 30. Accordingly, the pinion 4 moves to the ring gear 6 side integrally with the one-way clutch 5, and the end faces of the pinion 4 and the ring gear 6 come into contact with each other. In this state, since the movable contact 24 conducts the auxiliary contact 22 and the battery side fixed contact 19 from the battery 7, the battery side terminal bolt 18 → the battery side fixed contact 19 → the movable contact 24 → the auxiliary contact 22 → the starting resistance A current sufficient to rotate the starter motor 2 flows through the starter motor 2 through the terminal bolt 20 on the motor side 23, and the starter motor 2 rotates at a low speed (slowly). The rotation of the starting motor 2 is transmitted through the one-way clutch 5 to the pinion 4
Is transmitted to the ring gear 6, the pinion 4 that has been in contact with the ring gear 6 rotates at a low speed and meshes with the ring gear 6,
It can move forward together with the one-way clutch 5.

When the plunger 17 further moves along with this, the movable contact 24 moves while bending the auxiliary contact 22, and the other contact surface 24b of the movable contact 24 contacts the motor-side fixed contact 21 so that the motor contacts. The side fixed contact 21 is conducted (see FIG. 6). In addition, the movable contact 24 is the fixed contact 1
In the state where 9 and 21 are conducted, the operating load of the contact spring 39 is set to be larger than the operating load of the starting resistor 23.

When the movable contact 24 conducts the fixed contacts 19 and 21 to short-circuit the starting resistor 23, the battery 7 moves to the battery side terminal bolt 18 → the battery side fixed contact 19 →
Since a large current flows to the starting motor 2 through the movable contact 24, the motor side fixed contact 21 and the motor side terminal bolt 20, the starting motor 2 rotates at high speed at full load. As a result, the rotation of the starter motor 2 is transmitted via the one-way clutch 5 to the pinion 4
Is transmitted to the pinion 4 to rotate at high speed,
The engine can be driven via the ring gear 6.

Further, the movable contact 24 has two fixed contacts 19, 2
1 is conducting, the plunger 17 is fixed to the fixed iron core 16
Since the starting resistor 23 is short-circuited, the applied voltage of the other end of the suction coil 13 connected to the starting switch 12 is connected between the starting resistor 23 and the starting motor 2. Even if the magnetic force generated by the suction coil 13 becomes lower than the applied voltage at one end of the holding coil 14 in a direction to cancel the magnetic force of the holding coil 14 to some extent, it is possible to secure a suction force (adsorption force) that can sufficiently maintain that state. .

After the engine is started, the start switch 12 is turned off.
When the F operation is performed and the energization of the coils 13 and 14 is stopped, the magnetic force of the coils 13 and 14 disappears.
It is pushed back by the elasticity of 8 and returns to the stationary state (state shown in FIG. 2). Simultaneously with the movement of this plunger 17,
The pinion 4 also disengages from the ring gear 6 and returns to the initial position (the position shown in FIG. 1) together with the one-way clutch 5.

(Effect of this embodiment) Starter 1 of this embodiment
Even if the movable contact 24 conducts the auxiliary contact 22 and the battery-side fixed contact 19 to short-circuit the coils 13 and 14, the voltage applied to the other end of the suction coil 13 connected to the start switch 12 is Is set to be higher than the applied voltage at one end connected to the motor-side fixed contact 21 (between the starting resistor 23 and the starting motor 2), the suction coil 13 is short-circuited. It is possible to reduce the drop in the plunger attraction force (composite magnetic force of the coils 13 and 14) that decreases, and to secure an attraction force to attract the plunger 17 until the movable contact 24 conducts both fixed contacts 19 and 21.

As a result, even if the speed at which the plunger 17 is attracted is not sufficient because the voltage applied to the coils 13 and 14 is low or the sliding loss of the plunger 17 is large, the return spring 28 is It is possible to prevent the plunger 17 from being returned due to the elasticity. That is, from the state where the movable contact 24 makes the auxiliary contact 22 and the battery side fixed contact 19 conductive, both fixed contacts 19 and 21
It is possible to secure the suction force necessary for sucking the plunger 17 until it is conducted. As a result, a sufficient force for engaging the pinion 4 with the ring gear 6 can be obtained, so that a defective meshing between the pinion 4 and the ring gear 6 can be prevented.

After the engine is started, the start switch 12
When the plunger 17 is turned off and the plunger 17 is returned to the stationary state, the movable contact 24 is first separated from the motor-side fixed contact 21 to separate the fixed contacts 19 and 21, and then the auxiliary contact 22 and the battery-side fixed contact 19 are separated. Separate the spaces. Since the breaking current at this time is significantly reduced by the starting resistance 23, there is an effect that the fixed contacts 19 and 21 and the auxiliary contact 22 are less worn.

Further, in this embodiment, the two fixed contacts 1
9, 21, one movable contact 24, the starting resistor 23 that also serves as the auxiliary contact 22 can be configured without connecting parts, and the starting resistor 23 is formed in a spiral coil shape, so that a small space in the mold cover 34 can be obtained. The contact mechanism can be stored in. In addition, the starting resistor 2 of this embodiment
In No. 3, the stress can be relaxed by increasing the number of turns of the spiral coil as compared with the case where the auxiliary contact 22 and the starting resistor 23 are composed of a plate-shaped elastic body, and the durability life is significantly improved.

(Second Embodiment) FIG. 7 is an electric circuit diagram of the starter 1. The starter 1 according to the present embodiment is an example in which the movable contact 24 is provided with a contact member 41 provided by an elastic body such as a leaf spring. In this case, the plunger 17
When the movable contact 24 moves when the movable contact 24 moves
A contact member 41 provided in the elastically electrically contacts the auxiliary contact 22 connected to the starting resistor 23 and the auxiliary contact 42 integrally provided with the battery side fixed contact 19 to thereby electrically start the starting motor. When 2 rotates slowly and the plunger 17 moves further, the contact member 41 moves the auxiliary contact 22.
With the movable contact 24 conducting the battery-side fixed contact 19 and the motor-side fixed contact 21 while keeping contact with the auxiliary contact 42, the starting motor 2 can rotate at full load.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of a starter.

FIG. 2 is a cross-sectional view (stationary state) of a magnet switch.

FIG. 3 is a front view of a fixed contact and an auxiliary contact viewed from a movable contact side.

FIG. 4 is a side view (a) and a plan view (b) of a movable contact.

FIG. 5 is a cross-sectional view showing a state in which a movable contact electrically connects an auxiliary contact and a motor-side fixed contact.

FIG. 6 is a cross-sectional view showing a state in which a movable contact conducts both fixed contacts.

FIG. 7 is an electric circuit diagram of a starter according to a second embodiment.

[Explanation of symbols]

 1 Starter 2 Starter Motor 4 Pinion 6 Ring Gear 7 Battery 8 Magnet Switch 12 Starter Switch 13 Suction Coil 14 Holding Coil 17 Plunger 19 Battery Side Fixed Contact 21 Motor Side Fixed Contact 22 Auxiliary Contact 23 Starting Resistor 24 Moving Contact

Claims (1)

[Claims] 1. A magnet switch having a coil which receives a current from a battery to generate a magnetic force, and a plunger which is attracted by the magnetic force generated by the coil, a movable contact which is displaced as the plunger moves, and the battery. From the fixed contact, which is connected to the fixed contact in parallel with the fixed contact, which intervenes in the motor circuit that energizes the starting motor from the An auxiliary contact before which the movable contact is conducted, and a starter for limiting a current flowing through the auxiliary contact to the starter motor from the time when the movable contact conducts the auxiliary contact until the fixed contact is conducted. A starter that includes a resistor and that moves the pinion to the ring gear side of the engine as the plunger moves, The suction coil has one end connected between the starting resistor and the starting motor and the other end connected to the positive electrode of the battery via a start switch, and one end connected to the other end of the suction coil. A holding coil connected to the other end side of which is grounded, and the resistance value of the starting resistor has a resistance value of the suction coil during a period from when the movable contact conducts the auxiliary contact to when the fixed contact conducts. A starter characterized in that a voltage applied to the other end side is set to be higher than a voltage applied to one end side.