JP2005054706A - Engine starter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine starter 1 having a current fuse 32 capable of cutting off the continuous flow of current to a motor 4 and enabling the easy mounting of the current fuse 32 therein at low cost. <P>SOLUTION: The current fuse 32 is connected across the motor terminal 22 of an electromagnetic switch 9 and an attracting coil 9c. If the defective return of a starter switch 30 occurs, for example, after starting an engine, the holding force of a plunger 9a is lowered or eliminated by the thermal deterioration of the attracting coil 9d and a main contact is opened to flow a current from a battery 3 to the attracting coil 9c through the starter switch 30 (closed state) and to further flow the current from the attracting coil 9c to an armature 12 through the current fuse 32. In this case, when a current exceeding a specified value flows through the current fuse 32 continuously for a specified time (for example, one minute) or longer, the current fuse 32 is blown to cut off a switch circuit 29, and the continuous flow of the current to the motor 3 is suspended. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine starter for starting an engine.

As a prior art, there is an engine starter described in Patent Document 1.
As shown in FIG. 6, the engine starter includes a switch circuit 140 for supplying current from the battery 130 to the excitation coil 120 built in the electromagnetic switch 110 when the start switch 100 is closed. A normally closed bimetal 150 is connected between the 140 start switch 100 and the exciting coil 120. The normally closed bimetal 150 is attached in close contact with the outer periphery of the motor lead wire 170 connected to the motor terminal 160 of the electromagnetic switch 110, and opens when the temperature of the motor lead wire 170 exceeds a predetermined value.

As a result, when the return failure of the start switch 100 occurs after the engine starts, or when the driver keeps the start switch 100 in the start position due to an engine start failure or the like, the temperature of the motor lead wire 170 is increased. When the predetermined value is exceeded, the normally closed bimetal 150 is opened and the energization to the exciting coil 120 is cut off. As a result, the main contact 190 of the motor circuit 180 is opened and the energization to the motor 200 is interrupted, whereby the continuous energization to the motor 200 is stopped and the deterioration of the motor 200 can be prevented.
Japanese Patent Laid-Open No. 11-230014

  However, in the conventional technique described in Patent Document 1, it is necessary not only to connect the normally closed bimetal 150 to the switch circuit 140 but also to attach the normally closed bimetal 150 in close contact with the outer periphery of the motor lead wire 170. For this reason, a part of the switch circuit 140 must be wired close to the motor lead wire 170, and wiring is complicated.

  Further, as shown in FIG. 7, in the general starter of the biaxial type in which the electromagnetic switch 110 is arranged on the outer side in the radial direction of the motor 200, the outlet of the motor lead wire 170 taken out from the end frame 210 of the motor 200 Since the motor terminal 160 of the electromagnetic switch 110 to which the motor lead 170 is connected is close, the length of the motor lead 170 exposed to the outside is shortened. For this reason, attaching the normally closed bimetal 150 in close contact with the outer periphery of the motor lead wire 170 not only makes the attachment operation difficult, but also may damage the motor lead wire 170 during the operation. As a result, it is necessary to perform the attachment work of the normally closed bimetal 150 very carefully, so that the work efficiency is deteriorated and the cost is increased.

  The present invention has been made based on the above circumstances, and its purpose is to provide a shut-off means that can cut off the power to the motor when a return failure of the start switch or the like occurs. It is an object of the present invention to provide an engine starter that can be easily and inexpensively installed without requiring significant changes.

(Invention of Claim 1)
The present invention has a motor for generating a rotational force when a starting current is supplied from a battery, and a main contact for intermittently starting the starting current, and a motor for causing the starting current to flow from the battery to the motor via the main contact. A circuit, a suction coil that generates a magnetic force for attracting a built-in plunger, and a holding coil that generates a magnetic force for retaining the attracted plunger, and opens and closes the main contact according to the movement of the plunger An electromagnetic switch, a start switch for starting the motor, a switch circuit for passing an excitation current from the battery to the suction coil and the holding coil via the start switch, and a height of the suction coil with respect to the switch circuit; A blocking means connected in series to the potential side or the low potential side and capable of blocking the current flowing through the suction coil. Chi is when the long predetermined time or continuously for a specified value or more current to attracting coil than the time for closing the main contacts from being closed operation flow, characterized by interrupting the switching circuit.

  In the above configuration, after the engine is started, for example, when a return failure of the start switch occurs, or when the driver keeps the start switch at the start position due to an engine start failure or the like, When the holding force decreases or disappears, the main contact opens, and a battery current flows through the suction coil to the motor. At this time, if a battery current exceeding the specified value flows through the suction coil continuously for a predetermined time longer than the time from closing the start switch to closing the main contact, the shut-off means connected to the switch circuit shuts off the switch circuit. By doing so, the continuous energization to the motor is stopped.

  According to the present invention, since it is only necessary to connect the interruption means to the existing switch circuit, there is no need to change the wiring process of the switch circuit, and the wiring can be routed as in the prior art described in “Background Art”. There is no complexity. Further, since it is not necessary to attach the shut-off means connected to the switch circuit in close contact with other wiring (for example, a motor circuit), the shut-off means can be easily installed, and the shut-off means can be installed while the shut-off means is being installed. There is no risk of damaging the wiring.

(Invention of Claim 2)
The engine starting device according to claim 1, wherein the interrupting means is a current fuse, and the fusing current of the current fuse is set to 90% or less of the minimum value of the starting current capable of maintaining the rotation of the motor. Features.
As a result, when a battery current exceeding the specified value, that is, a current exceeding 90% of the minimum value of the starting current continuously flows in the switch circuit for a predetermined time or longer, the current fuse is surely blown and the switch circuit is cut off. it can.

(Invention of Claim 3)
3. The engine starter according to claim 1, wherein the electromagnetic switch is electrically connected to the battery terminal connected to the positive electrode of the battery, the motor terminal connected to the motor, and the battery terminal as a main contact. One of the fixed contacts and the other fixed contact electrically connected to the motor terminal are included, and the blocking means can be provided between the suction coil and the motor terminal on the low potential side of the suction coil.

(Invention of Claim 4)
The engine starter according to claim 3 is characterized in that the electromagnetic switch has a contact cover for holding the battery terminal and the motor terminal, and the blocking means is arranged outside the contact cover.
According to this configuration, when a return failure or the like of the start switch occurs, the switch circuit can be shut off by the shut-off means without affecting the resin member having low heat resistance accommodated inside the contact cover.

(Invention of Claim 5)
5. The engine starter according to claim 4, wherein the current fuse serving as the breaking means has a terminal plate on one end side, and the terminal plate is tightened with a nut together with a terminal of a motor lead wire connected to the motor terminal. It is characterized by being fastened to the motor terminal.
In this case, the terminal plate provided on one end side of the current fuse can be easily fixed to the motor terminal by tightening the nut.

(Invention of Claim 6)
6. The engine starter according to claim 5, wherein the current fuse serving as the breaking means has a second terminal plate on the other end side, and the second terminal plate is taken out of the contact cover. It is characterized in that it is soldered to the end of this.
In this case, a JIS standard standard claw fuse can be used, and the second terminal plate provided on the other end of the fuse can be easily fixed to the end of the suction coil by soldering.

(Invention of Claim 7)
6. The engine starter according to claim 5, wherein the electromagnetic switch has a metal guide tube insert-molded in the contact cover, and an end portion of the suction coil passes outside the contact cover through the inside of the guide tube. The current fuse, which is taken out and is a breaking means, has a second terminal plate on the other end side, and this second terminal plate is electrically connected to the end of the suction coil taken out outside the contact cover. It is characterized in that it is caulked and fixed to the end of the guide tube in a state of being in contact with.
In this case, a JIS standard standard claw fuse can be used, and the second terminal plate provided on the other end of the fuse is caulked to the end of the guide cylinder insert-molded in the contact cover. Can be fixed.

(Invention of Claim 8)
6. The engine starting device according to claim 5, wherein the current fuse serving as the breaking means is soldered at its other end to the end of the suction coil taken out of the contact cover.
In this case, since it is not necessary to provide the second terminal plate on the other end side of the current fuse, the cost of the current fuse can be reduced.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

FIG. 1 is a half sectional view (a) and an axial rear view (b) of a starter 2 used in an engine starting device, and FIG. 2 is an electric circuit diagram of the engine starting device 1.
The starter 2 used in the engine starter 1 is supplied with a starter current from a battery 3 (see FIG. 2) through a motor circuit and generates a rotational force, and the rotational force of the motor 4 is transmitted. The output shaft 5, the one-way clutch 6 and the pinion 7 disposed on the output shaft 5, and the one-way clutch 6 and the pinion 7 are pushed out in the anti-motor direction via the shift lever 8. It comprises an electromagnetic switch 9 and the like for opening and closing a main contact (described later) provided.

The motor circuit is an electric circuit for causing a starting current to flow from the battery 3 to the motor 4, and the starting current is interrupted according to the open / close state of the main contact.
The motor 4 is a well-known DC electric motor including a field 10 that generates magnetic flux, an armature 12 having a commutator 11, a brush 13 disposed on the outer peripheral surface of the commutator 11, and the like.
The field 10 forms a magnetic circuit and is composed of a cylindrical yoke 10a that also serves as a machine frame of the motor 4 and a plurality of permanent magnets 10b fixed to the inner periphery of the yoke 10a.

The yoke 10a is sandwiched between a front housing 14 that covers the front side of the starter 2 (left side of FIG. 1A) and an end frame 15 that covers the rear side of the motor 4, and is fastened and fixed by through bolts 16. Yes.
The plurality of permanent magnets 10b are arranged at equal intervals in the circumferential direction of the yoke 10a. Instead of using the permanent magnet 10b, a winding field means comprising a field coil and a pole core may be employed.

The armature 12 includes a rotary shaft 12a, an armature core 12b that is press-fitted and fixed to the rotary shaft 12a, and an armature coil 12c that is wound around the armature core 12b. The other end is rotatably supported by the end frame 15 via the bearing 18 and is supported by the output shaft 5 via the bearing 17.
The commutator 11 is configured by arranging a plurality of segments insulated and held on the outer periphery of the rotating shaft 12a in a cylindrical shape, and each segment is electrically and mechanically coupled to the armature coil 12c.

The brush 13 includes a + side brush 13 a and a − side brush 13 b (see FIG. 2). Each brush 13 is accommodated in a brush holder 19 and pressed against the outer peripheral surface of the commutator 11 by a brush spring 20. The + side brush 13a is connected to a motor terminal 22 (see FIG. 1) provided in the electromagnetic switch 9 via a motor lead wire 21 forming a part of the motor circuit, and the − side brush 13b is connected to a brush lead wire 23. (See FIG. 2).
The motor lead wire 21 is taken out of the end frame 15 through a grommet 24 attached to the end frame 15, and a terminal 21 a provided at the end is fitted to the motor terminal 22 of the electromagnetic switch 9. The nut 25 is fastened and fixed.

The output shaft 5 is disposed on the same axis as the rotating shaft 12a of the armature 12, and the rotational force of the motor 4 is transmitted through the speed reducer.
The reduction gear is configured by a known planetary gear mechanism, and reduces the rotational speed of the armature 12 by the revolving motion of the planetary gear 26. The revolution movement of the planetary gear 26 is transmitted to the output shaft 5 via a gear shaft 27 that rotatably supports the planetary gear 26.

The one-way clutch 6 transmits power from the outer 6b to the inner 6c via the roller 6a. A spline tube provided integrally with the outer 6b is coupled to a helical spline 5a provided on the output shaft 5, It is provided so as to be movable in the axial direction on the output shaft 5.
The pinion 7 transmits the rotational force of the motor 4 to an engine ring gear (not shown). The pinion 7 is disposed on the side opposite to the motor of the one-way clutch 6 and is provided integrally with the inner 6c. Are fitted to each other via a bearing 28 so as to be relatively rotatable.

The electromagnetic switch 9 has an exciting coil (described below) connected to a switch circuit 29 (see FIG. 2), and a plunger 9a arranged so as to be able to reciprocate inside the exciting coil. The shift lever 8 is connected to the hook 9b through the hook 9b.
The switch circuit 29 has a start switch 30 for starting the motor 4, and an excitation current flows from the battery 3 to the excitation coil by closing the start switch 30.
As shown in FIG. 2, the exciting coil is composed of a suction coil 9c that generates a magnetic force for attracting the plunger 9a and a holding coil 9d that generates a magnetic force for holding the attracted plunger 9a. Not wound on a bobbin in two layers.

As shown in FIG. 2, the suction coil 9c has one end connected to the start switch 30 via a connection terminal 31 provided on the electromagnetic switch 9, and the other end connected to the motor via a current fuse 32 (described later). The terminal 22 is electrically connected. One end of the holding coil 9d is connected to the start switch 30 through the connection terminal 31 together with one end of the suction coil 9c, and the other end is grounded.
When a magnetic force is generated by energizing both the coils 9c and 9d, the plunger 9a is attracted by the magnetic force and moves to the right in FIG. 1A while compressing the return spring 9e shown in FIG. When the energization of the exciting coil is stopped and the magnetic force disappears, the reaction force of the return spring 9e is received to push back to the initial position.

  The shift lever 8 has a fulcrum portion 8 a between an upper end portion engaged with the hook 9 b and a lower end portion engaged with the spline tube of the one-way clutch 6, and the fulcrum portion 8 a is interposed via the lever holder 33. The front housing 14 is swingably supported. When the plunger 9a is attracted by receiving the magnetic force of the exciting coil, the movement of the plunger 9a is transmitted to the upper end portion of the shift lever 8 via the hook 9b, so that the shift lever 8 is centered on the fulcrum portion 8a. Rotating clockwise in FIG. 1 (a), a force for pushing the one-way clutch 6 in the direction opposite to the motor is applied.

As shown in FIG. 2, the main contact includes one fixed contact 35 electrically connected to the battery terminal 34 provided on the electromagnetic switch 9 and the other fixed contact electrically connected to the motor terminal 22. 36 and a movable contact 37 movable in conjunction with (or integrally with) the movement of the plunger 9a. The movable contact 37 abuts both the fixed contacts 35, 36, and both the fixed contacts 35, The closed state is established by conducting between 36, and the movable contact 37 is opened by separating from the fixed contacts 35, 36.
As shown in FIG. 2, the battery terminal 34 is connected to the positive electrode of the battery 3 via a battery cable 38 forming a part of the motor circuit, and together with the motor terminal 22, the contact cover 9f of the electromagnetic switch 9 (FIG. 1). Insert).

  As shown in FIG. 3, the current fuse 32 is a JIS standard standard product (fuse with a pawl) having terminal plates 32a and 32b at both ends, and is arranged outside the contact cover 9f of the electromagnetic switch 9. The suction coil 9c and the motor terminal 22 are connected. Specifically, as shown in FIG. 4, the terminal plate 32 a on one end side of the current fuse 32 is fitted to the motor terminal 22 together with the terminal 21 a of the motor lead wire 21 and is fastened together by the nut 25, and the other end side. The terminal plate 32b (second terminal plate of the present invention) is fixed by caulking to a cylindrical rivet 39 (guide cylinder of the present invention) which is attached through the contact cover 9f, and further passes through the inside of the rivet 39. It is soldered together with the end of the suction coil 9c drawn to the outside of the contact cover 9f, and is electrically connected to the suction coil 9c.

The current fuse 32 is blown when a fusing current is set to 90% or less of the minimum value of the starting current capable of maintaining the rotation of the motor 4 and a current exceeding the fusing current flows continuously for a predetermined time (for example, 1 minute). Then, the switch circuit 29 is shut off.
As shown in FIG. 4, the contact cover 9f to which the motor terminal 22 is fixed has a step between the end surface 9g where the extraction opening of the suction coil 9c is formed and the end surface 9h where the motor terminal 22 is insert-molded. The end surface 9h where the motor terminal 22 is insert-molded is formed higher in the axial direction than the end surface 9g where the extraction opening of the suction coil 9c is formed. On the other hand, the current fuse 32 is bent in a bowl shape according to the level difference of the contact cover 9f, and a height difference is provided between the terminal plate 32a on one end side and the terminal plate 32b on the other end side.

Next, the operation of the starter 2 will be described.
When the exciting coil (suction coil 9c and holding coil 9d) of the electromagnetic switch 9 is energized by closing the start switch 30, the plunger 9a is attracted by the magnetic force generated by the exciting coil, and the inside of the exciting coil is shown in FIG. Move to the right of (a). When the movement of the plunger 9a is transmitted to the one-way clutch 6 via the shift lever 8, the one-way clutch 6 is pushed together with the pinion 7 on the output shaft 5 in the counter-motor direction, and the end surface of the pinion 7 is the ring gear. Stops by abutting against the end face.

On the other hand, when the main contact is closed by the movement of the plunger 9a, the suction coil 9c is short-circuited by the main contact, so that no current flows through the suction coil 9c, and only current flows through the holding coil 9d. The plunger 9a is held only by the magnetic force generated by 9d.
When the main contact is closed, a starting current is supplied from the battery 3 to the armature 12 of the motor 4 through the motor circuit, and a rotational force is generated in the armature 12. When the rotational speed of the armature 12 is reduced by the reduction gear and transmitted to the output shaft 5 and further transmitted from the output shaft 5 to the pinion 7 via the one-way clutch 6, the position where the pinion 7 can mesh with the ring gear. Rotating until it is meshed with the ring gear, the rotational force is transmitted from the pinion 7 to the ring gear, and the engine is cranked.

  When the start switch 30 is opened after the engine is started, the magnetic force of the holding coil 9d disappears, so that the plunger 9a held so far is pushed back by receiving the reaction force of the return spring 9e. As a result, the main contact of the motor circuit is opened and the power supply to the armature 12 is cut off, so that the rotation of the armature 12 is stopped. When the movement of the plunger 9a is transmitted to the one-way clutch 6 via the shift lever 8, the engagement between the pinion 7 and the ring gear is released, and the one-way clutch 6 and the pinion 7 are integrally moved on the output shaft 5. Retreat, move to the initial position shown in FIG.

  However, if a return failure of the start switch 30 occurs after the engine starts, or if the driver keeps the start switch 30 in the start position due to an engine start failure or the like, the holding coil 9d generates heat and deteriorates. The holding force of the plunger 9a is reduced or disappears. As a result, the plunger 9a is pushed back by the reaction force of the return spring 9e, and the main contact is opened accordingly, whereby a current flows from the battery 3 to the suction coil 9c via the start switch 30 (closed state). The armature 12 is energized through the current fuse 32 connected to 9c.

  Here, when a current exceeding a specified value flows through the suction coil 9c continuously for a predetermined time (for example, 1 minute) longer than the time from the closing operation of the start switch 30 until the main contact is closed, the suction coil 9c and the motor terminal 22 As the current fuse 32 connected between the fuse 4 and the switch circuit 29 is cut off, continuous energization of the motor 4 is stopped. Note that the “current exceeding the specified value” is a current larger than the fusing current of the current fuse 32, and in this embodiment, a current exceeding 90% of the minimum value of the starting current capable of maintaining the rotation of the motor 4. is there.

(Effect of Example 1)
In the engine starter 1 described in the first embodiment, since the current fuse 32 is connected between the suction coil 9c of the switch circuit 29 and the motor terminal 22, there is no need to significantly change the existing switch circuit. As in the prior art described in “Background Art”, the wiring arrangement is not complicated. Further, the current fuse 32 does not need to detect the temperature from the motor lead wire 21 as in the prior art that uses a normally closed bimetal as a blocking means, so the current fuse 32 needs to be attached to the motor lead wire 21 in close contact. Therefore, the current fuse 32 can be easily attached.
Furthermore, the current fuse 32 can be easily fixed to the motor terminal 22 by tightening the nut 25 by using a JIS standard standard claw fuse.

In the first embodiment, the terminal plate 32b on the other end side of the current fuse 32 is caulked and fixed by the rivet 39. However, the caulking and fixing by the rivet 39 is omitted, and the terminal plate 32b is soldered directly to the end of the suction coil 9c. May be. Alternatively, as shown in FIG. 5, the terminal plate 32b on the other end side of the current fuse 32 may be eliminated, and the other end side of the current fuse 32 may be directly soldered to the end portion of the suction coil 9c.
In the first embodiment, the current fuse 32 is connected between the suction coil 9c and the motor terminal 22. However, between the suction coil 9c of the switch circuit 29 and the start switch 30, or the switch circuit 29 A current fuse 32 may be connected between the battery 3 and the start switch 30.

It is a half sectional view (a) and a rear view (b) of the starter according to the first embodiment. 1 is an electric circuit diagram of an engine starter according to Embodiment 1. FIG. 3 is a side view of the current fuse according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view illustrating a state where the current fuse according to the first embodiment is attached. FIG. 6 is a cross-sectional view showing a mounting state of a current fuse according to Example 2. It is an electric circuit diagram of the engine starting apparatus concerning a prior art. It is a rear view of the starter concerning a prior art.

Explanation of symbols

1 Engine Starter 2 Starter 3 Battery 4 Motor 9 Electromagnetic Switch 9a Plunger 9c Suction Coil (Excitation Coil)
9d Holding coil 9f Contact cover 21 Motor lead wire (motor circuit)
21a Motor lead wire terminal 22 Motor terminal 25 Nut 29 Switch circuit 30 Start switch 32 Current fuse (breaking means)
32a terminal plate 32b terminal plate (second terminal plate)
34 Battery terminal 35 One fixed contact (main contact)
36 The other fixed contact (main contact)
37 Movable contact (main contact)
38 Battery cable (motor circuit)
39 Rivet (guide tube)

Claims (8)

A motor that is supplied with a starting current from a battery and generates a rotational force;
A motor circuit for passing a starting current from the battery to the motor via the main contact, the main contact for interrupting the starting current;
A suction coil that generates a magnetic force for sucking the plunger incorporated therein; and a holding coil that generates a magnetic force for holding the attracted plunger, and opens and closes the main contact according to the movement of the plunger. An electromagnetic switch;
A start circuit for starting the motor, and a switch circuit for passing an excitation current from the battery to the suction coil and the holding coil via the start switch;
The switch circuit is connected in series to the high potential side or the low potential side of the suction coil, and includes a blocking means capable of blocking the current flowing through the suction coil,
The shut-off means shuts off the switch circuit when a current exceeding a specified value flows through the suction coil continuously for a predetermined time longer than the time from when the start switch is closed until the main contact is closed. An engine starter characterized by that. The engine starter according to claim 1,
The engine starting device is characterized in that the interruption means is a current fuse, and a fusing current of the current fuse is set to 90% or less of a minimum value of the starting current capable of maintaining the rotation of the motor. The engine starting device according to claim 1 or 2,
The electromagnetic switch includes a battery terminal connected to a positive electrode of the battery, a motor terminal connected to the motor, one fixed contact electrically connected to the battery terminal as the main contact, and the motor terminal The engine starting device is characterized in that the shut-off means is provided between the suction coil and the motor terminal. In the engine starting device according to claim 3,
The engine starter characterized in that the electromagnetic switch has a contact cover for holding the battery terminal and the motor terminal, and the blocking means is arranged outside the contact cover. In the engine starting device according to claim 4,
The current fuse as the interruption means has a terminal plate on one end side, and this terminal plate is fastened to the motor terminal by tightening a nut together with a terminal of a motor lead wire connected to the motor terminal. An engine starter characterized by that. The engine starting device according to claim 5,
The current fuse as the interruption means has a second terminal plate on the other end side, and this second terminal plate is soldered to the end of the suction coil taken out to the outside of the contact cover. An engine starting device. The engine starting device according to claim 5,
The electromagnetic switch has a metal guide tube insert-molded in the contact cover, and an end of the suction coil is taken out of the contact cover through the inside of the guide tube.
The current fuse serving as the interruption means has a second terminal plate on the other end side, and this second terminal plate is in electrical contact with the end of the suction coil taken out of the contact cover. An engine starter characterized in that the engine starter is fixed by caulking to the end of the guide tube. The engine starting device according to claim 5,
The engine starter according to claim 1, wherein the current fuse as the interrupting means is soldered to the end of the suction coil taken out of the contact cover at the other end of the current fuse.

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