JPH05180130A - Starter of engine - Google Patents

Abstract

PURPOSE:To realize the miniaturization and light weight of a starter. CONSTITUTION:A high resistance sub movable contact point member 27 and a low resistance main movable contact point member 26 linking with a plunger 21 to make a pinion gear 12 that is driven by means of a motor 11, mesh with a ring gear 2 are equipped, and conduction between fixed contact points 24, 25 provided at the electrification circuit of the motor 11 is carried out by means of the sub movable contact point member 27, and then, conduction is carried out by means of the main movable contact point member 26. As the electric current value of the electrification start of the motor 11 becomes small and the start-up of the rotation number becomes slow, smooth meshing is carried out even if the miniaturization and light weight of a magnet switch 20 to press the pinion gear 12 against the ring gear 2 is conducted and its drive force becomes small.

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 engine mounted on an automobile or the like.

[0002]

2. Description of the Related Art In a starter for starting an automobile engine, in order to transmit the rotation of the motor to the ring gear of the engine only when the engine is started, a pinion gear that rotates in conjunction with the rotation of the motor passes through an overrunning clutch. Are provided. Prior to starting the motor, this pinion gear is brought into contact with or meshed with the ring gear of the engine through the drive lever by the drive plunger of the magnet switch, and then the contact of the magnet switch is closed to operate the motor. When activated, they are fully meshed and rotate the ring gear. On the other hand, recently, there has been a demand for reduction in size and weight of electric components in automobiles, and in starters, reduction in size and weight of motors has been attempted. In this case, the motor requires a torque and an output that are equal to or higher than a predetermined value to start the engine, so that the motor is downsized by improving efficiency, and the same capacity as the conventional one is secured.

[0003]

However, as described above, in the motor that is made smaller and lighter, the armature is also made smaller and lighter. Since the output of the motor is as large as that of the conventional armature, The rise of rotation at the time of starting the motor tends to be faster than that of the conventional one. On the other hand, the meshability between the pinion gear and the ring gear generally becomes worse as the rotation speed of the motor increases. For this reason, in a starter in which the motor is small and lightweight, in order to ensure sufficient meshing between the pinion gear and the ring gear while ensuring durability even when the motor starts to rotate at high speed, It is necessary to generate a large driving force in the magnet switch for contacting the ring gear with the ring gear. Therefore, in the magnet switch, the coil and the like cannot be made smaller than a certain size in order to secure this driving force, and there is a limit to the reduction in size and weight of the starter as a whole, and further reduction in size and weight can be achieved. There is a problem that it is difficult to do.

An object of the present invention is to reduce the size and weight of a starter.

[0005]

According to the present invention, a pinion gear is brought into mesh with a ring gear of an engine by the operation of a plunger driven by an electromagnetic force of a coil which is energized in response to a key switch operation. In a starter that energizes a motor for rotating and driving the pinion gear by connecting two fixed contacts with a moving contact that is interlocked with each other, in the starter, the movable contact connects the two fixed contacts with low resistance. The technical means is composed of a contact member and a second contact member that electrically connects between the two fixed contacts with high resistance prior to the first contact member.

[0006]

According to the present invention, when the key switch is operated and the coil is energized, the plunger operates to drive the pinion gear toward the ring gear. Further, the first contact member and the second contact member move together with the plunger toward the two fixed contacts. If the pinion gear meshes smoothly with the ring gear, there should be a second gap between the two fixed contacts.
After being conducted by the first contact member, the second contact member is subsequently conducted, so that a large current flows through the motor through the low-resistance first contact member. For this reason,
A large torque is generated in the motor to drive the ring gear via the pinion gear.

When the pinion gear collides with the ring gear without smoothly meshing with the ring gear, the second contact member precedes and electrically connects the two fixed contacts. Since the second contact member has a high resistance, the current value of the motor is small when the second contact member is conducted by the second contact member, and the motor starts up at low speed rotation. As a result, the pinion gear comes into contact with the ring gear and then rotates at a low speed, so that the pinion gear can easily engage with the ring gear, and after engagement, the fixed contacts are electrically connected by the low-resistance first contact member. Therefore, the ring gear can be driven with a large torque.

[0008]

According to the present invention, when the pinion gear does not mesh smoothly with the ring gear, the rotational speed of the motor can be reduced, so that the driving force for bringing the pinion gear into contact with the ring gear is small. However, the pinion gear can be easily meshed with the ring gear. Therefore, a plunger for driving the pinion gear, a magnetic circuit such as a coil, and the like can be downsized, so that the starter can be reduced in size and weight.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be explained based on a starter 1 for starting an automobile engine shown in FIG. The starter 1 serves as a rotary drive system for the ring gear 2 of the engine, a motor 11 in which a field coil and an armature are connected in series, a pinion gear 12 meshed with the ring gear 2, a motor 11 and a pinion gear 12
And an overrunning clutch (hereinafter referred to as a clutch) 13 that is provided between the pinion gear 12 and the rotational force of the motor 11 only when the engine is started, and a magnet for controlling these rotary drive systems. A switch 20 is provided.

The magnet switch 20 has a drive mechanism for abutting and engaging the pinion gear 12 with the ring gear 2 and a switch mechanism for controlling energization of the motor 11 by driving the same plunger 21. It is composed. In order to generate an electromagnetic force for driving the plunger 21, a pull-in coil 22 that exerts an attractive force on the plunger 21 and a holding coil 23 that holds the attracted plunger 21 in that state are provided. On the other hand, as a switch for opening and closing the energizing circuit to the motor 11, two fixed contacts 24 and 25 provided between the battery B mounted on the vehicle and the motor 11 and the plunger 21 are elastically supported and interlocked with each other. A main movable contact member 26 and a sub movable contact member 27 for electrically connecting the fixed contacts 24 and 25 are provided.

In the magnet switch 20, one end of each of the pull-in coil 22 and the holding coil 23 is connected to the battery B via the key switch 3 of the automobile.
, The other end of the pull-in coil 22 is connected to the negative electrode of the battery B via the motor 11, and the other end of the holding coil 23 is directly connected to the negative electrode of the battery B. The fixed contact 24 on one side is the battery B.
, And the other fixed contact 25 is connected to the motor 11 together with the other end of the pull-in coil 22.

The main movable contact member 26 includes fixed contacts 24, 2
The auxiliary movable contact member 27 exhibits a low resistance value such as short-circuiting between 5, and the auxiliary movable contact member 27 exhibits a high resistance value between the fixed contacts 24 and 25, for example, the same resistance value as the starter motor 11.
The main movable contact member 26 and the auxiliary movable contact member 27 are elastically supported by the plunger 21, respectively. Further, the auxiliary movable contact member 27 is the main movable contact member 26.
Before contacting the fixed contacts 24 and 25, the fixed contact 2
It arrange | positions so that it may electrically connect between 4 and 25 by a high resistance value.

An intermediate portion of the drive lever 14 is rotatably supported by a fulcrum 15, one end of which is locked to a driving end of a plunger 21 and the other end of which is a load ring 17 provided in a clutch 13. The load is applied to the drive spring 16 to push the pinion gear 12 and the clutch 13 toward the ring gear 2 so that the pinion gear 12 abuts and meshes with the ring gear 2 when the plunger 21 is driven. Let Further, the output shaft and the clutch 13 are formed with a screw spline mechanism, and when a rotational force is generated, a thrust force that pushes the pinion gear 12 toward the ring gear 2 is generated, and the meshing during operation of the motor 11 is generated. Make sure the state.

2 and 3 show the specific construction of the first embodiment of the magnet switch 20. As shown in FIG. The pull-in coil 22 and the holding coil 23 are
Is wound around the bobbin 31 in two layers,
Inside the bobbin 31, a sleeve 32 for sliding the plunger 21 is provided. The sleeve 32 is provided with hollow disk-shaped or cylindrical cores 33, 34, 35 made of a plurality of magnetic metal members that also serve as the housing of the magnet switch 20, and a magnetic circuit for pulling the plunger 21 inward is provided. Has been formed. Also,
A resin mold 50 having the fixed contacts 24 and 25 is fitted into the core 33.

The plunger 21 is biased outward by a spring 36 provided between the plunger 21 and the core 35.
As shown in the figure, about half of the protrusion is normally protruding from the core 33 to the outside, and the bowl-shaped deformable rubber cap 37 is covered with the plunger 21 so as to cover the protruding portion. The drive lever 14 described above is attached to the protruding portion 21A penetrating the cap 37.
Is locked. The plunger 21 is provided with a shaft portion 21a penetrating the cores 34 and 35, and the shaft portion 21a is in contact with the fixed contacts 24 and 25 when the plunger 21 is driven to establish conduction between the fixed contacts 24 and 25. In addition, a movable contact portion 40 composed of a plurality of members is slidably provided on the shaft portion 21a.

The movable contact portion 40 is composed of a resin-made cylindrical substrate 41.
The main movable contact member 26, the insulating ring 42 made of resin, and the auxiliary movable contact member 27 are sequentially fitted to the outside of the, one end of which is locked by the flange 41a of the tubular base 41, and the other end thereof. Is a resin-made locking ring 43 provided slidably with respect to the shaft portion 21a together with the tubular base body 41.
It is locked by. The locking ring 43 is locked by a washer 44 fitted in a groove 21b formed in the shaft portion 21a, and an end portion 21c of the shaft portion 21a is heat-crimped, so that the movable contact portion 40 is movable. Are urged toward the end 21c by the contact spring 45. In the movable contact portion 40, the main movable contact member 26 is
The auxiliary movable contact member 27 is made of copper having a low resistance value.
It is made of a copper alloy such as phosphor bronze to provide elasticity.

The operation of the starter 1 using the magnet switch 20 of the first embodiment having the above construction will be described with reference to the characteristics of the motor 11 shown in FIG. When the key switch 3 is closed, the current from the battery B flows through the series circuit including the pull-in coil 22 and the motor 11 and the holding coil 23. As a result, the plunger 21 is pulled toward the core 35, and at the same time, the drive lever 14 pushes the pinion gear 12 toward the ring gear 2. At this time, the current flowing through the motor 11 is small and insufficient for rotating the armature, so the motor 11 does not start.

When the pinion gear 12 is pushed out and comes into contact with the ring gear 2, the pinion gear 12 and the ring gear 2
When the and are smoothly meshed with each other, the auxiliary movable contact member 27 comes into contact with the fixed contacts 24 and 25, and subsequently, the main movable contact member 2
6 contacts the fixed contacts 24, 25, and the fixed contacts 24, 2
Conductive connection between 5 with low resistance. As a result, a large current value A1 flows through the motor 11 to start it, the ring gear 2 is rotationally driven by the torque T1 to start the engine, and its rotational speed gradually increases as shown by the chain line rpm1. The current value decreases and the output P1 represented by the product of torque and rotation speed increases.

When the pinion gear 12 collides with the ring gear 2 without meshing smoothly, when the pinion gear 12 is pushed out to some extent, the auxiliary movable contact member 27 having a high resistance value comes into contact with the fixed contacts 24, 25, and the battery The current from B flows through the series circuit including the auxiliary movable contact member 27 and the motor 11. Since the resistance value of the auxiliary movable contact member 27 is set to the same value as the resistance value of the motor 11, the motor 1
1, a current value A2 flows, and this current causes the motor 1
1 starts, but the torque value is T because the current value A2 is small.
It is as small as 2. Therefore, the current value is smaller than that in the case of the current value A1, and the rotation is gentle. Therefore, when the pinion gear 12 does not mesh with the ring gear 2, the pinion gear 12 rotates at a low speed with the load applied to the ring gear 2 by the drive spring 16, and thus the pinion gear 12 is rotated. It surely meshes with 2.

When the amount of engagement is sufficient, the plunger 21
When is fully drawn, the main movable contact member 26 contacts the fixed contacts 24 and 25. As a result, the energizing circuit for the motor 11 is switched from the auxiliary movable contact member 27 to the main movable contact member 26, and the motor 11 keeps the rotation speed at that time and maintains the main movable contact member 26. Since the current value A3 directly flows in, a large torque T3 corresponding to the current value A3 is generated in the motor 11, and the ring gear 2 can be reliably driven to rotate.

In FIG. 4, the alternate long and short dash line indicates the case where the fixed contacts 24 and 25 are electrically connected by the main movable contact member 26, and the broken line indicates the fixed contact 2 only by the auxiliary movable contact member 27.
4 and 25 show the case where electrical continuity is established between P4 and P25, where P1 and P2 are output characteristics, rpm1 and rpm2 are rotational speeds, and R1 and R2 are added to the entire starter 1 including the respective movable contact members 26 and 27. The applied voltage. Therefore,
Here, the voltage applied to the motor 11 when the motor 11 is energized only through the auxiliary movable contact member 27 is R2.
From the voltage value at the intersection of the solid line V and the broken line R2, Vs obtained by subtracting the voltage value Vm indicated by the one-dot chain line R1 from the voltage value at the intersection of the solid line V and the broken line R2 Is being applied,
When the motor 11 is energized only through the auxiliary movable contact member 27, the voltage rises by this voltage value Vs.

FIG. 5 shows the pinion gear 12 and the ring gear 2.
The meshing width L of the pinion gear 12 and the ring gear 2 with respect to the rotation speed of the motor 11, which is an index of meshability with
That is, with respect to the number of rotations at the moment when the pinion gear 12 meshes with the ring gear 2, how much the pinion gear 12 can move with respect to the ring gear 2 is determined by two pressing forces F.
1 and F2 (however, F2> F1) are shown. here,
The mesh width L shown is given by the following equation.

[0023]

[Equation 1]

In Equation 1, G is each gear 2, 1
The gap between the two, F is the pushing force by the magnet switch 20, ω is the number of revolutions at the time of engagement, and W is the weight of the clutch 13 and the like. As shown here, in the case where the motor 11 starts up quickly and the number of revolutions at the time of meshing becomes a high number of revolutions centering on the number of revolutions N1, in order to obtain sufficient meshing property, the pinion gear 12 is set to the ring. While it is necessary to press the gear 2 with a large force, the motor 1
It can be seen that when the rising of 1 is gentle around the rotation speed N2, the same meshability can be obtained by merely pressing the pinion gear 12 against the ring gear 2 with a small force. Therefore, as in the present invention, the movable contact member is provided in two stages, and the resistance value of the auxiliary movable contact member 27 that comes into contact with the fixed contacts 24 and 25 in advance is increased, thereby slowing the rising of the motor 11. If so, the plunger 21 of the magnet switch 20 does not require a large force. Therefore, even if a coil smaller than the conventional one is used, the driving force is sufficient, and the magnet switch 20 can be reduced in size and weight.

FIG. 6 shows a second embodiment of the magnet switch 20. In this embodiment, the sub movable contact member 27 includes
Elasticity is not given, and a spring 45 for giving a load to the auxiliary movable contact member 27 is separately provided. Also in this case, as in the first embodiment, the auxiliary movable contact member 27 comes into contact with the fixed contacts 24 and 25 prior to the main movable contact member 26, so that the motor 11 can be gently started. , The pinion gear 12 with a weak force to the ring gear 2
The pinion gear 12 can be reliably meshed with the ring gear 2 even if the pinion gear 12 is brought into contact with. Therefore, the magnet switch 20 does not require a large driving force, and a driving force obtained by a small one is sufficient, so that the starter 1 as a whole can be reduced in size and weight. 7, 8 and 9 show specific examples of the shape of the auxiliary movable contact member 27 in the second embodiment. The auxiliary movable contact member 27 of FIG. 7 has a simple disk shape that fits outside the cylindrical base body 41, and the auxiliary movable contact member 27 of FIG. 8 has a plate shape extended only to the portions corresponding to the fixed contacts 24 and 25. 9 has a deformed coil shape so as to be able to contact the fixed contacts 24 and 25.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a starter according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a first embodiment of the magnet switch in the starter of the embodiment of the present invention.

FIG. 3 is a cross-sectional view of essential parts of a first embodiment of a magnet switch according to an embodiment of the present invention.

FIG. 4 is a characteristic diagram showing operating characteristics of the starter according to the embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between a rotation speed at the time of meshing in a starter and a meshing width of a pinion gear and a ring gear.

FIG. 6 is a cross-sectional view of essential parts of a second embodiment of the magnet switch according to the embodiment of the present invention.

FIG. 7 is a perspective view showing a shape example of a sub movable contact member in a second embodiment of the magnet switch according to the present invention.

FIG. 8 is a perspective view showing another example of the shape of the auxiliary movable contact member in the second embodiment of the magnet switch according to the embodiment of the present invention.

FIG. 9 is a perspective view showing a further different shape example of the auxiliary movable contact member in the second embodiment of the magnet switch of the embodiment of the present invention.

[Explanation of symbols]

 2 Ring gear 11 Motor 12 Pinion gear 21 Plunger 22 Pull-in coil 23 Holding coil 24, 25 Fixed contact (two fixed contacts) 26 Main movable contact member 27 Sub movable contact member

Claims (1)

[Claims] 1. A pinion gear is meshed with a ring gear of an engine by an operation of a plunger driven by an electromagnetic force of a coil which is energized in response to a key switch operation, and two fixed contacts are provided by a movable contact interlocking with the plunger. In a starter for energizing a motor for rotating and driving the pinion gear by electrically connecting between the contacts, the movable contact includes a first contact member for electrically connecting the two fixed contacts with low resistance, and the two fixed members. A starter for an engine, comprising: a second contact member that conducts between the contacts with high resistance prior to the first contact member.