DE102007023413B4 - Hydraulic power unit - Google Patents

Abstract

Hydraulic drive unit (1) for the displacement of two vehicle body parts to each other
With a hydraulic pump with a pump motor (11),
- With a in a housing (29) running reciprocating piston (31) which is connected to a piston rod (32),
- With a fixed to the reciprocating piston (31) connected to the pivot point (6),
- With a housing-fixed articulation point (5),
With
A displacement sensor (40) for measuring the relative position of the piston rod (32) in the housing (29),
A control device (43) which is in signal connection with the pump motor (11) and with the displacement sensor (40),
characterized in that the displacement sensor (40) comprises a bobbin (42), wherein the bobbin (42) in the piston rod (32) is housed, wherein a metallic induction element (41) of the displacement sensor (40) is part of a housing-fixed guide rod (33). is, which runs in the piston rod (32) and which is surrounded by the bobbin (42).

Description

The The invention relates to a hydraulic drive unit for shifting two Vehicle body elements to each other according to the preamble of the claim 1. The invention further relates to a motor vehicle assembly with two body elements and such a drive unit and an operating method of a motor vehicle assembly with two body elements and such a drive unit.

The DE 10 2005 005 011 A1 describes a hydraulic cylinder which is acted upon by a pump with hydraulic oil. A reciprocating piston runs in a housing. The reciprocating piston is connected to a piston rod. With the reciprocating piston and the piston rod a pivot point is connected. To measure a relative position of the piston rod in the housing is a grinding pickup, which cooperates with a sliding contact. With the hydraulic cylinder, a control electronics works together.

The US 2005/0081710 A1 describes a hydraulic cylinder with a displacement sensor of any type.

Another drive unit is known from the AT 405 631 B , Such drive units serve, for example, for the driven opening and / or closing of a tailgate and for the driven opening and / or closing of a sliding door or a sunroof. The drive units used for this purpose must be accommodated as space-saving and as little disturbing positions as possible. This entails that the drive units are often articulated via deflecting elements to the body elements to be displaced relative to each other. This often requires a non-linear dependence of the displacement movement of the body to be displaced via the drive unit body elements of the movement of the reciprocating piston. Inharmonious and jerky driven movements of the moving body element are the result.

It An object of the present invention is a drive unit of the type mentioned in such a way that even in compact installation situations a harmonious movement of the driven shifted to each other Body elements guaranteed is.

These The object is achieved by a drive unit with the features specified in claim 1.

Of the inventive displacement sensor provides information the instantaneous position of the piston rod in the housing available. Starting from According to this information, the control device can have a nonlinearity of the dependency the movement of the body elements from the movement of the reciprocating piston by a corresponding adjustment of the speed of the pump motor compensate. It results in the possibility of being complex between the body elements hinged drive unit harmonic and not by jerky speed changes impaired To ensure movement sequence of the body parts to each other. Across from offers sophisticated servomotor solutions the hydraulic drive unit according to the invention a significant cost advantage. The displacement sensor has a bobbin. One such displacement sensor allows an induction measurement of the relative position of the piston rod in the housing. A Such measurement can be easily evaluated. Overall results a cost-effective Displacement sensor. The bobbin is housed in the piston rod. A metallic induction element the displacement sensor is part of a housing-fixed guide rod, the rod in the Kol runs and from the bobbin is surrounded. The bobbin with the piston rod becomes relative to the housing-fixed induction element the displacement sensor moves.

A Storage unit with calibration table according to claim 2 guaranteed an inexpensive option for harmonic motion control of the drive unit.

A Evaluation unit according to claim 3 can in particular ensure a fail-safe behavior. in the Case of using the drive unit to relocate a tailgate can over the evaluation unit, for example, a reversal of motion of the drive unit be initiated as soon as over the evaluation unit is detected that the tailgate to an obstacle encounters. A damage the tailgate can be reduced or even prevented in this way become.

With a reciprocating piston according to claim 4 is a driven in and out the drive unit possible.

The Advantages of a motor vehicle assembly according to claim 5 correspond those of the drive unit according to claim 2.

The Advantages of an operating method according to claim 6 correspond to those The drive unit according to claim 1.

The Advantages of an operating method according to claim 7 correspond to those The drive unit according to claim 3.

One embodiment The invention will be explained in more detail with reference to the drawing. In show this:

1 perspective view of an overall view of a hydraulic drive unit;

2 a perspective view of a pump assembly of the drive unit according to 1 ;

3 an end view of the pump assembly according to viewing direction III in 2 ;

4 a section along line IV-IV in 3 ;

5 a section along line VV in 3 ;

6 a section according to line VI-VI in 3 ;

7 a side view of a cylinder assembly of the hydraulic drive unit according to 1 with inserted piston;

8th a section according to line VIII-VIII in 7 ;

9 an excerpt from 8th ;

10 the cylinder assembly in one too 7 similar view with ejected piston;

11 a section along line XI-XI in 10 ;

12 an excerpt from 11 ,

A hydraulic drive unit 1 serves for the displacement of two vehicle body elements to each other, for example, for opening and / or closing a motor vehicle tailgate. Other applications of the hydraulic drive unit 1 in the automotive field are conceivable, for example, the opening and / or closing a sliding door or sliding roof. The hydraulic drive unit 1 can also be used to open and / or close other doors, sliders or flaps.

The hydraulic drive unit 1 in the 1 Overall, is divided into a pump assembly 2 that in the 2 to 6 is shown, and in a cylinder assembly 3 that in the 7 to 12 is shown. The two modules 2 . 3 are in a connection area 4 firmly and fluid-tightly connected. At its free end has the pump assembly 2 a rod end 5 for fastening the hydraulic drive unit 1 on a first body element, not shown. At its free end has the cylinder assembly 3 a ball joint head 6 for fastening the hydraulic drive unit 1 on a second body element.

The pump assembly 2 has a cylindrical housing 7 , which is divided into a motor housing or a motor base 8th , in a pump housing 9 and in a tank valve block housing 10 , The motor housing 8th is the rod end 5 next to each other. The pump housing 9 lies between the motor housing 8th and the tank valve block housing 10 ,

In the motor housing 8th is a pump motor 11 housed, which is designed as a DC electric motor with a rated voltage of 12 V. A drive shaft 12 the pump motor 11 is rotatable with a rotor 13 a pump unit 14 the hydraulic pump in connection. The pump unit 14 is on the suction side via a suction hole 15 with a storage container 16 for hydraulic fluid in connection. The delivery side, so the pressure side, is the pump unit 14 depending on the direction of rotation of the rotor 13 with one of two pressure-discharge lines, namely a Ausschub-discharge line 17 and a drawer delivery line 18 in connection. An undesirable flow direction of the hydraulic fluid is prevented by valve units 19 in a valve block 20 inside the tank valve block housing 10 are housed. The components of the pump unit 14 and the valve block 20 are all made of plastic. In an alternative variant of the hydraulic drive unit 1 Individual components can also be made of aluminum or steel.

The storage tank 16 is from the valve block 20 pass. The storage tank 16 So it is designed as a ring container. The storage tank 16 surrounds next to the valve block 20 also in sections a housing-fixed control shaft 21 that the rotor 13 is adjacent and whose axis of rotation with a central longitudinal axis 22 of the housing 7 coincides. In the control shaft 21 are two line sections 23 housed the suction hole 15 with the exhaust delivery pipe 17 on the one hand and with the slide-in delivery line 18 on the other hand. The suction hole 15 has next to a spur line to the reservoir 16 one more along the longitudinal axis 22 extending line section.

The storage tank 16 is not rotationally symmetrical, but has an average of the 4 and 6 a smaller cross-section than in section 5 , The container 16 is on the inside complementary to the likewise not rotationally symmetrical designed valve block 20 executed.

To the valve units 19 include two pressure relief valves 19a in a fluid connection section between the conduit sections 23 and the suction hole 15 in the control shaft 21 are housed. The limiting valves 19a each have a spherical valve body 24 , which under bias against a valve seat of the respective line section 23 is pressed. For the bias each provides a coil spring 25 extending between the respective valve body 24 and a wave cap 26 the control shaft 21 supported.

Instead of a spherical valve body, the pressure relief valve 19a Also, a conical valve body may be provided, wherein the valve seat on the line section 23 Complementary to the valve body is executed.

The pressure relief valves 19a are arranged to provide a flow of hydraulic fluid to the suction bore 15 in the line sections 23 always sure to prevent. In the opposite direction, so from the line sections 23 towards the intake hole 15 remain the pressure relief valves 19a closed to a predetermined limit pressure. If this limit pressure is exceeded, lift the valve body 24 against the bias of the coil springs 25 from the valve seats of the pipe sections 23 so that a controlled flow of hydraulic fluid from the pipe sections 23 over the suction hole 15 back to the reservoir 16 is possible. In special operating states of the hydraulic drive unit 1 In this way damage to the pump unit in particular 14 and the valve block 20 prevented. The pressure relief valves 19a So in this case give an overload conveying path between the line sections 23 and the suction hole 15 free.

The cylinder assembly 3 has one over the connection area 4 with the pump assembly 2 connected cylinder base 27 , a cylinder head 28 as well as between the cylinder base 27 and the cylinder head 28 running cylinder housing 29 , Coaxial in the cylinder housing 29 arranged is a cylinder tube 30 , In the cylinder tube 30 a piston is running 31 Fixing with a piston rod 32 connected is. The piston rod 32 is sealed from the cylinder head 28 led out. The free end of the piston rod 32 carries the ball joint head 6 , A stroke movement of the piston rod 32 is guided by a central guide rod 33 at the cylinder base 27 is fixed and in the cylinder tube 30 coaxial with its longitudinal axis 34 runs. The longitudinal axes 22 . 34 fall together. For holding the guide rod 33 has the piston rod 32 a guide bore designed as a blind bore 35 ,

The piston 31 divided an annular interior in the cylinder tube 30 in a cylinder base 27 adjacent extension room 36 and in a the cylinder head 28 adjacent insertion space 37 , With mounted hydraulic drive unit 1 is the Ausschubraum 36 via a discharge line formed in the cylinder base 38 with the exhaust delivery pipe 17 the pump assembly 2 in fluid communication. The insertion space 37 stands with mounted hydraulic drive unit 1 with the plug-in delivery line 18 the pump assembly 2 via a plug-in line 39 in fluid communication. The plug-in line 39 is sections as a loop between the cylinder housing 29 and the cylinder tube 30 executed.

Depending on whether on the pump unit 14 the exhaust delivery pipe 17 or the drawer delivery line 18 is pressurized, the piston rod 32 pushed out or inserted. The hydraulic drive unit 1 So has a double-acting piston 31 ,

For measuring the relative position of the piston rod 32 in the cylinder housing 29 , So to measure the current stroke position of the piston rod 32 , serves a displacement sensor 40 , The displacement sensor 40 has an induction element 41 at the free end of the guide rod 33 is appropriate. To the way sensor 40 still belongs in the 8th shown bobbin 42 , The induction element 41 is connected to a control device 43 in the 5 shown by dashed lines, the hydraulic drive unit 1 in signal connection. This signal connection can be realized wired or wireless. The control device 43 again stands with the pump motor 11 in signal connection. The control device 43 can also be an external component.

The control device 43 has one also in the 5 Dashed line indicated storage unit 44 , In this a calibration table is stored, the each relative position of the piston rod 32 in the cylinder housing 29 an operating speed of the pump motor 11 assigns.

The control device also has a likewise in the 5 Dashed line indicated evaluation 45 on. The latter monitors the actual value of the relative position of the piston rod 32 in the cylinder housing 29 representing the relative position of the hydraulic drive unit 1 mutually displaced vehicle body elements corresponds, during operation of the pump motor 11 ,

The hydraulic drive unit 1 is part of a motor vehicle assembly, which further includes the two body elements, between which the drive unit 1 is articulated relative to each other for displacement of the two body elements. The articulation of the drive unit 1 at the two ka rosserieelementen done via not shown in the drawing deflection such that one on the hydraulic drive unit 1 caused displacement movement of the body elements to each other non-linearly from the stroke of the reciprocating piston 31 in the cylinder tube 30 depends. The calibration table in the memory unit 44 has each relative position of the piston rod 32 in the cylinder housing 29 such assigned pump motor operating speeds that during operation of the hydraulic drive unit 1 the displacement speed of the driven displaced body element over the displacement of the two mutually displaceable body elements to each other does not change abruptly. Despite the non-linear dependence of the displacement movement of the body elements to each other from the stroke of the reciprocating piston 31 then results in a harmonious and uniform displacement of the body elements to each other via the hydraulic drive unit 1 ,

The extension movement of the piston 31 is from a screw compression spring 46 supports that around the cylinder housing 29 wound around. The screw compression spring 46 on the one hand supports the cylinder base 27 and at the other end to a support plate 47 off, stuck to the piston rod 32 adjacent to the ball joint head 6 connected is.

The hydraulic drive unit 1 is operated as follows: At the start of operation is the hydraulic drive unit 1 For example, in a basic position, in which the piston rod 32 with the piston 31 completely in the cylinder housing 29 is inserted. This position is in the 7 to 9 shown.

In this basic position, for example, the tailgate of the motor vehicle, on which the piston rod 32 over the ball joint head 6 is hinged, closed. Now the pump motor 11 operated in an operating direction, so that the pump unit 14 the exhaust delivery pipe 17 pressurized with hydraulic fluid. The reciprocating piston 31 is now, actuated by the hydraulic fluid and supported by the helical compression spring 46 , pushed out so that the tailgate opens. The non-linearity of the displacement movement of the tailgate to the other body of the motor vehicle in response to the stroke of the reciprocating piston, the at constant speed of the pump motor 11 and at the resulting uniform Ausschubgeschwindigkeit the piston 31 would lead to an inharmonic and speed leaps opening movement of the tailgate is compensated by the displacement sensor 40 at any time of the piston stroke 31 the relative position of the piston rod 32 in the cylinder housing 29 to the controller 43 passes.

The displacement sensor 40 determines the relative position of the piston rod 32 in the cylinder housing 29 by detecting the in the induction element 41 when moving relative to the bobbin 42 induced voltage. The bobbin 42 is with the controller 43 in signal connection. These voltage values are within the control device 43 integrated and provide a direct measure of the respective piston position. In the memory unit 44 This relayed relative position is in each case an operating speed of the pump motor 11 and thus a Ausschubgeschwindigkeit the piston rod 32 assigned. Due to the nonlinearity of the displacement movement of the tailgate in response to the stroke of the reciprocating piston 31 adapted change in the operating speed of the pump motor 11 results in a harmonious displacement movement movement, so a harmonious opening of the tailgate, the opening speed does not change abruptly.

The evaluation unit 45 monitors the course of the relative position of the body elements to each other during operation of the drive unit 1 thus, monitors how the tailgate position during operation of the drive unit 1 changes over time. Once a deviation of the monitored relative position in a given operating situation of the drive unit 1 occurs from a default value, the evaluation module accesses via the control device 43 in the control of the drive unit 1 and in particular directs a reversal of motion of the pump motor 11 one. This happens, for example, when the tailgate this opens an obstacle, which via the displacement sensor 40 as an interruption to the normal movement sequence when opening the tailgate by means of the drive unit 1 can be measured.

To close the tailgate is driven by the control device 43 , the direction of rotation of the pump motor 11 vice versa, so now the plug-in delivery line 18 is pressurized. Also when closing the tailgate work the displacement sensor 40 and the controller 43 via control of the pump motor 11 such that, despite the non-linearity of the articulation of the drive unit 1 the tailgate closes with a harmonious closing movement without any pressure change of the movement speed.

The Calibration table for Pushing out may be consistent with the insertion calibration table. However, this is not mandatory. So can the opening of the tailgate altogether z. B. slower than closing.

When Hydraulic fluid can be used in particular a hydraulic oil.

It has shown to be advantageous, at least one of the components of Hydraulic drive unit, such as fasteners and / or pistons and / or cylinder tube and / or cylinder head and / or cylinder base and / or Valve block and / or poppet and / or pump block and / or motor base and / or Container, at least partially, from a polymeric material from the group Polyamide (PA), Liquid Crystal Polymer (LCP), Polyphenylene Sulfide (PPS) and polyetheretherketone (PEEK). Preferred is as Polyamide (PA) a PA 6, PA 66, PA 11, PA 12, PA 1212, PA 1012, PA 610, PA 612, PA 69, PA 6T, PA 6I, PA 10T, PA 12T, PA 121, PA 6/612, PA 6/66, PA 12T / 12, PA 10T / 12; PA 12T / 106; PA 10T / 106; PA 6/612; PA 6/66/610; PA 6/66/12; PA 6 / 6T, according to ISO 1874/1, or an aromatic Polyamide used. There are also mixtures of polymers possible. For the increase of Strength can also composites of the polymeric materials with glass fibers and / or Carbon fibers and / or rock fibers and / or metal fibers and / or Polymer fibers as reinforcing materials be added. Particularly advantageous effect on the strength a glass fiber content between 20 and 45%, preferably between 30 and 33% off. Also can fillers, such as metal oxides, metal carbides, metal nitrides, aluminum silicate, Mica and soot, in the polymer, according to claim 9, are introduced. The pump block and / or the motor base and / or the container may also, at least partially, from a polymeric material of the group polyester, Polyacrylonitrile, polyoxymethylene, styrene / acrylonitrile copolymer, Polycarbonate and / or from misery of the aforementioned substances and / or made of reinforced Polypropylene exist.

Claims (7)

Hydraulic drive unit ( 1 ) for the displacement of two vehicle body elements to each other - with a hydraulic pump with a pump motor ( 11 ), - with one in a housing ( 29 ) running reciprocating piston ( 31 ), which is equipped with a piston rod ( 32 ), - with a fixed to the reciprocating piston ( 31 ) connected link point ( 6 ), - with a housing-fixed articulation point ( 5 ), with - a displacement sensor ( 40 ) for measuring the relative position of the piston rod ( 32 ) in the housing ( 29 ), - a control device ( 43 ) connected to the pump motor ( 11 ) and with the displacement sensor ( 40 ) is in signal connection, characterized in that the displacement sensor ( 40 ) a bobbin ( 42 ), wherein the bobbin ( 42 ) in the piston rod ( 32 ), wherein a metallic induction element ( 41 ) of the displacement sensor ( 40 ) Part of a housing-fixed guide rod ( 33 ), which is in the piston rod ( 32 ) and the coil body ( 42 ) is surrounded. Drive unit according to claim 1, characterized in that the control device ( 43 ) a storage unit ( 44 ), in which a calibration table is stored, that of each relative position of the reciprocating piston ( 31 ) in the housing ( 29 ) an operating speed of the pump motor ( 11 ). Drive unit according to claim 1 or 2, characterized in that the control device ( 43 ) an evaluation unit ( 45 ), which the course of the relative position of the reciprocating piston ( 31 ) in the housing ( 29 ) during operation of the pump motor ( 11 ) supervised. Drive unit according to one of claims 1 to 3, characterized by a double-acting reciprocating piston ( 31 ). Motor vehicle assembly - with a first body element - with a second body element - with a hinged between the two body elements drive unit ( 1 ) according to one of claims 1 to 4, - wherein the articulation is such that one via the drive unit ( 1 ) caused displacement movement of the body elements to each other non-linearly from the stroke of the reciprocating piston ( 31 ), the memory unit ( 44 ) has the calibration table with values assigned in such a way that the displacement speed over the displacement path of the two body elements does not change abruptly relative to one another. Operating method of a motor vehicle subassembly - with a first body element, - with a second body element, - with a drive unit articulated between the two body elements ( 1 ) according to one of claims 1 to 4, - wherein the articulation is such that one via the drive unit ( 1 ) caused displacement movement of the body elements to each other non-linearly from the stroke of the reciprocating piston ( 31 ), - with the method step of the driven displacement of the two body elements relative to one another by means of the drive unit ( 1 ), - wherein the displacement speed over the displacement path of the two body elements to each other does not change abruptly. Operating method according to claim 6, characterized in that the evaluation unit ( 45 ) via the control device ( 43 ) initiates a movement reversal of the displacement movement of the body elements to each other, as soon as a deviation of the monitored relative position of the reciprocating piston ( 31 ) in the cylinder housing ( 29 ) in a given operating mode situation of the drive unit ( 1 ) occurs from a default value.