JPH0843004A - Detecting device for position of driving element - Google Patents

Abstract

PURPOSE: To detect a position of a drive element which is not arranged directly in the drive element by providing a measurement plunger which slides inside of a case in a control conductor of the drive element and using the position of the measurement plunger inside of the case as a yardstick with respect to the position of the drive element. CONSTITUTION: A case 4 divides a measurement plunger 3 into a primary chamber 5 and a secondary chamber 6. The primary chamber 5 is connected with a pressurizing medium circulating passage through a distribution valve 20, and the secondary chamber 6 is connected with a follow-up cylinder 2. The plunger 3 is brought to its stationary position, via the pressurizing medium circulating passage against the application of pressurizing medium through a compression spring 15. Plungers 9, 10 inside of an inner wall of the case 4 through packings 17, 19. A measurement rod 12 having measurement graduations 11 formed as teeth between the plungers 9 and 10 is fixed and connected to the plungers 9, 10. The translation motion of the plungers 9, 10 is converted into the rotary movement by a gear 13 fitted in the rod 12 and is transmitted to a rotary potentiometer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the position of a drive element, which is driven by pressure or pneumatic pressure through a control conduit, using at least one position measuring transducer.

[0002]

BACKGROUND OF THE INVENTION Hydraulically actuated drive elements are used, for example, in the actuation of friction clutches in motor vehicles which act between the drive machine and the transmission mechanism. In other words, a friction clutch that operates automatically is known, for example, from DE 4011 850 A1. This clutch can connect / disconnect the clutch via an operating mechanism having a disengaging bearing and a clutch coupling box fitted therein. The operating mechanism is again operated via an adjusting unit in the form of a pressurizing cylinder, the drive element being connected to the pressurizing medium circuit via a drivable pressurizing distribution valve. Furthermore, an electronic control unit is provided for controlling the distribution valve of the pressurized medium circuit in accordance with various characteristic quantities in order to coordinate the intervention of the corresponding clutch via the pressure regulating unit. Such characteristic quantities are, for example, the engine speed, the position of the throttle valve, the operation movement of the clutch, or the intervention state of the clutch.
In the known operating device, the actuation of the clutch or the intervention of the clutch is detected by means of a potentiometer which is arranged directly on the adjusting unit, which potentiometer detects and corresponds to the movement or position of the adjusting unit. The quantity of electricity is introduced into the electric control device. In a particular use case of such a pressure regulating unit, the direct placement of the position or distance measuring detector is problematic due to the occupied space or due to the required electrical conduit.

[0003]

SUMMARY OF THE INVENTION It is an object of the invention to provide a device for detecting the position of a pressure-operated drive element which is not arranged directly at the drive element.

[0004]

SUMMARY OF THE INVENTION According to the invention, at least one position measuring transducer is used to detect the position of a drive element hydraulically or pneumatically driven via a control conduit. In the device, the control conduit 1 of the drive element 2 is provided with a measuring plunger 3 that slides in a case 4 and the position of this measuring plunger 3 in the case 4 can be used as a guide for the position of the drive element 2. ing.

Further advantageous configurations according to the invention are described in the dependent claims.

[0006]

According to the present invention, a measuring plunger that slides in a case is provided in a drive conduit of a drive element that can be operated by applying a pressurizing medium, and the position of the plunger in the case is a measure of the position of the drive element. Can be used as

According to an advantageous embodiment of the invention, the measuring plunger divides the case into a primary chamber and a secondary chamber each having at least one flow connection to a control conduit driven by the application of a pressurized medium, It is in a stationary position with respect to the applied pressure of the driving medium. When the drive element is moved from the rest position, a pressurized medium is applied via the drive conduit to the primary chamber side of the measuring plunger, which acts as a transfer plunger and provides a corresponding movement of the drive element with an adjustable transfer ratio.

In an advantageous embodiment of the device according to the invention, the measuring plunger consists of a first split plunger and a second split plunger which slides in an airtight manner on the inner wall of the case, with a pressure between both split plungers. There is no room formed. This pressure-free chamber has a flow connection, which leads mainly to the balance container or tank for pressure relief.

To detect the position of the drive element, according to one embodiment, both split plungers are connected to one another via a measuring rod having a measuring scale. According to the configuration of this embodiment, the length of the measuring scale corresponds to the adjusting length of the drive element according to the transmission ratio. The conversion ratio of the pressurized medium is adjusted by providing different diameters of the primary and secondary chambers.

According to another configuration, the measuring graduation is formed by a toothed rod arranged between the divided areas, which toothed rod imparts a translational movement of the measuring plunger to a gear wheel fitted on the plunger. The gear converts this motion into rotary motion and transmits it to the potentiometer.

Another possibility of detecting the position or the movement distance is that the measuring graduation is magnetically formed and the measuring value is detected by electromagnetic induction. However, in addition to placing the measuring rod between the two split plungers, one of the two split plungers leads out through the primary chamber or the secondary chamber, where this split plunger acts on the measured value transducer. It may be connected.

It is particularly advantageous to use the device for detecting the operating distance of the clutch. In that case, the measuring plunger, which slides in the case, is arranged, for example, in the pressurized medium control conduit of the drive cylinder which operates by the application of pressurized medium.

In another configuration of the device for operating the clutch,
The measuring plunger divides the case into a primary chamber and a secondary chamber with at least one flow connection, in a rest position against the applied pressure of the drive medium, in which case the secondary chamber is in the rest position of the measuring plunger. Is connected to the discharge passage inside.

According to an advantageous configuration, at least one of the valves controlling the flow of the pressurized medium in the control conduit forms a structural unit with the sliding case of the measuring plunger. Thereby, the spatial position of the supply unit of the pressurized medium is such that the valve must be installed in the supply unit of the pressurized medium and the communication conduit between the measuring plunger and the valve for exhaust must be arranged so as to rise. You can choose freely against the device.

In addition to being used in devices for operating clutches, however, it is also recommended to use the device according to the invention, for example in pressure application valves.

[0016]

EXAMPLES The present invention will now be described in more detail based on examples. The device shown in FIG. 1 has a friction clutch 18,
This clutch 18 connects the internal combustion engine of the motor vehicle to the transmission mechanism in response to switching between fixed operating states or individual operating states. This friction clutch 18 has an operating mechanism 1
Connection / disconnection can be done via 4. This operating mechanism 14 is again operated via the drive element 2 in the form of a following cylinder.
The follow-up cylinder 2 is in communication with the pressurized medium circulation passage 21 via the drive conduit 1 and the distribution valve 20. The pressurized medium circulation path 21 is a pressurized medium pump 23 that can be driven by the engine 22.
This pressurizing medium pump 23 is connected to the liquid storage container 24 and applies pressure to the following cylinder 2 via the distribution valve 20. Between the pressurizing medium pump 23 and the distribution valve 20, a check valve 25 in the pressurizing medium circulating passage 21, a pressure switch 26 for opening and closing the engine 22 as necessary, and a pressure storage unit 27.
There is. The pressure store 27 is designed such that it can be disconnected at least once without introducing energy when the vehicle starts to operate. Therefore, no special engine is required for the pressurized medium pump 23, and the pressure storage unit 27 is supplied from the pressurized medium pump 23 driven via the internal combustion engine 22 during traveling operation.

An electronic control unit 28 is provided to coordinate the frictional intervention of the friction clutch 18. This unit 28 outputs an adjustment amount for operating the clutch to the distribution valve 20 according to the detected amount or a predetermined amount. The detected quantities are in particular the engine speed, the position of the throttle valve and the operating movement of the clutch or the clutch intervention state. A sensor cylinder 29 is arranged in the pressurized medium control conduit 1 of the following cylinder 2 in order to detect the operating movement of the clutch.
In this case, the control conduit 1 is a hydraulic rod, which displaces the liquid volume between the following cylinder 2 and the sensor cylinder 29.

The sensor cylinder 29 shown in detail in FIG. 2 is composed of a cylindrical case 4. This case 4 divides the measuring plunger 3 into a primary chamber 5 and a secondary chamber 6. Both the primary chamber 5 and the secondary chamber 6 are connected to the flow connections 7, 8. In that case, the primary chamber 5 is connected to the pressurized medium circulation path via the distribution valve 20, and the secondary chamber 6 is connected to the follow-up cylinder 2.
The measuring plunger 3 is brought to its rest position via the pressurized medium circulation path against the application of the pressurized medium via the compression spring 15. The measuring plunger 3 is composed of two split plungers 9 and 10. These split plungers slide on the inner wall of the case 4 via packings 17 and 19.
A measuring rod 12 with measuring graduations 11 formed as teeth is arranged between the split plungers 9 and 10 in fixed connection with these split plungers. Measuring rod 1
A pressure-free measuring chamber 16 for accommodating 2 is connected to a tank (not shown) via a connection hole 30.

A gear 13 fitted on the teeth of the measuring rod 12 converts the translational movement of the measuring plunger into a rotary movement,
As is well known, it is transmitted to a rotary potentiometer (not shown). In that case, the rotary potentiometer produces an electrical output signal which is linearly proportional to the distance traveled by the drive element 2. A leak valve 31 is provided in the case 4 in order to maintain the pressure balance or to remove air from the secondary chamber 6. The leak valve 31 connects the secondary chamber 6 to a tank or a balance container (not shown) when passing through the stationary position.

FIG. 3 shows a measuring cylinder with an electromagnetic induction measuring transducer. This includes split plunger 9
The measuring rod 12 arranged between the and 10 comprises a material 36 which influences the inductance of the measuring coil 35 arranged in the case 4. This material 36 has a structure which marks the position in the direction of movement. Therefore, each position of the material applied to this measuring rod has a different influence on the inductance of the measuring coil 35 in a characteristic way. A constant voltage having a relatively high frequency is applied to the measuring coil 35, and the flowing current is measured, for example. In that case, this current serves as a guide for the inductance of the measuring coil 35 and thus the position of the measuring plunger 3 in the cylindrical case 4 at that time.

[0021]

As described above, the device according to the present invention is not directly arranged at the drive element, and the position of the drive element can be accurately detected.

[Brief description of drawings]

FIG. 1 is a system diagram of an apparatus for operating a friction clutch.

FIG. 2 is a cross-sectional view of a device for detecting the position of a driving element having a mechanical position converter.

FIG. 3 is a cross-sectional view of a position detection device having an electromagnetic induction position converter.

[Explanation of symbols]

 1 Control Conduit 2 Drive Element 3 Measuring Plunger 4 Case 5 Primary Chamber 6 Secondary Chamber 7,8 Flow Connection 9,10 Split Plunger 11 Measuring Scale 12 Measuring Rod 13 Gear 14 Operating Mechanism 15 Compression Spring 16 Measuring Chamber 17, 19 Packing 18 Friction clutch 20 Distribution valve 21 Pressurized medium circulation path 22 Engine 23 Pressurized medium pump 24 Storage container 25 Check valve 26 Pressure switch 27 Pressure storage unit 28 Electronic control unit 29 Measuring cylinder 30 Connection hole 31 Leak valve 35 Measuring coil 36 Material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nikolaus Wanschaff, Federal Republic of Germany, 38444 Wohlfursbrück, Siegstraße, 29 (72) Inventor Heinz Reuhmer, Federal Republic of Germany, 38302 Wuerffenbiutel, Waldenburger Strasse, 51 arc

Claims (10)

[Claims] 1. A control conduit (1) for a drive element (2) in a device for detecting the position of a drive element hydraulically or pneumatically driven via a control conduit using at least one position measuring transducer. ) Is provided with a measuring plunger (3) that slides in the case (4), and the position of this measuring plunger (3) in the case (4) can be used as a guide for the position of the drive element (2). apparatus. 2. The measuring plunger (3) comprises a primary chamber (5) and a secondary chamber (6) each having at least one flow connection (7; 8) leading to a control conduit (1), and the casing (5). Device according to claim 1, characterized in that 4) is divided into a rest position against the applied drive medium pressure. 3. The measuring plunger (3) is formed of a first split plunger (9) and a second split plunger (10) that slides in an airtight manner on the inner wall of the case, with a pressure between both split plungers. Device according to claim 1 or 2, characterized in that a chamber (16) without a gap is formed. 4. A measuring rod (12) is arranged beside one of the two split plungers (9; 10), the measuring rod separating the primary chamber (5) or the secondary chamber (6) from the case (4). Device according to claim 3, characterized in that it is guided via and is connected to a measuring transducer forming a position measuring transducer outside the case (4). 5. Both split plungers (9; 10) are
4. Device according to claim 3, characterized in that it is connected to a measuring transducer forming a position measuring transducer and is connected to each other by a measuring rod (12) having a measuring scale (11). 6. Device according to claim 5, characterized in that the length of the measuring scale (11) corresponds to the displacement of the drive element (2) according to the conversion ratio. 7. The measuring scale is a split plunger (9; 1).
Device according to claim 5 or 6, characterized in that it is formed by a toothed rod (11) arranged between 0). 8. The toothed rod (11) is a gear (13) which transmits the movement of the measuring plunger (3) to the potentiometer.
8. The device of claim 7, operatively coupled to. 9. The device according to claim 1, wherein the position measuring transducer is embodied as an electromagnetically inductive or capacitive measuring transducer. 10. A pressurization circuit comprising at least one pressurized medium pump, a drive for operating this pressurized medium pump, a pressurized reservoir and a valve for controlling the pressurized flow, in particular via a follower cylinder. Device for operating a clutch of a motor vehicle, characterized in that the device according to any one of claims 1 to 9 is provided in the pressurized medium control conduit of the following cylinder (17).