JPH0264259A - Co-axial type starter device - Google Patents

Abstract

PURPOSE:To prevent magnetic attraction force from being lowered as well as to improve the way of installation onto an engine to a great extent by forming the magnetizing coil of an electromagnetic switch device into a non- circular shape in a starter device for starting a vehicle engine. CONSTITUTION:An electromagnetic switch device 24 is arranged on the rear side of a rear bracket 11c which is coupled with the rear end of a DC electric motor 15 so as to be mounted wherein the switch slides an output rotating shaft 18 and also enables the DC electric motor 15 to be energized. A magnetizing coil 28 is formed into a non-circular shape with a section coming close to a case 25 except a section wherein a through bolt is arranged. This constitution can thereby prevent magnetic attraction force from being lowered, thereby improving the way of installation onto an engine to a great extent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coaxial starter device, and more particularly to a coaxial starter device used for starting a vehicle.

(Prior art) Conventionally, this type of coaxial starter device was developed in U.S. Pat.
This method is well known as disclosed in Publication No. 474 (Utility Model Application No. 166198/1988). The conventional coaxial starter device disclosed in this publication includes a DC motor 1 having a tubular armature rotating wheel 1a, as shown in FIG.
An output supported slidably in the axial direction to which the rotation of the armature rotating shaft 1a is transmitted via a driving force transmission device 3 that is provided on the axial end side of the DC motor 1 and includes a planetary gear reduction mechanism 2. A rotating shaft 4, a pinion 5 provided at the front end of the output rotating shaft 4, and a pinion 5 provided at the other end in the axial direction of the DC motor are slid by pushing the output rotating shaft with a plunge rod 6a at the same time as the DC motor is energized. The armature rotating shaft 1a of the DC motor 1 and the plunge rod 6a of the electromagnetic inching device 6 are arranged on the same axis.

In such a conventional coaxial starter device, an electromagnetic switch device 6. The front machine frame 7 housing the DC electric motor 4i111 and the driving force transmission device 3 is assembled so as to be connected to each other by two through bolts 8. That is, each through bolt 8 is connected to the case 6 of the electromagnetic switch device 6.
b It is inserted into a hole provided in the flange portion 6c formed on the outer periphery of the front end, and the direct fL electric! The case 6b of the electromagnetic switch device 6 is screwed through the outer periphery of the yoke Ib of the ill to the screw hole of the front machine frame 7 and tightened.
and the front machine frame 7 are brought together and crimped to the yoke ends of the DC motor 1, thereby connecting these three elements to each other, and thereby assembling them together to form a coaxial starter element. Was.

(Problems to be Solved by the Invention) As mentioned above, in the conventional coaxial starter device, 1 is replaced by a magnetic switching device 6. Since the through bolt 8 for integrally connecting the direct current motor 1 and the front machine frame 7 is located outside the DC motor 1, the through bolt 8 may get in the way when installing the coaxial starter device 1 to the engine. It may happen,
Its installation sometimes caused problems.

Therefore, it has been proposed to insert the through bolt 8 from the rear end surface of the case 6b of the electromagnetic switch device 6 in order to locate it inside the DC motor 1, but with such a configuration, the excitation coil of the electromagnetic switch device 6 becomes smaller. , a problem arises in that it is not possible to obtain a predetermined suction force.

An object of the present invention was to solve such conventional problems, and the purpose of the present invention is to insert a through bolt connecting an electromagnetic switch device, a DC motor, and a front machine frame into the case from the rear end of the electromagnetic switch device. It is an object of the present invention to provide a coaxial type starter device that does not cause a decrease in magnetic attraction force in an electromagnetic switch device even when the starter device is inserted and passed through the inside of a DC motor.

(Means for Solving the Problem) The present invention arranges an armature rotating shaft of an electric motor, an output rotating shaft having a pinion at the front end and slidably supported in the axial direction, and an electromagnetic switch device on the same axis. °ζ coaxial starter device, in which the electromagnetic switch device includes a cylindrical case surrounding a through bolt extending in the axial direction along an inner circumferential surface, an excitation coil disposed within the case, and the excitation coil. and a plunger disposed so as to be slidable in the axial direction inside the coil, and the excitation coil has a non-circular shape having a portion close to the case except for the portion where the through bolt is arranged.

(Function) According to the coaxial starter device of the present invention, in order to allow the through bolt to pass through the inside of the electric motor, the through bolt must be inserted into the cylindrical case of the electromagnetic switch device along its inner peripheral surface. Insert it in the axial direction.

Therefore, an annular space with a radial width equivalent to the diameter of the through bolt is created along the inner circumference of the case, but the excitation coil has a part close to the case except for the part where the through bolt is located. Since it has a non-circular shape, the cross-sectional area increases, and it is possible to obtain sufficient magnetic attraction force to attract and move the plunger.

(Embodiments) Hereinafter, the coaxial starter device of the present invention will be described in more detail with reference to embodiments shown in the accompanying drawings.

1 to 3 show a coaxial star-starting device 10 according to an embodiment of the present invention. This coaxial starter device IO has a yoke l that constitutes a magnetic circuit and forms an outer wall.
permanent magnets 12 fixed to the inner peripheral surface of the yoke 11a at intervals in the circumferential direction; an armature 13 rotatably disposed in the center of the yoke 11a; The DC motor 15 includes a commitake 14 and a DC motor 15.

The armature 13 in this straight 2 & electric motor 15 has a hollow armature rotating shaft 16 and a
The rotation of the armature 13 is transmitted to an output rotary wheel 18 disposed on one axial end side of the DC motor 15, that is, on the front side (on the right side in FIG. 1).
9.

This driving force transmission device 19 includes a planetary gear reduction device 20 and a one-way clutch device (overrunning clutch device) 21.
, and a helical spline 18a formed on the output rotating wheel 18 and meshing with a cluff inner 21a of the one-way clutch device 21. The output rotation shaft 18 is disposed on the same axis as the armature rotation shaft 16 of the DC electric motor Ia 15, and its lower end is inserted into the internal passage 16a of the armature rotation wheel 16, and is interposed between the output rotation shaft 18 and the inner peripheral surface thereof. is slidably supported in the axial direction via a sleeve ring,
A binion 22 is attached to the front end of the output rotating wheel 18,
As the output rotating shaft 18 slides, the pinion 22 protrudes from a front end opening 23a formed in a front machine frame 23 housing the driving force transmission device 19, and meshes with a ring gear (not shown) of the engine.

On the other hand, an output rotary wheel 18 is slid on the rear side of the DC electric motor [15 fitted to the rear end of the bracket] and when a key switch (not shown) of the wheel is closed, the DC motor 15 is powered from the battery. An electromagnetic switch device 24 is arranged to enable power supply to. This electromagnetic switch device 2
Reference numeral 4 denotes an excitation coil 28 wound around a plastic bobbin 27 supported by front and rear cores 26a26b which together with the case 25 constitute a magnetic path, and a plunger slidably disposed in the central opening of the bobbin 27. 29, a non-magnetic tubular rod 30 whose one end is attached to the plunger 29 and whose other end enters the internal passage 16a from the rear end of the armature rotating wheel 16; It is configured to include a movable contact 32 that is held by the user. A push-in loft 33 is slidably fitted into the tubular loft 30, and the push-in rod 33 extends forward from the front end opening of the tubular loft 30, and its front end is formed on the end surface of the output rotating shaft 18. w4LJi on the back wall of the recess
It is abutted via 34.

The outer case 25 of the electromagnetic switch device 24 has a cylindrical shape,
Two through bolts 35 are arranged close to the inner surface and extending in the axial direction. This through bolt 35 is inserted through a hole formed on the rear end surface of the case 25, passes through the case 25, and passes through the DC electric power +! The threaded end portion 35a passes through the rear bracket lie of A15, passes through the space between the permanent magnets 12 in the yoke lla, and is screwed into the threaded hole 23b formed in the front machine frame 23 (Fig. 3). Due to the axial force, the yoke lla is attached to the front machine frame 23,
is fitted into the yoke Ila, and the outer case 25 of the electromagnetic switch device 24 is fitted into the rear bracket llc, respectively, and the entire assembly is fixed. When the through bolt 35 is constructed so as to cover the inside of the case 25 in this way, in order to prevent the plunger 29 from becoming inoperable due to a decrease in the magnetic attraction force in the electromagnetic switch device 24, etc.
As shown in FIG. 2, the outer shape of the plunger 29 is barrel-shaped. The bobbin as well as the rear core 26b has a barrel shape corresponding to the shape of the plunger 29, and therefore the excitation coil 28 wound around the bobbin also has a barrel shape. Here, the term "barrel shape" refers to a shape in which a pair of opposing sides of a square or rectangle are curved lines that protrude outward.

In such a barrel-shaped excitation coil 28, a pair of opposing flat side portions 28a are located close to the through bolt 35, and another pair of opposing curved surface portions 28b have the same curvature as the case 25. and is sized to be located close to its inner surface. This allows the excitation coil to expand into the annular space that would have been created by the presence of the through-bolt if the excitation coil was circular as in the past, making it possible to prevent the magnetic attraction from decreasing as well. , the increase in coil volume makes it easier for heat to dissipate.

Furthermore, if the outer shape of the plunger 29 is made non-circular in this way, rotation due to vibration or the like can be prevented, resulting in less wear and tear. In addition, in FIGS. 1 to 3, the reference numeral 36
shows the guide busher during plunge.

In the electromagnetic switch device 24 in the coaxial starter device IO of the above-mentioned embodiment, the outer shape of the plunger 29 and the excitation coil 28 were in a solid shape, but the present invention is not limited to this shape, but an elliptical shape. Similar effects can be achieved as long as the shape has a portion close to the inner surface of the outer case 25 of the electromagnetic switch device 24, such as a polygonal shape, as long as it can be manufactured.

(Effects of the Invention) As explained above, according to the coaxial Stark device of the present invention, even if the through bolt is placed inside the case of the electromagnetic switch device in order to pass through the motor, the excitation coil of the electromagnetic switch device is not operated. The circular shape prevents a decrease in magnetic attraction force and allows a predetermined operation to occur. In other words, by making the excitation coil of the electromagnetic switch device non-circular, it is possible to place the through bolt inside the starter device instead of exposing it to the outside, making installation to the engine much easier. can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a coaxial starter device of the present invention, FIG. 2 is a cross-sectional view of an electromagnetic switch device taken along the line ■-■ in FIG. 1, and FIG. FIG. 4 is a partial side view of a coaxial starter device showing only the electromagnetic switch device surface partially cut away along a line, and FIG. 4 is a sectional view showing a conventional coaxial starter device. lO... Coaxial starter device, 15... DC motor, 16... Armature rotating shaft, 18... Output rotating shaft, 2
2... Pinion, 24... Electromagnetic switch device, 25
...Case, 28...Exciting coil, 29...Plunging, 35...Through bolt. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] In a coaxial starter device comprising an armature rotating shaft of an electric motor, an output rotating shaft having a pinion at the front end and slidably supported in the axial direction, and an electromagnetic switch device arranged on the same axis, the electromagnetic switch device is A cylindrical case surrounding a through bolt extending in the axial direction along the inner peripheral surface, an excitation coil disposed within the case, and a plunger disposed slidably in the axial direction within the excitation coil. Equipped with
A coaxial starter device characterized in that the excitation coil has a non-circular shape having a portion close to the case except for the through-bolt arrangement portion.