CLIAMS:
[0043] Claims:
We claim:
1) An apparatus for electromagnetic switching in a starter motor, the apparatus comprises of:
a) an outer sleeve (501) fixed firmly to a starter motor frame (203), wherein the starter motor frame (203) is rigidly fixed to the engine;
b) the outer sleeve (501) closed at one end forms a fixed core plate (104) for a first plunger (108);
c) a plurality of bobbins ((116) and (117)) arranged in axial direction to the outer sleeve (501);
d) a first electromagnetic coil (103) comprising a single coil arranged in the first bobbin (117) wherein the first bobbin (117) is arranged in axial direction to the outer sleeve (501);
e) a plurality of magnetic material plates (102(a) and 102 (b)) arranged in axial direction to the outer sleeve (501);
f) a non-magnetic material plate (109) arranged in between the plurality of magnetic material plates (102(a) and 102 (b));
g) the plurality of magnetic material plates (102(a) and 102 (b)) arranged in between the non-magnetic material plate (109) and the plurality of bobbins ((116) and (117));
h) the first plunger (108) arranged in an inner circumference of the first electromagnetic coil (103) which moves in axial direction towards the second fixed core plate (104);
i) a shift lever (201) pivoted at the top end to the top of the starter motor frame (203) and connected to the pinion (202) at bottom end;
j) the shift lever (201) connected to the first plunger through an operating rod (105), wherein the distance between the operating rod (105) and the pivot is less than the distance between the pinion (202) and the pivot;
k) a second electromagnetic coil (114) placed in the second bobbin (116), wherein the second bobbin (116) is arranged in axial direction to the outer sleeve (501), wherein the second electromagnetic coil (114) comprises of a single coil;
l) a movable contact assembly (113) integrated with a second plunger (110) arranged in an inner circumference of the second electromagnetic coil (114), wherein the second plunger (110) moves in axial direction;
m) a terminal base arranged rigidly to the outer sleeve (501) in axial direction, wherein the terminal base carries a fixed contact terminal (112).
2) The apparatus as claimed in claim 1, wherein said shift lever arrangement increases the acceleration of the pinion movement.
3) The apparatus as claimed in claim 1, wherein said plungers (108 and 110) move away from the fixed non-magnetic plate (109).
4) The apparatus as claimed in claim 1 wherein the first electromagnetic coil (103) and the second electromagnetic coil (114) are single winding coils, wherein the lesser winding is sufficient for moving the first plunger as there is a lesser air gap across the first plunger.
5) The apparatus as claimed in claim 5, wherein the plunger air gap required for pinion movement in the shift lever arrangement decreases as the shift lever ratio increases.
6) The apparatus as claimed in claim 1, wherein said pinion movement and contact assembly have independent operations.
,TagSPECI:[0001] DESCRIPTION OF THE INVENTION:
[0002] The following specification particularly describes the invention and the manner in which it is to be performed:
[0003] Technical field of the invention
[0004] The present invention relates to an electromagnetic switching apparatus for starter motor which has separate pinion movement and contact closure to have an independent operation. The present invention also relates to producing faster pinion movement operating at a small air gap across the plunger and the core plate.
[0005] Background of the invention
[0006] In the existing starting devices for engines, a motor circuit is energized through an electromagnetic switch. When solenoid is energized, plunger will move and pinion will get meshed with the ring gear via lever. At this moment, the motor is energized by connecting the starter terminal and battery terminal using a movable contact plate. Thus, the engine is started by transmitting the torque of the motor to the ring gear via the pinion gear.
[0007] Various types of conventional starting devices for engines are known in the prior art, wherein most of them use the devices in which the pinion movement and contact closure are aligned in same line, axially and are dependent on each other for operation. For example, U.S Patent No. 8,193,882 describes theconstruction of starting devices for engines. The claimed construction includes, an electromagnetic switch unit comprising of a solenoid device that pushes out a pinion gear to a ring gear side of an engine via shift lever, and an electromagnetic switch that opens and closes a main point of contact of a motor circuit. Since the shift lever ratio is smaller, the plunger air gap for pinion movement is larger.Here, the pinion movement and the contact closure are dependent on each other for the operation and also in this prior art the shift lever is pivoted at the center for the pinion movement, which moves at a slow rate at the pinion side.
[0008] Typically,inthe existing starting devices, the engine has to be either kept in the “idling” state or has to be switched OFF, every time the vehicle encounters a “stop” signal in a traffic signal junction and also while traversing through heavy traffic. These types of starting devices fail to start the engines automatically and therefore every time the engine is switched OFF, it has to be ignited manually. This leads to a significant amount of time being wasted every time the vehicle encounters a “stop” signal in a traffic signal junction and also while traversing through heavy traffic. The other option available to the driver in such situations is to keep the engine in idling state, which increases the fuel consumption and reduces the efficiency of the engine.
[0009] Due to the single functioning of the starting device in which the pinion movement and closure movement is dependent on each other, the only options available to the driver of a vehicle is to either switch off the engine or keep it in the idling state.
[0010] Hence, there is need of a starting device with a system that will aid in restarting the engine quickly, even when the engine has not stopped completely, wherein the engine speed is gradually decreasing (less than the idle speed).
[0011] Summary of the invention
[0012] The present invention overcomes the drawbacks in the prior art and provides an apparatus for electromagnetic switching in a starter motor. In the present invention the shift lever ratio is higher. The plunger air gap required for pinion movement is small.Both the pinion movement and contact closure operate independently in the present invention. Therefore the engine is switched ON based on the driver’s request/desire for the movement of the vehicle.
[0013] The present invention comprises of an outer sleeve which carries a plurality of coils, wherein each coil carries a plunger in axial direction. A non-magnetic material plate is arranged at the center of the outer sleeve. An operating rod connected to the shift lever at one and the first plunger is connected to the other end of the operating rod. The outer end of the shift lever is connected to the pinion. The second plunger carries a moving contact, wherein the spindle is integrated into the second plunger. A core plate is placed at both the ends of the sleeve. The plungers move away from the non-magnetic plate, which is fixed in between the two bobbins. A terminal base is fixed at the end of the outer sleeve which carries the fixed contact assembly. The present invention has a separate contact closure movement and separate pinion movement for starting the engine. The pinion movement is coupled by a shift lever arrangement so that the pinion action is fast. A single winding coil is used each for the operation of pinion movement and contact closure.
[0014] In one embodiment of the present invention, the apparatus for electromagnetic switching in a starter motor comprises ofan outer sleeve fixed firmly to a starter motor frame wherein the starter motor frame is rigidly fixed to the engine. The outer sleeve is closed at one end which forms a fixed core plate for the first plunger. A first electromagnetic coil is arranged in a bobbin in an axial direction to the outer sleeve and a magnetic material plate is arranged next to the bobbin. The first plunger is arranged in an inner circumference of the first electromagnetic coil wherein the first plunger moves in an axial direction towards the mounting end of the outer sleeve which forms as a fixed core plate for first plunger.
[0015] Further, the top end of a shift lever is pivoted at the top of the starter motor frame wherein the operating rod is connected to the shift lever at a smaller distance from the pivot and the bottom end of the shift lever is connected to the pinion which is at a larger distance from the pivot. A non-magnetic material plate is arranged at the centre of the outer sleeve which carries the magnetic material plate. A second electromagnetic coil is placed in a bobbin which is arranged in axial direction to the outer sleeve, wherein the second electromagnetic coil is arranged between the magnetic material plate and the core plate. A movable contact assembly is integrated with a second plunger such that it is arranged in an inner circumference of the second electromagnetic coil. The movable contact assembly moves in axial direction of the second plunger along with the second electromagnetic coil. Further, the fixed core plate is arranged after the second electromagnetic coil in axial direction to the outer sleeve and a terminal base, which carries fixed contact terminals is arranged rigidly to the outer sleeve in axial direction.
[0016] According to preceding embodiments of the invention, the said shift lever arrangement accelerates pinion movement at a fast rate and the plungers move away from the non-magnetic plate. The shift lever ratio is higher because of pivoting the lever at the top, the plunger air gap required for pinion movement is small. The pinion movement and contact assembly have independent operations.
[0017] The invented electromagnetic switching apparatus uses a shift lever, wherein the top end of the shift lever is pivoted to the starter motor. Hence, the pinion movement accelerates at a fast rate. In the present invention, since the shift lever ratio is high, the plunger air gap required for pinion movement is small.Both the pinion movement and contact closure operate independently in the present invention, therefore the engine may be switched ON based on the request of the driver for movement of the vehicle.
[0018] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
[0019] Brief description of the drawings:
[0020] The foregoing and other features of embodiments will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
[0021] Figure 1 shows a cross sectional view of the electromagnetic switch, according to one embodiment of the invention.
[0022] Figure 2 shows a cross sectional view of the arrangement of electromagnetic switch with starting motor via shift lever, according to one embodiment of the invention.
[0023] Figure 3 shows a circuit diagram of the electromagnetic switch, according to one embodiment of the invention.
[0024] Figure 4 shows a perspective view of the shift lever, according to one embodiment of the invention.
[0025] Figure 5 shows a perspective view of the arrangement of electromagnetic switch with starting motor via shift lever, according to one embodiment of the invention.
[0026] Figure 6 shows the front view of the arrangement of electromagnetic switch with starting motor via shift lever, according to one embodiment of the invention.
[0027] Detailed description of the invention:
[0028] Reference will now be made in detail to the description of the present subject matter, one or more examples of which are shown in figures. Each embodiment is provided to explain the subject matter and not a limitation. These embodiments are described in sufficient detail to enable a person skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, physical, and other changes may be made within the scope of the embodiments. The following detailed description is, therefore, not be taken as limiting the scope of the invention, but instead the invention is to be defined by the appended claims.
[0029] The term “Shift lever ratio” as claimed in the embodiments refers to the ratio of the distance between the pivot and the pinion to the distance between the operating rod and the pivot.
[0030] The present invention provides an apparatus for electromagnetic switching in a starter motor. The present invention comprises of an outer sleeve which carries two separate coils, wherein each coil carries a plunger in axial direction. A non-magnetic material plate is arranged at the center of the outer sleeve. The second plunger carries a moving contact, wherein the spindle is integrated into the second plunger. An operating rod is connected to the shift lever at one end and the first plunger is connected to the other end of the operating rod. The other end of the shift lever is connected to the pinion. A core plate is placed at both the ends of the sleeve, wherein the plungers move away from the non-magnetic plate. A terminal base is placed at the end of the outer sleeve which carries the fixed contact.
[0031] The present invention has a separate contact closure movement and pinion movement operating independently for the starting the engine. The contact closure movement and pinion movement is coupled by a shift lever arrangement such that the pinion action is fast. The single winding coil is used for the operation of pinion movement and contact closure. Also, the plunger has small air gap for pinion movement.
[0032] Figure 1 shows a cross sectional view of the electromagnetic switch, according to one embodiment of the invention. The electromagnetic switch (100) comprises ofan outer sleeve (501) fixed firmly to a starter motor frame (203), which is rigidly fixed to the engine. The outer sleeve (501) is closed at one end which forms a fixed core plate (104) for the first plunger (108). A first electromagnetic coil (103) is arranged in a first bobbin (117) which is further arranged in axial direction to the outer sleeve (501). Magnetic material plates ((102 a) and (102 b)) are arranged such that the magnetic material plate (102 a) is attached to the second bobbin (116) and the magnetic material plate (102 b) is attached to the first bobbin (117). The first plunger (108) is arranged in an inner circumference of the first electromagnetic coil (103), which moves in axial direction towards the second fixed core plate (104). The first plunger (108) and the second plunger (110) move away from the fixed non-magnetic plate (109).
[0033] Further, the top end of a shift lever (201) is pivoted at the top of the starter motor frame (203), wherein the operating rod (105) is connected to the shift lever (201) at a smaller distance from the pivot and the bottom end of the shift lever (201) is connected to the pinion (202) which is at a larger distance from the pivot as shown in FIGURE 2. Due to the larger distance, the shift lever (201) tends to accelerate the pinion with greater speed. Also, the plunger air gap required for pinion movement is small.
[0034] A non-magnetic material plate (109) is arranged at the centre of the outer sleeve (501) which carries the magnetic material plate ((102 a) and (102 b)). A second electromagnetic coil (114) is placed in a second bobbin (116) which is arranged in axial direction to the outer sleeve (501), wherein the second electromagnetic coil (114) is arranged between the magnetic material plate (102 a) and the first core plate (111). A movable contact assembly (113) is integrated with a second plunger (110) such that it is arranged in an inner circumference of the second electromagnetic coil (114). The movable contact assembly (113) moves in axial direction of the second electromagnetic coil (114). Further, the first fixed core plate (111) is arranged after the second electromagnetic coil (114) in axial direction to the outer sleeve (501) and a terminal base which carries fixed contact terminals (112) is arranged rigidly to the outer sleeve (501) in axial direction.
[0035] A single winding coil is used for pinion movement operation and contact closure operation.
[0036] Figure 2 shows a cross sectional view of the electromagnetic switch associated with starting motor via shift lever, according to one embodiment of the invention. The outer sleeve (501) of the electromagnetic switch (100) is firmly fixed to a starter motor frame (203), wherein the starter motor frame (203) is rigidly fixed to the engine as shown in FIGURE 2.
[0037] Figure 3 shows a circuit diagram of the electromagnetic switch, according to one embodiment of the invention. When the starter switch is energized, the second plunger (110) is moved away from the fixed non-magnetic plate (109) via a spindle (115). The other end of the first plunger (108) engages with the operating rod (105), wherein the operating rod (105) is connected to the shift lever (201). The operating rod (105) is engaged with the first plunger (108) through an engagement spring (107). The top end of the shift lever (201) is pivoted at the top of the starter motor frame (203), wherein the operating rod (105) is connected to the shift lever (201) at a smaller distance from the pivot and the bottom end of the shift lever (201) is connected to the pinion (202) which is at a larger distance from the pivot. This arrangement of the shift lever enables the shift lever to accelerate at a great speed and increases the speed of the pinion movement.
[0038] Figure 4 shows a perspective view of the shift lever, according to one embodiment of the invention. The top end of the shift lever (201) is pivoted at the top of the starter motor frame (203), wherein the operating rod (105) is connected to the shift lever (201) at a smaller distance from the pivot and the bottom end of the shift lever (201) is connected to the pinion (202) which is at a larger distance from the pivot. Hence, the plunger air gap required for achieving high speeds of pinion movement is small.
[0039] Figure 5 shows a perspective view of the arrangement of electromagnetic switch with starting motor via shift lever, according to one embodiment of the invention. The electromagnetic switch (100) is firmly fixed to a starter motor frame (203), wherein the starter motor frame (203) is rigidly fixed to the engine.
[0040] Figure 6 shows the front view of the arrangement of electromagnetic switch with starting motor via shift lever, according to one embodiment of the invention.
[0041] The invented electromagnetic switching apparatus uses a shift lever, wherein the top end of the shift lever is pivoted to the starter motor, hence the pinion movement is accelerated at a fast rate. In the present invention, since the shift lever ratio is higher, the plunger air gap for pinion movement is small. Both, the pinion movement and contact closure operate independently in the present invention, therefore the engine is switched ON based on the driver’s request for the movement of the vehicle.
[0042] It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed