DE102020201278A1 - Position measuring device for measuring a position of a piston with respect to a cylinder along an axial direction, release system for actuating a clutch - Google Patents

Abstract

The present invention relates to a displacement measuring device (100) for measuring a position of a piston (202) with respect to a cylinder (204) along an axial direction (191). The displacement measuring device (100) comprises a first measuring component (130) which is rigidly coupled to the piston (202) in the axial direction (191) via a first joint (110). The displacement measuring device (100) further comprises a second measuring component (140) for measuring a position of the first measuring component (130) with respect to the second measuring component (140) in the axial direction (191). The second measuring component (140) is rigidly coupled in the axial direction (191) to the cylinder (204) movable in the axial direction (191) to the piston (202) via a second joint (120). The first measurement component (130) and the second measurement component (140) are secured against pivoting relative to one another.

Description

The present invention relates to a displacement measuring device for measuring a position of a piston along an axial direction, in particular in a release system. The present invention also relates to a release system for actuating a clutch, in particular a clutch for a vehicle.

In particular, pneumatically actuated, concentric release systems have established themselves as the standard in commercial vehicles for actuating a clutch. Due to a higher functional integration compared to other release systems and a more compact design in combination with the use of existing peripherals, such as compressed air, such systems offer several advantages.

Such a release system requires information about a position of a piston that can be moved for actuating the clutch, for example for control purposes. Distance measuring devices are known which are based on the fact that a signal transmitter or a sensor is coupled to the piston of the release system.

Due to interfering influences, such as circumferential misalignments of the piston, the signal transmitter can be deflected in relation to the sensor with known displacement measuring devices. As a result, in particular a signal quality of the known displacement measuring devices can be impaired.

In addition, the circumferential misalignments of the piston can lead to undesired wear in known displacement measuring devices.

It can therefore be regarded as the object of the present invention to create an improved concept for a displacement measuring device.

This object can be achieved with the aid of the independent and dependent claims of the present disclosure.

According to a first aspect, the present invention relates to a displacement measuring device for measuring a position of a piston with respect to a cylinder along an axial direction. The displacement measuring device comprises a first measuring component which is rigidly coupled to the piston in the axial direction via a first joint. Furthermore, the displacement measuring device comprises a second measuring component for measuring a position, which indicates the position of the piston, of the first measuring component with respect to the second measuring component in the axial direction. The second measuring component is rigidly coupled in the axial direction via a second joint to a cylinder which can be moved in the axial direction relative to the piston. The first measurement component and the second measurement component are secured against pivoting relative to one another.

In some exemplary embodiments of the displacement measuring device, the first measuring component is designed as a signal transmitter and the second component is designed as a sensor for measuring the position with respect to the signal transmitter in the axial direction.

The sensor is designed, for example, to measure an axial position of the signal transmitter in order to determine the position of the piston in the axial direction.

In further exemplary embodiments, the sensor and the signal transmitter can be interchanged with respect to the previously described exemplary embodiments, so that the first measurement component is designed as a sensor and the second measurement component is designed as a signal transmitter.

The first and the second measurement components are arranged offset from one another in a radial direction, for example.

As a result of an articulated connection of the first measuring component to the piston via the first joint, the first measuring component can, for example, be pivoted with respect to the piston in order to compensate for tilting of the piston with respect to the cylinder. The first measuring component can, for example, be pivoted in the radial direction and optionally in a circumferential direction relative to the piston in order to compensate for circumferential misalignments of the piston.

By means of an articulated coupling of the second measuring component to the cylinder, the second measuring component can be pivoted in such a way that the second measuring component can follow swiveling of the first measuring component.

The first and the second measuring component support each other against relative pivoting, for example.

The first and the second measuring components therefore have a constant spacing in the radial direction, for example even in the case of circumferential misalignments of the piston (within the scope of a movement play).

Deteriorations in signal quality due to mechanical interference from the piston, such as the circumferential misalignment, can thereby be reduced or ideally prevented.

In some exemplary embodiments, the displacement measuring device according to FIG. 1 furthermore comprises a first guide element for receiving the first measurement component and a second guide element for receiving the second measurement component. The first and the second guide element are secured against pivoting relative to one another.

The first and the second guide element have, for example, a pocket for receiving the first and the second measuring component and connect the first and the second measuring component to the first and second joint, respectively.

The guide elements serve, for example, to protect against external influences such as dirt or moisture and to connect the first and second measuring components to the first and second joint, respectively.

In some exemplary embodiments of the displacement measuring device, the first guide element engages in a guide of the second guide element in a form-fitting manner, so that the first and second guide elements are secured against pivoting relative to one another.

The second guide element has, for example, a recess as a guide. The first guide element can engage positively in the recess of the second guide element, so that the first measurement component is secured against pivoting relative to the second measurement component.

In some examples, the recess has, for example, a rectangular, trapezoidal or round cross section.

The trapezoidal cross-section allows, for example, a so-called dovetail guide to be implemented which, for example, enables the first and second guide elements to be secured to one another in the circumferential direction.

Owing to the round cross section, tilting of the first guide element within the recess can be avoided.

The recess with the rectangular cross section can, for example, be implemented in a technically simpler manner than the aforementioned recesses.

The first and the second guide element thereby guide each other, for example, so that no additional structural components may be necessary to guide the first and the second guide element.

In some exemplary embodiments of the displacement measuring device, at least the first joint comprises a first elastic connection piece for the articulated coupling of the first measuring component to the piston or the second joint comprises a second elastic connection piece for the articulated coupling of the second measuring component to the cylinder.

The first or second elastic connecting piece is, for example, elastically shaped and the first elastic connecting piece is arranged, for example, between the piston and the first measuring component. As a result, the first measuring component, for example, can be pivoted with respect to the piston.

Analogously, the second connection piece can, for example, elastically couple the second measurement component to the cylinder in such a way that it can be pivoted.

Joints designed in this way can be referred to as elastic joints.

An implementation of elastic joints can, for example, be more cost-effective and technically simpler than other possible joints.

In some exemplary embodiments of the displacement measuring device, at least the first joint or the second joint is designed as a ball joint.

Ball joints, for example, have several degrees of freedom. As a result, constraining forces which can occur when pivoting between the first and the second measuring component can be reduced compared to other possible designs of the first and second joint.

In some exemplary embodiments of the displacement measuring device, at least the first joint or the second joint is designed as a swivel joint.

The swivel joint can, for example, allow pivoting in the radial direction or in the circumferential direction. In particular in applications in which pivoting of the first or second measuring component should be limited to one degree of freedom, it may therefore be desirable to implement the first and / or second joint as a rotary joint.

In some exemplary embodiments of the displacement measuring device, at least the first or the second joint is designed to be separable.

For example, when the first and / or second joint is designed as a ball joint, a joint head of the respective joint can be arranged detachably in a joint socket. The first and / or the second joint can be separated by releasing the joint head.

As a result, the first and / or the second measuring component or the first and / or the second guide element can be exchanged for maintenance purposes, for example. The first and / or the second joint can be separable in such a way that no tool is necessary to separate the joints.

According to a second aspect, the present invention relates to a release system which comprises a cylinder and a piston which can be moved in an axial direction relative to the cylinder. The release system also includes a travel measuring device. The displacement measuring device comprises a first measuring component, which is rigidly coupled to the piston in the axial direction via a first joint, and a second measuring component for measuring a position indicating the position of the piston relative to the first measuring component in the axial direction, which is connected via a second joint in the axial direction is rigidly coupled to the cylinder. The first and second measuring components are secured against pivoting relative to one another.

The release system can in particular be a pneumatic release system which is designed to actuate a clutch, such as a friction clutch of a vehicle.

The position measuring device is used, for example, to measure the position of the piston in the axial direction (axial position). The axial position can be used, for example, as a control variable for controlling the release system.

Further exemplary embodiments of the release system can include various of the exemplary embodiments of the displacement measuring device described above.

• 1a ein Ausrücksystem mit einem ersten Ausführungsbeispiel einer Wegmessvorrichtung in einer Draufsicht;
• 1b das Ausrücksystem mit dem ersten Ausführungsbeispiel der Wegmessvorrichtung in einer Seitenansicht;
• 1c ein erstes Führungselement und ein zweites Führungselement des ersten Ausführungsbeispiels der Wegmessvorrichtung mit einem integrierten Sensor;
• 1d ein erstes Führungselement und ein zweites Führungselement des ersten Ausführungsbeispiels der Wegmessvorrichtung mit einem separaten Sensor;
• 2a ein zweites Ausführungsbeispiel der Wegmessvorrichtung in einer Gesamtansicht;
• 2b das zweite Ausführungsbeispiel der Wegmessvorrichtung im Schnittbild;
• 3a ein drittes Ausführungsbeispiel der Wegmessvorrichtung in einer Gesamtansicht;
• 3b das dritte Ausführungsbeispiel der Wegmessvorrichtung im Schnittbild;
• 3c ein erstes Führungselement des dritten Ausführungsbeispiels; und
• 3d ein elastisches Gelenk des dritten Ausführungsbeispiels.

Some examples of exemplary embodiments of the invention are explained in more detail below with reference to the accompanying figures, merely by way of example. Show it:

• 1a a release system with a first embodiment of a displacement measuring device in a plan view;
• 1b the release system with the first embodiment of the displacement measuring device in a side view;
• 1c a first guide element and a second guide element of the first embodiment of the displacement measuring device with an integrated sensor;
• 1d a first guide element and a second guide element of the first embodiment of the displacement measuring device with a separate sensor;
• 2a a second embodiment of the displacement measuring device in an overall view;
• 2 B the second embodiment of the displacement measuring device in a sectional view;
• 3a a third embodiment of the displacement measuring device in an overall view;
• 3b the third embodiment of the displacement measuring device in a sectional view;
• 3c a first guide element of the third embodiment; and
• 3d an elastic joint of the third embodiment.

Various embodiments will now be described in more detail with reference to the accompanying drawings, in which some embodiments are shown.

Although exemplary embodiments can be modified and changed in various ways, exemplary embodiments are shown in the figures as examples and are described in detail herein. It should be made clear, however, that the intention is not to restrict exemplary embodiments to the respectively disclosed forms, but rather that exemplary embodiments are intended to cover all functional and / or structural modifications, equivalents and alternatives that are within the scope of the invention.

In known displacement measuring devices, in disengagement systems, for example, due to circumferential misalignments of a piston, the signal transmitter can be deflected in relation to a sensor. As a result, in particular a signal quality of the known displacement measuring devices can be impaired.

In addition, the circumferential misalignments of the piston can lead to undesired wear in known displacement measuring devices.

It can therefore be regarded as the object of the present invention to create an improved concept for a displacement measuring device.

1a and 1b show a first example of a displacement measuring device 100 to measure a Position of a piston 202 opposite a cylinder 204 along an axial direction 191 with a release system 200 . 1a shows the position measuring device 100 in a plan view and 1b in a side view.

The position measuring device 100 comprises a first measurement component 130 which has a first joint 110 in the axial direction 191 rigid with the piston 202 is coupled.

In addition, the position measuring device includes 100 a second measuring component 140 for measuring a position of the first measuring component 130 compared to the second measuring component 140 in the axial direction 191 . The second measuring component 140 is about a second joint 120 in the axial direction 191 rigid with the cylinder 204 coupled. For example, is the second measurement component 140 over the second joint, as shown here 120 pivotable with a holding element 206 coupled, which is fixed to one opposite the piston 202 in the axial direction 191 movable cylinder 204 is coupled.

The first and the second measuring component 130 and 140 are in contact with one another, so that they are secured against relative pivoting to one another. A first guide element engages for this 132 for taking up the first measuring component 130 and a second guide element 142 for taking up the second measuring component 140 form-fitting into each other. The first guide element 132 and the first measurement component 130 For example, as shown, “dive” into the second guide element 142 on. This is the first component to be measured 130 for example, protected from external influences such as dirt and / or moisture.

The first and the second joint 110 and 120 are each designed as a ball joint. This allows the first and second guide elements or the first and second measuring components to pivot 130 and 140 in a circumferential direction 192 and / or radial direction 193 to with simultaneous application of the first and second measuring components 130 and 140 to secure against relative pivoting to one another.

The second guide element 142 can for example by pivoting within the second joint 120 a deflection of the first guide element 132 adjust so that the guide elements 132 and 142 Do not tilt to one another and mutual securing against relative pivoting to one another is possible.

This can create constraining forces between the guide elements 132 and 142 are reduced or avoided with simultaneous contact to one another to secure against relative pivoting to one another.

In that the first and the second measuring component 130 and 140 in the axial direction 191 rigid with the piston 202 , or with the cylinder 204 are coupled, gives a position / relative movement of the first measurement component 130 compared to the second measuring component 140 a position / relative movement of the piston 202 opposite the cylinder 204 again.

The measured position of the first sample component 130 compared to the second measuring component 140 in the axial direction 191 can therefore be used, for example, as a control variable for controlling the release system 200 be used.

The first measuring component 130 is designed, for example, as a signal transmitter and in particular as a magnet.

The second measuring component 140 is designed, for example, as a sensor which is used to determine a relative position with respect to the magnet 130 suitable is. The sensor 140 includes, for example, a magnetic field sensor.

The magnetic field sensor can, for example, be a magnet to determine the relative position 130 Measure outgoing magnetic field, whereby based on the measured magnetic field on the relative position of the magnet 130 can be closed.

Because the magnet 130 axially rigid with the piston 202 coupled can depend on the relative position of the magnet 130 on the position of the piston 202 in the axial direction 191 getting closed.

1c shows the first guide element 132 and the second guide element 142 the position measuring device 100 in a sectional view, which can be generated with a section along "AA".

The in 1c The example shown is the sensor 140 in the second guide element 140 “Integrated”, for example within the second guide element 140 arranged.

The magnet 130 is radially inside the sensor 140 on (fixed) the first guide element 132 arranged.

Compared to the in 1c The example shown is the sensor 140 at an in 1d shown example executed separately. The sensor 140 is, as shown, (fixed) on the second guide element 140 for example, positively and / or non-positively arranged.

The in 1d example shown can be the sensor 140 For example, it is technically easier to replace for maintenance purposes than with the one in 1c shown example.

2a and 2 B show a second embodiment of the displacement measuring device 100 in an overall view or in a sectional view.

This in 2a and 2 B The second exemplary embodiment shown differ from the previously described exemplary embodiment in that the first joint is an elastic connecting piece 114 comprises, which in the first guide element 132 fitted and / or glued and (rotatably mounted) around a pin 112 is arranged.

Thus, the elastic connector couples 114 the first guide element 132 for example in this way about the pin 112 with the piston 202 so that the first guide element 132 in the circumferential direction 192 opposite the piston 202 is rotatably mounted. In addition, the first guide element 130 by elastic deformability of the elastic connecting piece 114 opposite the piston 202 in the radial direction 193 be pivotable, for example, to circumferential misalignments of the piston 202 balance.

The first joint 110 of the second embodiment of the displacement measuring device 100 can be understood as a combination of an elastic joint and a swivel joint.

Alternatively, the elastic connector 114 rotatably around the pin 112 be arranged to the first guide element 132 against rotation in the circumferential direction 192 to secure.

Also show 2a and 2 B a version of the second joint 120 as a swivel joint. Here is one fixed to the second guide element 142 coupled bolt 144 rotatable in a warehouse 146 stored so that the second guide element 142 in the radial direction 193 is pivotable. The warehouse 146 is fixed to the holding element 206 arranged.

The first guide element 132 so engages in a leadership 148 of the second guide element 142 form-fitting, so that the first guide element 132 and the second guide element 142 are secured against relative pivoting to one another. The leadership 148 includes, for example, a recess.

As already described above, the recess can have a rectangular, round or trapezoidal cross section.

In 2 B is also a bag 134 shown which one to accommodate the magnet 130 suitable is.

3a and 3b show a third embodiment of the displacement measuring device 100 .

The first joint 110 is designed as a ball joint.

The ball joint 110 includes, for example, a joint head 116 which stuck to the piston 202 is coupled and from a joint socket 118 is at least partially enclosed.

As related to 3c shown is the acetabulum 118 designed in such a way that the joint head 116 can be plugged into the joint socket 118 can be coupled. A circumference of the joint socket can be used for a plug connection 118 be elastic and through several webs 119 be supported towards the inside of the circumference.

The circumference of the joint socket 118 can result when the ball joint is plugged together 110 deform elastically so that the joint head 116 in the socket 118 (in the axial direction 191 ) locks into place.

The ball joint 110 can thus be separated, for example, to remove the piston for maintenance purposes 202 and / or the magnet 130 to be able to separate and exchange. In some cases the ball joint can 110 be designed in such a way that it can be separated without the use of tools.

As in 3d shown includes the second joint 120 in the third embodiment of the displacement measuring device 100 an elastic connector 122 , which is the second guide element 142 elastic with the holding element 206 couples.

The second guide element 142 , or the sensor 142 is thus, for example, pivotable with respect to the holding element 206 , or opposite the cylinder 204 .

The second joint 120 can for example be referred to as an elastic joint.

The aspects and features that are described together with one or more of the previously detailed examples and figures can also be combined with one or more of the other examples in order to replace an identical feature of the other example or to add the feature in the other example to introduce.

Furthermore, the following claims are hereby incorporated into the detailed description, where each claim can stand on its own as a separate example. While each claim may stand on its own as a separate example, it should be noted that although a dependent claim in the claims may refer to a particular combination with one or more other claims, other examples also combine the dependent claim with the subject matter of each other dependent or independent claims. Such combinations are explicitly suggested here unless it is indicated that a particular combination is not intended. Furthermore, features of a claim are also intended to be included for any other independent claim, even if that claim is not made directly dependent on the independent claim.

List of reference symbols

100

Position measuring device

110

first joint

112

Cones

114

elastic connector

116

Swivel head

118

Joint socket

119

Bridges

120

second joint

122

elastic connector

130

first measuring component / magnet

132

first guide element

134

pocket

140

Sensor / magnetic field sensor

142

second guide element

144

bolt

146

warehouse

148

guide

191

axial direction

192

Circumferential direction

193

radial direction

200

Release system

202

piston

204

cylinder

206

Retaining element

Claims (10)

Position measuring device (100) for measuring a position of a piston (202) with respect to a cylinder (204) along an axial direction (191), comprising: a first measuring component (130) which is rigidly coupled to the piston (202) in the axial direction (191) via a first joint (110); and a second measuring component (140) for measuring a position, indicating the position of the piston (202), of the first measuring component (130) with respect to the second measuring component (140) in the axial direction (191), wherein the second measuring component (140) is rigidly coupled via a second joint (120) in the axial direction (191) to a cylinder (204) movable in the axial direction (191) relative to the piston (202); and wherein the first measurement component (130) and the second measurement component (140) are secured against pivoting relative to one another. Distance measuring device (100) according to Claim 1 , further comprising: a first guide element (132) for receiving the first measurement component (130); and a second guide element (142) for receiving the second measurement component (140), the first guide element (132) and the second guide element (142) being secured against relative pivoting to one another. Distance measuring device (100) according to one of the preceding claims, wherein the first guide element (132) engages positively in a guide of the second guide element (142) so that the first guide element (132) and the second guide element (142) pivot relative to one another are secured. Displacement measuring device (100) according to one of the preceding claims, wherein at least the first joint (110) has a first elastic connecting piece (114) for the articulated coupling of the first measuring component (130) to the piston (202) or the second joint (120) has a second elastic Connection piece (122) for the articulated coupling of the second measuring component (140) to the cylinder (206). Distance measuring device (100) according to one of the preceding claims, wherein at least the first joint (110) or the second joint (120) is designed as a ball joint. Distance measuring device (100) according to one of the preceding claims, wherein at least the first joint (110) or the second joint (120) is designed as a swivel joint. Distance measuring device (100) according to Claim 5 , wherein the guide has a recess with a rectangular cross-section, with a trapezoidal cross-section or with a round cross-section. Distance measuring device (100) according to one of the preceding claims, wherein at least the first or the second joint (110, 120) is designed to be separable. Distance measuring device (100) according to one of the preceding claims, wherein the first measuring component (130) is designed as a signal transmitter; and wherein the second component (140) is designed as a sensor for measuring the position with respect to the signal transmitter (130) in the axial direction (191). A release system (200) comprising: a cylinder (204); a piston (202) movable in an axial direction (191) with respect to the cylinder (204); a displacement measuring device (100) according to any one of the preceding claims, comprising: a first measuring component (130) which is rigidly coupled to the piston in the axial direction (191) via a first joint (110); a second measuring component (140) for measuring a position indicating the position of the piston (202) with respect to the first measuring component (130) in the axial direction (191), which via a second joint (120) is rigidly connected in the axial direction (191) is coupled to the cylinder (204), the first measuring component (130) and the second measuring component (140) being secured against pivoting relative to one another.

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