CN102418640A - Starting motor with magnetic switch - Google Patents

Abstract

The invention relates to a starting motor with a magnetic switch. In the magnetic switch, a sucking coil and a holding coil are made of aluminum wires or aluminum-clad wires, and the thickness of a yoke of the magnetic switch is 3 to 4mm. Compared with the conventional starting motor, the starting motor has the advantages that: the volume of the magnetic switch of the motor is only 63 percent of the original volume, and the weight of the coils is reduced by 80 percent; and the using amount of a precious material is greatly reduced, and cost and resources are saved.

Description

Starter motor with magnetic switch

technical field

The present invention relates to a starter motor for a vehicle mounted on a passenger car, a truck, etc., and particularly relates to an improved magnetic switch for the starter motor.

Background technique

In recent years, there has been a demand for downsizing automotive starters. That is, it is required to provide a vehicle starter that is small in size and high in output at a reasonable price.

Generally, a starter for a vehicle, especially a starter for a commercial vehicle with a large output has a typical structure as shown in FIG. 1 .

The starter mainly includes three parts: a motor 3, a one-way clutch 2 and a magnetic switch 1, and also includes related connecting parts: a shift lever and a pinion. The starter is installed on the main body of the engine. Through the operation of the starter switch, the pinion of the starter meshes with the ring gear (not shown) arranged on the outer periphery of the flywheel, and the crankshaft is rotated by the power of the motor 3 to start the engine. The meshing between the pinion and the ring gear is carried out by moving the pinion on the drive shaft through the electromagnetic force of the magnetic switch 1 .

The working principle and structure of the motor and the one-way clutch are known technologies, and will not be described in detail here.

As shown in Figure 2, the magnetic switch 1 is composed of an attracting coil 11, a holding coil 10, a magnetic core 13, a return spring 16, a plunger 12, a main contact 14, a main terminal 15, etc. Gear shift lever 5 is connected at one end.

As shown in FIG. 3 , one end of the shift lever 5 is connected to the plunger 12 , and the other end is connected to the one-way clutch 2 , and is fixed on the starter with a fulcrum 18 . When the magnetic switch 1 acts, the plunger 12 is attracted to the right, and the one-way clutch 2 is pushed out through the shift lever 5 .

Figure 4 shows the starter circuit, which includes the starter switch 19 and the excitation coil 20. After the starter switch 19 is turned on, the current flows to the excitation coil 20 and the armature coil of the motor through the attraction coil 11, and also flows to the holding coil 11. Coil 10. As a result, the armature slowly starts to rotate, the plunger 12 is attracted by the common magnetic force of the attracting coil 11 and the holding coil 12, the shift lever 5 swings, and the push pinion 6 meshes with the ring gear.

When the plunger is attracted, the main contact 14 will be closed, and the large current flowing from the battery will flow to the excitation coil and the armature coil, and the starter will start to rotate strongly. At this time, both ends of the attracting coil 11 are short-circuited, so the magnetic force of the attracting coil disappears, and the plunger is held only by the attractive force of the holding coil.

When the engine is started and the starter switch is turned off, the direction of the current flowing to the attracting coil and the holding coil is opposite, the magnetic forces generated by the two coils cancel each other out, the attractive force becomes zero, and the plunger 12 returns to its original state under the force of the return spring 16 bit. Furthermore, due to the movement of the plunger 12, the one-way clutch 2 is pulled back via the shift lever 5, and the engagement of the pinion 6 with the ring gear is released.

The current flowing to the motor must generate enough torque to start the engine, and the value of the current is usually determined solely by the resistance value of the magnet switch pull-in coil. In order to suppress the temperature rise of the attraction coil under this current, an appropriate current density is selected and the cross-sectional area of the coil is determined. In the past, copper wire was used to make the attracting coil 11 of the magnetic switch 1, so the length of the coil had to be increased in order to match the required resistance value. Therefore, the size of the magnetic switch depends on the space for winding the required coil. On the other hand, since the attractive force of the plunger needs to be zero when the starter switch is turned off, the number of windings of the holding coil 10 must be the same as that of the attracting coil 11 . Since the resistance value of the holding coil is not the only factor that determines the motor torque at start, it can be designed relatively freely. However, in order to prevent heating or fusing due to the current when the starter switch is turned off, an appropriate current density is selected. The cross-sectional area of the coil.

FIG. 5 is a schematic diagram of the size of the magnetic switch yoke in the prior art. The thickness of the magnetic switch yoke is thin, which easily leads to magnetic saturation. The above has become a bottleneck for reducing the volume and weight of the starter, and its reason is that the current during starting is determined solely by the resistance value of the attracting coil.

Contents of the invention

The present invention provides a starter motor for a vehicle in order to solve the above existing defects, so that its own weight can be greatly reduced under the premise of ensuring performance.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

A starter motor with a magnetic switch, characterized in that: in the magnetic switch, the attracting coil and holding coil are made of aluminum wire or aluminum-covered wire, and the thickness of the magnetic switch yoke is 3-4mm.

In the magnetic switch of the starter motor, the attracting coil and the holding coil are made of aluminum wire, and the number of windings is reduced by using aluminum wire. In order to prevent the reduction of the attractive force, the thickness of the magnetic switch yoke is increased to reduce magnetic saturation. In this way, although the number of windings is small, it does not reduce the attractive force.

Compared with the existing starter motor, the volume of the magnetic switch of the motor described in the present invention is only 63% of the original, and the weight of the coil is reduced by 80%. Significantly reduces the amount of precious materials used, saving costs and resources.

Description of drawings

FIG. 1 is a structural diagram of a prior art starter motor (starter) for a vehicle.

Fig. 2 is a sectional view of a prior art magnetic switch.

Fig. 3 is an action schematic diagram of a magnetic switch in the prior art.

Fig. 4 is a circuit of a prior art starting device.

Fig. 5 is a schematic diagram of the dimensions of a magnetic switch yoke in the prior art.

Fig. 6 is a schematic diagram of the size of the magnetic switch yoke in the present invention.

specific implementation plan

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

In the present invention, the coil material of the magnetic switch is replaced with aluminum wire or aluminum-covered wire, thereby greatly reducing the length of the coil. In magnetic switches, the resistivity of copper wire is usually 1.58 times that of aluminum wire. If the wire diameter is the same, when aluminum wire is used to make the attracting coil, the length is about 63% of copper wire, and the weight can be reduced by about 80%.

As the length of the coil becomes shorter and the number of windings decreases, the attractive force of the plunger will also weaken. For this reason, the thickness of the magnetic switch yoke is set to 3 to 4mm, preferably 3.5mm, so that the magnetic saturation of the yoke is reduced. Although the number of windings is small, It didn't make it any less attractive. Fig. 6 is a schematic diagram of the size of the magnetic switch yoke in the present invention.

Compared with the existing motor, the volume of the magnetic switch attracting coil and holding coil of the motor in the present invention is only 63% of the original volume.

The following table is a comparison of the quality of electric wires used in the existing motor and the magnetic switch for the Φ83 motor of the present invention

It can be seen from the table that in the existing motor, the total weight of the attracting coil and the holding coil is 0.502kg, but under the same specification, when the aluminum wire is used in the present invention, the weight is only 0.099kg, which is about 80% lighter.

Claims (2)

1. A starter motor with a magnetic switch, characterized in that: in the magnetic switch, the attracting coil and the holding coil are made of aluminum wire or aluminum-covered wire, and the thickness of the magnetic switch yoke is 3-4mm. 2. The starter motor with magnetic switch according to claim 1, characterized in that: the thickness of the magnetic switch yoke is 3.5mm.

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