DE102017208377A1 - Pump unit, in particular for controlling a brake pressure in an electronic slip-controllable vehicle brake system - Google Patents

Abstract

The invention relates to a pump unit (10), in particular for controlling a brake pressure in an electronically slip-controllable vehicle brake system. Known pump units (10) are provided with a housing block (12), a drive motor (16) for actuating a pressure generator (26), an electronic control unit (10). 20) for controlling the drive motor (16) and a contact element (44) which contacts the drive motor (16) with the electronic control unit (20). The contact element (44) is passed through a leadthrough (42) of the housing block (12) and has a spring contact (46) enclosed by an insulator (48). According to the invention, the insulator (48) of the contact element (44) is divided into sections (54 , 56), which extend in the axial direction of the contact element (44). A first section (54) has a circumferentially constant wall cross section and a second section (56) projects circumferentially radially relative to an outer contour of this first section (54). The protruding second section (56) of the insulator forms peripherally with an inner wall of the bushing (54). 42) from a gap filter, which prevents passage of particles from a determinable particle size from one end to the second end of the passage (42).

Description

State of the art

The invention relates to a pump unit, in particular for controlling a brake pressure in an electronically slip-controllable vehicle brake system according to the features of the preamble of claim 1.

Such a pump unit is for example from the DE 199 49 221 A1 already known. This known pump unit has a housing block with a pressure generator arranged thereon. The latter is actuated by a drive motor, which is attached to the housing block. In addition, an electronic control unit is anchored to the housing block, which in turn determines the control of the drive motor. Control unit and drive motor are contacted by contact elements electrically to each other. These contact elements each comprise a rigid, rigid spring contact made of electrically conductive material and a spring contact enclosing insulator. Since the drive motor and the control unit are arranged on opposite sides of the housing block, the contact elements are passed through passages of the housing block. For manufacturing or assembly reasons, there is a gap between the contact elements and a wall which determines the cross section of the associated bushing. Disadvantageously, particles can potentially penetrate into the electronic control unit through this gap and possibly cause disturbances there.

In the cited prior art, the insulator on Spreizzungen, which are spread apart by introduction of the spring contact and ensure a play-free contact of the contact element in the implementation. By means of the expansion tongues, positional tolerances of the contact element within the bushing can be reduced, thereby improving the mechanical contactability of the contact element with the electronic control unit. However, a possible transfer of particles, in particular of particles of relatively large dimensions, from the motor side into the electronic control unit can not be reliably prevented by a contact element designed in this way.

Since a minimum distance to the nearest conductive material of at least 1 mm is prescribed for non-isolated areas of the contact element, particles penetrating into the electronic control unit of a particle size greater than 1 mm can cause damage, for example an electrical short circuit. To prevent this, there is the cleanliness requirement in the production of the pump unit or the drive motor is to cause no impurities greater than 1mm or eliminate inevitable impurities of this magnitude during the assembly. The fulfillment of this requirement thus determines the applicable manufacturing methods or causes additional cleaning costs.

Disclosure of the invention

A pump unit according to the features of independent claim 1 has the advantage that, by means of a further developed contact element, the bushing in the housing block is mechanically blocked against the passage of particles of a definable particle size. Since larger particles can no longer pass through the implementation, a relaxation of cleanliness requirements in the processing and assembly of the drive motor and the pump housing is possible, which ultimately affects a possible reduction in manufacturing costs.

According to the invention, the insulator of a contact element has a first section with circumferentially constant wall thickness and can therefore be injection-molded inexpensively attached to the spring contact. In addition, the insulator has a second section, which protrudes circumferentially radially with respect to an outer contour of the first section. The radially projecting second section is circumferentially matched to a contour of the wall surrounding the implementation and forms a particle filter impermeable to particles of a certain size.

Further advantages or advantageous developments of the invention will become apparent from the dependent claims and from the following description.

Particularly simple and inexpensive, the second portion of the insulator can be displayed, if it is shaped plate-shaped and with a circular outer contour. A circular outer contour is particularly easy to tune to a usually also circular inner contour of the implementation.

The fact that the extent of the second portion in the axial direction of the contact element is smaller than the axial extent of the first portion of the contact element, the circumferentially variable wall thickness of the insulator in the region of the second portion does not adversely affect an injection molding connection of the insulator to the spring contact and Moreover, it does not hinder a non-coaxial introduction of the contact element into the passage of the pump housing. The gap between the contact element and the inner wall of the implementation is sufficient to keep inadmissible large chips away from the electronic control unit and to install a represent mechanically stress-free contacting of the drive motor with the electronic control unit. The contact element is also free of any lateral forces in the implementation can be arranged and the drive motor or the electronic control unit are centered on each other or with respect to the pump housing anchored to the pump housing.

Preferably, the first portion and the second portion of the insulator are formed in one piece and can thereby be mounted together in one operation on the spring contact. This attachment is particularly efficient by insert molding of the spring contact with the material of the insulator feasible.

The formation of two opposing flats on the first portion of the insulator helps ensure that the insulator in the region of its first portion with circumferentially constant wall thickness can be displayed and thereby favors the described injection molding training of the insulator on the spring contact. In addition, the two flats form the handling of the contact element in the production facilitating gripping and clamping surfaces.

In an advantageous embodiment of the insulator is designed with two end portions and a second portion arranged therebetween, because thereby the second portion with the mounting of the contact element in the interior of the implementation is stationary placeable.

list of figures

An embodiment of the invention is illustrated in the drawing and will be explained in detail in the following description.

• 1 ein der Erfindung zugrundeliegendes Pumpenaggregat im Längsschnitt;
• 2 ein mit einem Lippendichtelement versehenes Kontaktelement in perspektivischer Darstellung;
• 3 ein erfindungsgemäßes Kontaktelement in der Draufsicht;
• 4 ein erfindungsgemäßes Kontaktelement im eingebauten Zustand.

Shown is in

• 1 a pump unit on which the invention is based, in longitudinal section;
• 2 a provided with a lip sealing element contact element in a perspective view;
• 3 an inventive contact element in plan view;
• 4 an inventive contact element in the installed state.

Description of the invention

That in the 1 illustrated pump unit 10 consists of a total of three main components, a centrally or centrally arranged housing block 12 , one on a first side surface 14 this housing block 12 attached drive motor 16 and one on a second side surface 18 arranged electronic control unit 20 , The side surfaces 14 . 18 of the housing block 12 are aligned plane-parallel to each other and face each other. The housing block 12 is with a continuous recess 22 provided in which a cylinder 24 a pressure generator 26 is included. Inside the cylinder 24 is a plunger 28 arranged axially displaceable. An actuation of the plunger 28 done by the drive motor 16 , which from the electronic control unit 20 is controllable. With a drive of the drive motor 16 becomes a drive shaft 30 imposed a rotational movement, which via a drive motor 16 Subordinate planetary gear 32 to a ball screw 34 is forwarded. At a conversion of the rotational movement in an axial movement of the ball screw 34 with a rotatably driven spindle nut 36 as well as with one inside the spindle nut 36 mounted axially movable and on the plunger 28 acting threaded spindle 38 fitted. Between an end face of the plunger and a closed end of the cylinder 24 is one to the control unit 20 closed working space 40 of the pressure generator 26 educated. Depending on its direction of movement, the plunger moves 28 in this workroom 40 while decreasing its volume or it extends and increases the volume. Accordingly, with the movement of the plunger takes place 28 in the workroom 40 a pressure build-up or a pressure build-up instead.

In the housing block 12 is at least one implementation 42 provided, which extends from the first side surface 14 with the attached drive motor 16 to the opposite second side surface 18 with attached electronic control unit 20 extends. This implementation 42 is preferably designed as a straight bore with a circular cross section and extends perpendicular to the two side surfaces 14 . 18 of the housing block 12 , Inside this implementation 42 is a contact element 44 arranged, which the drive motor 16 with the electronic control unit 20 contacted. This contact element 44 consists of a rigid, rigid spring contact 46 made of electrically conductive material and from a spring contact this 46 enclosing insulator 48 , The latter is preferably made of an electrically non-conductive plastic material and in an injection molding on the spring contact 46 appropriate. Only the two outer ends of the contact element 44 are not for the formation of contact surfaces of the material of the insulator 48 molded. The contact element 44 is usually fixed to the drive motor 16 connected and faces one, the first side surface 14 of the housing block 12 facing bearing plate 50 this drive motor 16 axially forward. In the course of an attachment of the drive motor 16 at the first side surface 14 of the housing block 12 an introduction of the contact element 44 in the assigned implementation 42 To facilitate, exists circumferentially between the insulator 48 of the contact element 44 and one the implementation 42 delimiting wall a circumferential gap 52 , This circumferential gap 52 allows part or manufacturing tolerances in the mounted state of the drive motor 16 compensate or permitted under operating conditions relative movements of the contact element 44 opposite the housing block 12 , Due to the circumferential gap 52 However, there is also an open connection between the drive motor 16 and the electronic control unit 20 , through which particles in the electronic control unit 20 penetrate and cause possible malfunctions there. To exclude this potential source of interference is an insulator of the contact element 44 in sections 54 . 56 divided. A first section 54 of the insulator 48 is characterized by a circumferentially constant wall thickness and allows the insulator 48 Inexpensive injection molding technology on the spring contact 46 of the contact element 44 can be trained. A second section 56 of the insulator 48 In contrast, it is designed with a cross-section which is opposite to an outer contour of the first section 54 circumferentially protrudes radially. This radially projecting second section 56 of the insulator 48 is in its external dimensions on the implementation 42 bounding wall adjusted so that the gap between the two components 52 reduced to a determinable gap size. The second section 56 of the insulator 48 forms together with a wall of carrying out 42 a split filter, which is a passage of particles of a certain particle size from the one side of the housing block 12 , on which, for example, the drive motor 16 attached to the opposite side, on which, for example, the electronic control unit 20 is attached, prevented.

2 shows such a configured contact element 44 as an individual part in perspective view. It consists, as already explained, of the rigid spring contact 46 and from a spring contact 46 enclosing insulator 48 , The two ends of the spring contact 46 are for the formation of contact surfaces 58 not from the insulator 48 includes. The spring contact 46 is exemplified in the form of a flat, once rectangular stepped sheet metal strip made of electrically conductive material. This metal strip can for example be cut out inexpensively from a circuit board, for example. By sawing, punching or laser cutting and then bent. After the mechanical shaping is the spring contact 46 for the formation of the insulator 48 overmoulded with a non-conductive plastic material. This encapsulation extends, apart from production-related recesses, along the entire circumference of the spring contact 46 and is divided in the direction of the longitudinal axis of the contact element 44 into several sections 54 . 56 , According to the invention has a first section 54 of the insulator 48 a least approximately rectangular outer contour with two opposing flat and narrow sides. The first paragraph 54 has circumferentially a largely constant wall thickness, which is the injection molding attachment of the insulator 48 at the spring contact 46 favored. The narrow sides can be flat or curved, while the flat sides opposite flats 60 form around the machine handling, in particular a gripping and an alignment of the contact element 44 in the room during its manufacture and assembly easier.

A in the axial direction of the contact element 44 to the first section 54 subsequent second section 56 of the insulator 48 In contrast, has a circular outer contour and faces the outer contour of the first section 54 circumferentially radially over. The second section 56 has the shape of a plate and has a smaller by a multiple multiple smaller extent in the axial direction of the contact element 44 on, as the first section 54 , This affects the second section 56 the introduction of the contact element 44 in a planned implementation 42 of the housing block 12 Not. The second section 56 closes in the axial direction, a third section 62 which, for example, according to the first section 54 shaped and dimensioned. All sections 54 . 56 . 62 of the insulator 48 are exemplary in one piece and made of a uniform material. This preparation can therefore be made in a single operation, wherein the dimensions of the respective sections by an injection mold used therein 54 . 56 . 62 can be specified or maintained.

3 shows the illustrated contact element 44 again as an item in top view. At the center of this view is the strip-shaped spring contact 46 of which in this view the cross section can be seen. At the latter is the first section 54 of the insulator 48 molded with its rectangular outer contour. The opposite flats 60 in the area of the first section 54 are easy to recognize. In the drawing plane behind the first section 54 is the second section 56 of the insulator 48 , This is, as mentioned, plate-shaped and has a circular, circumferentially radially opposite to the outer contour of the first section 54 protruding outer contour. The third section 62 of the insulator 48 is not visible in this view because its cross section is from the second section 56 is covered.

4 shows the installation situation of the contact element 44 in an enlarged perspective View. It is assumed that in 4 down the drive motor 16 is located while a not drawn electronic control unit 20 in 4 is arranged above. Shown is also a portion of the housing block 12 with two contact elements formed thereon 44 receiving bushings 42 ; in the background is a part of the cylinder 24 of the housing block 12 arranged pressure generator 26 recognizable. One of the bushings 42 is cut longitudinally, so that one receives the contact element received therein 44 able to see. From the contact element 44 is the strip-shaped spring contact designated 46 and the spring contact this 46 enclosing insulator with 48. The insulator 48 in turn is divided into a first, in the 4 down-facing section 54 and the axially adjoining, overhead second section 56 , An adjoining third section 62 is no longer recognizable due to the drawing section. Between the circular outer contour of the second section 56 , in the 4 only half of its size is drawn and the implementation 42 surrounding wall is the gap 52 , the gap size by tuning the outer diameter of the second section 56 of the insulator 48 on the inner diameter of the bushing 42 is set application-specific. One in the area of the second section 56 of the contact element 44 trained gap filter prevents passage of particles whose dimensions are greater than the gap dimension of one end of the implementation 42 to the opposite second end.

For example, if the gap is 1mm, production-related particles larger than 1mm may no longer be in the electronic controller 20 penetrate and cause damage there and accordingly lower the cleanliness requirements in the manufacture and assembly of the pump set 10 fail. Reduced cleanliness requirements allow the use of less expensive manufacturing methods and / or reduce any costs incurred for parts cleaning or quality control. Both ultimately affect lower production costs while increasing the robustness of the pump units produced 10 out.

Not shown in the figures, but in principle it would be conceivable, the second section 56 of the insulator 48 perform in the form of a separate annular component, the non-positive and / or positive fit on the molded first portion 54 of the insulator 48 is attached, for example, postponed and anchored by a clip attachment. Such a solution would be cost-effective, although it would require an additional assembly operation.

Of course, further changes or additions to the described embodiment are conceivable without departing from the spirit of the invention.

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 19949221 A1 [0002]

Claims (9)

Pump unit (10), in particular for controlling a brake pressure in an electronically slip-controllable vehicle brake system, comprising a housing block (12) having a pressure generator (26), a drive motor (16) arranged on the housing block (12), for actuating the pressure generator (26), an electronic control unit (20), for driving the drive motor (16) and one, an electrically conductive spring contact (46) and a spring contact (46) partially enclosing insulator (48) having contact element (44) via which the drive motor (16) with the control unit (20) is contacted, wherein the contact element (44) in a passage (42) of the housing block (12) is arranged, characterized in that the insulator (48) in a first portion (54) and in a second portion (56) is articulated, wherein the second portion (56) has a circumferentially with respect to an outer contour of the first portion (54) radially projecting cross-section t. Pump unit after Claim 1 , characterized in that on the first portion (54) of the insulator (48) has two opposite flattenings (60) are formed and that the second portion (56) of the insulator (48) is plate-shaped with a circular outer contour. Pump unit after Claim 1 or 2 , characterized in that the first section (54) and the second section (56) are arranged successively in the axial direction of the contact element (44) and that the first section has a constant wall cross-section in the circumferential direction. Pump unit according to one of Claims 1 to 3 , characterized in that an extension of the second portion (56) in the axial direction of the contact element (44) by a multiple several times smaller than the extent of the first portion (54) in the axial direction of the contact element (44). Pump unit according to one of Claims 1 to 4 , characterized in that the second portion (56) in its outer dimensions on the inner dimensions of the passage (42) of the housing block (12) is tuned such that between the second portion (56) and a wall of the passage (42) has a circumferential gap (52) with a predetermined gap. Pump unit after Claim 5 , characterized in that the gap of the circumferential gap (52) is between 0.8 and 1.2 mm, preferably 1 mm. Pump unit according to one of Claims 1 to 6 characterized in that the second portion (56) is integrally formed with the first portion (54) of the insulator (48). Pump unit according to one of Claims 1 to 7 , characterized in that the spring contact (46) with the material of the insulator (48) is encapsulated. Pump unit according to one of Claims 1 to 8th characterized in that the second portion (56) of the insulator (48) is disposed between two opposite end portions of the insulator (48) inside the leadthrough (42), the second portion (56) being circumferentially opposite the outer contours of both end portions has radially projecting cross-section.

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