JPS6185575A - Magnetic switch of starter - Google Patents

Abstract

PURPOSE:To make a magnetic switch a simple structure and obtain suction force characteristics by providing a solenoid coil and a plunger on an electromagnetic suction means and providing a notch on the outer periphery of the plunger. CONSTITUTION:A magnetic switch is provided with an electromagnetic suction means applying a thrust force to a pinion gear providing a starting rotating force. The electromagnetic suction means has a plunger 28 magnetically sucked by a solenoid coil 31. A notch 37 is provided on the outer periphery of the plunger 28 so that a gap between the plunger 28 and the solenoid coil 31 is changed. Accordingly, suction force characteristics corresponding to the energizing force of a pinion return spring on the starter side can be obtained with a simple structure.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic switch installed in an engine starter, and particularly to a magnetic switch that applies a thrust force in the meshing direction to a pinion gear that meshes with the ring gear of the engine and provides starting rotational force. This article relates to a magnetic switch equipped with an electromagnetic attraction means.

FIG. 4 shows an arrangement diagram of a starter motor equipped with this type of magnetic switch.

39 is a battery, and a 40 Vi key switch opens and closes the coil 31 of the magnetic switch.

41 is a starter, and the electric motor 1, movable contact 20, fixed contact 21, and coil 31 are connected as shown in the figure.

The plunger 28 attracted by the coil 31 has the function of pushing a pinion gear (not shown) in the thrust direction and meshing with a ring gear (not shown).

[Background of the invention]

The conventional Stark magnetic switch is the Special Publication Showa 5B.
-21102, the area of the plunger remains constant despite changes in the air gap. That is, when the plunger is magnetically attracted and slides against the coil, the gap between the two members remains unchanged.

When the magnetomotive force is constant, the magnetic field strength changes due to the magnetic conduction resistance that exists in the middle of the magnetic path, and as the magnetic conduction resistance due to the air gap decreases, the attractive force increases.

On the other hand, the force of the return spring, which acts in the opposite direction to the direction in which the pinion is engaged, tends to decrease significantly at a predetermined gap when the pinion engagement is completed. For this reason, the excitation coil was wound twice with different wire types, and when the pinion had finished biting, one of the coils was short-circuited to reduce the magnetomotive force and the attractive force.

For these reasons, conventional magnetic switches for starters often suffer from the disadvantages of production complexity due to the double winding of the coil and reduction of coil excitation force due to backflow from the short-circuited coil.

In addition, the large suction force after the end of the pinion biting requires an improvement in the strength of the entire device, which often has the drawback of increasing its size from the point of view of reliability.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and can achieve attraction force characteristics commensurate with the biasing force of the pinion gear return spring on the starter side with a simple configuration without having to double-wind the solenoid coil for magnetic attraction. It is intended to provide a magnetic switch with

[Summary of the invention]

First, the basic principle of the present invention will be briefly described below.

According to the present invention, as the plunger slides, the gap between the plunger and the solenoid coil! By changing +2, the derived resistance in the gap described above is changed and the magnetic attraction force is changed. As a specific means for changing the above-mentioned gap, a notch is provided on the outer peripheral surface of the plunger. As a result, even if the attraction solenoid coil has a simple single-wound structure, the magnetic attraction force can be changed in accordance with the sliding stroke of the plunger.

Based on the above-mentioned principle, the magnetic switch for starters of the present invention meshes with the ring gear of the engine to control the starting rotation. In a magnetic switch equipped with an electromagnetic attraction means that applies a thrust force in the meshing direction to a pinion gear that applies force, the electromagnetic attraction means has a solenoid coil and a plunger that is magnetically attracted to the solenoid coil, and the electromagnetic attraction means has a solenoid coil and a plunger magnetically attracted to the solenoid coil. The solenoid coil is characterized in that a notch is provided on the outer peripheral surface so that the gap between the plunger and the solenoid coil changes as the plunger slides under attraction.

[Embodiments of the invention]

Next, the configuration of an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

Fig. 1 is a sectional view of a starter motor equipped with an embodiment of the magnetic switch of the present invention, Fig. 2 is a sectional view of the magnetic switch of the above embodiment, and Fig. 3 is the same as Fig. 2 viewed from the right side of the figure. This is an end view depicting the location.

(See FIG. 1) The electric motor 1 is a DC series-wound electric motor, and one end of the armature shaft 2 is supported by a wasting 4 via a bearing 3. A gear 5 is formed at the tip of the shaft 2. Reference numeral 6 denotes a pinion clutch, which is composed of a clutch outer 8 having a gear 7 formed on its outer periphery, a row 29, and a clutch inner 1O.

A helical spline L1 is provided on the inner periphery of the clutch inner 10, and is connected to the pinion shaft 12. The axial position of the pinion shaft 12 is determined by the plunger/
The shaft return spring 14 is provided between the shaft 10 and a spring receiver 13 fixed to one end of the shaft 12 of the pinion 7.

Bearings 15, 15' are provided at both ends of the clutch inner 10. Bearing retainer 16
It is supported by The power generated by the electric motor l is transferred to the gear 5.
From the clutch outer 8 gear 7° roller 9. ri2 noteinna10. It is transmitted to the pinion shaft 12 via the helical spline 11.

A pinion 17 is formed at one end of the pinion shaft 12, and a ring gear 18 (not shown) is connected to the engine (not shown).
The pinion 17 transmits the biting power.

19 is a magnetic switch, the details of which are shown in Figure 5%2. This switch includes a movable contact 20 and a fixed contact 21 that open and close the power supply of the electric eJJ machine 1, a contact shaft 22 that moves the movable contact 20, a contact push spring 23 that applies a predetermined pressure between the contacts, and a contact shaft. It is composed of a contact return spring 24 that returns the contact point 22 and an electromagnet part 25. The magnetic circuit components of the electromagnet portion 25 have the following configuration.

A magnetic field indicated by a broken line arrow 28 is formed through the coil case 26, the fixed iron core 27, and the plunger 28. With respect to this magnetic field formation, &) the air gap 301 between the plunger 228 and the fixed iron core 27, and (b) the fixed air gap 29 between the coil case 26 and the plunger 28 exhibit magnetic conduction resistance. Therefore, as these voids decrease, the magnetic attraction increases,
As the air gap increases, the magnetic attraction force decreases.

31 is a single-wound coil of the same wire 81t, which is wound around a bobbin 32 made of an insulating material.

The fc 33 shown in FIG. 1 is supported by a shift lever, one end of which is supported by a square hole 34 of the plunger 28, and the other end supported by a contact point 35 of the housing 4 as a fulcrum.

Reference numeral 36 is a biasing spring of a binion, and one end is attached to the coil case 26 and the other end is attached to the l/par 33.

As shown in FIG. 2, the plunger 28 is a substantially cylindrical member, and is provided with a square hole 34 for engaging the shift lever 33 shown in FIG. As shown in FIGS. 2 and 3, a notch 37 is formed by cutting out only a portion of the plunger 28 (section L in the figure) on two parallel surfaces having a width W.

When the plunger 28 is magnetically attracted from the illustrated state and slides to the left in the figure, the air gap 3 (l) decreases.

However, on the other hand, the notch 37 of the plunger 28 faces the inner circumferential surface of the coil case 26, and the magnetic conduction resistance of this portion increases.

FIG. 5 is a characteristic chart of the magnetic switch of this embodiment, in which the horizontal axis indicates the dimension of the gap 300 described above. That is, the horizontal axis represents the position of the plunger 28 in the right direction.

The vertical axis in the figure indicates the magnetic attraction force F1 and the biasing force f of the biasing spring 36.

When the key switch 40 (FIG. 4) is closed, the coil 31 shown in FIG. 2 is energized and a magnetic flux 38 is generated. Plunger 28 moves in a direction to shorten gap 30. The driving force at this time is the suction force F shown in FIG. The generated suction force F1 increases as the air gap 30 becomes smaller.
Since the magnetic conduction resistance of F2 decreases, the force tends to increase.
It becomes the power of However, when the plunger notch 37 faces the inner periphery of the coil case 26, the fixed gap 29 increases, and the magnetic conduction resistance of the fixed gap 29 also increases, so that the attractive force decreases to F3. Furthermore, when the plunger slides and the decrease in the magnetic conduction resistance of the air gap 30 exceeds the increase in the magnetic conduction resistance of the fixed air gap 29, the attractive force increases to F4.

(See Figure 1) When the plunger 28 slides (toward the left in the figure) with the suction force F, the shift lever 33 engaged with the square hole 34 moves the pinion shaft around the contact point 35 of the housing 4 as a fulcrum. Pushing one end of the pinion 12, the pinion 17 comes into contact with the ring gear 18. When the troughs of each tooth face each other, the biting action is performed well, but when each tooth faces each other, the rotational force to shift the teeth and the thrust force to push are generated. is necessary. The thrust force is provided by the magnetic attraction force, and the pushing force is provided by the biasing spring 36, respectively.

As described above, when the magnetic attraction force F changes due to the meshing action of the pinion, on the other hand, the force of the biasing spring 36 changes as if it were missing.

After the engagement starts (8 points), the spring force of the urging spring 36 (dashed line curve) increases from fl to fl. Next, plunger 28
When it hits the contact shaft 22, the spring force of the contact return spring 24 is applied, resulting in f3.

When the plunger 28 moves further, the movable contact 2o comes into contact with the fixed contact 21, and the spring force at this time becomes F4.

When the contacts 20, 21 are closed, voltage is applied to the motor 1 and it begins to operate. When this torque is applied, the pinion 1
7 are partially released from facing each other by rotational force, and the pinion 17 (FIG. 1) meshes with the ring gear 18.

When the engagement of the pinion gear 17 is completed, the pinion biasing spring 36 becomes free, and the spring force f is applied to the shaft return spring 1.
4. Only the force of the contact return spring 24 is used, and the force is greatly reduced to f5.

The plunger 28 further moves in the direction of narrowing the gap 30, and the spring force f6 of the contact push spring 23, the contact return spring 24.7, and the shaft return spring 14 is applied.

In Figure 5, the curve of magnetic attraction force (F
') and the curve (f) of the spring biasing force shown by the broken line. Since the gap between the magnetic attraction solenoid coil 31 and the magnetic attraction solenoid coil 31 is configured to change half as much as the plunger 28 slides, the magnetic attraction occurs when the pinion gear is fully engaged (0 point on the horizontal axis in FIG. 5). The force t'' Fz is reduced to F3, thereby reducing the generation of excessive impact force.

As shown in this embodiment, the solenoid coil 31 for magnetic attraction is configured in a complicated double-wound shape (i). (F)) can be set arbitrarily.

〔Effect of the invention〕

As described in detail above, the present invention can be applied to the slide and the solenoid coil for magnetic attraction with a simple configuration that can match the biasing force of the pinion gear return spring on the starter side without double winding. A magnetic switch with
It has an excellent practical effect of being able to perform four functions.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the present invention, Fig. 2 is a sectional view of the magnetic switch in the above embodiment, Fig. 3 is a side view of the magnetic switch, and Fig. 4 is the electric circuit of the starter motor. Figure 5 shows the relationship between the a-air suction force against the gap and the spring force in the above embodiment. 1... motive, 6... pinion clutch, 12...
・Binion shaft, 14...Shaft return spring, 2
4... Contact return spring, 28... Plunger, 29...
... Fixed air gap, 30 ... Air Lai ... Coil, 36
...Binion push-in spring, 37...Plunger notch.

Claims (1)

[Claims] 1. In a magnetic switch equipped with an electromagnetic attraction means that applies a thrust force in the meshing direction to a pinion gear that meshes with a ring gear of the engine and provides a starting rotational force, the electromagnetic attraction means is magnetically attracted to a solenoid coil and the solenoid coil. A plunger, characterized in that a notch is provided on the outer peripheral surface of the plunger so that the gap between the plunger and the solenoid coil changes as the plunger slides under attraction. Starter magnetic switch.