DE102017215233A1 - NTC component for installation in the electrical circuit of an electrical unit - Google Patents

Abstract

An NTC component has a housing with a connection element, on whose protruding from the housing section a cable lug is positively supported.

Description

The invention relates to an NTC component (negative temperature coefficient) for installation in the circuit of an electrical unit, for example an electrical unit in a starting device for an internal combustion engine.

State of the art

In the DE 41 06 247 C1 a starter motor with a starter motor and a starter relay for transferring a starter pinion between a disengaged position and an engagement position with a ring gear of an internal combustion engine is described. After reaching the engaged position, the starter pinion is driven by the electric starter motor. For a temperature-independent function, the exciter winding of the starter relay is connected in series with a parallel circuit consisting of an NTC resistor (negative temperature coefficient) and an ohmic resistor. The NTC resistor conducts the electrical current better at high temperatures than at low temperatures and thereby limits the relay current, which is increased at low temperatures due to a positive temperature coefficient (PTC) behavior of the relay winding. The concomitant increased pull-in force, which acts on the starter pinion, can be compensated via the NTC resistance element.

Other starting devices with an NTC resistor element in the circuit of an electrical unit are from DE 41 22 252 A1 . DE 103 17 466 A1 . DE 10 2007 036 789 A1 and DE 2012 215 338 A1 known.

Disclosure of the invention

The NTC component (negative temperature coefficient) according to the invention can be used for installation in the circuit of an electrical unit, for example in the circuit of an electrical unit in a starting device, which is used to start internal combustion engines. Such a starting device has a starter pinion and an electromagnetic starter relay, which transfers the starter pinion between a disengaged position and an engagement position with a ring gear of the internal combustion engine. To drive the starter pinion in the engaged position is an electric starter motor. In the circuit of an electrical unit of the starting device - preferably the electric starter motor, optionally additionally or alternatively, the starter pinion - can be arranged NTC component that conducts the electric current better at high temperatures than at low temperatures. The NTC component limits in particular at the beginning of the starting phase, the short-circuit current, whereby a voltage drop in the electrical system of the vehicle is prevented or at least mitigated. Also, a higher electrical conductivity at low temperatures in the starter motor or in the starter relay can be partially or completely compensated by the NTC component and increased wear can be avoided.

The NTC component has a housing and two connection elements for the electrical connection to the circuit, wherein between the connection elements within the housing there is an NTC resistance element through which the electric current flows. At least one of the connection elements protrudes from the housing, this connection element is associated with a cable lug, which is connectable to an electrical connection cable or a strand of the circuit. The cable lug is connected to close the circuit with the associated connection element of the NTC component. The cable lug can be seen as part of the NTC component or as a separate component, which, however, can be brought into electrical connection with the protruding from the housing connecting element.

During the connection of the cable lug with the associated connection element of the NTC component, reaction forces act on the NTC component. In order to prevent such reaction forces from leading to damage to the NTC component, a form-fitting part is arranged on the connection element and / or on the cable lug, which serves for positive support of the cable lug on the connection element, in particular during the connection process. This makes it possible, for example, to screw the cable lug on the connection element, wherein the reaction forces arising during the screwing are transmitted via the form-fitting part between the lug and connection element. This ensures, in particular, that the housing of the NTC component is not directly loaded with such reaction forces which occur during the connection process between the cable lug and the connection element. Rather, a reaction force transfer takes place directly between the cable lug and the connection element.

According to an advantageous embodiment, the form-fitting part is located on the connection element. The form-fitting part is arranged, in particular, on the section of the connection element protruding from the housing of the NTC component. Alternatively, it is also possible that the connection part is located on the cable lug. In both cases, a positive support between the protruding connecting element and the cable lug, in particular in a rotary connection between the lug and Connection element reached. According to yet another advantageous embodiment, each a form-fitting part is arranged both on the connection element and on the cable lug, wherein the form-fitting parts reach during the connection process of cable lug and connection element in positive support either together or on each other component.

The form-fitting part is designed, in particular, as a component which protrudes beyond the outer contour of the connection element and / or the cable lug and which is firmly connected to the connection element or the cable lug without possibility of relative movement.

The form-fitting part may optionally be formed integrally with the connection element or the cable lug. It is for example possible to bring the connection element or the cable lug by forming into a shape in which the form-fitting part is formed and projects beyond adjacent wall sections of the connection element or the cable lug. The forming takes place for example by embossing, bending or deep drawing.

As an alternative to a one-piece design of the form-fitting part and connection element or cable lug, an embodiment of the form-fitting part is also considered as a separate component, which, however, is firmly connected to the connection element or the cable lug, for example by gluing, soldering, welding or by further connection measures such as, for example Screw in or clipping.

According to a further expedient embodiment, a connection opening is introduced into the connecting element, which serves for establishing the connection with the cable lug. In the connection opening, an internal thread may be introduced, in which a screw can be screwed, wherein the screw may optionally be guided by a further opening which is introduced into the cable lug. In this way, the cable lug can be screwed to the connection element. During screwing in of the screw, a moment acts on the cable lug, which acts on the cable lug in the screwing direction of the screw. About the form-fitting part of the cable lug enters a stop position on the connection element and prevents relative rotation of the cable lug during screwing.

The form-fitting part is arranged, for example, on the connection element next to the connection opening or additionally or alternatively on the corresponding connection opening which is introduced into the cable lug. It is sufficient in principle that only one of the connection openings - either in the connection element or in the cable lug - is provided with an internal thread into which the connecting screw can be screwed. Optionally, both connection openings each have an internal thread.

The connection is made by coinciding the connection openings in the connection element and in the cable lug and inserting a connection component, such as a screw, through the connection openings.

The form-fitting part is located on at least one connection element of the NTC component or the associated cable lug. It is sufficient in this case that only one connection element protrudes beyond the housing of the NTC component, whereas the second connection element is located exclusively within the housing and has, for example, an insertion opening. In a further embodiment, on the other hand, it is provided that both connection elements protrude beyond the housing; In this case, it is expedient that the two connection elements run parallel to one another. According to a further expedient embodiment, which relates to two protruding from the housing connecting elements, only one of the connecting elements on a form-fitting part on or cooperates with a positive locking element on the associated cable lug. Alternatively, it is also possible that in each case a form-fitting part is arranged on both connection elements in the section projecting beyond the housing or cooperates with a form-fitting part on a cable lug.

• 1 einen Schnitt längs durch eine Startvorrichtung für eine Brennkraftmaschine, wobei im Stromkreis eines elektrischen Startermotors ein NTC-Bauteil angeordnet ist,
• 2 einen Schnitt durch das NTC-Bauteil,
• 3 einen Kabelschuh, der einem Anschlusselement des NTC-Bauteils zugeordnet ist,
• 4 ein Kabelschuh in einer weiteren Ausführung.

Further advantages and expedient embodiments can be taken from the further claims, the description of the figures and the drawings. Show it:

• 1 a section longitudinally through a starting device for an internal combustion engine, wherein in the circuit of an electric starter motor, an NTC component is arranged,
• 2 a section through the NTC component,
• 3 a cable lug, which is associated with a connection element of the NTC component,
• 4 a cable lug in another embodiment.

In the figures, the same components are provided with the same reference numerals.

The starting device 1 is used to start internal combustion engines and has in a shield forming a housing 2 an electric starter motor 3 on, a gearbox 4 , which is designed as a planetary gear, a drive shaft 5 , an overrunning clutch 6 as well as a starter pinion 7 to be adjusted axially between a retracted disengagement position and an advanced engagement position (shown in phantom) in which the starter pinion 7 in engagement with a sprocket 23 the internal combustion engine is stationary. The axial adjustment movement of the starter pinion 7 is using an electromagnetic starter relay 8th carried out on the bearing plate of the starting device 1 is held or flanged.

The starter motor 3 is in the embodiment as a permanent-magnet DC motor with permanent magnets on the inside of the motor or Polgehäuses 10 executed. The starter motor 3 has an anchor 11 with a rotating armature shaft 12 on, one on the armature shaft 12 seated anchor package 13 with currentable windings and a commutation device 30 with a collector 14 for power transmission and application to the windings of the anchor packet 13 ,

The planetary gear 4 is from the armature shaft 12 the starter motor 3 driven and has a housing fixed held ring gear 15 with internal toothing, planet gears 17 on a planet carrier 18 as well as a central sun wheel 19 on. The gear parts are in a gear housing component 16 added. The sun wheel 19 sits on the front side of the armature shaft 12 on and is non-rotatable with the armature shaft 12 connected. The sun wheel 19 meshes with the planet wheels 17 at the same time on the toothed inside of the ring gear 15 roll. The planet wheels 17 are rotatable on shafts on the planet carrier 18 mounted, the rotationally fixed to the drive shaft 5 connected on which the starter pinion 7 seated. In this way, the drive movement of the armature shaft 12 the starter motor 3 over the planetary gear 4 in a rotational movement of the drive shaft 5 implemented. The gear 4 has the function of a reduction gear.

The overrunning clutch 6 includes a driver 20 and sits on the drive shaft 5 on. The driver 20 is over a steep thread 21 with the drive shaft 5 coupled. To overrunning clutch 6 further includes a pinion shaft 22 , which are integral with the starter pinion 7 trained and with the driver 20 is rotationally coupled via rolling elements. The overrunning clutch 6 allows a torque transmission in the rotational or drive direction of the starter motor, whereas in the opposite direction no movement or torque transmission is possible. This ensures that after starting the internal combustion engine in a overhaul of the ring gear relative to the starter pinion damage to the starter motor is avoided.

The axial adjustment movement of the starter pinion 7 is activated by an actuation of the electromagnetic starter relay 8th generated, which has an axially adjustable lifting armature 24 which has a fork lever 25 with the driver 20 is coupled. When the starter relay is actuated 8th becomes the lifting anchor 24 axially adjusted, this adjusting movement is via the fork lever 25 in an axial deflection movement of driver 20 and starter pinion 7 implemented. Due to the coupling of the driver 20 over the coarse thread 21 with the drive shaft 5 leads in the axial feed movement, the overrunning clutch 6 including starter pinion 7 a rotational movement, which facilitates the meshing in the sprocket in a tooth-on-tooth position.

Once the starter pinion 7 has reached its axially advanced engagement position with the ring gear, the electric starter motor 3 started and the rotational movement of the armature shaft 12 on the starter pinion 7 transfer.

The starting device 1 is trained free ejecting. The drive shaft 5 is in the area of its free end face in the housing or end shield 2 taken in an open recess and there in a warehouse 26 rotatably mounted. Axially adjacent to the bearing 26 located on the inside of the bearing plate 2 a stop ring 27 on the drive shaft 5 that is axially fixed to the drive shaft 5 connected is. The drive shaft 5 has for this purpose a circumferential groove into which the stop ring 27 or a stop ring 27 supporting circlip is inserted.

The windings in the anchor package 13 be via the commutation device 30 energized. In the circuit in which the commutation device 30 is arranged, lies an electrical connection cable 28 which is electrically connected to a negative temperature coefficient (NTC) member 29. The circuit of the commutation device 30 is from the electric starter relay 8th upon deflection of a lifting armature of the starter relay 8th closed. The NTC component 29 in the circuit of the commutation device 30 of the electric starter motor 3 conducts at high temperatures the electric current better than at low temperatures and thereby compensates for a reverse behavior of the electric starter motor, so that over a wider temperature range, a balanced behavior of the starter motor is achieved. The commutation device 30 includes the collector 14 , which rotates with the armature shaft 12 the starter motor 3 is connected, and in brush guides adjustably mounted brushes that are in the circuit.

If necessary, an NTC component can also be incorporated in the circuit of the starter relay 8th be integrated.

In 2 is a sectional view of the NTC component 29 shown. The NTC component 29 includes a casing 31 and two electrically conductive connection elements 32 and 33 , which has one between the connecting elements 32 . 33 arranged NTC resistance element 34 are electrically connected. The NTC resistor element 34 is completely inside the case 31 of the NTC component 29 , The two connection elements 32 and 33 are used to connect to electrical connection cables and run parallel to each other and each protrude with a portion of the housing 31 out.

In the out of the case 31 protruding section of the connecting element 32 is a connection opening 35 introduced, which is advantageously provided with an internal thread. The connection opening 35 can completely through the connection element 32 extend therethrough or optionally be designed as a blind hole. Next to the connection opening 35 located on the outside of the connection element 32 a form-fitting part 36 , Both the connection opening 35 as the form-fitting part 36 lie outside the housing 31 ,

The further connection element 33 has neither a connection opening nor a form-fitting part. Optionally, but also this connection element according to a connection opening and / or a form-fitting part in which from the housing 31 outstanding section be provided.

In 3 is a cable lug 37 represented, to which the electrical connection cable 28 is welded. Also in the cable lug 37 is a connection opening 38 introduced, which, however, has no internal thread. The electrical connection cable 28 is at a distance from the connection opening 38 on the cable lug 37 attached.

To make a firm connection between the cable lug 37 and the connection element 32 make the connection openings 35 in the connection element 32 and 38 in the cable lug 37 brought into coincidence and is a screw through the connection opening 38 inserted and with the internal thread in the connection opening 35 screwed. The form-fitting part 36 at the connection element 32 Make sure the cable lug 37 during the Verschraubungsvorganges only up to a positive engagement with the form-fitting part 36 can be pivoted and unintentional support of the cable lug 37 on the housing 31 is avoided. Accordingly, the housing 31 of immediate support forces from the cable lug 37 go out, relieved.

In 4 is a variant of a cable lug 37 shown in which a form-fitting part 39 is arranged on the cable lug, wherein the form-fitting part 39 next to the connection opening 38 located. The form-fitting part 39 comes the same function as the form-fitting part 36 on the outside of the connection element 32 It should, during the connection and screwing process of the cable lug 37 at the connection element 32 only a positive support between the cable lug and connecting element and a support of the cable lug 37 on the housing 31 be prevented. The form-fitting part 39 on the cable lug 37 is either additional or alternative to the form-fitting part 36 at the connection element 32 arranged.

The mold parts 36 at the connection element 32 and 39 on the cable lug 37 are either formed as separate components, with the connection element 32 or the cable lug 37 be connected, or formed integrally with the respective component. In the latter case, the form-fitting part by forming the connection element 32 or the cable lug 37 be produced, for example by embossing, bending or deep drawing.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4106247 C1 [0002]
• DE 4122252 A1 [0003]
• DE 10317466 A1 [0003]
• DE 102007036789 A1 [0003]
• DE 2012215338 A1 [0003]

Claims (10)

NTC component (negative temperature coefficient) for installation in the circuit of an electrical unit, characterized in that the NTC component (29) has a housing (31) and two connection elements (32, 33), of which at least one connection element (32 ) protrude from the housing (31) and which are electrically connected via an NTC resistor element (34), wherein at least one out of the housing (31) protruding connecting element (32) of the NTC component (29) a cable lug (37), the with the connection element (32) outside the housing (31) of the NTC component (29) and / or on the cable lug (37) a form-fitting part (36, 39) for positive support of the cable lug (37) is arranged on the connecting element (32). NTC component after Claim 1 , characterized in that in the connecting element (32) has a connection opening (35) for connection to the cable lug (37) is introduced. NTC component after Claim 2 , characterized in that the connection opening (35) is provided with an internal thread. NTC component after Claim 2 or 3 , characterized in that the form-fitting part (36) is arranged on the connection element (32) next to the connection opening (35). NTC component after one of Claims 1 to 4 , characterized in that in the cable lug (37) has a connection opening (38) for connection to the connection element (32) is introduced. NTC component after one of Claims 2 to 4 and 5 , characterized in that for connecting the cable lug (37) with the connecting element (32), the connecting openings (35, 38) are in overlap and a connecting member through the connecting openings (35, 38) can be plugged. NTC component after one of Claims 1 to 6 , characterized in that both connection elements (32, 33) protrude from the housing (31). Starting device for an internal combustion engine, comprising a starter pinion (7) and a starter relay (8) for transferring the starter pinion (7) between a disengaged position and an engaged position in which the starter pinion (7) is engaged with a ring gear (23) of the internal combustion engine, with an electric starter motor (3) for driving the starter pinion (7) and with an NTC component (29) according to one of Claims 1 to 7 in the circuit of an electrical unit of the starting device (1). Starting device after Claim 8 , characterized in that the NTC component (29) in the circuit of the starter motor (3) of the starting device (1) is arranged. Starting device after Claim 8 or 9 , characterized in that the NTC component (29) in the circuit of the starter relay (8) of the starting device (1) is arranged.

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